EDAFOLOGÍA, Vol. 12 (1), pp. 43-52, 2005
UTILIDAD DE LAS SONDAS DE CAPACITANCIA EN EL ESTUDIO DE LOS PROCESOS DE LIXIVIACIÓN DE NITRATOS EN AGROSISTEMAS
M. ARAUZO SÁNCHEZ, J. A. DÍEZ LÓPEZ, P. J. HERNÁIZ
Departamento de Contaminación y Química Ambiental, Centro de Ciencias Medioambientales-CSIC, Serrano 115 dpdo.,28006 Madrid. mercedes@ccma.csic.es
In order to minimise the amount of nutrients leaching into water bodies, some issues must be addressed: precise fertilizer level, proper application and optimisation of irrigation systems. This work provides a methodology to calculate soil water balances, based on continuous monitoring of the soil water content, using capacitance probes. Drainage values and contents of nitrate in the soil water (extracted by a ceramic candle) were used to estimate nitrate leaching. Drainage of 201 mm and nitrate leaching of 60 Kg N-NO3- ha-1 were obtained during the maize crop (April-October of 2002), whereas drainage of 41 mm and nitrate leaching of 15 Kg N-NO3- ha-1 were estimated during the fallow period (November-April of 2003). The highest values of drainage and nitrate leaching were obtained during the watering season. This metho- dology provides an answer to the need for developing more accurate methods to study aquifer pollution in agricultural areas.
Key words: capacitance probes, drainage, evapotranspiration, nitrate leaching