Improving upland rice (Oryza sativa l.) performance through enhanced soil fertility and water conservation methods

Abstract

The experiment was conducted at Experimental sites of Tanzania Agricultural Research Institute (TARI) – Ukiriguru, Mwanza, Tanzania. The objective was to improve performance of upland rice through enhanced soil fertility and water conservation methods. A split–split plot experiment in a 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 30 cm inter–and intra–row spacing. Data on soil, weather, crop growth, yield components and grain yield were collected. Rainfall was 651.2 mm 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 2.09mgP/Kg and organic carbon 0.58%. The soil calcium was 3.38 cmolc/Kg and potassium was 0.36cmolc/Kg, while zinc was 0.39 mg/Kg. Cultivars had significant effect on yields which were 2856, 2507 and 2140 Kg/ha for WAB 450, NERICA4 and NERICA1 respectively. Fertilizer types also significantly affected grain yield in the order of urea (3368 Kg/ha) > FYM (2723 Kg/ha) and > control (1421 Kg/ha). Moisture conservation methods significantly affected yield in this order: tie ridges (2710 Kg/ha) > open ridge (2398 Kg/ha) > flat cultivation (2394 Kg/ha). Overall, the study results indicated low fertility status in the soil, 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 80 Kg N/ha gave high grain yield, while tie ridges were the best in soil moisture conservation.