42 HORTICULTURE, FORESTRY, FLORICULTURE 



By rotation, crops with different fertility requirements are alter- 

 nated so that the same elements are not drawn on so constantly. 

 Coyer crops which increase humus can succeed cultivated crop8 

 which exhaust it, and in the intervals of rotation any poisonous or 

 injurious excretion from the roots of a crop is neutralized. Deep 

 rooted crops may be employed to bring up plant food from the sub- 

 soil and leave it at the surface when they decay, where it will be 

 available for shallower rooted crops. The test of successful farming 

 is to produce large and profitable crops and at the same time to 

 build up the fertility of the soil, making it each year more produc- 

 tive. Diversified farming permits this to be done ; continuous cotton 

 growing never will. 



(2) A diversified cropping system places farm operations on a 

 safer and more economical basis. Regular and continuous employ- 

 ment for labor is secured if crops are grown which require attention 

 at different seasons. The danger of loss from unfavorable weather 

 or glutted markets is much diminished when several crops are grown. 

 It is particularly important that the growers of Sea Island cotton 

 should begin at once to practice diversification in order to gain 

 experience with other crops, because there is a possibility that the 

 invasion of the boll weevil into the eastern States may in a few 

 years make Sea Island cotton an unprofitable crop. Much hardship 

 will result unless other crops are established meantime. 



(3) Rotation of crops is one of the most effective means of con- 

 trolling weeds, insects, and plant diseases. Crab-grass, nut-grass, 

 and other weeds troublesome in cotton fields are reduced in numbers 

 by the shading and smothering effect of a heavy growth of cowpeas 

 or velvet beans. Most injurious insects and plant diseases attack only 

 one kind of plant. The continuous culture of any crop affords ideal 

 conditions for the multiplication of its pests, while rotation of crops 

 results in their destruction from lack of food. 



For example, the nematode worm, causing the destructive root- 

 knot of peaches, cotton, etc., is greatly increased by planting sus- 

 ceptible crops, but can be controlled by a succession of immune 

 crops, such as corn, oats, velvet beans, or peanuts. For several cot- 

 ton diseases, including anthracnose, boll-rot, and "black-arm," ro- 

 tation is advised as one of the several preventive measures. (F. B. 

 302.) 



Cotton Culture. As a general rule the soil should be plowed at 

 least three months before the time when the cotton seed is to be 

 planted. Cotton requires a firm, well-settled seedbed, and unless the 

 plowing is done early, this condition cannot be secured. The depth 

 to which the soil should be plowed will depend somewhat upon the 

 previous treatment of the field. In cases where shallow plowing has 

 been practiced, it is not advisable to make any radical change the 

 first season, and in working down to a greater depth a small increase 

 should be made each season. This year the soil is turned to a depth 

 of four inches, another year one inch can be added to this furrow, 

 and similar progression can be made until the necessary distance is 

 reached. A material change in the depth to which the soil is turned 



