30 BULLETIN 222, U. S. DEPARTMENT OP AGRICULTURE. 



has been exceeded by both, but the differences among the three 

 are only fractions of a bushel. At Amarillo disked corn land 

 has been between fall-plowed and spring-plowed stubble in yield 

 Its low cost of production has made it the most profitable method 

 under trial at all stations except Hettinger. It has been productive 

 of a profit at all stations except Garden City, Dalhart, and Amarillo. 

 This study, dealing with but one crop, does not consider the relative 

 profitableness of other crops in the farming system. 



It should be borne in mind that at all stations disking corn ground 

 as a preparation for all small grain crops has been done upon corn 

 land kept free from weeds. If weeds were allowed to develop in the 

 corn, similar results should not be expected. To the extent that 

 the weeds developed or were unhindered in their growth, just so far 

 would the corn ground approach a grain stubble in the condition of 

 the seed bed. If the weeds matured seed, further damage by their 

 growth might be done to the succeeding crop. 



Preparing the ground with a lister instead of a plow has been 

 practiced at eight stations. At only one station, Judith Basin, were 

 the yields very materially different from those on fall-plowed land. 

 But, as has been pointed out, the yields on fall-plowed land at that 

 station were lowered somewhat by damage done by gophers. At 

 the other stations, though it did nOt in all cases give higher yields 

 than plowing, it showed, owing to a lower cost of preparation, slightly 

 more profit where profits are shown and less loss where losses are 

 shown than plowing. 



The difference between spring and fall plowing is largely one of 

 season. In the average of the 13 stations at which both were under 

 trial there is practically no difference. At only three stations is 

 there a difference of over 2 bushels per acre. At the four more 

 southern stations the advantage has been with fall plowing. This 

 is the only consistent territorial difference to be noted in the com- 

 parison of these two methods, but production at these four stations 

 and at Belle Fourche has resulted in a loss by both methods. Spring 

 plowing shows a profit at all other stations, and fall plowing shows 

 a profit at all others except Scottsbluff. 



Subsoiling in preparation for the barley crop has been practiced at 

 seven stations. At only two of these has the consequent yield de- 

 parted far from that on fall-plowed land. At the Judith Basin 

 station there has been a marked gain and at Akron a marked de- 

 crease. In the average of the seven stations the yield from this 

 method has been only 0.4 of a bushel more than from fall plowing. 

 The cost of the method has been such that it has paid a profit at only 

 the Judith Basin station. 



The highest average yields at eleven of the fourteen stations have 

 been by summer tillage. At the Judith Basin station subsoiled land 



