Loss of ammonia from nitrogen fertilizers applied to maize and soybean straw

Abstract

In Brazilian agriculture, urea is the most commonly used nitrogen (N) source, in spite of having the disadvantage of losing considerable amounts of N by ammonia-N volatilization. The objectives of this study were to evaluate: N lossby ammonia volatilization from: [urea coated with copper sulfate and boric acid], [urea coated with zeolite], [urea+ammonium sulfate], [urea coated with copper sulfate and boric acid+ammonium sulfate], [common urea] and [ammonium nitrate]; and the effect of these N source son the maize yield in terms of amount and quality. The treatments were applied to the surface of a soil under no-tillage maize, in two growing seasons. The first season (2009/2010) was after a maize crop (maize straw left on the soil surface) and the second cycle (2012/2011) after a soybean crop. Due to the weather conditions during the experiments, the volatilization of ammonia-N was highest in the first four days after application of the N sources. Of all urea sources, under volatilization-favorable conditions, the loss of ammonia from urea coated with copper sulfate and boric acid was lowest, while under high rainfall, the losses from the different urea sources was similar, i.e., an adequate rainfall was favorablet o reduce volatilization. The ammonia volatilization losses were greatest in the first four days after application. Maize grain yield differed due to N application and in the treatments, but this was only observed with cultivation of maize crop residues in 2009/2010. The combination of ammonium+urea coated with copper sulfate and boric acid optimized grain yield compared to the other urea treatments. The crude protein concentration in maize was not influenced by the technologies of urea coating.

Nitrogen loss by volatilization of nitrogen fertilizers applied to coffee orchard

“…The effect of adding Cu, B and S to the urea reduces the N loss compared with that observed by adding urea alone in maize and sugar cane (Faria et al 2013;Nascimento et al 2013).…”

“…Several compounds have been found to reduce the conversion of urea [(NH 2 ) 2 CO] into ammonium and, ultimately, ammonia in soil (Roberts, 2014). The main substances and elements that have been used for this purpose are NBPT (Watson et al, 2008;Cantarella et al, 2008;Menendez et al, 2009;Pereira et al, 2009;Trenkel, 2010;Silva et al, 2011), copper (Cu) and boron (B) (Krajewska;Zaborska;Chudy, 2004;Heringer, 2008;Gabrovska;Godjevargova, 2009;Faria et al, 2013;Nascimento et al, 2013;Stafanato et al, 2013).…”

Volatilização de amônia proveniente de fertilizantes minerais mistos contendo ureia

“…Dada a larga utilização desse fertilizante na agricultura, e o grande potencial de perdas do nitrogênio aplicado, pesquisas têm sido desenvolvidas para aumentar a eficiência de uso da ureia, principalmente com vistas à mitigação do processo de volatilização de amônia (Paiva et al, 2012;Faria et al, 2013;Frazão et al, 2014;Oliveira et al, 2014).…”

“…Nesse sentido, Faria et al (2013) sugerem a aplicação de ureia juntamente com outros materiais que possam atuar na redução das perdas do N-NH 3 volatilizado; tais como sulfato de cobre, ácido bórico, zeólita e sulfato de amônio. A zeólita é um mineral que, adicionado à ureia, é capaz de atuar na redução das perdas de N-NH 3 em virtude da sua capacidade de reter íons, como o amônio (NH 4 + ), e protegê-los fisicamente contra a volatilização (Englert & Rubio, 2005;Bernardi et al, 2010).…”

“…Oliveira et al (2014) afirmam que a adição de fertilizantes com características ácidas pode reduzir as perdas de amônia por volatilização da ureia em até 29%. Dessa forma, a formulação de fertilizantes nitrogenados a partir da adição de ácidos húmicos e zeólita à ureia pode reduzir as perdas de N e aumentar a eficiência agronômica desses fertilizantes (He et al, 2002;Latifah et al, 2011;Faria et al, 2013).…”