96 .The Bulletin. 



lated guano can easily satisfy the demands of liis formula from such uitrog- 

 euous materials as old leather wastes aud hair wastes which decompose and 

 give off the nitrogen in from two to ten years. There has been a custom 

 among the farmers of the South to use the cheapest ready-mixed fertilizer on 

 the market, regardless of content or quality of plant food contained therein. 



In order to judiciously deal with the subject of commercial fertilizers for 

 special crops it is necessary for the farmer to study the mechanical and 

 physical condition of the soil. It is a well-known fact that a given fertilizer 

 will not produce the same results on a shallow, compact soil, composed en- 

 tirely of sand aud clay, underlaid with a hard-pan, as it will produce on a mel- 

 low, well pulverized, deep soil which has been well drained. We must take into 

 consideration the water-holding capacity of the soil. The only form in which 

 the plant food can be of service to the plant is in solution, and if the water 

 is not in the soil to carry the plant food in solution, the crop will suffer for 

 lack of nourishment, it matters not how much fertilizer has been used. 



It is also true that a poorly drained soil prevents the proper action of the 

 fertilizer; because if there is too much water the solution will be too much 

 adulterated and the plant will suffer. 



It is an established fact thnt different soils contain the elements of plant 

 food in varying quantities. In fact, we frequently find soils in the same field 

 that vary widely in chemical composition. Almost all soil "contains some 

 plant food. It is therefore necessary for us to endeavor to find out those ele- 

 ments that are deficient in a given field or plat of land and increase the 

 amount of those elements in the fertilizer used, and not add any more of 

 that element that is ofttimes already present in a greater quantity than can 

 be used by the plant. The best way to get the above information is by experi- 

 ment on our own land. We should test the different elements on a small scale 

 and thus learn which gives the best results. AVe will then know which ele- 

 ment is most needed, and increase this in the mixing of the fertilizer aud 

 decrease the amount of those that seem to give no results. We should also 

 study the results from tests made by the Experiment Station and Test Farms 

 on soil most similar to that to be fertilized. We should never depend upon 

 chemical analysis for this information. No man can intelligently and eco- 

 nomically use fertilizers till he has learned the needs of his soil. 



Then, again, we should know something about the demands of the different 

 farm crops. The three important elements — nitrogen, phosphoric acid, and 

 potash — each has a special function in the growth of the plant. It is true 

 that these elements may sometimes fail to produce the anticipated results 

 because of the bad mechanical condition, or the lack of the required balanced 

 ration. From a general standpoint, it is agreed that nitrogen is the leaf and 

 stem producing element. In other words, it stimulates plant growth. Phos- 

 phoric acid is the seed and fruit producing element. Potash produces the 

 woody fiber, the tuber in the case of the tuber crops. It gives the peach its 

 ruddy hue and is necessary to the best maturity of all fruit. 



It is also true that the different farm crops demand these elements in a 

 widely varying proportion. No two crops draw on the soil for precisely the 

 same amounts of these elements. We should learn the function of the various 

 elements of plant food, the demands of the different farm crops in which we 

 are interested, and, by using this knowledge, stop buying and adding to our 

 soils those elements that actually in many cases have an adverse infiuence 

 upon the growth of the crop. For instance, we grow cotton for the lint — the 

 fruit, as we call it. We use a fertilizer too rich in nitrogen; the plant grows 

 too rapidly, the limbs are too long, the squares are thinly set along the 

 branches on account of the rapid growth, and the fruit is sacrificed for leaf 

 and stem or stalk. Furthermore, the crop is apt to grow too late and the 

 cotton not to open. The same thing may be true with reference to other 

 plants. A farmer may use a fertilizer for wheat rich in nitrogen and phos- 

 phoric acid ; the plants grow tail and make good heads, but in the absence of 

 potash the stalks are weak and slender, have not enough of the woody fiber, 

 and the wheat falls down so it can't be harvested. We should feed to the 

 crops those elements that produce whatever results we are aiming for. If we 

 are growing a grass crop for hay we should use freely that element (nitrogen) 



