Volatilization of Ammonia From Surface-Fertilized Soils

Model of ammonia volatilization from calcareous soils

“…It was reported (Freney et al, 1981) that little ammonia was volatilized from flooded rice fields. One may also conclude that with increasing Vg in a drying soil ammonia volatilization will increase, as was indeed observed (Martin and Chapman, 1951). However, it has been found that in a very dry soils there is direct physical adsorption of gaseous ammonia and a subsequent actual decrease in NH3 losses from the soil (Fenn and Kissel, 1976).…”

“…It also depends on a number of external factors such as soil temperature, rate of fertilizer application and a particular agrotechnical procedure. Detailed studies provided information about the effect of each of the above parameters (Gasser, 1964;Martin and Chapman, 1951;Mills et al, 1974, Fenn andKissel, 1976;van Veen, 1977;Freney et al, 1987;Vlek et al, 1981).…”

Volatilização de N-NH3 na cultura de milho: I. efeito da irrigação e substituição parcial da uréia por sulfato de amônio

“…O aumento da temperatura favorece as perdas à medida que aumenta a atividade da urease e, assim, a taxa de hidrólise da uréia (Chin & Kroontje, 1963). Em solo úmido, próximo da capacidade de campo, as perdas gasosas de amônia acompanham o processo de evaporação de água (Martin & Chapman, 1951;Bouwmeester et al, 1985). Em solo seco, as perdas podem ser significativas somente se a umidade relativa do ar é alta (Black et al, 1987).…”

Nitrate-bromide movement analysis under saturated field condition

“…Nitrate was not completely lost with lower NO^-N application. Martin and Chapman (1951) found that the amount of NH^loss by volatilization was dependent on several soil factors. They point out that as pH exceeds 7.0» NH^is volatilized, that moisture loss may cause simultaneous NH^loss, that increased temperature increases loss, and that as the amount of NH^applied increases the total quantity lost increases.…”