[Winter crops - Catch crops - Leaching. Soil nitrogen dynamics and nitrogen leaching in a clay till in Skaane]

agua superficial azote catch crops clay soils cultivos de invierno cultivos intermedios culture d'hiver cycle de l'azote eau superficielle escorrentia leaching lessivage du sol nitrogen nitrogen cycle pollution de l'eau rotation culturale rotational cropping ruissellement runoff sol argileux suecia suelo arcilloso surface water sweden water pollution winter crops