202 Nebraska Agricultural Exp. Station, Research Bui. 6. 
amount of growth it supports. Manure might then be applied, 
thereby combining for the individual plant a greater abundance 
of moisture and a greater production per unit water transpired 
resulting from increased fertility. There would doubtless be a 
counter tendency for more water to be lost by evaporation directly 
from the soil surface when the stand is reduced because of less 
protection given by the crop. This loss, however, would not be 
equal to the additional amount made available for the individual 
plant, and we might by such means hope to increase the efficiency 
of the total water available. But the writer believes that this 
increase of water efficiency is not due to any effect of the denser 
soil solution upon transpiration as a plant function, but simply 
to a more responsive growth of the plant. This would eliminate 
the conception that feeding the plant a more concentrated soil 
solution (or thick soup, as it is sometimes called) diminishes the 
need for, and actual amount of, transpiration. 
It has been a very common experience of farmers in Nebraska 
and many other regions, that during relatively dry seasons, corn 
on alfalfa sod, except on irrigated or subirrigated land, produces 
a lower yield than on land which has not been in alfalfa. As is 
commonly said, "the corn burned up." The reason for this is 
twofold. (1) An old stand of alfalfa dries out the subsoil more 
than any other crop, and consequently a shortage of moisture 
exists for the corn to begin with. (2) Because of increased avail- 
able fertility, corn on alfalfa sod makes a greater vegetative 
grcwth, having a greater leaf surface exposed to the climatic 
evaporation factors. As a result, there is a greater demand for 
moisture than on less fertile soil. This combined smaller supply 
of water and greater demand results in reduced yields during dry 
seasons. This difficulty could probably be overcome in a large 
measure, and the benefit of the increased fertility taken advantage 
of, by planting the corn at a thinner rate on alfalfa sod. Where 
corn is grown at the rate of three plants in hills 3.5 feet apart on 
normal soil, a stand of approximately two plants per hill should 
be suitable for rich alfalfa sod. 
Listing corn on very fertile soil suggests itself as a rational 
practice. Listing tends to reduce or stunt the vegetative growth 
without proportionately reducing the ear development, and there- 
by less vegetative surface is exposed to the action of a drying 
atmosphere. 
Another suggestion of possible practical value under semiarid 
conditions is that of Cunningham (1914) to space the corn rows 
twice as far apart as is commonly practiced, with double the 
normal number of plants in the row. The principle involved is 
that the plants will be reduced in vegetative growth because of 
