SOIL SESSION. 



107 



The average annual unfertilized yield of corn has fallen oflf 3.8 

 bushels per acre for the second period as compared with the first ; that 

 of oats is 1.6 bushel greater during the second period; that of wheat 

 is I.I bushel smaller; that of clover is 20 pounds greater and that of 

 timothy is 178 pounds smaller. 



The unfertilized yields above given are the average for the en- 

 tire series of unfertilized plots. In comparing the efifect of the differ- 

 ent fertilizers, however, the yield of each fertilized plot is compared with 

 that of the two unfertilized plots between which it lies, not with the 

 general average. On this basis the land which has received acid phos- 

 phate only is found to have" produced the yields, in excess of those given 

 by the unfertilized land alongside, shown in table III. 



HI. -AVERAGE INCREASE PER ACRE FROM ACID PHOSPHATE. 



5 years— 1894-1898. 



7 years— 1899-1905. 



Corn 



Oats . . . 

 Wheat- 

 Clover... 

 Timothy 



3.96 bus. grain, 3 lbs. stover. 

 5.34 " " 83 " straw. 



3.14 " " 426 " 

 389 lbs. hay. 

 186 



(I I ( 



9.67 bus. grain, 304 lbs. stover. 

 10.44 " " 412 " straw, 

 10.25 " " 884 " 

 285 lbs. hay. 



67 " ' • 



If we value corn at 40 cents per bushel, oats at 30 cents, wheat at 

 80 cents, hay at 8. dollars per ton, corn stover at 3 dollars and straw at 

 2 dollars, the increase produced by a total application of 320 pounds of 

 acid phosphate, costing about $2.40, will have a total average value of 

 $8.44 per acre for each rotation during the first 5 years, and of $18.20 

 per acre during the 7-year period following, leaving a net gain, after 

 deducting the cost of the fertilizer, $6.04 per acre for the first period 

 and $15.82 per acre for the second. 



On that portion of the land fertilized with both acid phosphate and 

 muriate of potash the increase has been as shown in table IV. 



IV.-AVEUAGE INCREASE PER ACRE FROM ACID PHOSPHATE AND MURIATE OF 



POTASH. . - 



Corn 



Oats 



Wheat... 

 Clover . . 

 Timothy 



5 years— 1894-1898. 



7 years— 1899-1905. 



7.21 bus. grain, 285 lbs. stover. 

 6.87 " " 277 '• straw. 



5.22 •• " 465 " 

 806 lbs. hay. 



1,130 " 



15.80 bus. grain, 692 lbs. stover. 

 14.70 " " 623 " straw. 

 11.16 " " 896 " 

 526 lbs. hay. 

 441 " " 



