196 SUCCESSFUL FARMING 



slowly in the spring and late in the fall — a condition favorable to 

 boll-weevils. 



Along the rivers and smaller streams are strips of alluvial land called 

 bottoms. They are usually fertile, well watered and produce a rank growth 

 of plants that do not make fruit in proportion to their size. On such land, 

 hay or corn is a more profitable crop. 



FERTILIZER AND CULTIVATION 



Plant Food Removed by Cotton.— There is probably no cultivated 

 crop that draws so lightly upon the fertility of the soil as cotton. The 

 average crop per acre in the United States is slightly less than 600 pounds 

 seed cotton yielding 200 pounds lint. This amount of lint removes from 

 the land only .42 pound nitrogen, .15 pound phosphoric acid and 1.32 pounds 

 potash. When both seed and lint are removed, the loss is 13 pounds nitro- 

 gen, 4.74 pounds phosphoric acid and 5.70 pounds potash. The roots, 

 stems, leaves and burs contain about as much nitrogen and phosphoric 

 acid, and about three times as much potash, as the seed cotton. These 

 parts of the plants are seldom removed from the field. 



Need of Humus. — In the cotton belt the amount of humus in the soil 

 is small. The warm, moist conditions that prevail during a large part of 

 the year favor rapid nitrification; and the heavy winter and spring rains 

 rapidly leach out the soluble plant-food. As a general practice, cotton 

 follows cotton year after year and receives clean cultivation and furnishes 

 little organic matter to replenish the humus. There is needed on every 

 farm some system of crop rotation in which one crop is plowed under to 

 renew the humus. 



Need of Nitrogen. — The small size of the cotton plants over large 

 areas is evidence of the deficiency of nitrogen in the soil. In many fields 

 the plants are large enough to make only two or three bolls. To make a 

 profitable crop they should be two or three feet high, full of fruit and have 

 a rich black color during the growing season. The only lands that do not 

 need a supply of nitrogen are the rich bottoms or those that have received 

 a heavy crop of clover or some other legume for soil improvement. 



The chief sources of nitrogen in commercial fertilizer are cottonseed 

 meal, which also furnishes some phosphoric acid and potash, nitrate of 

 soda, tankage and calcium cyariamid. If quick results are desired, as in 

 the case of a side application to a growing crop, some soluble form like 

 nitrate of soda is used. 



Need of Phosphoric Acid. — The need of phosphoric acid is almost 

 universal. Most fertilizer experiments show an increased yield whenever it 

 is used. The only soils that do not show an increased yield from its use 

 are the rich alluvial lands and Houston and Victoria clays. A liberal 

 application of acid phosphate on heavy clay soil often hastens the maturing 

 of a crop of bolls that would not ripen and open before frost. When a 

 crop of 200 or 300 pounds lint cotton is expected, it is usual to 



