[Soil and plant cultivation 1998. Cereals, potato, seed production, environment. Experimental results 1997]

agricultura alternativa agriculture alternative alternative agriculture amendement du sol cereal crops conduite de la culture crop management crop yield cultivos de cereales cultivos de semillas diffusion de la recherche diffusion of research enmiendas del suelo ensayos de variedades ensemencement fertilisation fertilizer application labranza manejo del cultivo noruega norway oil crops papa plant production plant protection plantas oleaginosas pomme de terre porte graines potatoes protection des plantes rendement des cultures rendimiento de cultivos seed crops siembra soil amendments sowing tillage travail du sol variety trials