HOW TO PREPARE AND FERTILIZE LAND 1 9 
as farm manures are not early available. 
For medium and late maturing crops 
farm manures are much the best. The 
whole problem of manuring is a local one, 
and is best determined by experiment. 
Water is necessary for the assimilation 
of food. If the plants have plenty of 
food and no water, it is of no value to 
them. Tillage aids in keeping the water 
supply constant by preventing the evapo- 
ration of moisture by the sun when the 
weather is dry and by allowing the top- 
soil to dry out and get air when wet. 
Plants to succeed must have food and 
care; the most important is care, and 
care is largely tillage. 
