Farmers' Week in Agricultural College. 215 



the third period averaged 59.8 bushels — practically 60 bushels. You 

 see what a good rotation means. In the course of the 15 years we 

 applied under continuous culture 75 tons of manure, and only 48 tons 

 in the rotation, and yet in spite of that 75 tons our yields declined 20 

 per cent., whereas, with only a little more than one-half the amount 

 of manure under rotation our yields increased 47 per cent, in round 

 numbers. I have mentioned a five-year rotation. I do not mean that 

 that is necessarily the ideal rotation. We have secured better yields of 

 corn under a shorter rotation. For instance, under a three-year rotation 

 we have a 12-year average yield of 64I/2 bushels. I simply want to get 

 before you what I take to be a fact — that it pays to prpotice a good 

 rotation of crops. 



Now I think farmers pretty generally understand that rotation of 

 crops pays. They also understand that it pays to husband the manure 

 product of the farm and make intelligent use of it. Some of our Ohio 

 farmers, however, have been slow in learning that the element phos- 

 phorous or phosphoric acid can be used with profit in their farming. 

 The Ohio station has been conducting some experiments for this same 

 period — 17 years — in the use of phosphorous. We have used different 

 carriers but in the main we have used the treated roek phosphate, com- 

 monly called acid phosphate. Where we have used 320 pounds of acid 

 phosphate per acre in the five year rotation noted above, at a cost of 

 $2.40, we have secured a net return from this investment of $14.08. 

 Of course you want to know at what price we figured our increase of 

 crops to get this return. The figures may be a little high for you. We 

 figured our increase of corn at 40 cents a bushel, wheat at 80 cents, oats 

 at 30 cents, hay at $8, straw at $2, stover at $3. I expect that the price 

 of the stover will be a stumbling block here, but it is worth more than 

 that with us. Now, a farmer who can invest $2.40 and get a net return 

 of $14 would surely be satisfied. If you want to figure the per cent, of 

 profit on the investment it will be 586 per cent. That's a little better 

 than stock in "Standard Oil," isn't it? 



The figures that I have given you are for the use of acid phosphate 

 alone. We did not get as large corn yields as we want, however, with the 

 use of acid phosphate alone. Where we used 8 tons of manure per 

 acre once in the rotation and the same amount of acid phosphate with 

 it, we raised our corn yields considerably but the net profit per acre was 

 not quite as great — it was $10.66. We also used the untreated rock, 

 mixing it directly with manure. When we used 320 pounds of the 

 latter we got a little larger net profit — $11.78 ; but I want to sound this 

 word of caution in the use of untreated phosphate. One should use it in 



