The field monitoring of the terbuthylazine shows that the largest herbicide losses (40%) in the soil under traditional tillage (PB) is associated with runoff and leaching soil processes, because it happens just after a rainy period. The comparison in lab experiments of the terbuthylazine soil processes (adsorption, dissipation and column leaching) occurring in the same soil under traditional tillage (PB) and under green cover crops (SCC) allows to reveal important differences in herbicide soil behavior in both soils which are relevant from the environmental point of view. The results show an important increase in soil organic matter (SOM) and the porosity in the small radius pores in SCC, as compared with PB, which enhance the adsorption and porous retention of the herbicide in the soil matrix components. This increased soil herbicide adsorption and retention finally caused a dramatic decrease of the herbicide losses by leaching in the SSC (20%) soil as compared with PB soil (68%). These laboratory data reveal the importance to maintain the cover crops because, besides their benefits as physical barriers to decrease soil losses and runoff, they also contribute through enhancing the physic-chemical herbicide soil processes, to the decrease the herbicide losses associated to the water movements (runoff and infiltration) and hence the water contamination.

Grupo PAIDI AGR-264 de la Junta de Andalucía y proyecto P08-AGR-03643, cofinanciados con fondos FEDER-FSE del PO 2007-13.

Comunicación presentada en el XVI Simposium de EXPOLIVA, celebrado en Jaén del 8 al 11 de mayo de 2013.

Peer Reviewed