The Soil: Its Use and Abuse 1361 



between the particles. It is moisture in this latter form that is required 

 by the roots of such crops as beans, corn, and wheat. 



When the soil is so wet that water fills the pores and appears on the 

 surface, most farm plants will not thrive. For such conditions, drainage, 

 the drawing off of excess water, is necessary. To drain the soil, ditches 

 are constructed, either open or with short lengths of pipe, usually clay 

 pipe, in the bottom to permit the water to percolate away. Over 10,000 

 square miles of farm lands in New York require drains to render them most 

 profitable. 



When the excess of water has been cared for by either natural or arti- 

 ficial drainage, the remainder of the water in the soil, the capillary water, 

 must be husbanded carefully for the use of the crop. If it becomes defi- 

 cient, the crjp suffers in yield and quality, even though every other condi- 

 tion may be fa\'orable. In order to conserve the soil moisture tillage 

 is required. A farmer keeps the surface, to the depth of an inch or two, 

 loose, level, and dry by proper tillage. He calls this layer a mulch, " a 

 dust blanket," that holds the moisture in the soil below so that it escapes 

 only through plants and thereby accomplishes its work on the way. In 

 this operation of tillage are required knowledge and skill to cultivate 

 each particular soil, at the right time and in the right way to secure the 

 desired results. Soils are as peculiar as folks and sometimes as obstinate. 



When good tillage will not maintain a supply of water, it may be added 

 artificially by means of irrigation. In New York, with 3 5 inches of rain- 

 fall, irrigation is not often necessary, and when required it is usually on 

 the very light sandy soils that are used for special crops, such as truck 

 or fruit. 



The two types of conditions just described may be observed if we watch 

 any common field plant, or even a window plant, through the summer. 

 Note when it wilts or when it is drowned, and how it behaves in each 

 instance. Then note the corresponding soil conditions. 



FOOD SUPPLY IN THE SOIL 



The store of available plant food in the soil is a matter of special con- 

 cern to many persons. Plants require a variety of foods, just as do cattle. 

 They use nitrogen (which costs 20 cents per pound if purchased), phos- 

 phorus, potash, lime, magnesia, sulfur, and iron, besides the elements 

 obtained from water and air, which are hydrogen, oxygen, and carbon. 

 The potash and certain other materials are contained in the soil in great 

 quantities, yet the farmer frequently rushes to the fertilizer bag at the 

 first sign of reduction in the crop yields. The average New York soil 

 contains 2,500 pounds of phosphorus, 35,000 pounds of potash, and 

 20,000 pounds of lime per acre of soil one foot deep. The average weight 



