526 Circular No. 4. 



(2) This tendency to compact, also hastens the loss of water, which 

 must be counteracted by keeping the soil loose to absorb the rainfall 

 and to prevent evaporation. 



(j) The loss of humus has made the plant food less readily avail- 

 able. Tillage, by admitting air, and liming the soil, by changing its 

 form of combination, makes the plant food more soluble. Hence, 

 w^here humus is deficient more thorough tillage must be practiced. 



The bad condition into which the soil has been brought by faulty 

 farming makes it necessary that better tillage be given. 



One essential is deep plowing. The soil can never give the best crops 

 unless a deep, mellow root bed is provided. 



Increase in the depth of plowing should be done gradually. If 5 

 inches have been the custom it may be injurious, on some soils, suddenly 

 to increase this to 8 inches. If manure is plowed under at the same 

 time, the possibility to injury is lessened. 



Fall plowing on heavy clay improves the tilth by exposing the lumps 

 to the action of frost. There is less likelihood of injury from plowing 

 wet soil if the operation is not delayed until spring. 



Subsoiling heavy clay soil increases its storage capacity for water, and 

 allows plant roots a greater range. 



Clods left after plowing should be harrowed down at once. If al- 

 lowed to stand for several days they rapidly lose moisture and become 

 hard. Harrowing immediately after plowing saves moisture, time and 

 labor. Frequent cultivation is highly desirable. 



Efficiency of Fertilizers 



Commercial fertilizers have been largely used to make up for de- 

 ficiencies in tillage and for other unfavorable soil conditions. This is 

 usually a mistake. Their chief use is to supply readily available food. 

 Their use should not be resorted to until all has been done that can be 

 accomplished by means of the practices already mentioned, that is, 

 maintenance of the humus supply, drainage, liming for acidity, and 

 good tillage. Indeed, fertilizers can not give their full value until these 

 other conditions of the soil have been made reasonably favorable to crop 

 growth. Up to that point their use involves a waste of money. As the 

 former practices are neglected, fertilizers must be used in continually 

 increasing quantities. This should not be the case. In crop production 

 the soil should be looked on as a store-house, a factory from which food 

 and other materials for crop growth are derived by means of good farm 

 practice. Fertilizers should supplement and not supplant this native 

 store of each farm. The fertilizer bag should be kept secondary to the 

 manure heap, the tile drain and the cultivator, which means dollars and 

 cents in profits. 



T. L. Lyon, 



G. W. Cavanaugh, 



E. O. FiPPiN. 



