The Bulletin 93 



Effect of Nitrogen, Phosphoric Acid, Potash and Lime Alone and in 

 Combinations. — These experiments were planned to test the effect on 

 yield of nitrogen (jST), phosphoric acid (P), and potash (K) when 

 applied singly; when two of the constituents were applied together, as 

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

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

 constituents were applied to make a complete fertilizer (N P K). 

 Lime (L) alone and with a complete fertilizer (N P K L) is also 

 studied. 



The results are shown in average yields of hay in pounds and peas 

 in hushels per acre for the several years, and average increases over 

 the unfertilized (O) plats, Avhich represent the effect of the fertilizer 

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

 the value of the increased yield over cost of fertilizer. 



EFFECT ON YIELDS OF HAY. 



Xitrogen, N" (Plats 1 and 1). From nitrogen alone in Field C there 

 were increased yields of hay in 1904 and 1905 and decreases in 1906 

 and 3907 over the unfertilized plat (8), the average increase being 475 

 pounds, while in 1908 in Field A the plat (1) receiving nitrogen and the 

 unfertilized plat (4) produced the same yield. Plat 1 had had an 

 application of nitrogen alone in corn and cotton tests during the pre- 

 vious six years and plat 4 had had no fertilizer during the same time. 



Phosphoric Acid, P (Plats 2 and 2). Phosphoric acid alone pro- 

 duced increased yields in all of the five years on the plats in both fields, 

 the average for the first four years being 720 pounds of hay, and for the 

 fifth year in Field A 1,700 pounds, worth at $18 per ton respectively 

 $5.28 and $14.10 over the cost of fertilizer. 



Potash, K (Plats 3 and 3). From potash alone in Field C the yields 

 increased in 1904, 1905, and 1907, and decreased in 1906, the average 

 annual increase being 340 pounds of hay. In Field A there was no 

 increase due to potash in 1908 and the fertilizer application was used 

 at a loss. 



Nitrogen and Phosphoric Acid, N P (Plats 4 and 5). ISTitrogen and 

 Phosphoric acid combined gave increased yields over the unfertilized 

 plats in all five years on the plats in both fields, the annual average 

 for the first four years in Field C being 460 pounds of hay (less than 

 for phosphoric acid alone, which was 720 pounds). For the fifth year 

 (1908) in Field A the increase was 1,800 pounds, or 100 pounds more 

 than the phosphoric acid alone gave. 



Nitrogen and Potash JST K (Plats 5 and 6). From the application of 

 nitrogen and potash combined the yields were increased in three years 

 and gave the same yield in one year in Field C, the average increase 

 for the four years being 292 pounds of hay, the smallest increase from 

 any of the applications in the test. In Field A in 1908 there was a 

 gain of 500 pounds of hay, due to nitrogen and potash. 



Phosphoric Acid and Potash, P K (Plats 122 ^nd 7). Phosphoric 

 acid and potash combined produced increased yields of hay in all five 

 years of the tests on the plats in both fields over the unfertilized plats, 

 the annual average increase for the first four years in Field C being 

 840 pounds per acre (120 pounds more than phosphoric acid alone). 



