136 EXPERIMENT STATION RECORD. [Vol. 41 



experimental soil and it is regarded as doubtful whether they would ever be 

 limed sufficiently to maintain them in a neutral condition. 



[Crop rotations for northeastern Ohio], C. W. Montgomery {Mo. Bui. Ohio 

 Sta., 4 (1919), No. 4, pp. 117-120, fig. i).— Results secured on the Northeastern 

 Test Farm, Cuyahoga County, with 3- and 5-year rotations for the period of 

 1915 to 1918, inclusive, together with a study of crop costs and net receipts 

 per acre in the 5-year rotation for 1917 and 1918, have led to the conclusion 

 that under present conditions a rotation of corn, oats, wheat, and clover would 

 be most profitable in a majority of cases for this section of the State. It is 

 suggested that the fertilizer treatment comprise an application of 6 tons of phos- 

 phated manure on the corn, 160 lbs. of acid phosphate on the wheat with 

 4 tons of phosphated manure as a top-dressing, and 2 tons of ground limestone 

 applied before either the com or the wheat. A mixture of 5 lbs. of red clover 

 and 3 lbs. each of alsike clover and alfalfa is recommended for seeding with 

 the wheat. 



[Report of field crops work at the Delaware Experiment Station, 1918], 

 A. E, Gkantham {Delaware Sta. Bui. 122 {1918), pp. 10-20.)— Thi^ describes 

 the progress of soil and crop investigations in continuation of similar work 

 previously noted (B. S. R., 39, p. 127). 



Observations on the effect of commercial fertilizers, green manure, and 

 stable manure used with and without lime in a rotation of corn, soy beans, 

 wheat, and clover showed marked results from liming, the hay yield being in- 

 creased nearly 40 per cent and the corn yields from 6 to 8 bu. per acre over 

 the untreated or unlimed areas. Wheat did not respond readily to liming, 

 while soy beans made a more vigorous growth of vines where lime was applied. 

 Liming also appeared to hasten the maturity of corn. Little effect from the 

 use of lime was noted on wheat and corn grown continuously. 



With regard to the application of single plant food elements, phosphorus 

 exerted a marked effect on wheat during the earlier years of the experiment, 

 while later potash appeared to be more important. Wheat receiving phos- 

 phorus ripened from 3 to 5 days earlier than when it was omitted. Phosphorus 

 and potassium in combination gave the greatest net profit per acre. Com- 

 mercial nitrogen applied in conjunction wath phosphorus and potassium failed 

 to show any consistent profit with either wheat or corn. Potassium proved to 

 be the most important element for both corn and soy beans. The number of 

 nodules on the roots of the soy beans was found to be considerably greater 

 where potash was used than with any other fertilizer treatment. Potash also 

 effected the fullest development of the ear and grain in corn. 



A number of crop rotation experiments were begun in 1910 to study the value 

 of green manures for maintaining crop yields. The principal crops in the 

 rotations were corn, wheat, potatoes, red clover, timothy, winter oats, and soy 

 beans, while the green manure crops included crimson clover, red clover, vetch, 

 rye, and cowpeas. Except on the potato crop only green manure and mineral 

 fertilizers other than nitrogen were used. The results secured indicate that 

 red clover requires considerable potash for the best results. Corn produced 

 much better in rotation with red clover than in rotation with soy beans and 

 timothy, the difference amounting to as much as 25 bu. per acre. Soy beans 

 were found to exhaust the soil to a marked extent. Wheat after soy beans 

 gave good results, but the best wheat yields were secured after potatoes. The 

 corn yields obtained in a rotation of corn, wheat, and alfalfa two years were 

 larger than where 700 lbs. of commercial fertilizer was used in a rotation of 

 corn, soy beans, wheat, and red clover, while the wheat yields averaged about 

 SO bu. per acre. 



