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



Spring plowing has averaged a little better than fall plowing, irre- 

 spective of the kind of stubble plowed. The relative merits of the 

 two vary from year to year, depending upon the season and the 

 condition of the ground at plowing time. Generally, when the 

 ground is wet at the time of fall plowing, the better results are ob- 

 tained from it. On the other hand, if fall plowing is done when the 

 ground is dry, it has not been as good as spring plowing. 



When the cost of production is considered, as in the second part of 

 Table VIII, it is seen that the high cost of green manure has caused 

 the growth of oats by this method to be done at a loss of $1.16 per 

 acre. The high yields and low cost of preparation of disked corn 

 ground have combined to make it show the largest profit of any 

 method, $9.75 per acre. Intermediate between these are spring 

 plowing with $5.23, fall plowing with $4.01, and summer tillage with 

 $3.72 profit per acre, respectively. 



EDGELEY FIELD STATION. 



The field station at Edgeley, N. Dak., is located on a soil that is 

 derived from the decomposition of shale, which in undecomposed 

 particles is found very near the surface. In the third foot the shale, 

 while broken and offering fairly free passage to water, is not as yet 

 broken down into soil. The depth of feeding of crops is practically 

 limited to the first 2 feet. The first foot carries an unduly large sup- 

 ply of water available to the crop. The limited depth of soil that 

 functions in the storage of water and in the development of the crop, 

 however, limits the quantity of available water that can be carried 

 in the soil to about half that carried by soils of greater depth. This 

 makes the crop practically dependent upon rains that fall while it 

 is growing. 



Edgeley offers for study of oat production an unbroken record of 

 eight years. Five of the eight years have been productive of heavy 

 crops from practically all methods, while three have been years of 

 light production from practically all methods. 



The range of yields from different methods of preparation and 

 cropping as exhibited in the average of the eight years is compara- 

 tively small. This is as might be expected from the soil on which 

 the station is located. Its shallowness makes the crop much more 

 dependent upon the seasonal precipitation than it is in deeper soils. 

 It is, consequently, impossible to realize much benefit from methods 

 of cultivation calculated to store water in the lower zone of normal 

 crop-feeding depth. 



Oats on land which was summer tilled the previous year have 

 produced an average yield of 38.3 bushels per acre, but this is only 

 4.8 bushels more than the average on disked corn ground and 6.4 

 bushels more than the average of all crops following small grain. 



