Irrigation and fertility management technologies for saline-sodic soils of Nguruman irrigation scheme,Kajiado District

Abstract

An increasing number of pastoralists are incorporating cultivation and commercial farming into traditional livestock economy in Nguruman Irrigation Scheme. However, the continuous decline in production of okra, the major crop for export market is causing concern. A research was conducted to identify the cause of the problem and also develop a design criteria for efficient use of limited water and nutrient resources. Biophysical conditions of land resources were investigated at the scale of 1: 10,000 along a transect from the upper slopes of the piedmont to the bottomland. Observations were made in terms of land qualities that influence the choice of irrigation methods as well as fertility management strategies. The irrigation treatments were drip, border strip, furrow and basin. The fertility treatments were manure alone, manure + NPK, compost + Glycine + NPK and compost+ Glycine. Ofthe four irrigation methods tested, drip proved most promising with 70% germination as compared to border, furrow and basin, which had 25, 24 and 23% respectively. All the fertility treatments resulted in higher crop performance under drip irrigation than the other three. Under the three methods, manure + NPK resulted in crop performance in the following order: border Furrow Basin. The effects of Compost + Glycine +NPK and Compost + Glycine were the lowest. Therefore the main cause of the production decline is inefficient irrigation practices due to poor choice and design of irrigation methods and inadequate fertility replenishment. Based on these findings, drip irrigation in combination with manure is recommended as the best practice. However, where financial constraints are great, border strip in combination with manure + NPK would be the best option. To ensure efficient and sustainable production, land resources investigation and evaluation should be carried out as the basis on which to identify the appropriate irrigation method and fertility management strategies.