AGRICULTURE. 483 



be considered here, and that is whether or not the subsoil shall be brought 

 to the top. This question could only arise where the subsoil was a tenacious 

 clay and was not rich in plant food. Anywhere in the northwest that ques- 

 tion need not be considered, for any of the soils would be benefited by the 

 admixture with them of the underlying subsoil. 



There are several reasons that can be given in favor of deep tillage: 



1. It furnishes an additional amount of soil from which the roots of the 

 plant may derive the nourishment necessary. Below the depth of a few 

 inches that has been broken up by the ordinary cultivation and which con- 

 stitutes the soil, the subsoil is very often so compact that the rootlets can not 

 penetrate it, and only the amount of plant food in the soil is available, but if 

 more plant food is brought within the reach of the roots by subsoiling great 

 advantage will necessarily result. 



2. It permits the water to percolate through the soil to a greater depth 

 and deposit the gases obtained from the atmosphere by it so essential to plant 

 life. Carbonic acid as well as some others are taken from the atmosphere 

 by rains, and are carried by water into the soil and there deposited or held 

 for future use. 



3. It loosens the subsoils so that the heat and air may permeate through 

 it and elaborate the elements needed by the plants. Where the subsoil is so 

 hard and compact that the air and heat can not pass through it the elements 

 that would otherwise be available for the growing plant had just as well not 

 exist. The material when reached by the .atmosphere is put in such condi- 

 tion either by combination or disintegration that it becomes possible for the 

 plant to assimilate these elements. 



4. The excess of water that falls upon the ground runs off and carries with it 

 many of the fertile qualities of the soil. If there is a deeper amount of loose 

 earth made by deep plowing, that surplus water goes into the ground and de- 

 posits the fertile qualities into the soil. In a word, deep plowing makes a store- 

 house where the elements needed for plant life may be kept for future use, 

 instead of being carried off by excessive rainfall. 



5. By deep plowing the excess of moisture is taken up and the surface 

 dries much quicker in spring time, and plowing can be done much earlier in 

 the season. Deep plowing provides a storage for the rains that fall, so that 

 there may be moisture in the ground within reach of the roots of the plant 

 during drouths. In all the northwest the average rainfall is sufficient to 

 make good crops if the largest part of the water did not run off into the creeks 

 and rivers. All soils will take up and hold a large amount of water that can 

 be utilized by the roots of the plants if the soil is only deep enough. And 

 then deep plowing will so loosen up the soil that the water may be raised by 

 capillary attraction to within the reach of the rootlets of the plant. This is 



