[Good practices in agricultural production]

afforestation air du sol aire del suelo amaranthus hypochondriacus ammonia ammoniac avena sativa brassica napus cereal crops compost composts conduite de la culture conservation du paysage crop management cropping systems cultivos de cereales cultural methods desechos urbanos environmental factors erosion escarda exploitation agricole explotaciones agrarias explotaciones privadas facteur du milieu factores ambientales farms fertilisation fertilizer application gramineas graminee grasses heavy metals humulus lupulus integrated control labranza land management landscape conservation lucha integrada manejo del cultivo meadows metales pesados mixed pastures mode de culture modele modelos models national parks nitrate nitrates nitratos nitrogen content parc national parques nacionales pastizal mixto pastizales pastures piggeries pisum sativum pocilga poland pollution du sol pologne polonia porcherie prados de siega prairie de fauche prairie mixte private farms secale cereale sistemas de cultivo soil air soil pollution teneur en azote tillage travail du sol trifolium triticum aestivum urban wastes weed control