44 



Increase of seed cotton per acre when kainit was 

 added : 



To unfertilized plot 226 lbs. 48 lbs. 



To cotton seed meal plot 20G lbs. 120 lbs. 



To acid phosphate plot 440 lbs. —SO lbs. 



To cotton seed meal and acid phosphate 



plot —12 lbs. —72 lbs. 



Average increase with kainit 216 lbs. —4 lbs. 



In both years the most profitable fertilizer was a mix- 

 ture of acid phosphate and cotton seed meal. Both cot- 

 ton seed meal and acid phosphate, whether applied alone, 

 or in combination, were highly profitable. Kainit had 

 no beneficial effect in the presence of a mixture of phos- 

 phate and cotton seed meal, but in 1899, kainit was quite 

 effective when used alone or in combination with either 

 one (but not both) of the other materials; this was the 

 season when rust was injurious on certain plots receiv- 

 ing no kainit. 



Two experiments made in the same region by G. O. 

 Sellans, at Lumber Mills, (see Bulletin No. 102) accord 

 Avith Mr. McClure's experiments in showing that these 

 soils are highly responsive to acid phosphate and cotton 

 seed meal and that kainit is decidedly beneficial only in 

 seasons w^hen black rust is severe. 



Experiment made in 1899 by C. H. Mason, i mile n. of 

 Wilson, Escambia County. 



Light shandy loam; mth red clay subsoil. 



This field of upland was cleared of its growth of long- 

 leaf pine two years before the beginning of the test and 

 during these two years the land was occupied by cow- 

 peas, presumably grown for hay. 



