32 Growing 5'ea Island Cotton Under Florida Conditions 



Fertilization 



Proper fertilization is an important factor in the growing 

 of Sea Island cotton under weevil conditions, not only from 

 the standpoint of causing the plants to put on and mature a 

 good crop of bolls, but also for securing earliness of maturity. 

 Unfertilized Sea Island cotton will suffer from summer wee- 

 vil migrations to a considerably greater extent than properly 

 fertilized Sea Island cotton. 



It is impossible to make inflexible recommendations for 

 the proper composition or amount of fertilizer best to use. 

 No two plats of ground are exactly alike, and no two seasons 

 are alike. Since on the average Florida farm a wide range of 

 soil conditions are found, it is impossible to give any one for- 

 mula as the best to use. The following general principles, 

 however, should be useful as a guide in laying out the fer- 

 tilization program. 



Most light soils in Florida are deficient in potash, and this 

 element should be used liberally. Phosphate is an essential 

 plant food element, and its liberal use is seldom a mistake, 

 especially since most of the phosphate that is not used by the 

 crop to which it is applied remains in the soil for succeeding 

 crops. 



Nitrogen should be applied only in quantities sufficient to 

 secure the plant growth needed. On light soils a consider- 

 able amount of this element is usually needed. On heavier 

 soils, less will be required. However, it should be remem- 

 bered that even on light soils too much nitrogen can easily 

 be applied. The water holding capacity of Florida sandy 

 soils is very low. Soil moisture studies in Madison county 

 in 1936 demonstrated that if excessive plant growth is forced 

 by heavy nitrate applications, excessive shedding will result 

 if the fruiting season is dry. Balance in fertilization, as in 

 most other things, is the safest policy. 



Fertilizer tests on Sea Island cotton — conducted by the 

 WPA in Madison county in 1936 and 1937, indicated that on 

 light sandy Norfolk soil, about 200-300 pounds per acre of 

 a fertilizer approximating a 5-7-5 or 4-10-6 analysis at plant- 

 ing, and a side dressing of about 75 pounds per acre of 

 nitrate of soda, or better, a combination nitrate and potash 

 side dressing, such as a 9-0-15 or 9-0-12, appeared to be about 

 the safest practice. On somewhat heavier soils in the shallow 

 bottoms, the side dressing showed less profit, but the heavier 

 applications of the general formula applied at planting paid 

 well, whereas they did not on the light soils. 



