Efeito de doses de P e N em repolho (brassica oleracea var. capitata) da época fresca sob três níveis de adubação orgânica com estrume bovino na Estação Agrária de Umbelúzi

Abstract

Effect of doses of P and N in cabbage (Brassica oleracéá var. capitatd) of the fresh season under three levels of organic fertilization with in Estação Agrária de Umbeluzi The present work was carried out, in the Agricultural Station of Umbeluzi - EAU, which is part of the network of Experimental Units of the Institute of Agricultural Research of Mozambique (IIAM), in the agricultural year of 2004, under an irrigated system, in a soil with a French texture. sandy-clay, grayish to whitish black. This work aimed to evaluate the effects of P and N doses under three levels of organic fertilization, with bovine manure, on the production of cabbage (Brassica oleracea var. capitata) in the fresh season. The cabbage cultivar Marcanta F1.0 was used. The experimental design used was the randomized complete blocks (DBCC), in a 4*4 factorial arrangement (nitrogen factor 4 levels x phosphorus factor 4 levels), with three replications. The factors tested were 4 levels of P (0, 30, 60 and 90 kg/ha) and of N (0, 60, 120 and 150 kg/ha). The phosphorus source was single superphosphate and the nitrogen source was urea. The response variables were the number of marketable heads, total number of heads, weight of marketable heads and the total. In general, the cabbage crop responded positively to the combination of nitrogen and phosphorus without the application of manure and with the application of 5 tons of manure, except when applying 10 tons of manure, where the effect of these nutrients occurs in isolation, being important only for the nitrogen. After the statistical analysis of the data collected, it was found that cabbage grown under mineral fertilization was superior to that grown under organic fertilization, in terms of production and yield. There was influence of organic and mineral fertilization on the parameters analyzed.