THE USE OF COMMERCIAL FERTILIZERS 143 



April, May aud June is 9J inches, and duriuo' May, June, 

 July and August it is 12y8^ inches. If this rain were uniformly 

 distributed, it would be fully enough for grass aud a little too 

 much for corn. As it is not, both crops need the soil in such 

 condition that it will hold enough water at all times for their 

 needs, while allowing the surplus to drain away. 



On soils of average texture the requisite moisture condi- 

 tions can be maintained by tillage, and if needed, b}^ drainage 

 on low levels ; but with extreme types, as heavy clay loams, 

 or light sandy loams, there is needed more thorough treatment 

 by increasing the amount of vegetable matter, since there is 

 no more effective way of making over a soil in its relation to 

 water and air than this. 



In using commercial fertilizers as a source of the food ele- 

 ments needed by crops, it should be remembered that there is 

 little positive evidence that they can make over the soil in its 

 relation to water, hence they always do their best work and 

 are most profitable on soils which are in good average condi- 

 tion, neither too heavy and wet nor too light and dry. Fur- 

 thermore, the continuous growth of annual crops, whether 

 hoed or broadcast, adds no vegetable matter to the soil, 

 except in the roots and stubble, and it is common to find that 

 the first crop of corn on sod land, with commercial fertilizers, 

 is superior to that of the second year, undoubtedly because 

 the vegetable matter of the old turf helped maintain a satis- 

 factory moisture condition in the first year and was largely 

 destroyed before the second year. 



The most economical use of commercial fertilizers is only 

 reached when they are applied in rotations in which the soil is 

 maintained in good moisture condition by the use of barnyard 

 manure or the vegetable matter from crops grown for the 

 purpose. 



Although the food elements in a commercial fertilizer form 

 but one of the several conditions needed for the best develop- 

 ment of the crop, it is important that these elements should be 

 suited to the demands of the crop at every stage of its growth, 

 else the product will not be as large as the other conditions 

 would permit. It is the most common practice to use this 



