94 TALKS ABOUT THE SOIL. 



water is obtained in times of drought. A hard soil, 

 with the surface beaten down by rain and baked by 

 the sun, resists the next rainfall ; and the water runs 

 off over the surface, tearing up and carrying away the 

 light parts of the soil, and leaving the soil below un- 

 touched. Rain falling on land freshly raked, or tilled 

 by any tool, quickly sinks into the soil, carrying down 

 food from the air to the thirsty plants. This is the 

 philosophy of tillage. It improves the soil by letting 

 in the air, the rain, frost, and sunlight, to work on the 

 sand and broken rock in the soil, and continuing the 

 work of soil-making ; it enables the elements to meet, 

 and form new combinations suitable for the food of 

 plants ; and it makes it easy for the roots of all plants 

 to push their way through the soil in search of food. 

 The roots do not appear to actually push through the 

 soil, but to creep between the small grains and lumps, 

 and to feed on their surfaces. Thus we can easily see, 

 that in a barrel of nuts there is much more surface on 

 the nuts than in a barrel filled with squashes. It is 

 the same with a fine soil and a lumpy soil. 



Of course we see that tillage costs money. If a 

 field of corn is planted, and cultivated once, it will 

 cost more to cultivate it again or three or four times 

 more. How can we find out this ? how tell how often 

 it will pay to hoe any crop ? Mark off a portion of 

 the field, say an eighth of an acre, and give this 

 twice as much or even three times as much cultivation 

 as another piece near it that gets no more care than 

 the rest of the field. Gather the crop from each eighth 



