Research Topics

EPAR Technical Report #354
Publication Date: 11/29/2018
Type: Research Brief
Abstract

Precise agricultural statistics are necessary to track productivity and design sound agricultural policies. Yet, in settings where intercropping is prevalent, even crop yield can be challenging to measure. In a systematic survey of the literature on crop yield in low-income settings, we find that scholars specify how they estimate the yield denominator in under 10% of cases. Using household survey data from Tanzania, we consider four alternative methods of allocating land area on plots that contain multiple crops, and explore the implications of this measurement decision for analyses of maize and rice yield. We find that 64% of cultivated plots contain more than one crop, and average yield estimates vary with different methods of calculating area planted. This pattern is more pronounced for maize, which is more likely than rice to share a plot with other crops. The choice among area methods influences which of these two staple crops is found to be more calorie-productive per ha, as well as the extent to which fertilizer is expected to be profitable for maize production. Given that construction decisions can influence the results of analysis, we conclude that the literature would benefit from greater clarity regarding how yield is measured across studies.

EPAR Technical Report #240
Publication Date: 07/28/2016
Type: Data Analysis
Abstract

There is a wide gap between realized and potential yields for many crops in Sub-Saharan Africa (SSA). Experts identify poor soil quality as a primary constraint to increased agricultural productivity. Therefore, increasing agricultural productivity by improving soil quality is seen as a viable strategy to enhance food security. Yet adoption rates of programs focused on improving soil quality have generally been lower than expected. We explore a seldom considered factor that may limit farmers’ demand for improved soil quality, namely, whether farmers’ self-assessments of their soil quality match soil scientists’ assessments. In this paper, using Tanzania National Panel Survey (TZNPS) data, part of the Living Standards Measurement Study – Integrated Surveys on Agriculture (LSMS-ISA), we compare farmers’ own assessments of soil quality with scientific measurements of soil quality from the Harmonized World Soil Database (HWSD). We find a considerable “mismatch” and most notably, that 11.5 percent of survey households that reported having “good” soil quality are measured by scientific standards to have severely constrained nutrient availability. Mismatches between scientific measurements and farmer assessments of soil quality may highlight a potential barrier for programs seeking to encourage farmers to adopt soil quality improvement activities. 

EPAR Research Brief #79
Publication Date: 07/29/2009
Type: Literature Review
Abstract

The Government of Kenya (GoK) has historically encouraged its farmers to use fertilizer by financing infrastructure and supporting fertilizer markets.  From 1974 to 1984, the GoK provided a fertilizer importation monopoly to one firm, the Kenya Farmers Association.  However, the GoK saw that this monopoly impeded fertilizer market development by prohibiting competing firms from entering the market and, in the latter half of the 1980s, encouraged other firms to enter the highly regulated fertilizer market. This report examines the state of fertilizer use in Kenya by reviewing and summarizing literature on recent fertilizer price increases, Kenya’s fertilizer usage trends and approaches, market forces, and the impact of government and non-government programs. We find that most studies of Kenya’s fertilizer market find it to be well functioning and generally competitive, and conclude that market reform has stimulated fertilizer use mainly by improving farmers’ access to the input through the expansion of private retail networks. Overall fertilizer consumption in Kenya has increased steadily since 1980, and fertilizer use among smallholders is among the highest in Sub-Saharan Africa. Yet fertilizer consumption is still limited, especially on cereal crops, and in areas where agroecological conditions create greater risks and lower returns to fertilizer use.