702 



IOWA DEPARTMENT OF AGRICULTURE 



year period the land will be in legumes for 7 years, in corn 6 years and in 

 oats, the least profitable crop, for but 3 years. 



Using rotation number 4 the land will be in alfalfa one-fourth of the 

 time. The distribution of crops on the various fields as illustrated in 

 table XXII. 



TABLE XXII. 



Showing the distribution of crops to various fields in a 16 year rotation of corn, corn, 

 oats; 12 years, then alfalfa 4 years. 



For each one hundred acres devoted to this rotation there would be 

 each year 50 acres of corn, 25 acres of oats and 25 acres of alfalfa. Reports 

 from practical farmers as recorded elsewhere in this bulletin indicate 

 that even a much larger acreage than this can be properly taken care of 

 on an average farm. 



With this rotation it will be observed that any particular field, as 

 A or D, for example, will be in corn and small grain continuously for 

 12 years, after which it will be in alfalfa for 4 years. A short rotation of 

 corn, corn, and oats will be repeated 4 times in the 12 years. With this 

 rotation a legume is grown one-fourth of the time, which is exactly the 

 same condition that is found in the more common rotations of corn, corn, 

 oats and clover. This rotation has an advantage over the common rotation 

 of corn, corn, oats, clover, in which a seeding of clover has to be made 

 every year, in that the alfalfa will not be plowed up until after the new 

 stand of alfalfa is assured. The fact that clover is a biennial makes 

 necessary the plowing of this land after one season's cutting and as ap- 

 proximately 50 per cent of the clover seedings in the state fail on the 

 average, the rotation is continually being disarranged. 



The rotations mentioned may be modified in any way to suit local con- 

 ditions. In some parts of the state the introduction of winter wheat may be 

 very desirable; while potatoes may also enter into the rotation very ac- 

 ceptably. A rotation of corn, oats, clover, wheat or corn, corn, oats and 

 clover might be used to advantage. As suggested this latter rotation for 

 12 years followed by four years of alfalfa would certainly be very desir- 

 able from the soil fertility standpoint, and we believe would prove very 

 profitable and practical by materially increasing the yield of other money 

 crops. 



