96 The Bulletin 



The four years' experiments, represented on these latter plats, taking 

 the results as a whole, show some profit, as is shown in the yield of hay 

 from the increased quantities of nitrogen, though it is small over the 

 profits produced by phosphoric acid alone. 



EFFECT ON YIELD OF PEAS. 



The experiments were intended, as were those with hay, to show the 

 effect of vaiying quantities of nitrogen on the yield of peas, the phos- 

 phoric acid and potash remaining constant. The results show that the 

 most profitable yields on the plats in both fields were where one-half 

 the quantity of nitrogen was applied, or 0.7 per cent in the fertilizer mix- 

 ture, and the profits on these plats were but slightly in excess of those 

 where phosphoric acid alone and where phosphoric acid and potash 

 were applied. The large application of nitrogen gave less profitable 

 yields than phosphoric acid alone. 



On the whole, the results in the production of peas are unfavorable to 

 the application of nitrogen. Taking the results as a whole and con- 

 sidering the value of the peas and hay together the heavier applications 

 of nitrogen yielded the greatest profit per acre above the cost of ferti- 

 lizer. 



Effect of Varying Quantities of Phosphoric Acid. — -This part of ex- 

 periments was planned to shoAV the eft'ect on the yield of hay and peas 

 of varying quantities of phosphoric acid, the nitrogen and potash 

 remaining constant. On one plat one-half the normal quantity of 

 phosphoric acid was applied, or a quantity represented by 75 pounds 

 of 16 per cent acid phosphate, an equivalent to 12 pounds of phosphoric 

 acid. To two plats were applied two and three times the normal quan- 

 tities of phosphoric acid represented by 300 and 450 pounds of 16 per 

 cent acid phosphate respectively, or 48 and 72 pounds of phosphoric 

 acid per acre. 



EFFECT ON YIELD OF HAY. 



The results on the plats in both fields in all the years show with 

 marked unanimity decided increases in the yields of hay for increased J 

 quantities of phosphoric acid. On an average, increasing the applica- ^ 

 tion of 16 per cent acid phosphate from 75 pounds to 450 pounds, used 

 with 23 pounds of blood and 60 pounds of manure salt, gave an in- 

 crease of 1,002 pounds per acre worth $9.02 at a cost of $3 for the 

 increase. The most profitable yield on the plats in Field C was from 

 the plat receiving two quantities phosphoric acid or the equivalent of 

 300 pounds of 16 per cent acid phosphate per acre, while the most^ 

 profitable return from the plats in Field A is from the one having three 

 quantities of phosphoric acid or the equivalent of 450 pounds acid 

 phosphate per acre, the profit in these cases being $8.06 and $20.31 per 

 acre respectively. 



The results, as a whole, show in the most striking way the need of 

 this soil for phosphoric acid in the growth of pea-vine hay. 



EFFECT ON YIELD OF PEAS. 



The pea yields point to the same conclusions as for hay, the most 

 profitable results coming from two quantities of phosphoric acid on the 

 plats in Field C and three quantities from the plats in Field A. 



