8
grams of straw and 29 ears, containing 415 kernels weighing 11.188
grams. The three cylinders of soil from humid eastern Nebraska
produced only 11.2 grams of straw and 13 ears containing 114
kernels, weighing 3 grams. This experiment shows conclusively that
rains are not needed during the growing season, if the soil is well
filled with moisture at seedtime, to bring crops to maturity.
What becomes of the rainfall?
The water that falls on the land is disposed of in three ways:
First, under ordinary conditions, a large portion runs off without
entering the soil; secondly, a portion enters the soil, but remains
near the surface, and is rapidly evaporated back into the air; and,
thirdly, a portion enters the lower soil layers, from which it is
removed at later periods by several distinct processes. The run-off
is usually large and is a serious loss, especially in dry-farming
regions, where the absence of luxuriant vegetation, the somewhat
hard, sun-baked soils, and the numerous drainage channels, formed by
successive torrents, combine to furnish the rains with an easy
escape into the torrential rivers.
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