20 PRINCIPLES OF FARM PRACTICE 



to check the loss by some means. It will be noticed that the 

 soil under a board or a similar covering is often damp, al- 

 though the adjacent soil may appear quite dry. This suggests 

 the use of some cover on the soil to prevent a loss of water. 

 For such purpose, except in protecting certain valuable 

 garden crops, boards are not practical because of the expense 

 and labor. Straw is sometimes successfully used as a covering. 

 But another much simpler and less expensive method is to 

 stir, or otherwise pulverize, the upper two or three inches of 

 the soil until it is finely divided. The finely-divided upper 

 layer of soil serves the same purpose as a board or other 

 covering and effectually checks the loss of water through 

 evaporation. Such a covering is called a soil mulch and is 

 always used in the best farm practice. 



How to make best use of a soil mulch. There are a few 

 things that should be kept in mind when using a soil mulch. 

 First, the mulch should be as perfect as possible; that is, 

 the part of the soil forming the mulch should be uniformly 

 fine, without clods, but not fine enough to form a dust. 

 Second, the mulch should be renewed from time to time, for 

 the water is likely to ascend gradually from below through 

 capillary attraction until the surface is reached and there 

 evaporate. Third, the mulch is always destroyed by rain 

 and therefore should be renewed after each rain. 



The series of farm operations necessary to prepare the soil 

 is not complete until a good mulch is formed. If a crop is a 

 cultivated one, like corn, it will be necessary to renew the 

 mulch from time to time. Incidentally, if a good mulch is 

 secured and maintained, weeds, which also occasion loss of 

 water, will be kept down. 



How to bring water to the surface of the soil. Some- 

 times the upper part of the soil becomes so dry that it does 



