Dryland agriculture in winter precipitation regions of the world; status of the technical art

afrique du nord arid zones aridoculture carne cereales cereals conduite des herbages dry farming economic situation fertilidad del suelo fertilisation fertilizer application grassland management grazing labranza manejo de praderas meat middle east moyen orient north africa oriente medio parcours pastoreo plantation planting rangelands rumiante ruminant ruminants soil fertility tierras de pastos tillage travail du sol viande weeding zone aride