The Bulletin. 25 



annual average increase for four years in Field A being 712.5 

 pounds of seed cotton; for two years in Field B (JUG. 'J pounds ; and for 

 one year in Field C 780 pounds, or an annual average increase per 

 acre for the seven years in three fields of 717.7 pounds, worth $28.09 

 over cost of fertilizer. 



Lime, L (Plats 14^, 4'' and 7-). Lime was applied at the rate of 

 500 pounds of rock or 1,000 pounds slaked lime per acre every 

 fourth year. On plat in Field A during two years there was a 

 profit of 50 cents per acre from use of lime alone ; on plat in Field 

 B in two years' experiments a loss of $2.54 annually per acre; and on 

 the plat in Field C in a one year's test a profit of $7.02, or an average 

 for the seven years of a net profit of 59 cents annually per acre. 



Lime with Complete Fertilizer, N P K L (Plats 15-, 6^ and 92). 

 Where lime was used in combination with the three fertilizer constit- 

 uents there was less cotton produced on all the plats in all three of 

 the fields than where the three fertilizer constituents were used with- 

 out lime, showing a net loss in the use of lime in combination with a 

 complete fertilizer for the production of cotton on this soil. 



Taking the experiments as a whole, the average results show that 

 nitrogen alone on this soil for the production of cotton was used at a 

 loss ; 



Potash alone gave a small profit; nitrogen and potash combined 

 less by practically one-half than potash alone ; 



Lime alone had very little effect on the yield ; 



Phosphoric acid alone gave a large increase in yield and profit 

 (practically two-thirds as large as nitrogen, phosphoric acid, and 

 potash combined) ; 



Nitrogen combined with phosphoric acid added but slightly to the 

 increased yields ; 



Potash added to phosphoric acid gave profitable returns ; 



Nitrogen added to phosphoric acid and potash was at a small profit, 

 and the yields from lime added to nitrogen, phosphoric acid, and 

 potash were smaller than for the three fertilizer constituents com- 

 bined. 



The main increased yields and profits, therefore, came from phos- 

 phoric acid ; the next most profitable constituent was potash, nitrogen 

 being of no value except where used in combination with phosphoric 

 acid and potash, and the profit from its use then was not large. It 

 will be well to bear these facts in mind for comparison with the re- 

 sults presented in the tables to follow. 



