83 



Increase in seed cotton per acre when kainit was added: 



To unfertilized plot 266 lt)s. 



To cottonseed meal plot 132 " 



To acid phosphate plot 87 " 



To cottonseed meal and acid phois. plot. . . .181 " 



Average increase with kainit 1()7 *' 



Plainly the chief need of this soil was for nitrogen. It 

 is equally clear that phosphoric acid was also needed by 

 this soil. Kainit was highly advantageous by reason of its 

 rust-restraining tendency. Whether the latter fertilizer 

 would be profitable in a normal season when rust is 

 less prevalent is an open and interesting question. The 

 complete fertilizers, made up of cottonseed meal, acid 

 phosphate and kainit, were decidedly more profitable in 

 1897 than any single fertilizer or mixture of two fertilizers. 

 Two hundred pounds per acre of kainit was more profitable 

 tha-n half that quantity. 



In 1896, on the same farm, but on a different field, with 

 a poor reddish soil, only fertilizers containing nitrogen were 

 profitable, the increase in yield from the use of acid phos- 

 phate and kainit being scarcely apx>reciable. Both experi- 

 ments agree in giving pre-eminence to cottonseed meal. 



GROUP IV. PHOSPHORIC ACID, POTASH AND NI 

 TROGEN ALL EFFECTIVE. 



Experiment Made by J. P. Anderson on Farm ov Du. 

 Thoafas, Thomaston, Marengo County. 



Gray, sandy soil, 4 inches deep, with red clay subsoil. 



This field had been in cultivation for thirty or forty years. 

 All recent crops consisted of cotton. The original growth 

 was oak, hickory, gum and pine. Rust wa.s very injurious, 

 especially on the plots where kainit was not used. 



