Proceedings of Seventeenth Normal Institute 107 



when not exceedingly sliallo.w, prunes off many roots and makes 

 quite a portion of the soil unavailable to the plant as a feeding 

 ground. 



Thorough preparation of the seed bed, on brown silt loam, gave 

 an increase of 14:1^2 bushels to the acre over no seed bed, and 

 on gray silt on tight clay, 211/2 bushels; killing weeds gave in- 

 creases of 38.6 bushels and 21 bushels, respectively, on the two 

 soils. 



Subsoiling and deep tilling tests did not indicate sufficient ad- 

 vantage from these processes to justify their use; and in some 

 cases they appeared to be detrimental to the corn. 



Corn experimeyits. (Ohio, 282.) During the past five years 

 many experiments in corn cultivation have been made by the 

 Ohio Station, and these, with much previous work, are summarized 

 in this bulletin to make practically a manual of corn culture. 



A five-vear rotation has been found much better than continuous 

 cropping with corn, and a three-year rotation better than the five- 

 year. The use of manure alone has given much larger yields 

 than the use of acid phosphate alone, and the use of the two to- 

 gether larger increases than the sum of the gains from the two 

 separately. Liming has increased the yield of corn considerably, 

 most on unfertilized plats, and has produced gains through the 

 rotation worth nearly three times the cost of the lime. Some gain 

 has resulted from deep plowing, but more from subsoiling, though 

 not enough to make either operation very profitable. 



In distance experiments one plant every foot in the row has 

 given better results than three plants in hills one yard apart, but 

 the maximum yields have been secured from four plants in hills 

 three and one-half feet apart each way. 



Shallow cultivation has been superior to deep cultivation, and 

 late working with one horse cultivators has given profitable in- 

 creases in yield. Difference in ear length of seed corn has not 

 materially affected the yield ; seed from tapering ears has pro- 

 duced more than that from cylindrical ears, and ears with filled 

 tips have been slightly better as sources of seed than those with 

 bare tips. Little difference has been shown in results from butt, 

 middle or tip kernels, and from ears with 14, 16 or 18 rows of 

 kernels. 



