Research finds no basis for farmers’ negative perception of the quality of fertilizers in Tanzania


By Rootooba contributor , 17 May  2021

Soil fertility and nutrient management are crucial factors in crop production; however, fertilizer adoption in Tanzania (and indeed Africa) remains below the recommended rate contributing to poor crop yields and poverty. This is partly due to farmers’ persistent suspicion that the quality of fertilizers in the market is sub-standard. 

However, a recent study titled “Misperceived quality: Fertilizer in Tanzania”, published in the Journal of Development Economics found no reliable evidence to support farmers’ beliefs that the fertilizers available to them at local markets were of poor quality. 

The study found that farmers judged the nutrient quality of the fertilizers through physical attributes (visible caking, powdering, foreign material like bugs or small bits of dirt, or discoloration). Many fertilizers appeared degraded, and farmers relied on these observable attributes to incorrectly assess nutrient content. This reduced their trust in fertilizer and willingness-to-buy. 

The study, led by Hope Michelson, Associate Professor at Department of Agricultural and Consumer Economics, the University of Illinois at Urbana-Champaign, USA in collaboration with the International Institute of Tropical Agriculture (IITA) and the University of Sussex, explored the reasons for the under-use of fertilizer. 

The research team purchased and analyzed 633 fertilizer samples from 225 sellers in Morogoro, which were then tested in laboratories in Kenya and the United States. The results confirmed that the quality of fertilizers is good. Only 2 out of 300 urea samples did not meet industry standards. 

Moreover, the study found that the nutrient content in marketed fertilizer, especially for urea, was consistent with recent large-scale assessments undertaken by the International Fertilizer Development Corporation (IFDC) across sub-Saharan Africa.

“Why that belief of rampant product adulteration persists among farmers? We found evidence of a quality inference problem in the market: 25% of fertilizer samples showed degradation in physical attributes, but there is no (statistically significant) correlation between fertilizer’s physical characteristics and its unobservable nutrient content,” said Victor Manyong, an Agricultural Economist and Emeritus Director based in Tanzania, who was part of the research team.

Manyong further added that farmers are willing to pay less for untested fertilizers than for lab-certified fertilizers. But when presented with information about the good quality, farmers frequently revise their beliefs and increase their willingness-to-pay, even at a higher price. 

The study notes that problems related to physical attributes likely begin upstream in the supply chain. The long supply chain process affects the physical appearance of the product. These issues are generally attributable to poor packaging and re-packaging, transport and storage conditions, and a lack of unbiased information on fertilizer quality in the domestic markets for users to make a comparison, explained Manyong.