94 The Bulletin 



and for the fifth year (1908) in Field A 1,900 pounds (200 pounds 

 more than phosphoric acid alone), valued over the cost of fertilizer 

 respectively at $5.76 and $15.30 per acre. 



Nitrogen, Phosphoric Acid and Potash, IST P K (Plats 6_ and 8). 

 These three materials combined in a complete fertilizer gave increased 

 yields in all of the tests on all the plats, the annual average increase 

 for the four years in Field C being 962 pounds of hay and for the fifth 

 year in Field A 1,800 pounds. The net value of the increase (value 

 over the cost of fertilizer) was $6.17 in Field C and $13.71 in Field A, 

 or 89 cents more than phosphoric acid in Field C and 39 cents less in 

 Field A. 



For the production of hay these experiments, as a whole, show that 

 phosphoric acid (Acid phosphate) produced the increased yields and 

 that nitrogen and potash had very little effect, and in a number of 

 tests none at all. 



Lime alone, L (plats 7^ and 14). On the Plat in Field C lime alone 

 gave a profitable yield of pea-vine hay in the four years' test, the aver- 

 age increase being worth $3.38 per acre. On the plat in Field A in one 

 year's test there was no increase in yield over the unfertilized plat, and 

 the lime was therefore used at a loss. 



Complete Fertilizer with Lime, [N" P K L (Plats 9^ and 15). Where 

 lime was used in combination with the three fertilizer constituents there 

 was a slight increase over what the complete fertilizer alone gave, but 

 not sufficient to make the profit any greater than was obtained from the 

 three fertilizer constituents by themselves. 



Taken as a whole, lime was of doubtful value in increasing the yield 

 of pea-vine hay. 



EFFECT ON YIELD OF PEAS. 



The yields of peas given in Table X for the singles and combinations 

 were obtained on the same plats as the hay, the hay being cut on one- 

 half of each plat and the peas gathered on the other half. 



Nitrogen, N (Plats 1 and 1). After the first year (1904) nitrogen 

 alone gave no material increase in the yield of peas; in two years (1906 

 and 1907) there was a decided decrease. 



Potash, K (Plats 3 and 3). Potash alone did not increase the pea 

 yields, the net result being a small loss in yields and the loss of the 

 cost of tbe fertilizer application. 



Nitrogen and Potash, IST K (Plats 5 and 6). Nitrogen and potash 

 combined did not help the yield of peas, and the cost of the fertilizer 

 was lost. 



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

 an annual average increase of 2 bushels of peas per acre for the four 

 years' test in Field C and 5 bushels for the fifth year in Field A. 



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

 phosphoric acid combined increased the yield of peas in each of the 

 tests, the annual average for the four years in Field C being 3.1 bushels, 

 and for the fifth year in Field A 7.2 bushels. These were the largest 

 and most profitable increases obtained frotn any of the fertilizer appli- 

 cations. 



Phosphoric Acid and Potash, P K (Plats 122 ^^^ 7). From phos- 



J 



