Resumen

FAGERIA, Nand K.  y  SANTOS, Alberto B. dos. Response of irrigated rice to green manure and chemical fertilization in the State of Tocantins. Rev. bras. eng. agríc. ambient. [online]. 2007, vol.11, n.4, pp. 387-392. ISSN 1807-1929.  http://dx.doi.org/10.1590/S1415-43662007000400007.

Lowland rice is an important crop in Brazil due to its socio-economic value. Often due to inadequate fertilization, production is limited. Two field experiments were conducted at Xavante Farm, Municipality of Dueré, State of Tocantins, Brazil, during two consecutive years to determine the response of irrigated rice to green manure and to chemical fertilization grown in an Inceptisol. The treatments consisted of green manure + N₀P₀K₀; green manure + N₁₀₀P₁₂₀K₁₀₀; green manure + N₅₀P₆₀K₅₀; green manure + N₇₅P₉₀K₇₅; green manure + N₄₅P₁₂₀K₁₀₀ (application of N, P, and K at sowing); green manure + N₄₅P₁₂₀K₁₀₀ (application of P and K at sowing and N topdressing); green manure + N₁₀₀P₁₂₀K₁₀₀ + 4 Mg lime ha^-1; and without green manure + N₁₀₀P₁₂₀K₁₀₀. Maximum grain yield was obtained with the application of green manure + N₄₅P₁₂₀K₁₀₀ (application of P and K at sowing and N topdressing). Among yield components, panicle length was significantly and positively influenced by fertilization. These results show that green manure can reduce chemical fertilization, and hence cost of production.

Palabras llave : lowland soil; Oryza sativa; nutrient uptake; grain yield.