20 The Bulletin. 



Effect of ISTiTROGEisr, Phosphoric Acid, Potash and Lime Alone and 

 IN Combination With Each Other on Cotton Yields. 



The experiments, the results of which are presented in Table I, were 

 planned to determine the effect on yield of cotton of different fertilizer 

 applications when two of the constituents were applied together, as 

 nitrogen and phosphoric acid (IST P), nitrogen and potash (N K), and 

 phosphoric acid and potash (P K), and when all three of the fertiliz- 

 ing constituents were applied to make a complete fertilizer (jST P K) ; 

 also to test the effect of lime (L) when used alone and when used in 

 connection with a complete fertilizer (N P K L). The results are shown 

 in yields of seed cotton per acre for the several years, average yields, 

 average increases over the unfertilized (O) plats which represent the 

 effect of the fertilizer applications, the value of increase, cost of the 

 fertilizer, and value of the average annual increase over cost of ferti- 

 lizer. 



Nitrogen and Phosphoric Acid, N. P. (Plats 10- andlp.) ^^itrogen 

 and phosphoric acid gave increased yields over the unfertilized plats four 

 of the seven years on the two fields, the annual average increase for the 

 three years in field B being 288 pounds; for four years on field A an 

 average loss of 9 pounds, or an average annual increase for seven years 

 in the two fields of 167 pounds, worth $3.81 over the cost of fertilizer. 



Nitrogen and Potash, N K. (Plats 8 and 8.) The application of 

 nitrogen and potash combined gave large increased yields for all years 

 except one. The average increase on field B was 630 pounds per acre, 

 and 185 on field A. The average increase for the seven years was 

 greater than that given by any of the other applications except com- 

 plete fertilizer and lime. The average profit from this application was 

 $14.11 per acre. 



Phosphoric Acid and Potash, P K. (Plats 9 and 9.) Phosphoric 

 acid and potash combined gave a large average annual increase for the 

 three years on field B — 444 pounds — but for the four years on field A 

 the average increase was only 46 pounds. This gives an average in- 

 crease on the two fields of 217 pounds, worth $9.77, which is $7.87 more 

 than the cost of the fertilizer. 



Phosphoric Acid, Potash and Nitrogen, N P K. (Plats 10 and 11.) 

 These three materials combined in a complete fertilizer gave average in- 

 creased yields in both fields. The average annual increase for four 

 years on field A was 163 pounds of seed cotton; and for three years on 

 field B, 593 pounds; or an average increase per acre for the seven years 

 of 348 pounds, worth $11.45 over the cost of fertilizer. 



Lime, L. (Plats 6^ and 53.) Eor the four years on field A the lime 

 plat showed an average annual loss of 56 pounds of seed cotton, repre- 

 senting a financial loss of $3.15. On field B however, this material gave 

 an increase each of the three years, averaging 218 pounds more than 

 the unfertilized plat, and the profit was $9.18. As an average of these 

 two apparently contradictory results lime gave an average increase of 

 62 pounds, representing a profit of $2.16. 



Lime with Complete Fertilizer, N P K L. . (Plats 7^ and 63.) _ With 

 the exception o^ the year 1905 on field B, lime in combination with the 



