Applications in natural resource management

Abstract

The Gambia is a small, densely populated country in West Africa with most of the population dependent on subsistence agriculture. Groundnut (Arachis hypogea) is the dominant cash crop, with significant areas of other grain crops, such as millet (Pennisetum glaucuni) and maize (Zea mays), also present. An initial soil fertility survey of the country was conducted during the 1991 and 1992 cropping seasons. Soil and tissue samples were taken from 1159 fields planted to groundnut, maize and millet to develop a soil fertility database for the country. The data was also summarized using the existing political divisions and districts in the country. Results from this initial survey were used to help guide research and extension programs in The Gambia in addition to being used as a reference for many national reports which discuss soil fertility issues. In 1998, a follow‐up survey was conducted to determine if soil fertility was continuing to decline or had stabilized. Soil and tissue samples were taken from 341 fields planted to groundnut, maize and millet. Soil test results indicate that there has been very little change in soil pH, organic matter, available phosphorus, or exchangeable potassium and magnesium. In general, soil test levels in The Gambia have remained quite steady during the past decade.