Improving upland rice (oryza sativa L.) perfomance through enhanced soil fertility and water conservation methods at Ukiriguru Mwanza, Tanzania

The experiment was conducted at Agricultural Research Institute (ARI)–Ukiriguru Mwanza, Tanzania from November 2011 to May 2012, aiming at improving upland rice performance through enhanced soil fertility and water conservation methods. A split–split plot experiment in randomized complete block design with three replications and three factors that were (a) upland rice cultivars (WAB 450, NERICA1 and NERICA4) (b) fertilizer types, (urea 80kg N/ha, farm yard manure 5 t/ha and control) (c) three water conservation methods (flat cultivation, open ridge and tie ridge were applied). Rice was sown in seven rows at 30cm inter–and intra–row spacing. Data on soil, weather, crop growth, yield components and grain yield were collected. Rainfall was 651.2mm during the cropping season which was poorly distributed. Average temperature was 24oC with mean relative humidity of 75%. Soil analysis results showed that total nitrogen was 0.08%, phosphorus 2.09 mgP/kg and organic carbon 0.58%. The soil calcium was 3.38cmolc/kg, potassium was 0.36cmolc/kg, while zinc was 0.39 mg/kg. Cultivars had significant effect on yields which were 2 856, 2 507 and 2 140kg/ha for WAB 450, NERICA4 and NERICA1 respectively. Fertilizer types also significantly affected grain yield in the order of urea (3 368kg/ha) > FYM (2 723kg/ha) and > control (1 421kg/ha). Further, moisture conservation methods significantly affected yield in the order of tie ridges (2 710kg/ha), open ridge (2 398kg/ha) and flat cultivation (2 394kg/ha). Overall the study results indicated low soil fertility, although it was found to be suitable for upland rice production with further improvement. It is concluded that rice cultivar, WAB 450 had the highest yield potential, while application of urea at 80kg N/ha gave high grain yield, and tie ridges were the best in soil moisture conservation.Commission of Science and Technology, (COSTECH