Analysis of nutrition factors in spring barley

azote barley catch crops cebada cultivo intermedio cultivos de primavera culture de printemps engrais pk engrais potassique essai exigence des plantes fertilizantes fosfatados fertilizantes nitrogenados fertilizantes pk fosforo necesidades de las plantas nitrogen nitrogen fertilizers orge phosphate fertilizers phosphore phosphorus phosphorus potassium fertilizers plant requirements potash fertilizers potasio potassium pruebas spring crops trials