Integrating In-Situ Rain Water Harvesting Technologies and Organic Manure for Improved Soil Moisture and Maize Performance in Semi-Arid of Morogoro, Tanzania

Abstract

Tanzania experiences water scarcity caused by unreliable rainfall and prolonged droughts. The objective of this study was to determine in-situ rainwater-harvesting technologies used by smallholder farmers to cope with water scarcity and assess the effect of integrated in-situ rainwater harvesting technologies with organic manure on soil moisture content and maize performance in the semi-arid part of Morogoro region in Tanzania. This study included both experimental and survey method. A household survey was conducted in Gairo district while the experiment was carried out at Sokoine University Agricultural farm. The treatments were traditional cultivation without manure (TOM), mulching without manure (MOW), furrows without manure (FOM), Zai pits without manure (ZOM), Zai-pits with manure (ZWM), mulching with manure (MWM), furrows with manure (FWM) and traditional cultivation with manure (TWM) which laid out in a randomized complete block design and replicated thrice. The experimental data were subjected to the analysis of variance using Statistical Analysis Software version 9.4. Survey data were analyzed using Statistical Package for Social Sciences version 16. The survey results showed that smallholder farmers in Gairo district had no knowledge on Rainwater Harvesting techniques for overcoming water scarcity, where, 95.8% of Ibuti and 89.6% of Tabuhoteli farmers planted drought-tolerant crops as a coping strategy during water scarcity periods. This was attributed to lack of in-situ RWHTs knowledge expressed by 97.9% of Ibuti and 83.3% of Tabuhoteli farmers. Experimental results showed that there were significant differences (p<0.05) in soil moisture retention among treatments at 0 –20 cm and 20–40 cm of soil depths, which ranged from 9.72%-16.16% and 13.52%-17.67%, respectively. The highest soil moisture content was observed in the mulching treatments without manure 16.16% at 0–20 cm and 17.67% at 20–40 cm compared with the control that had 10.44% at 0–20 cm and 13.52% at 20–40 cm. Maize and stover yields differed significantly among the treatments.. Conventional traditional practice had the lowest maize grain weight and biomass weight (3.2 t ha-1 and 3.4 t ha-1) compared to other treatments. The integration of mulching and organic manure resulted in the highest maize grain weight and biomass weight (5.1 t ha-1 and 6.2 t ha-1) compared with the traditional practice. This implies that there is a need for promoting a combination of insitu rainwater harvesting technologies and manure applications especially the use of mulching technology with manure.