CROPS AND SOIL IMPROVEMENT 



follow soon, permitting rapid escape of water. 

 The roller or plank-drag is employed to compress 

 the soil, and to crush crumbs of soil that are too 

 large for good soil conditions. The harrow fol- 

 lows to make a mulch of fine, loose soil at the sur- 

 face to assist in prevention of evaporation. 



A sandy soil will retain its mulch in effective 

 condition for a longer time than a fine clay, if no 

 rain falls. When the air is laden with moisture, 

 clay particles absorb enough water to pack to- 

 gether and form an avenue for the rise of water 

 to the surface, where the dry air has access to it. 



Mulches of Foreign Material. The truth 

 that moisture is a leading factor in soil productive- 

 ness is evidenced by the value of straw and similar 

 material as a mulch. A covering of straw around 

 trees in an orchard, or bush fruits, or such plants 

 as the potato, may give better results than an 

 application of fertilizer when no effort is made to 

 prevent the escape of water. People so situated 

 that little attention can well be given to the fruit 

 and vegetable garden obtain good results by re- 

 placing tillage with a substantial mulch that 

 keeps the soil mellow, prevents weed growth, and 

 retains an abundant supply of water. 



In grain-producing districts where all the straw 

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