138 FERTILITY AND FERTILIZER HINTS 



ammonia, and calcium nitrate are soluble in water and are not 

 fixed in the soil. They should be applied in small quantities and 

 at the proper time, or when nitrogen is needed, to give the 

 best results. When large applications of these materials are 

 made, some of the nitrogen may be lost by leaching. These 

 fertilizer materials should never be worked into the soil too 

 deeply as they may be lost by leaching before the plant can 

 appropriate them. The organic materials furnishing nitrogen 

 all have to be oxidized and converted into nitrates before they 

 may readily be acquired as plant food. These materials may be 

 applied early enough so that they may be acted upon by the soil 

 organisms and partially decomposed to furnish food for the 

 young plant. The very slowly available organic substances 

 will of course be decomposed more slowly than dried blood, cot- 

 ton-seed meal, tankage, steamed horn and hoof meal, castor 

 pomace and similar substances. One of the functions of nitro- 

 gen is to produce growth. It would be wasteful to apply any 

 nitrogenous substance to hasten maturity. It seems almost un- 

 necessary to make this statement but some farmers use nitrate 

 of soda late in the season to help fill out ears of corn after the 

 crop has been made. If nitrate of soda is added in the middle 

 of the growing period before the ears are formed it will help to 

 produce more vigorous growth. Generally speaking, the nitrog- 

 enous fertilizers may be applied in the spring at planting time 

 and during the growing period when needed. 



Phosphoric acid is readily fixed in the soil. When soluble 

 phosphoric acid is added from superphosphates, it becomes well 

 distributed in the soil, because of its fine mechanical condition, 

 and changes to insoluble forms which are not apt to be lost by 

 leaching. Superphosphates are very beneficial to young crops 

 and tend to produce strong plants that can better resist the 

 attacks of fungi and insects. Superphosphates may be applied 

 before or during planting time. Raw bone-meal and ground 

 rock phosphate may be applied at most any tiine because they 

 are slowly available : but other fertilizers carrying phosphoric 

 acid in the available form should be applied just before, or at 

 planting time. 



