Effects of slope position and fertilization on the performance of upland rice planted on inland valley soils at Minna and Bida, Nigeria.
Field trials were carried out at inland valleys of the Research Farms of the National Cereals Research Institute (NCRI), Badeggi and Federal University of Technology, Gidan Kwano, Minna, Nigeria during the 2012 wet season to determine their suitability for rice production. The trials were conducted to determine the effect of slope position and fertilization on the performance of upland rice grown on inland valley soils at Minna and Bida, Nigeria. FARO 45 (ITA 257) early maturing upland variety of rice was used as the test crop at each slope level. The experiment was a 3 x 2 factorial combination of three slopes (upper, middle and hydromorphic fringe) and two fertilizations (without fertilizer and with fertilizer) in a Randomized Complete Block Design (RCBD), replicated three times. The soil textures were loamy sand in Bida and Sandy loam in Minna. Generally, low to high nutrient values were observed in the two inland valley ecosystems. Higher levels of nutrient were observed at the lower slope than the upper slope. However, the hydromorphic fringe gave high to moderate levels of nutrients while the upper slope gave low to very low nutrient levels. On the other hand the middle gave a nutrient of low to moderate. The values of pH (H2O) were slightly acidic in both Bida and Minna. Organic carbon in Bida was low to moderate while that of Minna was rated high to very high. Parameters measured were plant height, number of days to 50% flowering, number of seeds per panicle, dry weight of straw, panicle weight, tiller count, dry weight of 100 seeds and grain yield. In both sites, tiller count ranged from 1 to 3 along the slopes (that is from upper slope to hydromorphic fringe). In addition, in Bida, days to 50% flowering ranged from 77 to 85 days while that of Minna ranged from 75 to 84 days. Grain yield in Bida ranged from 218.64 kg ha-1 to 689.69 kg ha-1 while that of Minna ranged from 268.81 kg ha-1 to 689.69 kg ha-1. However, hydromorphic fringes with or without fertilizer gave better growth and yield data and the most suitable for rice production in the two study areas. The study revealed that growing of upland rice in hydromorphic fringes of the inland valley with fertilizer (30 kg P ha-1, 30 kg K ha-1 and 80 kg N ha-1) in both locations supports good growth and grain yield.
Keywords: fertilization, hydromorphic fringe, inland valleys, slope, position.