Agricultural Lime in Tanzania: A Comprehensive Analysis of Resources, Application, Market Dynamics, and Strategic Outlook

Kilimokwanza.org Team

Executive Summary

Agricultural lime (aglime) presents a transformative opportunity for Tanzanian agriculture, a sector grappling with widespread soil acidity that significantly curtails crop productivity and national food security. Extensive geological resources of limestone and dolomite, the raw materials for aglime, are distributed across the country, offering substantial potential for local production. Currently, dedicated aglime production is relatively modest compared to the scale of the cement industry, which also utilizes these carbonate resources. The application of aglime has demonstrated remarkable impacts on neutralizing soil acidity, enhancing nutrient availability, and dramatically increasing yields for staple crops such as maize and beans, particularly in severely affected regions like the Southern Highlands.

However, the realization of aglime’s full potential is impeded by several interconnected challenges. These include the high farm-gate cost of lime, influenced by production, transportation logistics, and taxation; inadequate infrastructure for efficient distribution, especially to remote farming areas; and insufficient farmer awareness and access to appropriate knowledge and extension services. The existing policy and regulatory framework shows positive intent, with initiatives like the draft National Lime Application Guidelines, but requires strengthening in areas such as specific quality standards for soil-applied aglime and streamlined support for local production.

Economically, investment in the aglime value chain, from resource extraction to farmer application, offers significant returns through increased agricultural output, enhanced rural incomes, job creation, and potential for import substitution. Overcoming the prevailing challenges necessitates a multi-pronged strategic approach. This includes policy interventions to improve affordability and market conduciveness, investments to enhance production capacity and local value addition, improvements in logistics and farmer access, and a concerted effort in research, development, and extension. A coordinated effort among government ministries, research institutions, the private sector, and development partners is crucial to unlock the agricultural lime sector, thereby contributing significantly to Tanzania’s agricultural transformation, economic growth, and the livelihoods of its farming communities.

I. The Critical Role of Agricultural Lime in Tanzanian Agriculture

A. Soil Acidity: A Pervasive Challenge to Agricultural Productivity in Tanzania Soil acidity is a significant and pervasive constraint to agricultural productivity across extensive areas of Tanzania. Estimates indicate that approximately 32.7 million hectares of Tanzanian farmland are affected by this issue, posing a substantial threat to crop growth and yields. Regions such as Iringa and Songwe in the Southern Highlands are particularly impacted, along with Njombe and Katavi, hindering the production of staple crops like maize. The problem is not confined to these areas, as soil sampling by the Tanzania Agricultural Research Institute (TARI) has also identified acidity in the Central, Northern, and Eastern Zones.  

Soil pH is a critical determinant of the soil’s chemical environment, influencing the availability of plant nutrients and the concentration of potentially toxic elements. A pH level of 5.5 is generally considered the critical threshold; below this, aluminum (Al³⁺) often becomes soluble and toxic to plants, impairing root development and nutrient uptake. The severity of soil acidity in Tanzania is categorized based on pH values: extremely acidic soils have pH values from 3.6 to 4.4, very strongly acidic soils range from pH 4.4 to 5.0, and strongly acidic soils fall between pH 5.1 and 5.5.  

The country’s primary crops, including maize, wheat, barley, beans, sunflower, and most vegetables, are sensitive to soil acidity. In contrast, crops like pigeon pea, coffee, and tea exhibit greater resilience. The economic consequences of widespread soil acidity are substantial. For instance, it is estimated that 1.1 million hectares of maize production area are affected, leading to an annual monetary loss of approximately US$400 million due to reduced output. This underscores that soil acidity is not merely an agronomic concern but a significant economic impediment, silently suppressing yields and acting as a drain on both individual farmer incomes and the national agricultural economy. Addressing this issue through interventions like liming represents a direct investment in economic development, poverty alleviation, and enhanced food security.  

The causes of soil acidity are multifaceted, stemming from both natural processes and human activities. Natural factors include climatic conditions such as high rainfall leading to leaching of basic cations, temperature, biological influences, and the parent rock material from which the soil develops. Human activities, particularly cultivation practices involving crop harvesting and the removal of crop residues (stover), can exacerbate soil acidification. The overuse of certain nitrogenous fertilizers, especially ammonium-based ones, can also contribute significantly by increasing the concentration of hydrogen ions (H⁺) in the soil as these fertilizers break down through microbial action.  

B. Understanding Agricultural Lime: Types (Calcitic and Dolomitic) and Agronomic Functions Agricultural lime, often referred to as aglime, encompasses materials containing calcium or calcium-magnesium compounds that are capable of neutralizing soil acidity and thereby increasing soil pH. The two primary types of agricultural lime are distinguished by their chemical composition:  

1. Calcitic lime: Predominantly composed of calcium carbonate (CaCO3​). It is the preferred type when soil tests indicate sufficient magnesium levels but a deficiency in calcium.  
2. Dolomitic lime: Consists of calcium magnesium carbonate (CaMg(CO3​)2​). This type is applied when soils are deficient in magnesium, as it supplies both calcium and magnesium.  

The agronomic functions of agricultural lime are diverse and extend well beyond simple pH adjustment. Its primary role is the neutralization of soil acidity. This occurs as the lime dissolves in the soil, releasing calcium (Ca2+) and, in the case of dolomitic lime, magnesium (Mg2+) ions. These basic cations replace exchangeable acidic ions, such as hydrogen (H+) and aluminum (Al3+), on soil colloids. The hydroxide (OH−) ions formed during the dissolution of lime react with H+ ions to form water, thereby reducing soil acidity and increasing pH.  

Beyond pH correction, agricultural lime offers several other crucial benefits for soil health and plant nutrition:

• Improved Nutrient Availability: By raising soil pH, lime enhances the availability of essential plant nutrients such as phosphorus (P) and molybdenum (Mo), which are often less available in acidic conditions.  
• Reduction of Metal Toxicities: Acidic soils often have high concentrations of soluble aluminum and manganese, which can be toxic to plants. Liming reduces the solubility of these metals, mitigating their toxic effects.  
• Supply of Essential Nutrients: Lime is a direct source of calcium and, in the case of dolomitic lime, magnesium, both of which are essential macronutrients for plant growth.  
• Influence on Micronutrient Availability: While generally beneficial, excessive liming leading to very high pH can decrease the availability of certain micronutrients like zinc (Zn) and iron (Fe).  
• Immobilization of Heavy Metals: Agricultural lime can decrease the solubility of potentially harmful heavy metals in the soil, reducing their uptake by plants and entry into the food chain.  

The multifaceted benefits of aglime underscore its importance as a comprehensive soil amendment. Effective promotion of its use should therefore encompass education on these broader nutrient management advantages and the critical role of soil testing in selecting the appropriate type of lime (calcitic or dolomitic) based on specific soil nutrient deficiencies. This holistic understanding can significantly enhance the perceived value and encourage wider adoption of liming practices.

C. Report Objectives and Structure This report aims to provide a comprehensive analysis of the agricultural lime sector in Tanzania. It will delve into the geological availability of raw materials, the current status and potential for aglime production, its application and profound impact on Tanzanian agriculture, market dynamics, economic considerations, the prevailing policy and regulatory landscape, and a forward-looking perspective complete with strategic recommendations. The subsequent sections will systematically explore these facets, drawing upon available data and research to build a cohesive understanding of the challenges and opportunities within Tanzania’s agricultural lime industry.

II. Geological Resources for Agricultural Lime Production in Tanzania

A. National Overview of Limestone and Dolomite Geology Tanzania is endowed with extensive and geologically diverse deposits of limestone and dolomite, which are the fundamental raw materials for producing agricultural lime. These carbonate resources are found in various geological settings and span a wide range of geological ages.  

The country’s Phanerozoic geology (0.54 billion years ago to present) encompasses coastal basins, Karoo Supergroup sediments, and younger volcanic sequences, many of which are rich in limestone, dolomite, and calcite. More ancient Precambrian rocks, including marbles and dolomitic marbles, are primarily located within the Neoproterozoic Mozambique Belt in eastern Tanzania and the Paleoproterozoic Usagaran and Ubendian Systems in the western part of the country.  

Along the coastal regions, massive limestone and dolomite formations of Jurassic to Tertiary age are prevalent. These include the significant Tertiary to Recent coral reef limestones found extensively along the Indian Ocean coastline, such as the deposits at Wazo Hill near Dar es Salaam. Further inland, the Neoproterozoic platform sediments of the Malaragazi Supergroup, particularly northeast and east of Kigoma, contain compact, fine-grained limestones and dolomitic stromatolitic limestones that are utilized locally for lime production.  

The Karoo Supergroup, deposited from the Late Carboniferous to the Early Jurassic, also hosts limestone occurrences, notably in the basins of Lake Rukwa and the Ruhuhu area. Younger carbonate formations include calcretes, travertines, and lacustrine limestones. Calcretes are often the only carbonate rocks found within the central Tanzania Craton, while voluminous travertine deposits are associated with rift-related areas, such as those near the Songwe River in Mbeya. Additionally, carbonatite complexes, which are igneous rocks rich in carbonate minerals, occur in Tanzania and are often associated with phosphate mineralisation.  

This wide spectrum of geological ages and depositional environments (marine, lacustrine, metamorphic, igneous-carbonatite) for Tanzania’s limestone and dolomite resources implies considerable variation in their mineralogical composition, purity, and the presence of associated elements. For example, coral limestones will likely differ in characteristics from Precambrian marbles or carbonates associated with carbonatite intrusions. Consequently, not all deposits will be equally suitable for agricultural lime production in terms of their Calcium Carbonate Equivalent (CCE), magnesium content, or reactivity without thorough geological assessment and appropriate processing. A national strategy for agricultural lime development must, therefore, prioritize detailed characterization of these diverse deposits to align them with specific agricultural needs and processing capabilities, moving beyond a generalized approach to resource exploitation.  

B. Significant Deposits for Agricultural Lime: Location, Type, and Potential Tanzania’s limestone and dolomite resources are distributed across various regions, with notable concentrations in coastal areas and specific inland geological formations.

• 1. Coastal Limestone and Coral Reef Deposits:
  • Tanga Region: Hosts Jurassic limestones, prominently the Tanga Limestone formation of Bathonian age, which is a key raw material for Tanga Cement. Specific occurrences are documented at Pongwe and Amboni. The Tanga onshore basin also reportedly contains dolomitic limestone as a potential source rock. Neelkanth Lime Ltd, based in Tanga, is a known producer of agricultural lime.  
  • Dar es Salaam Region (Wazo Hill): Characterized by Tertiary fossil reef limestone, representing one of the largest carbonate occurrences on the Tanzanian coast. These deposits are extensively quarried by Tanzania Portland Cement Company (TPCC). The Wazo Hill limestone is primarily composed of calcium carbonate (CaCO3​) with some silica (SiO2​). Coral limestone from the Mpiji Borrow area in the Bagamoyo District has also been used for construction purposes.  
  • Mtwara Region: Possesses extensive limestone occurrences. The Dangote Cement plant in Mtwara utilizes substantial limestone reserves, estimated at around 500 million tonnes, which are projected to last for approximately 149 years. This facility produces high-quality 32.5 and 42.5 grade cements, indicating good quality limestone feedstock.  
  • Zanzibar: Recent surveys by the Geological Survey of Tanzania (GST) have revealed the presence of high-quality limestone suitable for cement production. Sedimentary deposits on the east coast of Zanzibar, such as in Chwaka Bay and Pongwe, are reported to consist of almost 100% biogenic calcium carbonate. Coral stones from Zanzibar exhibit high calcium oxide (CaO) content and are predominantly composed of the mineral aragonite.  
  • Selous Basin: Preliminary findings from GST surveys have indicated limestone occurrences within the Nyerere National Park and Selous Game Reserve. The regional stratigraphy of the Selous Basin includes limestone units within the Kidugalo and Mtumbei Formations.  
• 2. Inland Sedimentary and Metamorphic Carbonates:
  • Mbeya Region: Notable for travertine deposits in the Songwe valley, particularly near Nanyala in the Mbozi district. These deposits cover an area of approximately 13 km2, with thicknesses ranging from 5 to 70 meters, equating to an estimated volume of over 150 million cubic meters. This travertine is utilized for cement production (by LafargeHolcim’s Tembo Cement plant at Songwe) and local lime manufacturing. There is also potential for a dedicated lime factory at Nanyala, with reports of six million tonnes of available raw material.  
  • Kigoma Region: The Neoproterozoic Malaragazi Supergroup in this region contains compact, fine-grained limestones and dolomitic stromatolitic limestones. These are used on a local scale for lime production.  
  • Morogoro Region: Known for its white marble deposits, which include high-purity limestone and dolomite. These resources have potential for dimension stone and refractory grade limestone, and by extension, for agricultural lime.  
  • Dodoma Region (Kiteto, Chemba, Chamwino districts): Geological and geochemical surveys conducted by GST have led to the discovery of limestone deposits in these districts. The Chamwino district is part of the Dodoma Region, characterized by the geology of the Archean Tanzania Craton and the Dodoman Belt. Limestone in this broader region can be associated with Karoo Supergroup deposits or crystalline limestones within the Mozambique Belt. General geological information on limestone formation is also relevant.  
  • Ruvuma Region: While primarily noted for alluvial gemstone occurrences, the region also forms part of a belt known for base metals, which can sometimes be associated with carbonate host rocks. Limestone is generally listed as an industrial mineral found in Tanzania.  
• 3. Carbonatite-Associated Resources (and co-existing phosphates): Several carbonatite complexes in Tanzania are significant not only for their carbonate rock content (potential raw material for aglime) but also for associated phosphate deposits. This co-location is strategically important. Acidic soils often suffer from multiple nutrient deficiencies, including phosphorus, alongside issues like aluminum toxicity that lime addresses. Developing these carbonatite deposits could offer integrated solutions for soil fertility management by enabling the co-production of agricultural lime and phosphate-based fertilizers. Such co-production could reduce logistical costs and provide a more holistic soil amendment approach for farmers, particularly those in proximity to these deposits.
  • Panda Hill (Mbeya Region): A Cretaceous carbonatite complex located about 25 km west-southwest of Mbeya. Primary carbonatite resources are estimated at 480 million tonnes with an average grade of 3.5% P2​O5​. Additionally, approximately 1 million tonnes of residual phosphates with an average grade of 10.31% P2​O5​ have been delineated in the Kunja-Mtoni zone. The complex is also known for pyrochlore mineralization.  
  • Sangu-Ikola (Lake Tanganyika): This is the most extensive Proterozoic carbonatite complex in Tanzania. Apatite, the primary phosphate mineral, is reported to be fairly abundant, locally constituting up to 50% by volume. Initial exploration work identified residual phosphate-rich soils with P2​O5​ concentrations up to 15%, while the primary soevitic (calcium-carbonate) carbonatite contained up to 7% P2​O5​.  
  • Ngualla (Southwest Tanzania): A Proterozoic carbonatite where phosphorus concentrations in the primary rock range from 0.4% to 6% P2​O5​. Exploration pits have revealed residual red soils containing 12-20% P2​O5​ to depths of 5 meters or more.  
  • Minjingu (Manyara Region): Known for its sedimentary phosphate rock (MPR) deposits, which occur in association with lacustrine sediments. These sediments include beds cemented with calcite and dolomite. The Minjingu Quarry is listed as a locality for calcite, dolomite, and fluorapatite. While primarily a phosphate source, the associated carbonates could potentially be utilized.  

The strategic co-location of carbonate rocks and phosphate minerals in these carbonatite complexes suggests that investment and development strategies should consider the dual potential for aglime and phosphate fertilizer production. This approach could yield synergistic benefits for the agricultural sector, particularly in regions like Mbeya and the Western Rift.

C. Assessment of Reserves and Quality: CaCO3​, MgCO3​ Content, Purity, Reactivity, and Calcium Carbonate Equivalent (CCE) for Key Deposits Tanzania possesses an “ample inventory of unexplored mineral ground,” which includes industrial minerals like limestone. While comprehensive reserve data for all deposits specifically for agricultural lime is not uniformly available, some notable figures exist:  

• Reserves:
  • Mtwara (Dangote Cement): Approximately 500 million tonnes of limestone reserves are reported.  
  • Songwe Valley (Mbeya, travertine): Estimated at over 150 million cubic meters, which could translate to over 375 million tonnes (assuming a density of 2.5 tonnes/m3).  
  • Nanyala (Mbeya, potential lime factory): Six million tonnes of raw materials are reportedly available.  
  • Panda Hill (carbonatite): Primary resources are estimated at 480 million tonnes.  
  • Wazo Hill (Dar es Salaam): Described as “one of the largest limestone reserves of the country”.  
• Quality (CaCO₃, MgCO₃, Purity, CCE):
  • General: High-purity limestone and dolomite resources are known to occur in Tanzania. For example, the white marble deposits in the Morogoro Region are noted for their high purity. Coastal areas, stretching from Tanga to Mtwara, host extensive limestone occurrences of high quality suitable for lime and cement production, as well as other industrial applications.  
  • Wazo Hill: The limestone is mainly composed of CaCO3​ and SiO2​. It is a fossil reef limestone.  
  • Mtwara (Dangote): The production of high-quality 32.5 and 42.5 grade cements implies good quality limestone feedstock.  
  • Zanzibar: Discoveries indicate high-quality limestone suitable for cement. Sediments on the east coast are reported to be almost 100% biogenic calcium carbonate. Coral stone samples show high CaO content and are predominantly aragonite.  
  • Tanga: Limestone from this region is used for cement production. Dolomitic limestone is also present.  
  • Mbeya (travertine): Used for cement and lime production.  
  • Minjingu: Associated lacustrine sediments include calcite and dolomite.  
  • Commercial Aglime Producers: ABM Equipment Services Ltd (Tanga) offers agricultural lime with a stated Calcium Carbonate Equivalent (CCE) of at least 80% and also supplies dolomitic lime. Neelkanth Lime Ltd (Tanga) is another producer of agricultural lime.  
  • CCE (Calcium Carbonate Equivalent): This is a critical measure of the neutralizing value of agricultural lime, comparing its effectiveness to pure calcium carbonate. The CCE value is a key quality parameter for aglime.  
• Reactivity: The reactivity of agricultural lime, its ability to neutralize soil acidity effectively, is dependent on its fineness of grind and the inherent properties of the source rock. Finer particles have a larger surface area and therefore react more quickly in the soil. For instance, the phosphate rock from Panda Hill is noted for its low solubility, which suggests that associated carbonate materials might also require fine grinding to ensure adequate reactivity for agricultural purposes.  

While many sources describe limestone deposits as “high-quality” for cement or general industrial use , specific data directly relevant to agricultural lime, such as detailed CCE values, precise CaCO3​/MgCO3​ breakdowns for various potential aglime sources, and comprehensive reactivity assessments, are often not readily available for many deposits. Cement-grade limestone has specific chemical requirements (e.g., high CaCO3​, controlled MgO and SiO2​ levels). However, agricultural lime quality is determined by CCE, fineness, and the crucial balance of Ca and Mg to address specific soil deficiencies. A deposit suitable for cement might not be optimally processed or ideal for all agricultural applications without further, aglime-specific characterization. For example, a high CaCO3​ limestone would be excellent for producing calcitic aglime but unsuitable if dolomitic lime (requiring higher MgCO3​) is needed. Data from commercial producers like ABM provide some benchmarks (e.g., CCE >80%), but such detailed information is not consistently available across all identified geological deposits. This highlights a critical data gap: the need for systematic assessment of known limestone and dolomite deposits specifically for their agricultural lime potential, going beyond general descriptions of quality for other industries. The Geological Survey of Tanzania has a vital role to play in filling this gap.  

D. The Geological Survey of Tanzania (GST): Role in Resource Mapping, Data Provision, and Recent Discoveries The Geological Survey of Tanzania (GST), established in 1925, is the principal government agency responsible for acquiring, processing, and disseminating geoscientific information about the country. Its mandate includes geological mapping, reconnaissance mineral exploration, and prospecting for various resources, including industrial minerals like limestone and groundwater.  

GST has made significant strides in mapping the country. Approximately 94% of Tanzania has been geologically mapped, with outputs typically in the form of Quarter Degree Sheets (QDS) at various scales. However, a considerable portion of this mapping is not at a detailed scale suitable for specific resource evaluation, and many existing maps are relatively old, necessitating updates with modern technology and geological understanding. The process of updating QDS maps is ongoing but can be slow and costly. To enhance mapping efficiency, GST has been incorporating modern techniques such as remote sensing (RS) as an aid in geological mapping.  

GST plays a crucial role in providing geological information pertinent to industrial minerals, including limestone and dolomite. It maintains the Geological and Mineral Information System (GMIS), intended as a public database for geoscientific information, although access to this portal was reported as problematic during the period of this research. A “Geology and Mineral map of Tanzania (2008)” produced by GST is a key reference document.  

Recent activities by GST have led to important discoveries relevant to agricultural lime resources. Surveys have identified new limestone deposits in Zanzibar, and in the Kiteto, Chemba, and Chamwino districts of the Dodoma Region. Looking forward, GST plans to significantly expand its high-resolution airborne geophysical survey coverage from the current 16% to 34% of the country. Furthermore, the construction of a state-of-the-art laboratory in Dodoma is planned to enhance the analytical capabilities for mineral samples, which will support research and promote growth in the mining sector.  

The GST is, therefore, a linchpin for the development of agricultural lime resources in Tanzania. Its foundational geological data and ongoing exploration and mapping activities are central to identifying, quantifying, and characterizing raw material sources for aglime. The planned upgrades in survey coverage and laboratory facilities will further strengthen this capacity. For the agricultural sector to fully benefit, it is imperative that GST’s efforts include specific characterization of limestone and dolomite deposits for their suitability as agricultural lime, including assessments of CCE, magnesium content, and reactivity. Enhanced collaboration between GST and agricultural research institutions like TARI would be highly beneficial to ensure that geological assessments are closely aligned with agronomic requirements and agricultural development priorities.

Table 1: Key Limestone and Dolomite Deposits in Tanzania with Potential for Agricultural Lime

Region	District/Specific Location	Geological Formation/Type of Deposit	Estimated Reserves (if available)	Key Quality Indicators (e.g., CaCO₃/MgCO₃ content, CCE, suitability notes for aglime – if available)	Key Source Snippets
Tanga	Pongwe, Amboni	Jurassic Tanga Limestone, Dolomitic Limestone	Not specified for aglime	Used for cement; dolomitic limestone present. ABM Aglime (Tanga) CCE ≥80%; Neelkanth Lime (Tanga) produces aglime.
Dar es Salaam	Wazo Hill	Tertiary Fossil Reef Limestone	“One of the largest limestone reserves”	Mainly CaCO3​ and SiO2​; used for cement.
Mtwara	Dangote Cement Plant area	Limestone (likely Tertiary/Cretaceous marine)	~500 million tonnes	High-quality for 32.5 and 42.5 grade cements.
Zanzibar	General, East Coast (Chwaka Bay, Pongwe)	High-quality limestone, Biogenic Calcium Carbonate, Coral Stone	Not specified	Suitable for cement; East coast almost 100% biogenic CaCO3​; Coral stone high CaO, aragonite.
Mbeya	Songwe Valley (Nanyala, Mbozi), Panda Hill, Ngualla	Travertine, Carbonatite	Travertine: >150 million m3; Nanyala raw material: 6 million tonnes; Panda Hill: 480 million tonnes (primary carbonatite)	Travertine used for cement & lime. Carbonatites associated with phosphates; Panda Hill primary P2​O5​ 3.5%, residual P2​O5​ 10.31%; Ngualla residual P2​O5​ 12-20%. Potential for co-production of aglime and phosphate.
Kigoma	Northeast & East of Kigoma	Neoproterozoic Malaragazi Supergroup (Limestone, Dolomitic Limestone)	Not specified	Compact, fine-grained; used locally for lime.
Morogoro	General	Precambrian White Marble (High-purity Limestone & Dolomite)	Not specified	High purity, potential for refractory grade.
Dodoma	Kiteto, Chemba, Chamwino districts	Limestone (likely Karoo or Crystalline – Mozambique Belt)	Not specified	Recent GST discoveries; quality for aglime not detailed.
Manyara	Minjingu	Lacustrine sediments associated with Phosphate Rock (Calcite, Dolomite)	Not specified for carbonates	Primarily phosphate; associated calcite and dolomite.
Selous Basin	Nyerere National Park, Selous Game Reserve, Kidugalo/Mtumbei	Limestone (Kidugalo & Mtumbei Formations)	Not specified	Preliminary GST findings; Kidugalo & Mtumbei Formations include limestones.

III. Agricultural Lime Production, Supply Chain, and Market Landscape

A. Current State of Agricultural Lime Production The production of agricultural lime in Tanzania appears to be undertaken by a mix of specialized producers and potentially as a by-product or secondary product line from larger cement manufacturing operations.

• 1. Profile of Key Producers and Their Operational Capacities:
  • ABM Equipment Services Ltd (Tanga): This company is a notable manufacturer, importer, and supplier of branded agricultural lime products, including “ABM Agricultural Lime” (with a stated CCE of at least 80%) and “ABM Dolomitic Lime.” Their products are specifically marketed for soil conditioning and amendment. They also supply Calcium Carbonate Powder. Packaging for their dolomitic lime is stated as 50kg PP bags with liners.  
  • Neelkanth Lime Ltd (Tanga): Another key producer of agricultural lime based in Tanga. As of 2022, the company reported a production capacity of 15,000 tonnes per year, which was suggested to be sufficient to meet the country’s prevailing demand at that time.  
  • Minjingu Mines and Fertilizer Ltd (Manyara): While primarily recognized for its Minjingu Phosphate Rock (MPR) production, the geological setting of Minjingu involves lacustrine sediments that include calcite and dolomite beds. The Minjingu Quarry itself lists calcite, dolomite, and fluorapatite as present minerals. Although Minjingu is a major fertilizer producer, its specific operational capacity or focus on agricultural lime derived from its limestone/dolomite resources for soil acidity correction requires more explicit confirmation.  
  • Cement Companies as Potential/Actual Suppliers: Large cement manufacturers in Tanzania operate extensive limestone quarries and crushing facilities, presenting a potential source of agricultural lime, either as fine material by-products or through dedicated production runs.
    • Tanzania Portland Cement Company (TPCC – Twiga Cement, Wazo Hill, Dar es Salaam): Processes significant quantities of fossil reef limestone. While their primary output is cement, the fine materials generated during crushing could be suitable for aglime.  
    • Dangote Cement (Mtwara): As the largest cement factory in Tanzania with vast limestone reserves, Dangote has substantial potential for aglime production alongside its cement operations.  
    • LafargeHolcim (Tembo Cement, Songwe, Mbeya): Utilizes local limestone for cement manufacturing. The use of high-quality limestone for cement production suggests the potential for producing quality agricultural lime. It is a common feature in the broader limestone market that major cement companies (such as Imerys, CEMEX, Holcim, as listed in global market reports) are also players in limestone supply for agricultural applications. This suggests a precedent for Tanzanian cement producers to engage more actively in the aglime market.  
  • Other Potential Producers: Several other entities are listed as suppliers of limestone and dolomite, which could potentially include agricultural grade materials:
    • Kusini Gateway Industrial Park (Dar es Salaam): Lists limestone, dolomite, and calcite among its product offerings.  
    • M1 Group (Richmond, Texas, Tanzania): Also lists limestone and dolomite.  
    • Springwood Capital: Identifies limestone for soil treatment (agricultural lime) as one of its products. It is noteworthy that Tanzania also imports some lime products, for example, hydrated lime from Limestone Resources Limited in Zambia for domestic use. This indicates an existing demand that is partially met by imports, further highlighting opportunities for local production.  
  A significant observation is the apparent disconnect between the massive scale of limestone quarrying and processing by major cement producers and the seemingly more modest scale of dedicated agricultural lime production. While cement plants are substantial potential sources, their core business remains cement. Aglime might currently be a secondary or opportunistic product line for them. This suggests an opportunity to better integrate aglime production into the operations of these large companies, perhaps by valorizing fine materials or dedicating specific grinding lines if consistent demand for aglime can be demonstrated and guaranteed. Such integration could leverage economies of scale to increase supply and potentially reduce unit costs.
• 2. Quarrying, Crushing, and Processing Technologies Employed: The extraction of limestone typically involves surface quarrying methods. At sites like Wazo Hill, this includes the removal of overburden soil followed by the blasting of the underlying limestone rock. Subsequent crushing and milling are essential to reduce the quarried rock to the fine particle sizes required for effective agricultural lime. This process often involves a series of crushers (e.g., jaw crushers, impact crushers) and hammer mills. The fineness of the ground lime is a critical quality parameter, as it directly influences the rate of reaction in the soil and thus its effectiveness in neutralizing acidity. For instance, ABM Agricultural Lime specifies grinding to 1.5mm with 65% of particles passing an 80-mesh sieve. For smaller-scale operations, particularly in rural areas closer to farms, low-cost production methods involving manual extraction, crushing, and the use of hammer mills are considered feasible, as has been explored in neighboring Zambia.  
• 3. Potential for New Production Ventures: The vast and largely untapped limestone reserves across Tanzania signify considerable potential for new agricultural lime production ventures. The Ministry of Minerals actively invites investment in the industrial minerals sector, which includes limestone. A specific prospect is the Nanyala area in the Mbeya Region, where Highland Building Company has reportedly offered to collaborate with the government to establish a lime factory. This site is said to have six million tonnes of available raw materials , and is located near the extensive travertine deposits of the Songwe valley. Such a venture points towards a strategic move to develop dedicated aglime facilities closer to regions with high agricultural demand.  

B. Supply Chain Analysis: From Quarry to Farm The journey of agricultural lime from its source to the farm level is fraught with challenges that significantly impact its accessibility and affordability for farmers.

• 1. Transportation and Logistical Challenges, particularly to remote agricultural areas: Aglime is inherently a bulky material, and its application often requires substantial quantities, typically around 1 tonne per hectare. This bulkiness makes transportation a major cost component and a significant hurdle to widespread use. In one project model analysis, transportation accounted for approximately 17% of the total project costs. The logistical difficulties are compounded when supplying remote agricultural areas, which often have poorly developed road infrastructure. Transporting large volumes of lime over challenging terrain demands meticulous planning and can lead to high transit costs. An example cited is the challenge of moving lime from production sites in Dodoma (a mentioned production area, though the specific producer is not named) to the southern highlands, a region with significant soil acidity problems.  
• 2. Distribution Networks and Associated Costs: Detailed information on established, dedicated distribution networks specifically for agricultural lime in Tanzania is limited in the available materials. Current distribution likely occurs through a combination of direct sales from producers, agro-dealer channels, or via project-based initiatives led by organizations like SAGCOT and TARI. The costs associated with the aglime supply chain are substantial. Lime procurement itself can constitute as much as 42% of overall project expenses in intervention programs. The high costs of lime and the associated services, including transport and application, are consistently identified as major barriers to adoption by farmers.   The “last mile” delivery of aglime to dispersed smallholder farmers in remote locations emerges as a critical bottleneck. Even if lime is produced at an affordable ex-quarry price, the logistical complexities and high costs of transporting such a bulky, relatively low-value product (compared to concentrated fertilizers) can inflate the farm-gate price to uneconomical levels for many smallholders. Poor rural road infrastructure exacerbates this problem, increasing transport time and expenses. This “last mile” challenge is a common impediment to agricultural input delivery across Africa. Therefore, strategies to enhance aglime adoption must place a strong emphasis on optimizing logistics. This could involve promoting decentralized, smaller-scale production facilities situated closer to farming clusters (as exemplified by the Nanyala prospect or the Zambian model ), investing in the improvement of rural road networks, or exploring innovative distribution models such as farmer cooperative bulk purchasing schemes and targeted government subsidies for transportation.  

C. Market Overview: Demand Drivers, Current Consumption, and Growth Potential The market for agricultural lime in Tanzania is characterized by strong underlying demand drivers, constrained current consumption, and significant growth potential.

• Demand Drivers:
  • The primary driver for aglime demand is the extensive prevalence of soil acidity, affecting an estimated 32.7 million hectares of farmland.  
  • There is a pressing need to improve crop yields to enhance food security and increase farmer incomes, both of which can be significantly boosted by addressing soil acidity through liming.  
  • Governmental and institutional promotion of lime use by bodies such as the Ministry of Agriculture, TARI, and SAGCOT is actively working to stimulate demand.  
  • Farmer awareness of the benefits of lime is growing, though it remains a challenge that needs continuous effort.  
• Current Consumption: Actual consumption figures for agricultural lime in Tanzania are not comprehensively detailed in the provided materials. However, the statement that Neelkanth Lime’s production capacity of 15,000 tonnes per year was considered to “meet country’s demands” in 2022 appears strikingly low when juxtaposed with the vast extent of acidic soils. This figure likely reflects the effective demand—shaped by current constraints such as high costs, limited access, and awareness—rather than the actual agronomic need. The use of aglime is widely reported to be hindered by its high cost and transportation difficulties.  
• Growth Potential: The growth potential for the agricultural lime market in Tanzania is immense. Given that millions of hectares of productive land suffer from acidity , and assuming an average application rate of around 1 tonne per hectare , the latent demand could be in the tens of millions of tonnes. If the existing barriers related to cost and access can be effectively addressed, a surge in demand is highly probable. There is a significant opportunity to develop a robust domestic lime production industry that could not only serve local needs but also potentially supply neighboring countries facing similar soil acidity challenges. Globally, the limestone market, which includes agricultural applications, is experiencing growth driven by both construction and agriculture sectors , and Tanzania’s market is expected to follow this expansionary trend.   The disparity between the vast agronomic need for lime (latent demand) and the current low levels of actual use (effective demand) is a key feature of the Tanzanian aglime market. Converting this latent demand into effective demand requires more than just increasing production; it necessitates aggressive farmer education and demonstration programs, strategies to improve affordability (such as cost reduction measures, targeted subsidies, or credit facilities), and the establishment of reliable and accessible supply chains. Projects that successfully demonstrate high yield responses and profitability from liming play a crucial role in this conversion process by showcasing the tangible benefits to farmers.  

Table 2: Profile of Known and Potential Agricultural Lime Producers in Tanzania

Company Name	Location (Region/District)	Type of Operation (Dedicated Aglime/Cement/Other)	Raw Material Source (if known)	Stated/Estimated Aglime Production Capacity (tonnes/year, if available)	Product Types (Calcitic/Dolomitic, CCE if stated)	Key Source Snippets
ABM Equipment Services Ltd	Tanga	Manufacturer, Importer, Supplier (Dedicated Aglime)	Not specified	Not specified	ABM Agricultural Lime (CCE ≥80%), ABM Dolomitic Lime
Neelkanth Lime Ltd	Tanga	Producer (Dedicated Aglime)	Not specified	15,000 (as of 2022)	Agricultural Lime
Minjingu Mines and Fertilizer Ltd	Manyara	Phosphate Producer (Potential Aglime co-product)	Lacustrine sediments (Calcite, Dolomite associated with Phosphate)	Not specified for aglime	Calcite, Dolomite present at quarry; Aglime product not detailed.
Tanzania Portland Cement Company (TPCC)	Wazo Hill, Dar es Salaam	Cement Producer (Potential Aglime by-product)	Fossil Reef Limestone	Not specified for aglime	Limestone fines potentially suitable.
Dangote Cement	Mtwara	Cement Producer (Potential Aglime by-product)	Limestone	Not specified for aglime	Vast limestone reserves; potential for aglime.
LafargeHolcim (Tembo Cement)	Songwe, Mbeya	Cement Producer (Potential Aglime by-product)	Local Limestone	Not specified for aglime	High-quality limestone source.
Kusini Gateway Industrial Park	Dar es Salaam	Supplier (Industrial Minerals)	Not specified	Not specified	Lists Limestone, Dolomite, Calcite.
M1 Group	Richmond, Texas, Tanzania	Supplier (Industrial Minerals)	Not specified	Not specified	Lists Limestone, Dolomite.
Springwood Capital	(Assumed Tanzania operations)	Supplier (Commodities)	Not specified	Not specified	Lists Limestone for soil treatment (agricultural lime).
Highland Building Company (Proposed)	Nanyala, Mbeya	Proposed Lime Factory (Dedicated Aglime)	Local raw materials (Travertine/Limestone)	Potential based on 6 million tonnes raw material	To be determined.

IV. Application and Agronomic Impact of Agricultural Lime

A. Prevalence and Severity of Soil Acidity Across Tanzanian Agricultural Zones As previously established, soil acidity is a widespread agricultural challenge in Tanzania, with an estimated 32.7 million hectares of farmland affected. The severity of this issue varies across different agro-ecological zones. The Southern Highlands, encompassing regions like Iringa, Songwe, Mbeya, Njombe, and Katavi, are frequently highlighted as areas with particularly acute soil acidity problems. These regions are also critical to Tanzania’s agricultural output, often referred to as the nation’s “grain basket”. Soil sampling and research by TARI have also confirmed soil acidity in the Central, Northern, and Eastern Zones.  

The classification of soil acidity is based on pH ranges: extremely acidic (pH 3.6-4.4), very strongly acidic (pH 4.4-5.0), and strongly acidic (pH 5.1-5.5). To effectively target interventions, accurate spatial data on soil acidity is crucial. The Ministry of Agriculture has recognized this need, with past requests for the preparation of national soil maps. More recently, digital tools like the Guiding Acid Soil Management Investments in Africa (GAIA) dashboard are providing valuable spatial information on soil acidity distribution, aiding in the identification of priority areas for liming interventions.  

The consistent identification of the Southern Highlands as a severely affected and agriculturally vital area suggests that national liming strategies should prioritize these regions. Here, the return on investment in terms of yield improvement and economic benefit is likely to be highest. Effective prioritization requires an integrated approach, linking soil acidity maps, data on crop production zones, and information on the location of potential lime sources.

B. Documented Impact of Liming on Soil Health and Crop Productivity The application of agricultural lime has demonstrated significant positive impacts on both soil health and crop productivity in Tanzania and similar agro-ecological contexts.

• 1. Yield Responses in Key Crops (Maize, Beans, etc.) – Evidence from TARI, SAGCOT, and other studies:
  • Maize: Trials and projects conducted by SAGCOT and TARI in the Iringa and Songwe regions have shown dramatic yield increases in maize following lime application. Yields have reportedly risen from a baseline of around 2 tonnes per hectare to as high as 7-8 tonnes per hectare, representing an improvement of nearly 300%. More broadly, studies suggest a potential for up to a 50% yield increase in maize due to liming. Research in Kenya, under comparable conditions, indicated maize yield effects ranging from a slight decrease (-6%) to a substantial increase (+24%), depending on location and application rates.  
  • Beans: Agricultural lime has shown even more pronounced effects on bean yields, with studies indicating a potential for increases of up to 360%. A study in Uganda, focusing on Ferralsols similar to some Tanzanian soils, found that lime application combined with manure significantly boosted bean yields. An application of 2.0 tonnes of lime per hectare resulted in a 117% yield increase over the control, while 0.5 tonnes of lime per hectare combined with 3.0 tonnes of manure per hectare led to a 95% yield increase. The general consensus is that lime application effectively restores soil pH to levels more conducive to plant growth, thereby enhancing the effectiveness of fertilizers and improving overall nutrient absorption by crops. The synergistic effect of lime applied in conjunction with other inputs, such as improved seed varieties, fertilizers, and organic matter (manure), has been noted for further amplifying yield benefits.  
• 2. Enhancement of Nutrient Availability and Fertilizer Efficiency: One of the primary mechanisms through which lime benefits crop production is by improving soil nutrient availability and the efficiency of applied fertilizers. In acidic soils, essential nutrients like phosphorus can become “fixed” or bound to soil particles, rendering them unavailable for plant uptake. Liming corrects the soil pH, which helps to release these fixed nutrients and improves the solubility and availability of others, such as molybdenum. Furthermore, acidic conditions often lead to increased solubility of aluminum and manganese, which can reach toxic levels for plants, impairing root growth and hindering nutrient and water uptake. Lime application reduces the concentration of these toxic elements in the soil solution. Consequently, by creating a more favorable chemical environment in the soil, lime improves the returns from fertilizer applications, as plants are better able to absorb and utilize the applied nutrients. This positions lime not merely as a standalone soil amendment but as a critical enabler of fertilizer effectiveness and a foundational component of Integrated Soil Fertility Management (ISFM). Promoting aglime should therefore be integrated with advice on appropriate fertilizer use and other ISFM practices to maximize benefits for farmers and ensure more sustainable soil health.  

C. Best Practices in Lime Application: Rates, Timing, and Methods The effectiveness of agricultural lime is highly dependent on its correct application, considering several factors:

• Application Rates: The appropriate rate of lime application varies significantly based on the initial soil acidity level, soil type (particularly texture and organic matter content, which influence buffering capacity), the specific crop being grown (as crops have different optimal pH ranges), and the quality of the lime itself (especially its CCE and fineness). While a general application rate of approximately 1 tonne per hectare is often mentioned in project contexts , this should be considered an indicative figure. ABM Equipment Services Ltd provides an application guide based on soil depth and pH levels. Research trials have explored a range of rates, from as low as 0.13 tonnes per hectare to 2.0 tonnes per hectare or more. Accurate determination of lime requirement necessitates soil testing.  
• Timing: Agricultural lime is not readily soluble in water, and its reaction in the soil to neutralize acidity is a gradual process. Measurable changes in soil pH may take up to a year or even longer to become apparent. Therefore, it is generally recommended to apply lime well in advance of planting, ideally several weeks or months, to allow sufficient time for it to react with the soil. For example, application one month before planting, followed by incorporation, is a practice reported in some studies.  
• Methods of Application and Incorporation: For lime to be effective, it needs to be thoroughly mixed with the acidic soil layer. Surface application without incorporation is generally less effective. Common methods involve broadcasting the lime evenly over the soil surface and then incorporating it into the plough layer (e.g., to a depth of about 15 cm) using implements like ploughs, harrows, or rotavators.  
• Fineness of Lime Particles: The particle size distribution of agricultural lime is a critical factor influencing its reactivity. Finer lime particles have a much larger surface area exposed to the soil, allowing them to dissolve and react more quickly and completely than coarser particles. Particles larger than 10-15 mesh (approximately 1-1.7 mm) are reported to dissolve very little over a typical 3-4 year period. In contrast, particles in the 50-60 mesh size range (around 250-300 micrometers) react rapidly. Standards in some regions, like Kentucky, specify targets such as 90% of the material passing a 10-mesh sieve and 35% passing a 50-mesh sieve. ABM Agricultural Lime in Tanzania reports a general particle size of 65% passing an 80-mesh sieve for its quick-acting product.  

The effectiveness of liming, therefore, hinges on applying the “Right Rate, Right Time, Right Place, and Right Source” principles, adapted for lime. Blanket recommendations are unlikely to be optimal due to the inherent variability in soil conditions, crop requirements, and lime quality. Soil testing is paramount for determining appropriate application rates. Farmer education programs must emphasize not just the benefits of liming but also the critical aspects of how to apply it effectively based on these principles. The forthcoming National Lime Application Guidelines for Tanzania are expected to play a crucial role in standardizing these recommendations and promoting best practices.  

D. Farmer Awareness, Adoption Challenges, and Extension Services Despite the proven benefits of agricultural lime, its adoption by farmers in Tanzania faces several hurdles related to awareness, cost, accessibility, and practical application.

• Farmer Awareness: There is an acknowledged gap in farmer knowledge regarding soil health, specifically soil acidity and the benefits of liming. The Minister of Agriculture noted that “Most of our farmers are not accustomed to checking the health of the soil before ploughing”. Consequently, there is a strong need to educate farmers about the problem of soil acidity and the corrective measures available, including the use of lime. Initiatives like the GAIA dashboard aim to fill these critical knowledge voids by providing accessible information on soil health and agronomy.  
• Adoption Challenges:
  • Cost: The high cost of lime itself, coupled with transportation and application expenses, is a primary deterrent for many farmers, especially smallholders.  
  • Bulkiness and Application Difficulties: Lime is a bulky material, and applying the required quantities (often 1 tonne/ha or more) is physically demanding and logistically challenging at the farm level, particularly without mechanization. The lack of simple spreading machines is a noted constraint.  
  • Labor Intensity: The application of lime is labor-intensive, adding to the overall cost and effort for farmers.  
  • Supply Issues: Untimely or late supply of lime can disrupt farming schedules and discourage adoption.  
  • Access to Finance: Limited access to credit or subsidies makes it difficult for farmers to afford the upfront investment required for liming.  
  • Interestingly, research indicates that farmers who are already using mineral fertilizers are often more likely to adopt new agricultural products like lime, suggesting a pathway for targeting early adopters.  
• Extension Services: Recognizing these challenges, the Tanzanian government and its partners are taking steps to strengthen extension support. The government has been distributing soil testing equipment to extension officers across the country to facilitate better soil diagnosis. The Ministry of Agriculture is in the process of preparing and disseminating comprehensive lime-use guidelines specifically for extension officers to enhance their capacity to train farmers. Training of Trainers (ToTs) programs are being conducted to build a cohort of local experts who can champion best practices in lime application.  

The path to widespread farmer adoption of agricultural lime is not solely an agronomic one; it is a complex socio-economic and logistical puzzle. Overcoming these multifaceted barriers requires an integrated strategy. This includes measures to make lime more affordable (e.g., through production cost efficiencies, targeted subsidies, or improved tax regimes), enhancing physical access (via better logistics and local supply points), providing practical application support (such as access to spreading equipment or promoting labor-saving techniques), and implementing sustained, practical farmer education and demonstration programs led by well-trained and adequately resourced extension services.

Table 3: Summary of Reported Crop Yield Responses to Agricultural Lime Application in Tanzania and Similar Contexts

Crop	Region/Country (if not TZ)	Soil Conditions (pH if stated)	Lime Rate (t/ha)	Other Treatments (e.g., fertilizer, manure)	Observed Yield Increase (%) or Benefit	Research Source/Snippet
Maize	Iringa & Songwe, Tanzania	Acidic	Not specified	Not specified	From 2 t/ha to 7-8 t/ha (nearly 300% increase)
Maize	Tanzania (general)	Acidic	Not specified	Not specified	Up to 50% yield increase
Maize	Kenya	Acidic	0.13 – 0.5	DAP, CAN fertilizer	-6% to +24% yield increase; profit changes up to $264/ha USD
Beans	Tanzania (general)	Acidic	Not specified	Not specified	Up to 360% yield increase
Beans	Uganda (Ferralsols)	Acidic	2.0	Chicken manure (varied rates)	117% yield increase over control (lime alone)
Beans	Uganda (Ferralsols)	Acidic	0.5	Chicken manure (3.0 t/ha)	95% yield increase over control (lime + manure)
Wheat	Ethiopia	Acidic	Not specified	Improved variety, NP fertilizer	78.8% increase with lime + NP fertilizer vs control (Kuma et al., 2018)
Barley	Ethiopia	Acidic	2.2	Phosphorus fertilizer (30 kg/ha)	Highest yield obtained with this combination (Temesgen et al., 2016)

V. Economic Dimensions of Agricultural Lime Utilization

A. Cost-Benefit Analysis of Liming for Smallholder and Commercial Farmers The application of agricultural lime, while requiring an initial investment, has demonstrated the potential for significant economic returns through enhanced crop productivity. Studies and project models indicate substantial yield increases in key crops like maize (reported increases of up to 50-300%) and beans (up to 360%) following lime application in acidic soils.  

Economic analyses from trials in Kenya showed that liming could lead to profit changes of up to $264 per hectare. A specific project model developed for the Njombe, Iringa, and Katavi regions of Tanzania projected a promising Internal Rate of Return (IRR) of 36% and a Net Present Value (NPV) of $2.3 million for a liming intervention. However, this model notably assumed that the initial costs of lime procurement and transportation would be fully subsidized. The same model estimated that over a four-year period, a typical 1.2-hectare farm could generate an additional revenue of $451 due to liming.  

These positive economic indicators are, however, sensitive to several factors. The cost of lime procurement can be a substantial portion of project expenses, estimated at 42% in one model, with transportation accounting for approximately 17% of the overall project cost. The overall economic viability of liming for farmers is therefore highly dependent on the actual application rates used, the magnitude of the crop yield response achieved, and prevailing farm-gate prices for the harvested produce.  

The profitability of liming, particularly for smallholder farmers, hinges critically on managing these significant upfront costs (lime purchase, transport, and application labor) and ensuring that the application leads to a tangible and valuable yield improvement. The fact that a positive IRR in one Tanzanian model was predicated on initial full subsidies for lime and transport highlights the substantial impact of these costs on farmer-level economics. To make liming an economically attractive and sustainable practice for farmers without relying on perpetual subsidies, concerted efforts are essential. These must focus on reducing the farm-gate cost of quality-assured agricultural lime through measures such as promoting efficient local production, lowering transportation costs via infrastructure improvements or logistical innovations, and potentially reviewing the tax structure. Furthermore, ensuring that farmers achieve good yield responses through correct application techniques and complementary good agricultural practices is paramount. Access to credit facilities to cover the initial investment for lime may also be a necessary component to facilitate wider adoption.  

B. Broader Economic Implications: Contribution to Food Security, Rural Incomes, and Potential for Import Substitution or Export The development of a robust agricultural lime sector in Tanzania carries economic implications that extend far beyond individual farm profitability, offering significant macroeconomic benefits. Increased crop productivity resulting from widespread lime use can make a substantial contribution to national food security and reduce reliance on food imports. As yields improve, so too do farmer incomes, which can stimulate rural economies through increased local spending and investment.  

The establishment and growth of a local lime production industry itself can be a source of economic dynamism. This includes job creation in quarrying, processing, transportation, and related support services. If Tanzania can develop into a competitive producer of agricultural lime, there is potential not only for import substitution (currently, some lime products like hydrated lime are imported, for example, from Zambia ) but also for exporting lime to neighboring countries that face similar challenges with soil acidity. This would positively impact the national trade balance.  

The mining sector, which includes the extraction of industrial minerals like limestone, already plays a role in Tanzania’s economy, contributing 9.1% to the Gross Domestic Product (GDP) in 2022/2023. Expanding the value addition to these limestone resources by producing agricultural lime aligns with national goals of industrialization and maximizing the benefits derived from local resources. Therefore, government support and investment in the aglime sector should be viewed not merely as an agricultural support program but as a strategic economic development initiative with the potential for significant multiplier effects on job creation, rural development, and foreign exchange savings or earnings.  

C. Investment Climate and Opportunities in the Aglime Value Chain Tanzania’s Ministry of Minerals actively encourages investment in the industrial minerals sector, which explicitly includes limestone. Government initiatives are also aimed at fostering a favorable investment climate within the broader mining sector. Given the nascent state of a dedicated agricultural lime market, coupled with vast untapped geological resources and a proven agronomic need, significant investment opportunities exist across the entire aglime value chain.  

These opportunities include:

• Quarrying and Processing: Investment in the exploration, quarrying, and processing of limestone and dolomite deposits specifically for the production of agricultural lime. This includes establishing new, modern, and efficient lime production facilities, with a particular opportunity for decentralized plants located closer to key agricultural regions to reduce transport costs. The Nanyala prospect in Mbeya is an example of such potential.  
• Transportation and Distribution: Development of efficient and cost-effective transportation and distribution networks for bulky aglime. This could involve investment in specialized logistics services, warehousing, or local depots.
• Equipment and Services: Manufacturing or provision of lime spreading equipment suitable for various scales of farming operations. There is also a growing need for soil testing services to accurately determine lime requirements.
• Value Addition: Opportunities for value addition, such as producing granulated or pelletized lime for easier handling and application, or blended lime products with other nutrients.

The current situation—abundant raw materials, strong agronomic demand, established proof of high returns on lime use, yet seemingly insufficient dedicated production and identified bottlenecks in processing, transport, and application —points clearly towards these untapped investment potentials. Public-private partnerships (PPPs) could play a crucial role in de-risking some of these investments, particularly those related to infrastructure development or the establishment of anchor processing facilities.  

D. Analysis of Lime Taxation and its Effect on Affordability and Market Development The cost of agricultural lime to the end-user is significantly influenced by taxation policies, which can act as a barrier to its affordability and market development. In Tanzania, imported granulated lime is reportedly subject to a 10% import duty, with an additional 16% Value Added Tax (VAT) levied on the final price. Such taxes directly inflate the cost of this crucial agricultural input. Locally produced powdered lime may also be subject to VAT in many countries, a category that could include Tanzania.  

Currently, there appears to be a lack of specific tax policy incentives aimed at encouraging lime production and use in many countries, including potentially Tanzania. Recognizing this issue, the Alliance for a Green Revolution in Africa (AGRA) is commissioning a study to assess the status of lime taxation in Tanzania (among other focus countries). This study will examine how existing tax regimes contribute to the high costs of lime and will aim to recommend appropriate fiscal incentives and instruments that do not significantly disrupt the business environment.  

While there are general mining sector incentives in Tanzania, such as reduced royalties on minerals sold to local refineries and the abolition of a 1% inspection fee , their specific applicability or impact on agricultural lime production needs clarification. The current tax structure, particularly for imported lime products, may be counterproductive to national agricultural goals. If lime is a critical input for improving soil health and boosting agricultural productivity, then imposing significant taxes on it can be economically inefficient, as it raises costs for farmers and discourages adoption. A thorough review of the tax regime for agricultural lime—both imported and locally produced—is therefore warranted. Fiscal incentives, such as VAT exemptions, reduced import duties for aglime or its raw materials, or tax breaks for local aglime producers, could substantially improve affordability and stimulate demand. This, in turn, could lead to greater agricultural productivity and broader economic benefits that might offset any direct revenue foregone from such tax adjustments. The findings and recommendations from the forthcoming AGRA study will be critical in informing policy in this area.  

VI. Policy, Regulatory, and Institutional Framework

A. National Agricultural Policies and Soil Health Initiatives (e.g., Kilimo Kwanza, National Lime Application Guidelines) Tanzania’s commitment to agricultural development and soil health is reflected in several national policies and initiatives. The Kilimo Kwanza (Agriculture First) Initiative serves as an overarching framework, emphasizing the modernization of agriculture through sustainable practices and strategic investments in soil health. The application of agricultural lime to address soil acidity aligns directly with these objectives.  

A key targeted intervention is the development of National Lime Application Guidelines. Drafted in early 2021, these guidelines have undergone reviews by soil experts, language translators, and various stakeholders, including the Ministry of Agriculture and the Southern Agricultural Growth Corridor of Tanzania (SAGCOT). Although formal endorsement was pending as of early 2024, preliminary Training of Trainers (ToTs) programs have commenced, indicating a pragmatic approach to field validation and dissemination. These guidelines are considered pivotal for standardizing advice on lime use across the country and are crucial for effective extension work.  

In the mining sector, the government’s long-term vision is articulated in “Vision 2030: Minerals are Life and Wealth”. The Mineral Policy of 2009 was formulated to address challenges within the sector and align mining activities with broader goals of sustainable economic development, laying a foundation for local value addition from mineral resources.  

The government has also demonstrated a focus on soil health through the activities of the Tanzania Agricultural Research Institute (TARI), which is conducting research on soil health across various agricultural zones, and through initiatives to distribute soil testing equipment to extension officers nationwide. This high-level policy intent is strong; however, its translation into tangible impact hinges on effective practical implementation, widespread dissemination of knowledge and tools like the guidelines, and robust coordination among the various government ministries and agencies involved. The formal endorsement and comprehensive rollout of the National Lime Application Guidelines should be a priority. Furthermore, establishing a cross-ministerial task force or a dedicated coordination mechanism for agricultural lime development could significantly enhance synergy between policies related to mineral extraction, agricultural input supply, quality control, farmer support, and environmental management.  

B. Roles and Mandates of Key Governmental and Research Institutions Several governmental and research institutions play crucial roles in the agricultural lime value chain in Tanzania:

• Ministry of Agriculture: Holds the primary responsibility for overall agricultural policy, including soil health management. It has been leading the development of the national lime-use guidelines and is tasked with supporting agricultural extension officers.  
• Tanzania Agricultural Research Institute (TARI): The principal agricultural research organization in the country. TARI conducts vital research on soil health, undertakes lime trials and demonstrations, and collaborates on the Training of Trainers programs for the lime guidelines. Key TARI research stations involved in these efforts include Mlingano, Uyole, and Ukiriguru.  
• Tanzania Fertilizer Regulatory Authority (TFRA): This authority is responsible for regulating fertilizers and “fertilizer supplements” in Tanzania. Agricultural lime, given its role in improving soil conditions and nutrient availability, could potentially fall under its definition of a fertilizer supplement. If so, producers and importers of aglime would be subject to TFRA’s registration, testing, and labeling requirements. The regulations stipulate that fertilizers and fertilizer supplements must undergo testing and registration prior to being marketed.  
• Tanzania Bureau of Standards (TBS): The national body responsible for developing and enforcing standards for products and services. TBS has established a specific standard for “Limestone for Animal Feed Use” (DTZS AFDC 9(1530)). Its role in setting and enforcing specific quality standards for agricultural lime intended for soil application is critical but needs to be clearly defined and actively pursued.  
• Geological Survey of Tanzania (GST): As detailed in Section II.D, GST is responsible for the mapping, assessment, and provision of data on national mineral resources, including limestone and dolomite deposits.  
• Mining Commission (under the Ministry of Minerals): This body manages mining rights and licenses throughout Tanzania, operating the Online Mining Cadastre Transactional Portal (Madini Portal).  
• Southern Agricultural Growth Corridor of Tanzania (SAGCOT): An initiative focused on developing agriculture in a key geographical corridor. SAGCOT has been actively involved in projects demonstrating the positive effects of lime, contributing to the refinement of the national lime guidelines, and participating in Training of Trainers programs.  

An examination of these institutional roles reveals a potential area for clarification regarding the specific regulatory framework for agricultural lime. While TFRA regulates “fertilizer supplements” and TBS has standards for limestone for animal feed , the precise regulatory pathway and enforceable quality standards for agricultural lime for soil application are not explicitly and consistently detailed across the available information. Clear quality standards (covering CCE, fineness, moisture, contaminants) are essential for a well-functioning aglime market and for protecting farmers from substandard products. There is a need to ensure that the regulatory framework is robust, clear, and practically implemented, facilitating rather than hindering the growth of the local aglime industry.  

C. Quality Standards, Specifications, and Regulatory Oversight for Agricultural Lime The quality of agricultural lime is paramount for its effectiveness in neutralizing soil acidity and providing agronomic benefits. Key quality parameters include:

• Calcium Carbonate Equivalent (CCE): This is the primary measure of a liming material’s acid-neutralizing capacity, expressed as a percentage relative to pure calcium carbonate (which has a CCE of 100%). ABM Agricultural Lime, for example, states a CCE of at least 80%.  
• Fineness of Grind: The particle size distribution of lime critically affects its rate of reaction in the soil. Finer particles have a larger surface area and react more quickly and completely. Standards often specify the percentage of material that must pass through sieves of particular mesh sizes (e.g., 10-mesh, 50-mesh, 60-mesh, 80-mesh).  
• Moisture Content: High moisture content can affect handling, spreading, and the effective concentration of the active liming material. The Tanzanian standard for limestone for animal feed specifies a maximum moisture content of 0.5%.  
• Calcium (CaCO3​) and Magnesium (MgCO3​) Content: The relative proportions of these carbonates determine whether the lime is calcitic or dolomitic, and thus its suitability for soils with specific calcium or magnesium deficiencies.  

Currently, Tanzania has a detailed national standard (DTZS AFDC 9(1530)) for Limestone for Animal Feed Use. This standard specifies different classes of limestone (High Calcium, Magnesian, Dolomitic, Ground), their respective CaCO3​ and MgCO3​ content requirements, maximum moisture levels, limits for heavy metal contaminants (Mercury, Lead, Arsenic, Cadmium), hygiene requirements during preparation, and detailed packaging and labeling instructions.  

However, a similarly specific and officially gazetted national standard for agricultural lime intended for soil application is not explicitly detailed in the provided research materials. While the National Lime Application Guidelines are under development and will provide recommendations on use , these would be significantly strengthened if they could refer to clearly defined and enforceable product quality standards. The absence of such standards creates a risk of substandard or ineffective lime products entering the market, which could undermine farmer confidence and the overall success of liming programs. This represents a critical gap. The Tanzania Bureau of Standards (TBS), in collaboration with the Ministry of Agriculture, TARI, and TFRA, should prioritize the development, gazettement, and enforcement of clear, practical quality standards for agricultural lime sold for soil amendment. These standards should cover CCE, fineness, moisture content, CaCO3​/MgCO3​ balance for classification (calcitic/dolomitic), and potentially limits for contaminants. A system for product certification and market surveillance would also be essential to ensure compliance.  

Regulatory oversight for fertilizer-related products, potentially including aglime as a “fertilizer supplement,” falls under the Tanzania Fertilizer Regulatory Authority (TFRA). TBS is the mandated body for setting national standards.  

D. Mining Legislation and Licensing for Limestone/Dolomite Extraction for Agricultural Use (Online Cadastre Portal) The extraction of limestone and dolomite, the raw materials for agricultural lime, is governed by Tanzania’s mining legislation. The Mining Act, Cap 123 is the primary law regulating mineral rights in the country. This Act provides for various types of mineral rights and licenses, including:  

• Prospecting Licences (PLs) for exploration.
• Special Mining Licences (SMLs) for large-scale mining operations (investment > US$100 million).
• Mining Licences (MLs) for medium-scale operations (investment US$100,000 to US$100 million).
• Primary Mining Licences (PMLs) for small-scale mining (investment < US$5 million, reserved for Tanzanian citizens or companies with Tanzanian citizenship).
• Licences for Processing Minerals (PCLs), Refining (RFLs), and Smelting (SLs), as well as Dealer Licences (DLs) and Broker Licences (BLs) for mineral trading. The extraction of limestone or dolomite for agricultural lime production would typically fall under a PL for initial exploration, followed by an ML, SML, or PML depending on the intended scale of the quarrying operation.  

To modernize and streamline the management of these mineral rights, the Ministry of Minerals, through the Mining Commission, has implemented the Online Mining Cadastre Transactional Portal (Madini Portal). This web-based system is designed to handle applications for various mineral rights, maintain geospatial records of all mining areas, track the status and compliance of licenses, process fee payments, and prevent the overlapping of claims. The portal also features an interactive map viewer that allows users to see active and pending applications, identify protected zones, view mineral potential areas, and overlay administrative boundaries, forest reserves, and topographic features. User guides and information on how to use the portal are available , and the portal can be accessed at portal.madini.go.tz (though some sources indicated temporary accessibility issues during research ).  

While the portal provides tools for viewing license information and mineral potential areas, the ease of specifically searching for “limestone licenses” or identifying all areas licensed explicitly for aglime raw material extraction is not detailed as a simple keyword search function in all provided information. Users can typically view their own license portfolios and navigate the map to see existing tenements.  

For the agricultural lime sector to thrive, access to raw materials is fundamental. The licensing process, even with the efficiencies introduced by the online cadastre system, must be clear and accessible for potential producers, including those who may be considering smaller-scale operations focused on local agricultural markets. It would be beneficial for the Mining Commission to ensure that the procedures for obtaining licenses for quarrying limestone or dolomite specifically for agricultural lime production are streamlined and perhaps even incentivized. This could involve clarifying how “agricultural lime” as an end-product might influence licensing terms or royalty structures, ensuring that mineral sector policies are harmonized with national agricultural development objectives. The continued accessibility, user-friendliness, and comprehensive data provision of the Madini Portal are crucial for transparency and facilitating investment in this vital input sector.

Table 4: Key Institutions and Regulatory Aspects for Agricultural Lime in Tanzania

Institution/Regulation Area	Key Mandate/Role related to Aglime	Relevant Legislation/Standard (if any)	Key Source Snippets
Ministry of Agriculture	Overall agricultural policy, soil health initiatives, development of lime-use guidelines, support to extension services.	National Lime Application Guidelines (Draft)
Tanzania Agricultural Research Institute (TARI)	Research on soil health, lime trials, demonstrations, Training of Trainers for lime guidelines.	–
Tanzania Fertilizer Regulatory Authority (TFRA)	Regulation of fertilizers and “fertilizer supplements”; potential registration, testing, and labeling of aglime if classified as such.	The Fertilizers Act, Fertilizer Regulations (e.g., GN. No. 350)
Tanzania Bureau of Standards (TBS)	Development and enforcement of national quality standards.	DTZS AFDC 9(1530) Limestone for Animal Feed Use. (Specific standard for soil aglime needed)
Geological Survey of Tanzania (GST)	Mapping and assessment of limestone/dolomite resources, provision of geoscientific data.	–
Mining Commission (Ministry of Minerals)	Management of mining rights and licenses, operation of Online Mining Cadastre Portal (Madini Portal).	Mining Act, Cap 123
Southern Agricultural Growth Corridor of Tanzania (SAGCOT)	Facilitation of agricultural development projects, involvement in lime guideline refinement and Training of Trainers.	–
National Environmental Management Council (NEMC)	(Implied) Oversight of Environmental Impact Assessments (EIAs) for mining and processing plants.	Environmental Management Act	(general EIA requirement)
Quality Standards for Soil Aglime	Critical need for specific national standards covering CCE, fineness, moisture, CaCO₃/MgCO₃ content, contaminants.	Currently a gap.	Insight 6.3
Taxation Policy	Current taxes (import duty, VAT) affect lime affordability; AGRA study to assess and recommend fiscal incentives.	–

VII. Overarching Challenges and Strategic Considerations

The development of a vibrant and effective agricultural lime sector in Tanzania is confronted by a series of significant, often interconnected, challenges that span the entire value chain from resource extraction to farmer application. Addressing these requires careful strategic consideration.

• A. Addressing Cost Barriers: Production, Transportation, and Application The high cost of agricultural lime at the farm gate is a primary impediment to its widespread adoption. This cost is an accumulation of expenses incurred at various stages: the initial procurement or production of lime can account for a substantial portion of project costs (e.g., 42% in one model). Transportation is another major cost driver due to the bulky nature of lime and the often long distances to farming areas, contributing around 17% to project costs in some estimates. Taxation, including import duties and VAT, further adds to the final price paid by farmers. Finally, the labor and/or equipment required for application also represent a cost to the farmer.
  • Strategic Consideration: A multi-faceted approach to cost reduction is essential. This includes promoting efficiencies in local lime production (e.g., through modern technologies or optimized quarrying), exploring options for transport subsidies or investing in infrastructure to lower logistics costs, undertaking a thorough review of the tax regime applicable to aglime, and developing and promoting more affordable and efficient lime application methods suitable for smallholders.
• B. Enhancing Infrastructure and Supply Chain Efficiency The efficiency of the aglime supply chain is heavily constrained by infrastructural limitations, particularly in rural areas. Poor road networks significantly increase transportation costs and limit timely access to lime for many farmers. Effective logistics planning is crucial for distributing this bulky commodity to often remote and dispersed farming communities. The potential for establishing decentralized lime production facilities closer to major agricultural zones, such as the proposed factory in Nanyala or adopting models similar to those explored in Zambia involving smaller-scale local production , could substantially reduce transport distances and associated costs.
  • Strategic Consideration: Strategic investments in improving rural road infrastructure are vital. Alongside this, exploring and supporting the development of efficient aglime supply chain models, which might include establishing local aglime hubs, depots, or leveraging existing agro-dealer networks, can improve accessibility.
• C. Strengthening Farmer Knowledge, Extension Support, and Access to Lime A significant barrier to lime adoption is the often low level of farmer awareness regarding soil acidity, its impact on their crops, and the benefits and proper use of agricultural lime. Effective agricultural extension services are therefore critical. While the government is taking steps, such as providing soil testing kits to extension officers and developing national lime application guidelines , the capacity of the extension system to deliver this knowledge and support effectively to millions of farmers needs continuous strengthening. Access to lime itself, in terms of consistent availability, affordability, and timely supply, remains a challenge for many.
  • Strategic Consideration: There is a need to scale up comprehensive farmer education programs that are practical and participatory. Extension officers must be thoroughly equipped with the National Lime Application Guidelines, soil testing capabilities, and adequate mobility. Developing accessible and reliable lime supply channels, possibly through agro-dealers, farmer cooperatives, or other community-based models, is also crucial.
• D. Ensuring Sustainable Resource Management and Environmental Considerations The extraction and processing of limestone for agricultural lime must be conducted in an environmentally sustainable manner. Mining activities can have potential negative impacts, including deforestation, land degradation, dust, and vibration, all of which require careful management and mitigation. Sustainable quarrying practices, such as the stockpiling of topsoil for later site restoration (as mentioned for Wazo Hill ), are important. Environmental Impact Assessments (EIAs) are typically required for establishing mining and processing operations.
  • Strategic Consideration: Strict enforcement of environmental regulations for quarrying and processing operations is necessary. Promoting best practices in land reclamation, waste management, and dust suppression at lime production sites will be key to ensuring the long-term sustainability of the sector.

The challenges outlined above—cost, infrastructure, knowledge, and sustainability—are not isolated issues. They are deeply interconnected. For instance, high transportation costs, an infrastructure issue, directly contribute to the unaffordability of lime, a cost barrier. Low farmer awareness can lead to weak demand, which in turn disincentivizes private sector investment in production and improvements in supply chains. Even if lime were affordable and available, a lack of knowledge on its proper application could lead to poor results, discouraging future use. Similarly, unsustainable quarrying practices could create long-term environmental problems that outweigh the short-term agricultural benefits. This interconnectedness demands a holistic, systems-based approach to developing the agricultural lime sector in Tanzania. Isolated interventions are unlikely to succeed; concurrent and coordinated efforts are needed across policy reform, infrastructure development, production support, extension and education, and environmental oversight.

VIII. Strategic Recommendations and Future Outlook for the Aglime Sector

Realizing the transformative potential of agricultural lime in Tanzania requires a concerted and strategic effort from the government, private sector, research institutions, and development partners. Based on the comprehensive analysis, the following recommendations are proposed to address the identified challenges and unlock the opportunities within the aglime sector:

• A. Policy Interventions to Foster a Conducive Aglime Market
  1. Taxation Review and Reform: Conduct an urgent review of the existing taxation structure for agricultural lime, including import duties, VAT, and any local levies. Consider targeted tax reductions, exemptions, or fiscal incentives for both imported and locally produced agricultural lime, as well as for raw materials and equipment used in its production. This aims to directly reduce the farm-gate cost of lime, making it more affordable for farmers.  
  2. Formal Endorsement and Dissemination of National Lime Application Guidelines: Expedite the formal endorsement of the National Lime Application Guidelines and ensure their wide dissemination to agricultural extension officers, agro-dealers, lime producers, and farmers. These guidelines are crucial for standardizing advice and promoting best practices in lime use.  
  3. Establishment and Enforcement of National Aglime Quality Standards: Mandate the Tanzania Bureau of Standards (TBS), in collaboration with the Ministry of Agriculture, TARI, and TFRA, to develop, gazette, and enforce clear, practical quality standards specifically for agricultural lime intended for soil application. These standards must cover CCE, fineness (particle size distribution), moisture content, calcium and magnesium content (for classification into calcitic and dolomitic), and permissible limits for contaminants. Implement a system for product certification and market surveillance to ensure compliance [Insight 6.3].
  4. Streamlined Licensing for Aglime Raw Material Extraction: The Mining Commission should review and, where necessary, streamline the licensing process for the quarrying of limestone and dolomite specifically for agricultural lime production. Consideration should be given to incentives or preferential terms for operations dedicated to producing agricultural inputs, aligning mineral sector policies with national agricultural development goals [Insight 6.4].
• B. Strategies for Enhancing Production Capacity and Local Value Addition
  1. Promote Investment in Diverse Production Facilities: Encourage and facilitate investment in new and existing lime production facilities. This should include support for large-scale, efficient plants as well as decentralized, smaller-scale operations strategically located closer to key agricultural regions to minimize transport costs (e.g., the Nanyala model in Mbeya or adapting successful small-scale production models from neighboring countries like Zambia).  
  2. Engage Cement Companies in Aglime Production: Actively engage major cement companies to explore and optimize opportunities for the co-production of quality agricultural lime from their existing limestone quarrying and crushing operations, potentially by valorizing fine materials or dedicating specific grinding lines where feasible [Insight 3.1].
  3. Support Research into Cost-Effective Technologies: Invest in research and development of cost-effective and environmentally sound quarrying, crushing, grinding, and potentially pelletizing/granulating technologies suitable for various scales of aglime production in the Tanzanian context.
  4. Integrated Development of Carbonatite Resources: For carbonatite deposits with co-existing phosphate mineralization (e.g., Panda Hill, Sangu-Ikola, Ngualla), promote integrated development strategies that consider the co-production of both agricultural lime and phosphate-based fertilizers to offer holistic soil fertility solutions [Insight 2.2].
• C. Improving Logistics, Distribution, and Farmer Access
  1. Investment in Rural Infrastructure: Prioritize public and private investment in the improvement of rural road networks, particularly those serving key agricultural areas with high soil acidity, to reduce the cost and difficulty of transporting bulky inputs like lime [Insight 3.2].
  2. Development of Efficient Distribution Networks: Support the establishment and strengthening of efficient and cost-effective agricultural lime distribution networks. This could involve leveraging existing agro-dealer networks, promoting farmer cooperatives for bulk procurement and distribution, or establishing strategically located lime depots or hubs.
  3. Pilot Innovative Delivery Models: Explore and pilot innovative delivery models for agricultural lime, potentially incorporating digital logistics platforms, group transport schemes, or partnerships with local transporters to optimize last-mile delivery.
• D. Investing in Research, Development, and Extension Services
  1. Strengthen GST’s Aglime Resource Assessment Capacity: Enhance the capacity of the Geological Survey of Tanzania (GST) to conduct detailed geological assessments of limestone and dolomite resources specifically for their agricultural lime potential. This should include systematic analysis of CCE, magnesium content, grindability, and reactivity for various deposits [Insight 2.3, Insight 2.4].
  2. Enhance TARI’s Agronomic Research: Support TARI in conducting further adaptive research on optimal lime application rates for different crops, soil types, and agro-ecological zones in Tanzania. Research should also focus on the long-term impacts of liming on soil health, nutrient cycling, and overall farming system sustainability.
  3. Empower Agricultural Extension Services: Comprehensively equip and train agricultural extension officers on soil acidity diagnosis (including the effective use of soil testing kits), interpretation of soil test results, making site-specific lime recommendations based on the National Lime Application Guidelines, and advising farmers on proper lime application techniques and complementary soil fertility management practices. Ensure extension officers have adequate mobility and resources.  
  4. Develop Farmer-Friendly Educational Materials: Create and widely disseminate clear, practical, and locally relevant educational materials (e.g., brochures, radio programs, digital content) for farmers on the causes and impacts of soil acidity, the benefits of liming, how to access quality lime, and correct application methods.
• E. Promoting Public-Private Partnerships and Investment
  1. Facilitate Public-Private Partnerships (PPPs): Actively promote and facilitate PPPs across the aglime value chain, including for the development of lime production facilities, investment in transportation and storage infrastructure, and the establishment of efficient distribution systems.
  2. Create Clear Investment Incentives: Develop and communicate a clear set of investment incentives specifically for the agricultural lime sector to attract both local and foreign investment. This could include fiscal incentives, access to land, and support for regulatory compliance.
  3. Support Market Information Systems: Foster the development of market information systems that provide transparent data on aglime demand, supply, pricing, and quality to help producers, distributors, and farmers make informed decisions.

Future Outlook: The future of Tanzanian agriculture can be significantly brighter with the effective harnessing of its agricultural lime resources. Addressing soil acidity is not merely a technical fix but a fundamental step towards unlocking the nation’s agricultural potential, improving food and nutrition security, and enhancing the livelihoods of millions of smallholder farmers. The path forward requires a paradigm shift from viewing lime as a niche product to recognizing it as a strategic national input.

If the challenges of cost, accessibility, awareness, and quality assurance are systematically addressed through the implementation of the recommended strategies, Tanzania can expect to see a substantial increase in crop yields, improved returns on fertilizer investments, and a more resilient agricultural sector. The development of a robust domestic aglime industry will also contribute to rural economic growth, job creation, and potentially position Tanzania as a regional supplier of this vital input. Success will depend on sustained political will, effective cross-sectoral coordination, active private sector engagement, and the continuous empowerment of farmers with the knowledge and resources they need to improve their soil and their yields. The journey requires commitment, but the rewards—a more productive, sustainable, and food-secure Tanzania—are well worth the endeavor.

IX. Conclusion

Agricultural lime holds immense and largely untapped potential to revolutionize Tanzanian agriculture. The pervasive issue of soil acidity across millions of hectares acts as a critical brake on crop productivity, directly impacting food security and the economic well-being of the nation’s farmers. This report has established that Tanzania is endowed with abundant and diverse geological resources of limestone and dolomite, the essential raw materials for aglime production. Furthermore, the agronomic benefits of applying lime to acidic soils—including significant yield increases for staple crops like maize and beans, enhanced nutrient availability, and improved fertilizer efficiency—are well-documented within Tanzania and in comparable agro-ecological contexts.

However, the translation of this potential into widespread, impactful practice is currently constrained by a complex interplay of challenges. These include the high farm-gate cost of lime, driven by production inefficiencies, substantial transportation and logistical hurdles, and a tax regime that may inadvertently hinder affordability. Farmer awareness of soil acidity and the benefits of liming, though growing, remains insufficient, and access to reliable information, quality-assured lime products, and effective extension support is limited. While a policy framework supportive of agricultural development exists, specific regulatory aspects for agricultural lime, particularly national quality standards for soil application and streamlined support for local production, require strengthening.

Realizing the transformative power of agricultural lime necessitates a concerted, multi-stakeholder, and strategic approach. The recommendations outlined in this report—spanning policy interventions, enhancements in production and local value addition, improvements in logistics and farmer access, investments in research and extension, and the promotion of public-private partnerships—provide a roadmap for action. A holistic strategy that concurrently addresses cost barriers, infrastructure deficits, knowledge gaps, and regulatory needs is paramount.

The future outlook for Tanzania’s agricultural lime sector is promising, provided there is a sustained commitment to overcoming these challenges. By strategically developing its aglime resources and ensuring their effective utilization, Tanzania can achieve substantial gains in agricultural productivity, bolster its national food security, enhance rural incomes, and foster a more sustainable and resilient agricultural system. This endeavor is not merely about amending soils; it is about cultivating a more prosperous future for Tanzania.

Sources used in the report

References on Agricultural Lime and Soil Health

🌱 Tanzania-Specific and Regional Sources

• Kilimo Kwanza – Agricultural Lime in Tanzania
  • https://kilimokwanza.org/agricultural-lime-a-game-changer-for-maize-yields-and-economic
  • https://kilimokwanza.org/tanzanias-agriculture-ministry-prepares-lime-use
  • https://kilimokwanza.org/tanzania-the-promise-of-the-national-lime-application-guidelines
  • https://kilimokwanza.org/investing-in-soil-health-cabis-user-testing-on-gaia-dashboard-in-tanzania
  • https://kilimokwanza.org/the-fight-against-soil-acidity-in-tanzania-the-bitter-truth-and-charting-a-sustainable-food-systems-future
• Tanzania Bureau of Standards (TBS): https://www.tbs.go.tz
• Tanzania Fertilizer Regulatory Authority (TFRA): https://www.tfra.go.tz
• Ministry of Agriculture – Soils of Tanzania: https://www.kilimo.go.tz
• Sustain Africa – External Report Tanzania: https://www.sustainafrica-initiative.org/SA__external-report–Tanzania.indd
• Tanzania | PDF | Limestone | Tanzania – Scribd: https://www.scribd.com/document/465486829/Tanzania-PDF-Limestone-Tanzania
• Tanzania: TARI Studies on Soil Health – AllAfrica: https://allafrica.com/stories/202403220114.html

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🧪 Agricultural Lime Research & Extension Publications

• University of Kentucky – Lime Quality Guide (ID-163): https://publications.ca.uky.edu/ID163
• UKnowledge – Lime Recommendations Based on Quality: https://uknowledge.uky.edu/pss_notes/199/
• Division of Regulatory Services – Interpreting Lime Lab Reports: https://www.rs.uky.edu/regulatory/lime_reports.php
• MSU – Facts About Soil Acidity and Lime: https://www.canr.msu.edu/news/facts_about_soil_acidity_and_lime
• One Acre Fund – Managing Soil Acidity with Lime: https://oneacrefund.org/blog/managing-soil-acidity-lime/
• IAAP – Illinois Association of Aggregate Producers: https://www.iaap-aggregates.org/agricultural-lime.html

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🌍 International Research & Case Studies

• FarmLime Project – NERC Archive: https://nora.nerc.ac.uk/id/eprint/8353/
• ResearchGate – Agricultural Lime Topics:
  • https://www.researchgate.net/publication/325534692
  • https://www.researchgate.net/publication/338954687
  • https://www.researchgate.net/publication/309492525
  • https://www.researchgate.net/publication/347356793
  • https://www.researchgate.net/publication/366982997
• IISD – Enhancing Soil Health with Lime: https://www.iisd.org/articles/soil-health-lime-tanzania
• Devex – Consultant Opportunity on Lime Tax Analysis: https://www.devex.com/jobs/undertake-a-comprehensive-analysis-of-agricultural-lime-taxation-structure-1030191
• Kenyatta University – Phosphate & Fertilizer Efficiency in Maize: https://ir-library.ku.ac.ke/handle/123456789/21221
• Semantic Scholar – Bread Wheat on Lime-treated Soil: https://journal.safebd.org/index.php/safety/article/view/346

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🏭 Industry & Supply Chain References

• Wakestone Corporation: https://www.wakestonecorp.com
• Springwood Capital (Emerging African Markets): https://www.springwoodcapital.com/our-products
• Limestone Resources Limited – Zambia: https://www.lrl.co.zm
• ABM Equipment Services – Dolomite & Limestone Products:
  • https://www.exportersindia.com/abm-equipment-services-ltd/
  • https://www.exportersindia.com/product-detail/dolomite-powder-1501991648.htm

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📚 Supplementary Educational Resources

• Wikipedia – Geology of Tanzania: https://en.wikipedia.org/wiki/Geology_of_Tanzania
• ResearchGate – Geology of Tanzania (PDF): https://www.researchgate.net/publication/256442616
• Science.gov – Minjingu Phosphate Rock: https://www.science.gov/topicpages/m/minjingu+phosphate+rock