HOW TO CARE FOR SOIL 323 



Under modern methods of progressive farming the de- 

 struction of weeds is merely a secondary matter, while 

 keeping the soil in a favorable condition for plant growth 

 is the principal reason for cultivating it. Besides the 

 destruction of weeds, the following are the chief objects 

 in the proper cultivation of the soil: 



(a) To loosen the soil for planting seeds. 



(b) To remove water during wet seasons. 



(c) To retain water during dry seasons. 



(d) To get air into the soil. 



(e) To cause the decay of humus. 



Soils are plowed and pulverized so that the seeds can 

 be planted at the proper depth and easily covered. It 

 is also easy for the young plants to grow to the surface 

 and for the roots to find food in a properly prepared soil, 

 thus giving the young plant favorable conditions for rapid 

 growth. In gardens the soil is prepared for the seed by 

 use of the spade, the hoe, and the rake. On western 

 farms large gang-plows, followed by drags and harrows, 

 are drawn by steam or gas traction engines. 



While the crops which need cultivation are growing, 

 the excess water during a wet season can be removed by 

 deep cultivation, because this permits much air to mix 

 with the soil and also exposes the lower soil to the open 

 air, allowing a large amount of water to pass off by 

 evaporation. Care must also be taken in order not to 

 cultivate when the soil is too wet, or both the crop and 

 the soil will be injured. 



During dry seasons the water can be kept from evapo- 

 rating from the soil by very shallow cultivation. Several 

 shallow cultivations during a dry season make dust of 

 the surface of the soil. This dust prevents the water 

 from escaping by evaporation. During dry seasons 



