Nitrogen balance in forage maize with different fertilization and phase of crop rotation with pastures [Balance de nitrógeno en maíz forrajero con diferente fertilización y fase de rotación con praderas]
Amendola-Massiotti R.,Posgrado en Produccion Animal |
Cach-Gomez I.,Posgrado en Produccion Animal |
Alvarez-Sanchez E.,Posgrado en Produccion Animal |
Lopez-Cruz I.,National Autonomous University of Mexico |
And 3 more authors.
Agrociencia | Year: 2011
The aim of this study was to evaluate the nitrogen (N) balance in soil during a crop cycle of forage maize (Zea mays L.), in different phases of a rotation with pastures (PU) and with different rates of N fertilization (NF). Nine treatments derived from the combination of two factors with three levels each were evaluated: 1) NF: 0 (N0), 100 (N100) and 200 (N200) kg N ha-1; and 2) PU: three and a half years of alfalfa (Medicago sativa L.) associated with orchardgrass (Dactylis glomerata L.) (P); three years of alfalfa associated with orchardgrass and a cycle of oats (Avena sativa L.) associated with ryegrass (Lolium multiflorum Lam.) (PA); and two and a half years of alfalfa associated with orchardgrass, a cycle of maize and a cycle of oats associated with ryegrass (PMA). The experimental design was split-plots in a randomized block design with three repetitions with UP as a large plot and NF as a small plot. Measurements included N extraction by the crop, N leaching and soil content. PU did not affect (p>0.05) any of the variables; NF had a linear effect (p≤0.05) on the extraction of N (in N0 274±15 kg N ha-1, 44.9 % less than N200) and leaching of N (98±19 kg N ha-1 in N100, 73 % less than N200). The levels of apparent effect of fertilization and fertilizer use efficiency were acceptable, but fertilization was not economically advisable. Fertilization increased the amount of N leached, which is ecologically unfavorable. During the growing season of maize the amount of N in the soil was reduced, emphasizing the importance of legume pastures associated with grasses, to maintain high levels of productivity in this rotation.