00453nam a2200109Ia 4500008004100000082002900041245008600070260004800156300001000204490010000214650002900314130903s9999    xx            000 0 und d  a631.816 1969 (082.2)  K9  aTransition from extensive to intensive agriculture with fertilizers; proceedings.  aBernebInternational Potash Institutec1969  a282p.  aProceedings of the VIIIth Colloquium of the International Potash Institute held in Israel, 1969  aSoil science,Fertilizers