86 Gardening 
Effects of the gardener’s work on the supply of soil 
water. From what we have now learned, it will be under- 
stood that garden plants can use only the capillary water 
of the soil ; that free water about roots is harmful to them ; 
and that to fit a soil for garden purposes, the free water 
must be drained off and the soil made to hold as much 
capillary water as possible. 
Nearly everything the gardener does to the soil affects 
the water supply in it. Drainage has for its direct aim 
the removal of free water, which makes it possible for the 
roots of crops to penetrate deeply. The addition of 
lime, manure, and compost causes the free water to drain 
off more quickly and increases the amount of capillary 
water held in the soil. Plowing and spading also increase 
the power of the soil to hold capillary water, and one of 
the reasons for the cultivation of growing crops is to 
retain the water in the soil for the use of the plants. 
The gardener, therefore, in large measure controls the 
supply of water in the soil. He removes the excess that 
is harmful; he increases the power of the soil to hold 
water in suitable form for his plants; he saves or con- 
serves the water present in the soil; and he supplies 
water when it is needed. By a study of the soil and of 
the water in it, he can do the things that regulate the 
water supply to the needs of his crops. 
Questions 
About what proportion of the entire living plant is composed 
of water? What are some of the uses of water to a green plant ? 
Give some facts that explain why plants need an abundant and 
a continuous supply of water. 
