FIBER CROPS 34/ 



the phosphorus occurring in rock phosphates. The acid phos- 

 phates are, therefore, generally recommended. 



"While a few of the earlier tests made at Auburn were thought at the tim 

 to indicate the possibility of the economical substitution of the cheaper raw 

 phosphate for the most costly acidulated material, our hundred or more ex- 

 periments bearing on this question, taken as a whole, declare emphatically that 

 under ordinary conditions and present prices it is more profitable to fertilize 

 cotton with acidulated than with raw phosphate. When the latter is employed 

 at all it is best to use in connection with it some form of organic nitrogenous 

 material as stable manure, cotton seed, or even cotton seed meal." 1 



These experiments, however, have not taken into account 

 the residual effect of the rock phosphate in a well ordered sys- 

 tem of rotation. 



441. Composting. It is a common practise to mix, say, four 

 parts of horse manure with one part each by weight of cotton 

 seed and acid phosphate and allow them to ferment for four to 

 ten weeks. To this mixture there may be added coarse litter of 

 any sort, such as oak leaves, pine needles. Among the things 

 accomplished by this process is a product which can be distrib- 

 uted in the fertilizer distributer, and the fermentation destroys 

 the germinating power of the seed. 



The experiments of the Alabama and other stations do not in- 

 dicate that the process of fermentation increases the yield of 

 cotton compared to using the same ingredients fresh, and ap- 

 plied early enough to prevent the cotton seed from germinating, 

 unless it be in making available the coarse litter which may be 

 employed. The chief consideration, therefore, in determining 

 the desirability of composting fine stable manure, cotton seed 

 and acid phosphate is convenience and cost of labor. Where 

 manure is available it is considered desirable to mix with the 

 commercial fertilizers and apply in the furrow rather than to 

 apply broadcast. When desired for immediate use it may be 

 necessary to screen the manure in order to remove the coarse 

 litter, which may be done with an ordinary sand screen. 



1 Alabama Sta. Bui. No. 107 (1899), pp. 251, 252. 



