Doses de nitrogênio associados à extratos de Nim (Azadirachta indica) sobre o crescimento e nutrição nitrogenada da berinjela.

Abstract

Nitrogen (N) is the main nutrient applied in agriculture as mineral fertilizers, which has lower efficiency, because their losses by various processem. Two experiments were conducted in order to evaluate the effect of neem extracts and N rates on nitrification and on the growth and nitrogen nutrition eggplant. In the first experiment. four treatments were tested regarding nitrification inhibition with neem-based products (urea only, urea + more neem seed extract, urea + extract of neem leaves); dried neem leaves applied to the soir) and two nitrogen leveis (0 and 320 mg dm'3). To assess the growth and nitrogen nutrition eggplant, a factorial scheme with four treatments nítrification inhibition (only urea, urea + more neem seed extract. urea + extract of neem leavesl dried neem leaves applied to the soil) and four N rates (10, 120, 220 and 320 mg dm'3 of N) were tested. To evaluate the nitrification and the recovery of N applied, they were tested four treatments related to the inhibition of nitrification from first experiment neem and two leveis of nitrogen (0 and 320 mg dm 3). The neem products not clearly inhibit the both mineralization and nitrification process after 28 days of incubation. Nitrogen supplied in the form of urea associated with seed extracts or neem leaves, little affect the growth of eggplant but provided higher accumulatíon of leaf nitrate. Eggplant responded positively to nitrogen leveis, which provided increase in their growth and nitrogen accumulation in the leaves.