464 MISCELLANEOUS FARM SUBJECTS 



increase the crop by increasing the amount of fertilizer, but beyond 

 a certain point, the increase in crop is no longer profitable. That is 

 to say, the additional amount of crop secured does not pay for the 

 additional quantity of fertilizer used. The point at which the addi- 

 tion of fertilizers ceases to be profitable depends upon the selling 

 price of the crop. Crops of high selling price per acre will of course 

 bear a profit in larger applications of fertilizer than low selling crops. 



In raising crops, therefore, we need not be at the expense of 

 supplying all of the deficient plant food contained in the crop we 

 raise, but only the excess which the crop contains over and above 

 that which the soil is capable of supplying, year in and year out, in- 

 definitely. It must be remembered, however, that not all of the plant 

 food supplied will be received by the crop. Thus only one-half (50 

 per cent) of the nitrogen applied in the fertilizer is recovered, the 

 remainder is either lost in the drainage water, or is carried down into 

 the subsoil or held in the soil. It has been demonstrated that very 

 little if any influence is exerted by the nitrogen in chemical fertilizer 

 after the second year, and even the second year this influence is very 

 slight. With potash and phosphoric acid the case is different, the 

 effect of a large application being felt for many years. This is ex- 

 plained by the fact that nitrogen in the form suitable to be used by 

 plants is readily washed out of the soil, while potash and phosphoric 

 acid combine with the soil, and though not immediately available 

 are gradually made so, and hence in time will be largely recovered. 



Where lands are greatly worn by years of cropping, more fer- 

 tilizer should be used to the acre, and it should contain about equal 

 parts of cotton-seed meal and high-grade acid phosphate. The bene- 

 ficial effect of commercial fertilizers depends largely upon the pres- 

 ence of humus in the soil ; hence the importance of using stable ma- 

 nure and plowing under green crops. In applying the foregoing in- 

 structions the farmer must use considerable judgment and modify 

 his practice where necessary to fit local conditions. 



Before applying commercial fertilizers prepare the soil thor- 

 oughly. Where 500 pounds of fertilizer or less is used for cotton put 

 it all out in one application in the furrow about 10 days before plant- 

 ing and mix well with the soil. Where 600 or more pounds per acre 

 are used two applications should be made, one-half in the furrow 

 before planting and the remainder as side applications at the first or 

 second working of the crop. When using 1,000 pounds or more, 

 make two or more applications or broadcast the entire amount before 

 planting. 



Where more than 200 pounds of fertilizer is used for corn on 

 thin soil two applications are recommended, 200 pounds in the fur- 

 row before planting and the remainder as a side application when 

 the corn is about a foot high. On medium or rich soils all the fer- 

 tilizer may be applied around the corn. The depth to which the 

 commercial fertilizer is applied is important. Experiments have 

 shown that 3 inches is about the proper depth in all except semiarid 

 sections, where it should be put deeper. It has been a common prac- 

 tice among farmers to apply fertilizers too deep. 



