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Conservation of Fertilizer Materials from Minor Sources
Charles Cloyes Fletcher
出版
U.S. Department of Agriculture
, 1932
URL
http://books.google.com.hk/books?id=nvx0oSW8uNAC&hl=&source=gbs_api
EBook
FULL_PUBLIC_DOMAIN
註釋
In maintaining soil fertility the periodic addition of organic matter plays and important part. Composts are constantly being made through the rotting of leaves, twigs, roots, and other organic matter as shown by the photograph on the title page of this publication. Composts of various substances may help supply organic matter, and they also often supply nitrogen, phosphoric acid, potash, and other elements needed by plants.