ABSTRACT
D.V. SANTOS, P.L. SOUSA and L.S. PEREIRA Depart, of Rural Engineering - High Institute of Agronomy, Technical University of Lisbon, Portugal.
Abstract The influence of hydrodynamic behaviour of the soil on water and nitrate movement in level basins with conventional (CT) and reduced tillage (RT) is discussed. Observations during the last five years have shown very low losses of nitrate by leaching in CT. Results indicated important upward fluxes from the water table during the irrigation season producing important contributions to the root zone. In CT this contribution was lower than RT because root development were limited by a compacted layer at tillage depth which reduces the fluxes. Losses of N to the atmosphere were important in CT and N mineralization assumed high values in RT. Keywords: denitrification. level basin irrigation, nitrate leaching, soil hydraulic properties, tillage.
1 Introduction
