24 BULLETIN 218, U. S. DEPARTMENT OF AGRICULTURE. 



The highest yields have followed summer tillage, peas and rye as 

 green manure, and disking potato and corn ground. 



Listing has given a little higher yields than plowing similar stubble. 

 Subsoiling is of doubtful advantage. Its average is slightly greater 

 than the average of similar stubble plowed either in the fall or in the 

 spring. There has been, however, no consistency in the results from 

 year to year. 



In spite of the combination of bad seasons, disked ground shows 

 an average profit of $2.07. With the exception of one plat cropped 

 to potatoes and one plat cropped to sorghum, the disked land was 

 previously in corn. Listing shows a nominal profit and spring plow- 

 ing a nominal loss. Both fall plowing and subsoiling show losses of 

 about $1.50 per acre. Summer tillage has the highest yield, but the 

 practice of this method has resulted in an average loss of $2.31 per 

 acre. Green manure, with a yield only slightly above the average 

 and with the highest cost of production, is debited with a loss of $7.64 

 per acre. 



SCOTTSBLUFF FIELD STATION. 



The work at Scottsbluff, Nebr., is conducted at a field station 

 located on the North Platte Irrigation Project. The soil is a com- 

 paratively light sandy loam. At a depth varying from 5 to 8 feet 

 there is a sharp break from sandy loam to either sand or Brule clay. 

 Above this point the soil offers no unusual resistance to the downward 

 passage of water or to the development of roots. Owing to its light 

 character, however, it is possible to store in it only a moderate supply 

 of available water. While the evidence on this point is not yet com- 

 plete, the proportion of water that can be stored in this soil is known 

 to be somewhere intermediate between the corresponding capacities 

 of the Belle Fourche and the North Platte soils. 



The results of three years are available from the Scottsbluff station. 

 In each of these years production was largely determined by the 

 supply of water available to the crop both from the rainfall and from 

 ■the water stored in the soil. Consequently, considerable differences 

 in production from differences in preparation were brought out. 



The highest yields each year have been produced on land summer 

 tilled the previous year. The average yield, 38.2 bushels per acre, 

 from this method is over twice that from fall-plowed land that had 

 raised a crop of small grain. 



The next highest yields have been those from the green-manured 

 plats. Between peas and rye for green manure the difference is small 

 and not consistent from year to year. 



Disked corn ground stands third in average yield of oats, but it 

 owes this position to a very high yield in one year only. 



Spring plowing has, on the whole, given better results than fall 

 plowing, although the one plat following oats on spring plowing has 



