MANAGEMENT OF THE SOIL 39 



more than is desirable except on very wet lands. 

 Where there is no trouble on account of drainage, 

 level cultivation is always to be preferred, since level 

 land presents a less surface for evaporation than when 

 it is thrown into sharp ridges. 



All authorities now agree that while the prepara- 

 tion of the soil should be deep and thorough, tillage 

 should be shallow and frequent, and that the surface 

 should be left as nearly level as the necessity for sur- 

 face drainage will permit. 



Mulching. — In some special cases mulching with 

 straw or other coarse litter may be resorted to instead 

 of tillage for the purpose of conserving the soil 

 moisture and preventing the growth of weeds. A 

 mulch is often used about fruit trees and with small 

 fruits, but as a rule it is too expensive for use with 

 field crops. A permanent mulch has tlie disadvan- 

 tage of tending to induce the formation of feeding 

 rootlets near the surface of the ground, while tillage, 

 on the contrary, tends to keep them down below the 

 part of the soil that is usually stirred. What is in 

 effect a temporary mulch is often cheaply provided by 

 planting some quick-growing plant as a cover crop. 

 Later when this cover crop is plowed into the soil, 

 it furnishes the organic matter that is so constantly 

 needed for maintaining its fertility. Tillage is usually 

 necessary during the period when the crop is making 

 its most rapid growth, but at all other times the land 

 should as far as possible be protected by some cover 

 crop to take up the elements of fertility rendered 

 soluble by the tillage and which would otherwise be 

 leached out from the soil and lost. The alternation 



