OHIO FIELD EXPERIMENTS 447 



crop; and yet such use of plant food is the most common practice 

 in the Eastern and Southern states. 



In this connection the following quotation from Director Thorne 

 of the Ohio Station is of interest (Ohio Farmer, January 2, 1904) : 



"For seven years raw bone meal and steamed bone meal have been used in 

 comparison on the Strongsville test farm, side by side with four brands of 

 factory-mixedj acidulated, complete fertilizers, these brands representing some 

 of the most reputable manufacturers in the state, and ranging from 4 per cent 

 of ammonia, 10 per cent phosphoric acid and 4 per cent potash, to i per cent 

 ammonia, 6 per cent phosphoric acid, and i per cent potash. The fertilizers are 

 all applied at the rate of 200 pounds per acre to corn and wheat, grown in ro- 

 tation and followed by one year in clover. Following is the average increase ob- 

 tained from each crop: 



Increase per acre 



Hay 

 Lbs. 



675 



658 



458 

 350 



1300 



" At present, steamed bone meal furnishes available phosphorus in prob- 

 ably the cheapest and most effective form in which it can be bought." 



In Table 83 are recorded the average results secured from the 

 potatoes-wheat-clover rotation during the fifteen years, 1894 to 

 1908. 



It should be stated that plots 32, 33, and 34 were started one 

 year later for the potatoes and clover, and two years lat,er for the 

 wheat, than the other plots, and that assumed yields for those plots 

 for the one or two years are introduced (based upon the yields of 

 other plots subsequently producing about the same as these three), 

 in order that the comparison of the averages may be fair. This is 

 essential, because the yield of potatoes the first year and the yields 

 of wheat the first two years were markedly smaller than the average 

 of all subsequent years. 



The yield of wheat straw is shown because the data are available, 

 and they complete the record for all crops, and especially because 

 comparison is thus afforded of the yields of grain and straw. 

 As an average for good yields for each bushel of wheat there are 

 about 100 pounds of straw. 



The financial statement is based upon the following prices, 

 potatoes, 30 cents (and 50 cents) a bushel ; wheat, 70 cents ; clover 



