Fertilizer Trials on Cotton and Other Annual Crops on Small Farms in Uganda

Abstract

SummaryIn 1963 and 1964 a total of 290 cotton trials, 78 groundnut trials and 51 finger millet trials were conducted on small farms in Uganda to determine the effects and profitability of applying ammonium sulphate and single superphosphate under local conditions. The organization and methods of these trials are described and their results discussed. Ammonium sulphate gave highly significant increases in millet and cotton yields, whilst superphosphate produced similar results on groundnuts but was less effective on cotton and unprofitable on millet. Recommendations are made for groundnuts and millet, but a further season's results are thought necessary before recommending fertilizer treatments for cotton. Soil and leaf samples were taken from the trials and analysed, and relevant agronomic field data were recorded. The correlations of these factors with trial yields and responses are discussed. In general, soil and leaf analyses have been disappointing in assessing responses to fertilizers, but these responses tend to be greater where better farming is practised.