USE OF PHOSPHORUS IN DIFFERENT FORMS 251 



is given for each series, counting 35 cents a bushel for corn, 70 

 cents for wheat, and $6.00 a ton for hay. These prices 1 are based 

 upon the ten-year average farm price for Illinois as reported by the 

 United States Department of Agriculture for the years 1899 to 

 1908, for which the reported averages are 40.1 cents a bushel for 

 corn, 76.5 cents for wheat, and $9.32 a ton for marketable hay. 

 The differences between these averages and the prices used in the 

 tables will probably cover the cost of husking corn and threshing 

 wheat, stacking and baling the hay, and marketing the increase. 

 The value of the increase in corn stover and wheat straw may per- 

 haps cover the extra cost of handling (binding twine, etc.) and 

 occasional losses for poor quality of grain and hay. The prices 

 used are intended to be sufficiently conservative to guard against 

 financial exaggeration. Other prices should be used to suit local 

 conditions. 



The special purpose of reducing all results to the basis of value 

 is to make possible a more simple comparison. From these total 

 values of the three crops by plots, the gain for treatment is computed 

 by the Ohio method, except that in Series C the results from plot i 

 are discarded 2 as being plainly abnormal and untrustworthy. 

 A comparison of the value of crops grown on plots A2, A3, and A5, 

 on plots B2, 63, and 65, and on plots C2, 3, and 5, plainly 

 indicates that plot C2 is normal; and the effect of manure and 

 phosphorus on plots C2 and 03 is determined by subtracting the 

 average results of plots C4 and 07. 



It. will be noted that the cost of raw phosphate is reckoned at 

 $7.50 per ton and the cost of acid phosphate at $15 per ton, or 

 $1.20 for 320 pounds of raw phosphate and $2.40 for 320 pounds 

 of acid phosphate, applied with the 8 tons of manure every three 

 years. 



Three important facts are clearly established by these data: 

 (i) the value of manure, (2) the superiority of stall manure over 



1 Elsewhere the author uses 30 cents a bushel for oats, the lo-year average price 

 for Illinois being 32.2 cents; 40 cents a bushel for barley, 44.7 cents being the 

 lo-year average price for Minnesota and Wisconsin, leading barley states; and 50 

 cents a bushel for potatoes, the New York ro-year average farm price being 57.6 

 cents. 



2 A personal communication from Director Thorne states that this plot occupies 

 a depression, running lengthwise of the plot, with higher land on each side. Evi- 



