Enhancing Water Use Efficiency Through Integrated Soil Management Practices in the Drylands of Kenya

Low water use efficiency in the dryland regions contributes to the low crop productivity. We assessed how selected soil management strategies affect soil moisture, and water use efficiency in the drylands of Tharaka-Nithi County in Kenya. The experiment was laid in a randomized complete block design and replicated four times. Three (120 N kg ha -1 , 60 N kg ha -1 , and 30 N kg ha -1 ) by three (Minimum tillage with mulch, tied ridges and conventional tillage) split plot arrangement was used to assess the interaction effect of soil fertility and soil & water conservation practices. Treatment combinations included manure + fertilizer + tied ridging under 120 N kg ha -1 , 60 N kg ha -1 and 30 N kg ha -1 ; manure + fertilizer + minimum tillage with crop residue mulch under 120 N kg ha -1 , 60 N kg ha -1 and 30 N kg ha -1 ; manure + fertilizer + conventional tillage under 120 N kg ha -1 , 60 N kg ha -1 and 30 N kg ha -1 ; Managing Beneficial Interactions in Legume Intercrops (MBILI) with 60 N kg ha -1 ; MBILI (Not fertilized); and the control. Minimum tillage with residue mulch had the highest soil moisture and water use efficiency followed by tied ridges, then conventional tillage. Manure plus fertilizer application at 30 N kg ha -1 had the highest soil moisture content, followed by 60 N kg ha -1 , then 120 N kg ha -1 . For water use efficiency, the highest was 120 N kg ha -1 followed by 60 N kg ha -1 , then 30 N kg ha -1 . Combination of soil and water conservation and soil fertility practices increased soil moisture by 30-91% and water use efficiency by 77-90% across the seasons and crop growth stages. The best treatment combination was manure + fertilizer (120 N kg ha -1 ) + minimum tillage with mulch