Response of Upland Rice to Phosphorus Fertilization on an Oxisol of Central Brazil1
- N. K. Fageria,
- M. P. Barbosa Filho and
- J. R. P. Carvalho2
Soils of the Cerrado region of Brazil are deficient in available P in their native state and require fertilizer P for optimum crop yield. But information on optimum rates of P application is lacking for upland rice production. Therefore, a 2-year study was conducted to evaluate the response of rice (Oryza sativa L. cv. IAC 47) to different levels of P in a dark red latosol. The P treatments were 0,22,44, and 66 kg P/ha (0, 50, 100, and 150 kg P2O5/ha). Grain yield, dry matter production, tillers, leaf area index (LAI), and nutrient (N, P, K) accumulation in aerial plant parts were determined at different stages of growth.
In the 1st year (1977–1978), grain yield increased significantly up to 66 kg P/ha application; in the 2nd year (1978–1979), significant differences in yield were only obtained by application of 44 kg P/ha. Under the existing soil fertility levels upland rice needed 44 to 66 kg P/ha for its optimum P nutrition. With application of these levels of P, yield between 4,451 and 4,811 kg/ha was obtained. Dry matter production, LAI, and number of tillers per unit area were increased with the use of higher levels of P. The maximum number of tillers/m2 was reached between 60 to 70 days of growth and then started to decline. The uptake of N, P, and K increased with higher levels of P and age of the plant.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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