SUBDUING THE LAND 135 



its growth the next spring, this food serving the 

 plant much as the stored-up food of the seed 

 nourishes the newly born plantlet. In the spring, after 

 the plant has drawn upon and used all the stored-up 

 food, and before it has had time to lay by a similar 

 supply for the next season, is the best time to kill it. 

 During this stage the leaves are very actively at work, 

 the new growth of roots and stems is succulent, and the 

 plant is in no condition to endure, after being cut in two 

 and turned with its top buried in the soil and its roots 

 exposed to the hot sun. The old portions of the plant 

 are in a weak condition, the new succulent parts have 

 not as yet become hardy and able to withstand rough 

 treatment, and under the influence of the moisture and 

 warm temperature of summer, and with conditions 

 favorable to the bacterial ferments, the sod will rapidly 

 soften and decay. Late in May or June, or early in 

 July, are the best times for breaking, in the middle North- 

 west, and earlier to the southward. The farmers of each 

 region soon learn the limits of time before and after 

 which the overturned prairie sods do not rot well. 



Prairie sods which are tough and strong, rot best if 

 cut only about 3 inches deep, or as shallow as the plow 

 can be made to " swim " and do perfect work. On 

 lighter lands where the grasses grow in bunches with- 

 out forming a continuous sod, or on prairie lands on 

 which the sod has been killed or much weakened by 

 close pasturing or by the tramping of stock, deeper 

 breaking may be done. 



Where heavy soils are broken early and shallow, they 

 may be " backset " in the autumn so as to secure a fine 

 seed bed. In backsetting tough sod, the plow is run in 

 the same direction as the breaker ran, and the furrow 

 is turned back and with it an inch or more of the sub- 

 soil. On lands upon which the sods are not tough, the 

 breaking plow or the stubble plow can be run across at 



