Oduor O Nathan, Mucheru-Muna Monicah, Mugwe Nyanuga Jayne, Sijali Isaya, Nyabuga George, Mugendi N Daniel
Department of Water and Agricultural Resource Management, University of Embu, P.O. Box 6-60100, Embu, Kenya.
Department of Environmental Sciences, Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya.
Heliyon. 2023 May 15;9(5):e16145. doi: 10.1016/j.heliyon.2023.e16145. eCollection 2023 May.
Soil moisture scarcity and soil fertility decline in the drylands contribute to declining crop productivity. The possible synergistic effects of integrating soil & water conservation, and soil fertility management practices on soil moisture, and hence water use efficiency (WUE) in the drylands of Tharaka-Nithi County in Kenya was assessed. The experiment was laid in a three by three split plot arrangement, with four replications, for four cropping seasons. Minimum tillage with mulch, tied ridges, and conventional tillage formed the main plot factors. The sub-plot factors included animal manure plus fertilizer at 120, 60, and 30 N kg ha. There was significant improvement in soil moisture by 35 and 28% by minimum tillage with mulch and tied ridges, respectively, compared to conventional tillage. Manure plus fertilizer rates of 120 and 60 N kg ha had significantly lower soil moisture by 12 and 10%, respectively than the 30 N kg ha across the seasons. The WUE was significantly enhanced by 150 and 65% under minimum tillage with mulch and tied ridges, respectively, compared to conventional tillage. Compared with 30 N kg ha, the 120 N kg ha and 60 kg ha significantly enhanced the WUE by 66 and 25%, respectively. Across the seasons, the best treatment combination for improving WUE was minimum tillage with mulch at 120 N kg ha rate of manure plus fertilizer.
干旱地区土壤水分稀缺和土壤肥力下降导致作物生产力降低。本研究评估了在肯尼亚塔拉卡-尼蒂县干旱地区整合水土保持和土壤肥力管理措施对土壤水分以及水分利用效率（WUE）可能产生的协同效应。试验采用三因素裂区设计，重复4次，进行4个种植季节。主区因素包括覆盖免耕、扎埂和传统耕作。副区因素包括施用量分别为120、60和30 N kg/ha的动物粪便加化肥。与传统耕作相比，覆盖免耕和扎埂分别使土壤水分显著提高了35%和28%。在整个季节中，施用量为120和60 N kg/ha的粪便加化肥处理的土壤水分分别比30 N kg/ha处理显著低12%和10%。与传统耕作相比，覆盖免耕和扎埂处理的WUE分别显著提高了150%和65%。与30 N kg/ha相比，120 N kg/ha和60 N kg/ha处理的WUE分别显著提高了66%和25%。在整个季节中，提高WUE的最佳处理组合是覆盖免耕且粪便加化肥施用量为120 N kg/ha。
