Soil, Water, and Air Sciences Research 

 - United States Department of Agriculture, Science and Education Administration, Agricultural Research  1979 
 - 255p. 
<br/><br/><label>Nat. Bib. No.: </label>4874 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agriculture
<br/><br/><label>Universal Decimal Class. No.: </label>631.95  / SOI