No. 6. DEPARTMENT OF AGRICULTURE. 469 



Cultivation After Planting. 



In order to retain the moisture after the crop has been planted, 

 cultivation should be deep, early, and' gradually lessened as the sea- 

 son advances, in order that in the early season the rainfall may 

 penetrate to the lower layers, and in the later season the mulch 

 provided by the cultivation may not be so deep as to enable the 

 complete drying of the surface soil. The advantages of continuous 

 cultivation are also marked, inasmuch as every time the soil is 

 stirred the connection between the lower layers and the surface 

 is broken and the water below must seek new outlets for escape; 

 and until these are obtained the water is retained for the use of the 

 plant. 



The method of cultivation also should be observed. On soils 

 naturally well drained, cultivation in ridges contributes to the 

 loss rather than the conservation of moisture, as the ridges lying 

 so much above the main surface of the soil dries out more 

 rapidly than if level cultivation is practiced. Naturally, in wet 

 climates it is frequently advantageous to ridge the soil, in order 

 to provide for the rapid drainage of the water, but in soils where 

 the need is for water rather than for lack of water, ridge culture 

 is not advantageous. 



Frequent tillage, or continuous cultivation, also tends to increase 

 fertility, by causing a more rapid change of the insoluble constit- 

 uents into soluble forms. The constant stirring of the soil brings 

 new particles into contact with sun and air. In soils rich in dor- 

 mant or locked-up food, this method of improvement, which results in 

 increasing their direct fertility is strongly commended, since it can be 

 accomplished without any outlay of cash and by the regular labor of 

 the farm. 



Further Methods of Improvement. 



Soils may be further improved, namely, in two directions, first, 

 by saving in the soil for the use of the plants those constituents 

 which by improvident and irrational methods of practice are likely 

 to be lost; and second, by adding to the soil such amendments as 

 may increase the activity of the constituents already there, or which 

 may contain such substances as are essential for the growth of 

 plants. 



Losses Due to Methods of Practice. 



One of the means whereby soils may become impoverished, or 

 at least be reduced in productivity, is through the losses that occur 

 from improvident methods. For example, it has been demonstrated 

 that plants obtain their food in a soluble form, and unless it is 

 taken up when it has become soluble there is danger of its being 



