Crescimento da rúcula sob doses de nitrogênio associadas a extrato de nim (Azadirachta indica) como inibidor de nitrificação.

Abstract

Nitrogen (N) is the main nutrient applied in agriculture as mineral fertilizers, which has lower efficiency, because their losses by various processes. The neem extract is an alternative to slow and, or inhibit nitrification, reducing losses of nitrate leaching. Two experiments were carried out with the objective of to evaluate the effect of neem extracts and N rates on nitrification and on the growth and nitrogen nutrition of Educa saf/va. 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 leavesl urea + dried neem leaves applied to the soil) and two nitrogen leveis (0 and 320 mg dm'3). To assess the growth and nitrogen nutrition eggplant, a factorial scheme with four treatments nitrification inhibition (only urea. urea + more neem seed extract, urea + extract of neem leavesl urea + dried neem leaves applied to the soil) and four N rates(lO, 120, 220 and 320 mg dm'3 of N) were tested. 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 dry neem leaves, provided lower total dry matter production under low nitrogen supply.Total nitrogen accumulation was greater when the nutrient was applied with dry leaves or seed extract neem. The response to nitrogen fertilization of Fraca saf/va, was dependent on the products of neem based added urea as a nitrogen source.