RICE COMMON BEAN ROTATION UNDER SPRINKLER IRRIGATION - EFFECTS OF ROW SPACING, FERTILIZATION AND CULTIVAR ON GROWTH, ROOT DEVELOPMENT AND WATER-CONSUMPTION OF RICE

The effects of row spacings (20, 35, and 50 cm), fertilizer levels (250, 400, and 550 kg/ha of formula 4-30-16), and cultivars/lines (Rio Paranaiba, Araguaia, CNA 6874, and CNA 6889), and the residual effects of previous common bean (Phaseolus vulgaris L.) crop fertilization (300 and 500 kg/ha of 4-30-16) on the growth, root development, and water consumption of rice (Oryza sativa L.), planted in rotation with common bean under center pivot were studied during two years. The last two favorable upland rice lines were replaced by CNA 6881 and CNA 6891 lines, in the second year. In general, increasing fertilization resulted in leaf area index (L), leaf area duration (D), and dry mater yield (W-t), increase. Reducing row spacing also increased L and D. Its effect on W-t, however, varied with the fertilizer level applied. The grain yield of the upland traditional cultivars (Rio Paranaiba and Araguaia) under limited plant development, and that of favorable upland rice lines was positively correlated to D. Relative root distribution was little affected by the treatments. In general, water consumption increased as L increased.