nitrate or final product is formed by the action of nitric acid upon
a mineral base, such as calcium, magnesium, or potassium, which may
have been in the soil in insoluble form, so that the nitrogen must
pass through the form of nitric acid in the transformation into
nitrates.

While the organic matter applied to the soil contains about twenty
times as much carbon as nitrogen, and while corresponding amounts of
carbonic acid and important amounts of intermediate organic acids
must be formed, it is of much interest to know that even the nitric
acid formed in the transformation of organic nitrogen to nitrate
nitrogen in sufficient quantity for a given crop is seven times as
much acid as would be required to convert raw rock phosphate into
soluble phosphate to furnish the phosphorus required for the same
crop. A knowledge of this definite quantitative relationship should
help us to appreciate the possibilities of decaying organic manures
in the important matter of making plant food available, including
potassium, calcium and magnesium as well as phosphorus and nitrogen.

The value of rye, rape, buckwheat and other non-legumes when used as
green manures is very largely due to the liberation of plant food by
their decomposition in contact with the natural phosphates, potash
and other minerals contained in the soil. The farmer has no more
important business than that of making plant food available,
especially by supplying liberal amounts of decaying organic matter.

The following suggestions are offered to the land owner:

To enrich the soil apply liberal amounts of limestone, organic
manures and phosphorus.