Sistemas de irrigação e preparo do solo para a cultura do algodão em Várzeas de Roraima.

Abstract

The present work aimed to evaluate cotton cropping on wetland soils in rotation with the irrigated rice and compare the effects of different irrigation methods and soil preparation systems on cotton and yield. An experiment was carried out from december/95 to april/96, on the experimental station of Bom Intento, Boa Vista-Roraima in geli slightly humid Tb alic, wetland soil.The CNPA early 1 cultivar was tested under furrow and sprinkler irrigaton, and two kind of soil preparation systems, as follows: plough grid + leveller grid and plough grid + aiveca plough + leveller grid. The experiment design consisted of a split plot on a randomized blocks design, with four replications.The soil prepared by grid + aiveca plough (25 cm deep) + leveller grid resulted in a bigger plants, height, number cotton boll and a higher yield (3.054,9 kg/ha) compared to the average obtained in the soil prepared with grids only. On the other hand furrow irrigation proved higher yield (3.420,3kg/ha).