Effect of Water Conservation Technologies on Water use Efficiency of Pearl Millet Green Gram Intercropping System in Semi-Arid Kenya

Abstract

The insufficient and inadequate soil moisture content in Kenyan’s arid areas has steadily reduced crop production. A field experiment was conducted during 2022/2023 short rain season to evaluate the effect of water conservation technologies and cropping systems on soil moisture dynamics and water use efficiency of selected pearl millet and green gram varieties planted in sole and intercrop system in Kambi-Mawe and Katumani research stations. The experiment was arranged in a split-plot design with individual treatments arranged in a randomized complete block design, replicated three times. The main plots comprised of water conservation technologies (ngolo pits, contour furrows) taking conventional tillage as a control. The cropping system included sole cropping of pearl millet (PMI, PM3), sole green gram varieties (N26 and Biashara) and their intercrops. Soil samples were collected at the depth of 0-20, 20-40 and 40-60 cm at 30 days, 45 days and 60 days after crop emergence and transported to laboratory for fresh weight determination. They were oven-dried at 105oC for 48 hours and the dry weight recorded. Water use efficiency (WUE) was calculated using seasonal crop evapotranspiration (ET) and crop yield. Collected data was analysed using GenStat statistical software 15th edition while mean separation was done using Tukey HSD at p ≤ 0.05 significance level. Results illustrated that water conservation technologies and cropping system significantly increased the soil moisture content recorded at different sampling times. Generally, significantly higher soil moisture was recorded in ngolo pits, followed by contour furrows, while conventional tillage recorded relatively lower soil moisture. Plots under intercropping systems recorded lower soil moisture compared to those under sole cropping irrespective of the crops. Higher WUE values were recorded in ngolo pits, and conventional tillage recorded the lowest values.