00425nam a2200109Ia 4500008004100000082002800041245006000069260004700129300001000176600007800186650005100264130903s9999 xx 000 0 und d a581.13:633.002(063) M0 aPhysiological aspects of crop productivity proceedings. aBernbInternational Potash Institutec1980 a274p. aColloquium of the International Potash Institute, 15th, Wageningen, 1980. aCrop yields-Conferences,Physiology Conferences