186 The Principles of Fruit-growing. 
dry, whilst one sowed late in the season upon land 
which has been thoroughly tilled during May, June 
and July, does not seriously rob the soil of mois- 
ture. At all events, there need be no fear of dry- 
ing out the soil by sowing a late crop, for the 
serious injury of drought is usually effected before 
such erops are established, and rainfall is then becom- 
ing abundant; and the tree needs to be checked, 
rather than stimulated, at this season, by the trans- 
fer of the nitrates and moisture to other plants. 
The most marked way in which such crops conserve 
moisture is by means of the fiber and humus which 
they impart to the soil when plowed under; but 
even this humus caunot compete with cultivation as 
a retainer of moisture. 
An experiment at Cornell* illustrates the value 
of cultivation over a green crop occupying the land 
the entire season, in a dry year. The orchard is 
a hard clay,—just the soil which is benefited by the 
loosening effects of green manures. The orchard was 
divided into three portions in 1890, a year after 
the trees were set. One-third has received liberal 
annual dressings of commercial fertilizers, and has 
been well tilled; another third has had no treat- 
ment except good tillage; and the remaining third 
has had liberal applications of potash, and has then 
been sown early to a nitrogenous (leguminous) green 
crop. This third portion has simply been plowed 
*Bull. 72, Cornell Exp. Sta. This experiment has not yet progressed far 
enough for report upon methods of fertilizing, and is mentioned here only 
for the purpose of contrasting methods of cultivation, 
