Excerpt from Crops and Methods for Soil Improvement Nitrogen, phosphoric acid, and potash are the three substances that may not be in available form in sufficient amount for a growing crop. The lack may be in all three, or in any two, or in any one, of these plant constituents. The nat ural strength of the soil includes the small per centage of these materials that may be available, and the relatively large stores that nature has placed in the land in inert form as a provision against waste. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.