00375nam a2200133Ia 4500008004100000082002500041100001700066245005500083260002000138300001200158490002700170600001600197650002800213140224s9999    xx            000 0 und d  a631.45.001.5(047) L0  aHauser, G.F.  aSoil fertility investigations on farmer' s fields.  aRomebFAOc1970  avi,78p.  aFAO Soils Bulletin, 11  aG.F. Hauser  aSoil fertility research