Crescimento da mamona e girassol sob irrigação com água residuária e adubação nitrogenada.

Abstract

Castor bean and sunflower growth under wastewater irrigation and nitrogen fertilization. Lately population growth contributed to a sensitive environmental imbalance, damaging several sectors on a global scale, intermediate and local levels, thereby increasing waste generation, and totally degraded areas by lack of adequate management. Studies of new forms of reuse of this waste in agriculture has become a good alternative because it can replace chemical fertilizer, providing a high supply of nutrients to plants, lowering the costs of agricultural production. Therefore, the aim of this study was to evaluate the use of organic compost derived from household waste and irrigation with domestic wastewater treated in the growth of the cultures of castor and sunflower, as well as the potential to absorb the metals nickel and chromium in sunflower cultivation. For this, the plants were grown in greenhouses belonging to the Federal University of Campina Grande - PB. The experimental design was in randomized blocks in 6 x 2 factorial design, with 3 replications, where the 6 doses of available nitrogen in compound of solid waste were (0, 60, 100, 140, 180, 220 kg.N. ha - 1) and 2 types of water (drinking water and domestic wastewater treated). It was found that the nitrogen significantly influenced, with regard to the growth until 75 DAE castor BRS - Paraguaçu and sunflower variety 122/V-2000 EMBRAPA, providing heights of 91.7 and 85.2, respectively, the nitrogen rate of 180 kg N ha- 1 and 220 kg N ha- 1. But the use of wastewater did not significantly influence the evaluated parameters. The sunflower was more efficient in the uptake and translocation of nickel and chromium in roots irrigated with 2 types of water, because the behavior of the elements have a tendency to be strongly adsorbed in soil. The coming of organic manure composting of urban waste and domestic wastewater irrigation with treated water, can replace chemical fertilizer in cultivation of castor and sunflower BRS Paraguaçu variety EMBRAPA 122/V-2000.