CROP ROTATION COMPARED WITH CONTINUOUS CROPPING. 



23 



We have seven crops of corn, grown as follows: 



No. 1. Corn after oats— fall plowing. No. 6. Corn after oats— fall plowing. 



No. 2. Corn after oats— spring plowing. No. 7. Corn after barley— spring plowing. 



No. 3. Corn after oats— fall plowing. No. 9. Corn after wheat— spring plowing. 

 No. 4. Corn after wheat — fall plowing. 



Oats enter into each of the nine rotations, and have been grown as 

 follows : 



No. 1. Oats after wheat— fall plowing. No. 6. Oats after barley— fall plowing. 



No. 2. Oats after wheat — spring plowing. No. 7. Oats after corn — spring plowing. 



No. 3. Oats after wheat — fall plowing. No. 8. Oats after summer fallow. 



No. 4. Oats after corn — stubbled in. No. 9. Oats after corn — spring plowing. 

 No. 5. Oats after wheat — fall plowing. 



Barley enters into but two of the rotations, as follows: 



No. 6. Barley after corn — stubbled in. | No. 7. Barley after oats — spring plowing. 



An inspection of this tabular arrangement of the crops will at once 

 show that there are a very large number of questions concerning soil 

 preparation and crop sequence that may be definitely answered by 

 this series of experiments, not from the result of a single instance but 

 by a system of cross-checking from the results of several crops grown 

 every year under different systems of soil preparation and crop 

 sequence. 



EXPLANATORY NOTES. 



The purposes of this series of rotations are to test the effect of crop 

 sequence and time of plowing. 



Good farming is practiced upon all the plats. No special methods 

 of moisture conservation are contemplated in this experiment. Plow- 

 ing is to a depth of 8 inches and is uniform for all plats. 



Fall plowing is done as early in the season as practicable. Whether 

 the land is disked or harrowed or left undisturbed after fall plowing 

 is left to the judgment of the man immediately in charge. Whatever 

 practice in this respect is adopted for one of these rotations is followed 

 for all in this series. The same general rule is applied to plowing 

 and the fitting of the seed bed in the spring. Such an amount of work 

 is done upon the land as will put it in good tilth. 



In spring plowing for corn the rule has been to have the plowing 

 deferred until corn-planting time, and for the planter to follow as 

 closely after the plowing as possible and the harrow immediately 

 after the planter. In some instances it has seemed desirable to disk 

 or harrow the ground before spring plowing for corn. This is left 

 to the judgment of the man in charge. 



The summer-tilled plats in this series have been treated like the 

 summer-tilled plats in the moisture-conservation series discussed in 

 the previous pages. 



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