Resumo

PARRY, Maurício M.; CARVALHO, Janice G. de; KATO, Maria do S. A.  e  VIELHAUER, Konrad. Nutritional state of rice cultivation at different planting times and fertilization under mulching. Rev. bras. eng. agríc. ambient. [online]. 2005, vol.9, n.1, pp. 57-65. ISSN 1807-1929.  http://dx.doi.org/10.1590/S1415-43662005000100009.

To evaluate the effect of planting time and fertilization on the nutritional state of rice (Oryza sativa L. var. "Maravilha") at harvest stage, an experiment was carried out at the Igarapé-Açu, in the State of Pará in a typical Argissol (cohesive Yellow Latosol). Four times of planting and two fertilization rates were tested in a completely randomized block design with split-plot arrangement. The evaluation of the nutritional stage was done in mature plants and grains. The highest concentrations of N, P, Ca, B and Cu were observed in the rice grains and the highest concentrations of K, Mg, S, Fe, Mn and Zn were found in the plants. The nutrient concentrations were affected significantly by the time of plantation 1 and 2, however, this fact did not prevent the presence of adequate contents of majority of nutrients in straw and grain. The fertilization with additional dose of P increased significantly only the concentrations of Cu and Zn in the plant and of P, K, Ca and Zn in the grains. A significant interaction was observed between the time of planting and the fertilization for Cu content in the straw and of Ca and Zn contents in the grains. In the rainy season higher concentrations of P and micronutrients were observed in the plants.

Palavras-chave : plant nutrition; soil fertility; Yellow Latossol (Oxisol); Eastern Amazon.