%0 Journal Article %T Quantifying Nitrate Leaching in Irrigated Wheat with Different Nitrogen Fertilization Strategies in an Alfisol Cuantificaci車n de la Lixiviaci車n de Nitratos en Trigo Regado con Diferentes Estrategias de Fertilizaci車n Nitrogenada en un Alfisol %A Marcelino Claret M %A Roberto Urrutia P %A Rodrigo Ortega B %A Stanley Best S %J Chilean Journal of Agricultural Research %D 2011 %I %X Consumption of water contaminated with nitrates is associated with important health effects such as methemoglobinemia and gastric cancer. Intensive agriculture, which uses large quantities of N fertilizer, is the main source of nitrates in water systems. There are several strategies to reduce leaching and increase Nitrogen Use Efficiency (NUE). An experiment was conducted with spring wheat (Triticum aestivum L.) under sprinkler irrigation (center pivot) to determine if adjusted N applications using precision agriculture tools and plant demand resulted in a lower groundwater nitrate load. Evaluated treatments were: produced fertilization (Pr), precision agriculture (Pa), chlorophyll meter (Sm), and control without N (W/N). The ceramic capsule methodology was used to evaluate N leaching losses that were sampled after each irrigation (six) and drainage water was also estimated. Differences among treatments in terms of N loss and grain yield were not significant (p > 0.05). However, N balance showed significant differences (p < 0.01) in soil residual N among treatments. A regression between applied and residual soil N after harvest showed that N, applied as fertilizer, explained 98% of residual soil N variation, which would probably be leached in the following winter since the soil would be bare. It was concluded that NUE can be improved to result in a lower environmental load by using precision agriculture tools and considering plant N demand El consumo de agua contaminada con nitratos produce importantes efectos en la salud tales como metahemoglobinemia y c芍ncer g芍strico. La agricultura intensiva es la principal fuente de nitratos en aguas superficiales y subterr芍neas. Hay varias estrategias para reducir lixiviaci車n y aumentar la eficiencia de uso de N (NUE). Se realiz車 un experimento en trigo de primavera (Triticum aestivum L.) bajo pivote central, con el objetivo de determinar si las aplicaciones ajustadas de N, mediante el uso de herramientas de agricultura de precisi車n y considerando la demanda de la planta, resultaban en una menor carga de nitratos para el agua subterr芍nea. Se evaluaron los siguientes tratamientos: productor (Pr); agricultura de precisi車n (Pa), medidor de clorofila (Sm) y sin N (W/N). Se utilizaron lis赤metros para evaluar las p谷rdidas de N; se tomaron muestreas seis veces durante la temporada, evaluando adem芍s el agua de drenaje en cada riego. Las diferencias en p谷rdida de N y rendimiento del grano entre los tratamientos no fueron significativas (p > 0,05). Sin embargo, el balance de N mostr車 diferencias significativas en N residual %K Triticum aestivum %K Triticum aestivum %K nitratos %K agricultura de precisi車n %K medidor de clorofila %K trigo %K nitrates %K precision agriculture %K chlorophyll meter %K wheat %U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392011000100018