Ammonia loss through volatilization and foliar emission in pasture fertilized with nitrogen sources / Perdas de amônia por volatilização e emissão foliar em pastagem adubada com fontes de nitrogênio

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

In search of alternatives to measure ammonia (NH3) foliar emission and minimize N-NH3 losses in pasture three research works were accomplished. The two first works aimed at checking whether or not the foam absorber, which was already used to quantify N-NH3 volatilization, is also efficient to measure foliar emission without interfering in nitrogen loss process. The third one was performed in Panicum maximum Jacq. cv. Colonião pasture during three different seasons and evaluated the use of irrigation levels after urea fertilization on N-NH3 losses through volatilization and foliar emission. The ammonia foam absorber does not alter N-NH3 loss process and when place at height of 1 cm from the upper leaves it is effective in capturing N-NH3 lost through foliar emission when fertilization is done superficially with ammonium nitrate and urea. Water application immediately after fertilization is efficient to reduce N-NH3 losses through volatilization. During summer the use of 3.2 mm water was enough to decrease N-NH3 loss to less than 3.1% of applied N, while the lack of irrigation caused 30.5% losses. Volatilization rate is influenced by the quantity of water available in the soil, being low when urea is applied to dry soil or when the soil dries fast even if the environment temperature is high. N-NH3 foliar emission was not influenced by water application after urea fertilization.

ASSUNTO(S)

irrigation levels lâminas de água nh3 ammonium nitrate nitrogen loss nh3 urea perda de n nitrato de amônio uréia

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