Fertilizer Quality Assessment in Markets of Uganda

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Joaquin Sanabria
Joshua Ariga
Job Fugice
Dennis Mose
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With funding from the United States Agency for International Development (USAID), the International Fertilizer Development Center (IFDC) is conducting a series of fertilizer quality assessments in Eastern and Southern Africa. Despite Uganda’s relatively small fertilizer market and low fertilizer consumption, it was selected for the assessment because the small fertilizer market and simple value chains exhibit characteristics that may influence fertilizer quality. In addition, there is potential for increasing consumption as imports have been increasing for the last decade with substantial fertilizer trade activity across its borders, mainly Kenya and Tanzania. The objectives of these studies are to conduct fertilizer quality diagnostics that reveal detailed quality conditions in the value chains of country members of the Common Market for Eastern and Southern Africa (COMESA) and East African Community (EAC) and to use this information to recommend policy solutions for the problems identified. These solutions are targeted at reforming regulations and policies both at country and regional levels. Crafting solutions only for incountry quality problems would be insufficient given the existence of significant fertilizer trade between neighboring countries. The IFDC fertilizer quality assessment team first trained a group of 29 oficials of the Uganda Ministry of Agriculture, Animal Industry, and Fisheries (MAAIF) to perform the role of quality inspectors and collect samples from fertilizer markets in various regions of the country. Then, a random approach was used to select fertilizer dealers and collect fertilizer samples for chemical analyses. Data were also collected on fertilizer markets, dealers, physical properties of the products, and storage conditions from the sample of dealers. After conducting chemical analyses on fertilizer samples in the labs, the estimated nutrient content for fertilizers and cadmium (Cd) content were then incorporated into the dataset for analysis. Based on the number of samples collected from the fertilizers available in the markets, the fertilizers were classified as “large trade” or “low trade.” The large trade fertilizer group included diammonium phosphate (DAP), urea, NPK 17-17-17, calcium ammonium nitrate (CAN), NPKS 25-5-5+5S, and ammonium sulfate. The low trade fertilizer group included numerous products with nutrient content in a wide range of grades and in the form of granulated, liquid, crystal, and powder fertilizers. Nutrient content shortages in fertilizers were quantified in terms of frequency (how often they occur) and severity (the extent to which the shortages are out of compliance). The total nitrogen contents out of compliance (OOC) for DAP, 17-17-17, and 25-5-5+5S were 0%, 13%, and 27%, respectively; the severities for total nitrogen OOC in the same fertilizers were 0%, -1.7%, and -3.9%, respectively. Available phosphorus (P2O5) shortages OOC for the same fertilizers were 6%, 0%, and 12%, respectively, and the shortage severities were -2.5%, 0%, and -2.3%, respectively. Soluble potassium (K2O) OOC shortage frequencies were 9% and 0% for 17-17-17 and 25-5-5+5S, respectively, and the OOC severities for the same nutrient and fertilizers were -5.5% and 0%, respectively. Total nitrogen OOC shortages in urea and ammonium sulfate were 10% and 0%, respectively. Total nitrogen OOC shortages occurred in four CAN samples out of 10. The OOC shortage severities of total nitrogen in urea, ammonium sulfate, and CAN were -1.25%, 0%, and -1.01%, respectively. The liquid fertilizers had significantly higher frequencies and severities of nutrient shortages OOC than the granulated fertilizers; among the granulated products, the set of fertilizers of low commercialization presented higher frequencies and severities of nutrient content shortages OOC than the set of fertilizers of high commercialization. This difference suggests the volume or market share of the products is related to the quality, that products with higher market share show evidence of being manufactured with more care than products of low market share, and/or products with higher market share are less affected by quality-influencing factors along the distribution chain. Ten percent of the fertilizer bags used for weight verifications presented weight shortages beyond the 0.5-kilogram (kg) tolerance limits. Since Uganda has negligible re-bagging of 50-kg bags, the weight shortages must originate in the manufacturing plants or in the in-country bagging of fertilizers that are imported in bulk. Most storage areas used by wholesalers and retailers do not regulate the temperature and relative humidity (RH) to the level required for the preservation of the physical and chemical properties of fertilizers, but due to appropriate granulation and the good quality of the bags used, cases of moist fertilizers, caking, and granular degradation in the fertilizers found in Ugandan markets were identified with low frequency. For these reasons, the nutrient content shortages found can hardly be attributed to degradation of physical properties. No evidence of fertilizer adulteration was found in the sampling and inspection of 50-kg bags, which make up more than 90% of fertilizers traded in Uganda. Exiting literature reports that have identified adulterated fertilizers in bags containing 1-5 kg base their conclusions only on chemical lab results. Additional verification to identify and quantify foreign materials that may have been used to dilute nutrient content is needed to ensure that the out-of-compliance shortages are not due to manufacture deficiencies or uncontrolled variability in chemical analysis. Even if adulteration in small fertilizer packs is proven, it is far from being a significant source of fertilizer quality problems in Uganda given the small fraction of the total trade represented by these small packs. Only 8% of smallholder farming households use inorganic fertilizers, 1 and their use is very low at about 1 kg of nutrient per hectare per year. 2 After discarding degradation of physical properties and adulteration in 50-kg bags as reasons for fertilizer nutrient content shortages, then what is left as the most likely cause is deficient manufacture of some of the imported fertilizers and inadequate port inspection. Cadmium is a toxic element that can accumulate in soil and crop products. The maximum cadmium content found in fertilizers containing P2O5 in Uganda was in a DAP sample with 23 parts per million (ppm) of Cd or 10.7 milligram (mg) Cd per kg P2O5. These two values are below the Kenya tolerance limit of 30 ppm and the European tolerance limit of 20 mg Cd/kg P2O5. The relatively small difference between the maximum Cd found in the fertilizers commercialized in Uganda and the international tolerance limits (TLs) justify continuing to monitor closely the Cd content and the origin of the phosphate rock used in the manufacture of fertilizers, since Cd content in phosphate rock varies with the location and type of deposit. On the regulatory side, the findings of this study point to the need for quality inspections at both domestic and international levels, because some of the quality issues identified may be connected to manufacture or points on the value chain outside of Uganda. It is also important to teach farmers that even with good quality fertilizers, raising yields to desirable levels requires a holistic approach to crop management that includes fertilizer use at rates suggested by soil characteristics and crop balance nutrition needs and the use of good quality seeds and crop protection inputs at the right rates and times.
Agricultural productivity, Fertilizers, Smallholder farmers
Sanabria, J., J. Ariga, and D. Mose. 2018. Fertilizer Quality Assessment in Markets of Uganda, IFDC.