Hygroscopicity and ammonia volatilization losses from nitrogen sources in coated urea

Hygroscopic fertilizers tend to absorb moisture from the air and may have undesirable characteristics such as moistness, clumping and lower fluidity, hampering the application. The increasing use of urea is due to its numerous advantages, although this nitrogen (N) source is highly susceptible to volatilization losses, particularly when applied to the soil surface of management systems with conservation of crop residues. The volatilization losses can be minimized by slow or controlled-release fertilizers, with controlled water solubility of the urea-coating materials; and by stabilized fertilizers, which prolong the period during which N remains in the amide or ammonia forms by urease inhibitors. This study evaluated the hygroscopicity of and ammonia volatilization from urea coated with boric acid and copper sulfate or with sulfur. The hygroscopicity of the sources was evaluated over time after exposure to five levels of relative humidity (RH) and volatilization evaluated after application to the soil surface covered with sugarcane trash. Ammonium nitrate has a low potential for volatilization losses, but is highly hygroscopic. Although coating with boric acid and copper sulfate or elemental sulfur reduced the critical humidity level of urea, the delay in the volatilization process is a potential positive factor.

Bibliographic Details

Main Authors:	Faria,Letícia de Abreu, Nascimento,Carlos Antonio Costa do, Ventura,Barbara Paquier, Florim,Gabriela Perissinotto, Luz,Pedro Henrique de Cerqueira, Vitti,Godofredo Cesar
Format:	Digital revista
Language:	English
Published:	Sociedade Brasileira de Ciência do Solo 2014
Online Access:	http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000300026
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