In a comprehensive treatise on the composition of American wheats, Mr.
Clifford Richardson says we cannot attribute the poverty of American
wheats in nitrogen as a whole to an enhanced starch formation, and for
the following reasons: An enhanced formation of starch, there being no
poverty of nitrogen in the soil, increases the weight of the grain and
diminishes the relative percentage of nitrogen. Were this the cause of
the relatively low percentage of nitrogen in the American wheats, the
grain from the Eastern States, which are poorest in this respect,
would be heavier than those from the middle West, which are richer in
albuminoids; but this is not the case. Formation of starch is
attributed by Messrs. Lawes & Gilbert to the higher ripening
temperature in America, but Clifford Richardson has found that there
is scarcely any difference in composition or weight between wheats
from Canada and Alabama, and if anything those from Canada contain
more starch than those from the South, and the spring wheat from
Manitoba with its colder climate more than those from Dakota and
Minnesota, with its milder temperature. In Oregon is found a striking
example of the formation of starch and increase in the size of the
grain, at the relative expense of the nitrogen, due to climate, but
not to high ripening temperature. The average weight per hundred
grains of wheat from this State has been found to be 5.044 grains, and
the relative percentage of nitrogen 1.37, equivalent to 8.60 per cent.
of albuminoids. These are the extremes for America, and are due, as
has been said, to the enhanced formation of starch. This, however, is
said to be not owing to high ripening temperature, because most of the
specimens examined were grown west of the Cascade Range, which has an
extremely moist climate and a summer heat not exceeding 82 deg. F. for
any daily mean. The climate in another way, however, is, of course,
the cause, by producing luxuriant growth, as illustrated by all the
vegetation of the country. Numerous other analyses form illustrations
of the important effect of surroundings and season upon the storing up
of starch by the plant, and consequent relative changes in the
composition of the grain.
As a whole, the poverty of American wheats in nitrogen, decreasing
toward the less exhausted lands of the West, seems to be due more to
influences of soil than of climate, while locally the influence of
season is found to be greater than that of manure, confirming the
conclusions of Messrs. Lawes & Gilbert. Also from the analyses of the
ash of different parts of the grain, as from the analyses of roller
milling products, we learn that a large percentage of ash
constituents, other things being equal, is indicative of large
proportion of bran, and consequently of a low percentage of
flour.--_The Miller._
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