SOILS AND FERTILIZERS 467 



There is much uncertainty among farmers as to the manner of 

 applying fertilizers. Generally they should be sown broadcast and, 

 cultivated into the soil. The feeding rootlets are not at the base of a 

 tree or plant, but usually are found some distance from the plant 

 where they form a perfect net-work of rootlets in the soil. If fer- 

 tilizers are applied just at the base of the plant they do but little good 

 and many times much harm. 



Nitrogen in the form of nitrate should not be applied until the 

 beginning of the growing season. If applied too early much may be 

 lost by leaching out of the soil before the crop assimilates it. It is 

 many times best to apply the nitrate in two or three partial applica- 

 tions, say one-third at the beginning of the growing season, one-third 

 three weeks later and the last third two weeks later. Other forms 

 of nitrogen may be applied earlier in the spring. 



Phosphoric acid and potash compound may be applied early in 

 the spring, or even during the fall and winter without danger or loss 

 by leaching out of the soil (except on very sandy soils). It is best 

 to apply those phosphates that contain much water-soluble phosphoric 

 acid early in the spring, for if applied in the fall the phosphoric acid 

 tends to revert and become insoluble. Many times when potash is ap- 

 plied it tends to become fixed near the surface of the soil ; it is better, 

 therefore, to apply it early in the spring and as soon as the ground is 

 dry enough to work thoroughly cultivate it into the soil. 



KIND OP FERTILIZER TO USE. 



The kind of fertilizer to be used should be determined (1) by 

 its composition that is, whether it is nitrogenous, phosphatic, or 

 potassic in its character, and not by the name of the brand or of the 

 manufacturer; and (2) by the form in which the fertilizer constit- 

 uents exist in it that is, by the extent of their availability. 



In deciding upon the kind of manure to use, the character of 

 the soil must, of course, be taken into account. Crops grown on soils 

 poor in decaying vegetable matter (humus) are, as a rule, benefited 

 by applications of nitrogenous manures, while those grown upon soils 

 well supplied with this substance are more benefited by phosphates 

 and potash. Upon heavy soils phosphates are likely to be more 

 beneficial than nitrogen, while the reverse is the case of light dry soil. 

 All sandy soils are, as a rule, deficient in potash, while clayey soils 

 contain this element in larger quantities. There are many excep- 

 tions to the general rules. The farmer, with the general principles 

 well in mind, must use his intelligence in applying them to his con- 

 ditions. 



The Cereals and Grasses. The cereals (Indian corn excepted) 

 and grasses are quite similar in their habits of growth, and may be 

 regarded as a class distinguished by extensive root systems and 

 long periods of growth, which enable them to extract the mineral 

 food necessary from relatively insoluble sources, and because of their 

 very rapid development of leaf and stem during a short season just 

 before maturity are unable to make normal growth during this 

 period without an abundance of nitrogen in immediately available 

 forms. This period usually precedes the time of rapid nitrification, 



