SOIL MANAGEMENT 51 



the soil. These three methods when combined will greatly 

 increase the water-holding capacity of sandy soils. 



The loss of water from sandy soils through evaporation 

 may be prevented by forming a good mulch. A mulch on 

 these soils lasts much longer than on heavier soils. In fact, 

 were it not for the necessity of cultivation for removal of 

 weeds, the mulch which forms at the surface of sandy soils 

 would often be sufficient to prevent loss of water, without 

 much cultivation. The effectiveness of a natural sand mulch 

 may be seen easily by examining a pile of sand. If some of 

 the top, dry layer is scraped away, the sand below will be 

 found moist. 



The ease with which water drains from sandy soils and 

 the naturally large spaces among the particles promote good 

 aeration. Therefore, no special measures need be taken to 

 keep up the supply of soil air. The difficulty, if any, will be 

 in the other direction. Owing to the presence of so much 

 oxygen, nitrification is apt to go on too rapidly, so that 

 nitrates tend to be formed faster than they are needed, and 

 consequently are drained off and lost. These losses may be 

 reduced considerably by compacting the soil, as suggested 

 for control of water. 



Large applications of manure serve the further purpose of 

 supplying food material which is so much lacking in sandy 

 soils. But manure contains too great a proportion of nitrogen 

 to that of phosphoric acid and potash to be used to advantage 

 without correcting or balancing. According to the facts 

 presented in a previous chapter, the application of phosphoric 

 acid, in the form of both rock phosphate and acid phosphate, 

 would seem to be desirable; the rock phosphate to furnish 

 a store of phosphoric acid to be made slowly available, and 

 acid phosphate for immediate use. Since sandy soils are 



