Ability of different cover crops to reduce N leaching in irrigated maize under Mediterranean conditions

Abstract

Maize grown in monoculture is a common practice in the irrigated areas of the Ebro Valley (Spain). Nitrate leaching in this area is associated to excessive N fertilization to maize and residual mineral N (Ninorg) left in the soil after crop harvest (Cavero et al., 2003). Winter cover crops could be sown after maize harvest. Deep rooted cover crops would scavenge residual Ninorg in the soil profile and incorporation of the cover crop biomass into the soil in early spring would provide N to the next spring maize crop (Isse et al, 1999). However, little is known about cover crop management and effects on irrigated maize in Mediterranean conditions.

The aim of the study was (1) to quantify the effect of winter cover crops on N leaching and soil Ninorg in a maize monoculture; and (2) to quantify the effect of cover crops on maize grain yields.