Doses de Nitrogênio associadas a extratos de NIM (Azadirachta indica) sobre o crescimento e nutrição nitrogenada da berinjela e da rúcula.

Abstract

The eggplant and arugula are demanding vegetables in nitrogen (N) to a suitable production, making the N meet as the nutrient usually applied in agriculture in the form of mineral fertilizer and which has lower efficiency, because their losses various processes. However, one way to avoid such loss in high CTC soils isinhibit nitrification. Thus, the adequate supply of N associated with products that retard this process can reduce the negative impacts caused by such losses. This work aimed to evaluate the effect of extracts and leaves of neem on the mineralization and nitrification of nitrogen in the soil and its effect on growth and nitrogen nutrition eggplant and arugula. Three experiments in completely randomized design were conducted with samples of soil sandy loam texture. In the first experiment, the treatments were factorial arrangement 4 x 2, comprising 4 treatments related to nitrification inhibition based on neem (leaf extracts; seed extract, dried leaves and without inhibitor) and two N rates (0 and 320 mg dm-3), with five repetitions. In the first experiment for 28 days, every seven days, were evaluated the levels of nitrate (NO3-), ammonium (NH4+), N-mineral and ammonium relationship/nitrate in the soil. The second was made with eggplants, cultivar "Embu" where treatments were factorial arrangement 4 x 4, with four treatments of nitrification inhibition (leaf extracts; seed extract, dried leaves and without inhibitor) and four nitrogen rates (20, 120, 220 and 320 mg dm-3) with three replications. In the pre-flowering stage, they were determined growth variables; leaf contents and accumulations of nitrogen. In the third experiment, used rocket plants, cultivar "grown arugula" where treatments were factorial arrangement 4 x 4, comprising four treatments of nitrification inhibition (leaf extracts; seed extract, dried leaves and without inhibitor) and four nitrogen rates (10, 120, 220 and 320 mg dm-3) with three replications. At the point of picking arugula, was evaluated growth; foliar and accumulations of nitrogen fractions. During the 28 days of incubation, the neem-based products not clearly inhibited the process of mining or nitrification of N applied to the soil, there was only a deceleration of mining this when N was associated with extracts of leaves or seeds. Nitrogen fertilization influenced the growth of eggplant and arugula, providing an increase in production and content and accumulation of N in the leaves. The Arugula response to nitrogen fertilization was dependent on the products of neem.