88 THE SOILS AND CEOPS OF THE FAEM. 



decay of this matter increases the humus and, ulti- 

 mately, the supply of available mineral plant food 

 near the surface. 



The objection to this practice is that no direct re- 

 turn, aside from the increase of fertility of the soil, is 

 made for the time, labor and seed used, or, in many 

 cases, the land brings no money crop for a year. 

 Sowing clover with small grain crops and plowing 

 this under in preparation for a wheat crop in the fall 

 or corn crop in the spring is a practice becoming 

 more and more common. The only extra expenditure 

 in this case is the cost of the seed. Some one has 

 said the only objection to this practice is that, as a 

 rule, it would be still better practice to allow the 

 clover to stand another year, utilizing the crop for 

 pasturage or hay, and then plowing under the sec- 

 ond growth. 



Fortunately it is not usually necessary to use a crop 

 solely for manuring. A part of the growth may be 

 utilized for hay or, better, for pasture, with little loss 

 of. the manurial value of the crop, it being under- 

 stood that the manure made from the crop taken oJBP 

 is to be returned, as well as the part of the crop not 

 removed plowed under. 



Choice of Crops in Rotation. — The crops to 

 be used in a rotation will be selected with reference 

 to the ease with which they can be grown, and their 

 market or feeding value, as well as their value in 

 maintaining fertility, and the needs of the soil of the 

 locality. Fixed rotations have never been so common 

 in the United States as in Great Britain, and, even 

 therO) more variation is allowed than formerly. Sjil 

 and climate must have large influence,, but the relative 



