ANSWERS OBTAINED. 



9 



wheat will give better average results than any other system so far tried. There are, 

 however, undoubtedly many localities where the growing of perennial grasses is so 

 uncertain as to make the adoption of this rotation inadvisable. It is possible that it 

 may be found practicable to substitute alfalfa for brome-grass in some localities. 

 Some other perennial grass or legume may be found that will prove adapted to the 

 conditions in some parts of the Great Plains. In some localities it may be found 

 practicable to shorten the rotation to four years and substitute red clover for the 

 brome-grass. (See paragraphs 14, 15, and 16 of Conclusions, p. 70.) 



(10) Where perennial grass or legumes can not be successfully grown, it will 

 undoubtedly be found profitable to resort to green manuring. Winter rye has so far 

 given the best results. Canada field peas and common sweet clover (Melilotus alba) 

 have also given good results, but the fact that they do not reach a sufficient stage of 

 growth to plow under before the end of the June rains is against them. On the other 

 hand, being nitrogen gatherers they will undoubtedly produce a higher quality of 

 organic matter in the soil than rye, although the quantity may be less. (See paragraph 

 18 of Conclusions, p. 70.) 



(11) Winter wheat should be grown to a greater or less extent wherever it is found 

 possible to do so, as it possesses some great advantages over spring wheat. It can be 

 fitted into any rotation adapted to the Great Plains. In some localities it may prove 

 profitable to summer till the land as a preparation for winter wheat, as it undoubtedly 

 responds to this preparation to a much greater extent than do spring-sown grains. 

 Green manuring may, however, be used instead of summer tillage. (See paragraph 

 10 of Conclusions, p. 69.) 



As will be seen from the foregoing answers, our investigations lead 

 strongly to the conclusion that the devising of systems of rotation 

 adapted to local conditions is of greater importance than tillage 

 methods. It is not to be inferred, however, that the subject of proper 

 tillage can be safely neglected. Such is far from being the case. 

 Tillage methods must be carefully studied and intelligently practiced. 

 But both the study and the practice must be carried on in connec- 

 tion with crop rotation and with a view to bringing about the best 

 possible physical and biological condition of the soil. In order to 

 do this intelligently, the requirements of the crops to be grown, the 

 local peculiarities of the soil, and the climate must be the main 

 factors considered. No hard and fast rules can be established. Each 

 farmer must study his soil, his climate, and his crop requirements, 

 and must adopt such systems of tillage as experience and observation 

 have shown to bring the desired results under the peculiar combina- 

 tions of conditions which prevail at the time and place and are most 

 likely to exist during the growing period of the crop. Nor should 

 the ultimate effect upon the soil of any system of tillage be neglected. 

 Favorable physical, chemical, and biological conditions of the soil 

 should at least be maintained and, if possible, improved from year 

 to year. 



The establishment of a system of crop rotations presents many 

 difficulties, particularly in a new country. Among these difficulties 

 is the need of immediate cash returns from the crops grown. Wheat 

 is not only the most staple cash crop, but on the basis of the prices 



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