The Bulletin. 



43 



Continued. 



YEARS IN FIELDS A, B AND C. 



assumed that there is a imiforra increase or decrease in the natural fertility between check 

 plats, and a corrected check was figured on this basis for each treated plat between checks. 



The results are quite uniform in all three of the fields, indicating 

 that 11/4 PGi" cent in the mixture, or 5 pounds of potash per acre, is 

 not sufficient for the most profitable yield of cotton on this soil, when 

 used in connection with the regular quantities of nitrogen and phos- 

 phoric acid employed in the mixtures. The largest average increase 

 in yield of cotton, as well as the greatest profit, was obtained from 

 the plats receiving the normal quantity of potash, which was 2^ 

 per cent in the mixture, or 10 pounds to the acre. This quantity is 

 supplied by 50 pounds of 20 per cent manure salt. 



EFFECT OF VARYING QUANTITIES OF FERTILIZER ON YIELDS. 

 IN 1904, 1906 AND 1909. 



