FIELD CEOPS. 35 



Coi'n experiments, C. G. Williams and F. A. Welton (Ohio Sta. Bui. 282 

 {1915), pp. 11-109, figs. 8). — This bulletin gives results of experiments with 

 corn that have been running for various lengths of time, in some cases covering 

 over 20 years. Data are presented in 36 tables. 



" Comparing a 5-year rotation system with the continuous growing of corn, 

 the former has given an increase of 13 to 14.79 bu. per acre, in spite of the 

 heavier use of manure and fertilizers under continuous culture. Comparing a 

 5-year with a 3-year rotation, the latter has given an increase of 6 to 8.39 bu. 

 per acre. Comparing a 3-year rotation with continuous cropping, no fertilizers 

 used in either case, the yield of corn from the former is 127 per cent greater 

 than the latter. 



" The use of phosphorus, alone, in the form of acid phosphate, has increased 

 the yield of corn 8.28 bu. i^er acre. The use of manure alone has increased the 

 yield 31.27 bu. per acre as an 8-year average. The use of acid phosiihate and 

 manure has increased the yield 40.58 bu., thus leaving 9.31 bu. to be credited 

 to the acid phosphate. 



" On such acid soils as are found on the station farm at Wooster, 1 ton of 

 burned lime or 2 tons of ground limestone, applied once in 5 years, has in- 

 creased the yield of corn on an average 7.35 bu. per acre on the fertilized plats, 

 and 8.25 bu. per acre on the unfertilized plats. Taking into consideration all 

 the crops of the rotation the application of lime has been worth, on the average, 

 $14.21 per acre per rotation. The cost of the lime has been $5. 



" Comparing very deep plowing with ordinary plowing and with subsoiling, 

 the 5-year average gain for subsoiling has been 2.32 bu. i)er acre, and for the 

 deep plowing 0.43 bu. jier acre. 



" Plantings of corn made at Wooster from May 4 to 10 have given larger 

 yields of shelled corn per acre than the plantings of other dates, though the 

 moisture content and the shrinkage have been lower from the plantings made 

 from April 24 to 29. Of the plantings of the latter dates, 78.62 lbs. of ears as 

 weighed in November have been required to equal a bushel of shelled corn in 

 April, while of the plantings of June 2 to 6, 91.95 lbs. of ears have been re- 

 quired. The variety of corn and all the conditions of growth except date of 

 planting have been the same. 



" Where the distance between rows and the number of plants per acre have 

 been the same, one plant every 12 in. has outyielded 3 plants every 36 in. by 

 4.55 bu. per acre. With hills 42 in. apart each way, the maximum yield of 

 shelled com, as a 10-year average, has been secured from 4 plants per hill, or 

 14,220 plants per acre. 



"Nine years' tests of deep (4 in.) as compared with shallow cultivation 

 (1^ in.) show an average gain of 4 bu. per acre in favor of shallow cultivation. 

 Two years' tests of late cultivations of corn with a one-horse cultivator, after 

 two-horse implements had to be discarded, show an average gain of 3.44 bu. 

 per acre for late cultivation. 



"A 10-year average variation of 6.25 bu. per acre has been found in varieties 

 of corn well acclimated to the locality where tested. A variation in yield of 

 84.29 bu. per acre has been found in varieties grown and sold for seed within 

 the State. 



"A comparison of ears varying 2.44 in. in length, on the average, shows a 

 difference in yield of only 1.39 bu. per acre, as a 10-year average — a difference 

 no greater than might have been exi^ected had the seed used been identical. 

 While there is a slight decrease in length of ear in the short-eared strain, it 

 has not materially affected the yield. As a 9-year average, tapering ears have 

 excelled cylindrical ears in yield by 1.65 bu, per acre. 



