Nitrogen in agricultural systems 
J.S. Schepers and W.R. Raun, co-editors 
 - Madison  American Society of Agronomy  Crop Science Society of America  Soil Science Society of America, Inc  2008 
 - 965 p.  il. col. y n.  24 cm 
 - Agronomy / ASA, CSSA, SSSA .
 - Agronomy / ASA, CSSA, SSSA .
<br/><br/><label>ISBN: </label>9780891181644 
<br/><br/><label>Subjects--Index Terms: </label>Impacto ambiental Suelos agricolas Sistemas de explotacion Ciclo del nitrogeno Nitrogeno