78 CAMBPELL/S SOIL CULTURE MANUAL 



From this kind of fitting as stated for each particular 

 field the following results were obtained. From a seven 

 years' rotation, wheat after corn, the average yield of 

 wheat was 15.9 bushels. In the rotation of wheat with 

 summer fallow, same number of years, the average yield 

 of the wheat was 15.8. In these rotations two sets of 

 plats were used so that there was a crop of wheat to har- 

 vest each year, making a fair and apparently honest com- 

 parison not only with the results between rotating with 

 summer fallow or with corn, but of these yields against 

 wheat continuously. 



Seven consecutive crops of wheat on same field showed 

 an average of 13.7 bushels. We wish to call attention 

 to the fact that the rotation with corn or summer fallow 

 only gave a gain of slightly more than two bushels per 

 acre, 



REAL SUMMER CULTURE. 



We would also call attention to the manner of summer 

 fallow, and as a comparison, note carefully our instruc- 

 tions under the heading of summer culture. 



Compare the above results as taken from Bulletin No. 

 98, South Dakota Agricultural College, with the Pomeroy 

 Model Farm at Hill City, Kansas, where the results after 

 our plan of summer culture in four consecutive years, 

 1901 to 1904 inclusive, the average was over forty bushels 

 per acre, while wheat in the same locality, grown under 

 the ordinary methods of tillage averaged less than ten 

 bushels. It will be noticed that the above four years 

 included the very unfavorable seasons of 1901 and 1904, 

 in which a large per cent of the wheat in that locality was 

 a total failure. At Holdrege, Nebraska, which is 200 

 miles west of Omaha, the lowest yield of wheat rotated 



