81 



Increase in seed cotton per acre when kainit was added: 



To unfertilized plot ^^ ^^• 



To cottonseed meal plot C 



To acid phosphate plot — 13 



To cottonseed meal and acid phos, plot. . . — 74 





Average decrease with kainit 12 *• 



It is clear that nitrogen was more effective than phos- 

 phoric acid. Potash was useless and unprofitable. The 

 most profitable fertilizer was cottonseed meal used alone. 



ExpERiMKNT Made by J. T. RobertsoxV, LeGraxd, Montgom- 

 ery County. 

 Gray soil, with clay subsoil at a depth ofS ii^ches. 



This land had been in cultivation about forty years, and 

 the crop in all recent years had been cotton. The original 

 growth was oak, hickory, pine, etc. 



The season was dry until several days of rainy weather 

 about the middle of August, following which rust injured 

 the plants growing on plots where no kainit was used. 



