354 Bui^ivirrix 82 



SUMMARY AND CONCLUSIONS 



Plowing dry in midsummer is slow, expensive and very hard on 

 horseflesh, yet it is much more effective than plowing when the ground 

 is moist or at other seasons of the year. Costs of dry plowing in 

 summer with horses have run as high as seven dollars per acre in the 

 work described above and usually are not less than four and one- 

 half dollars per acre. Deep plowing in midsummer when the land 

 is very dry can best be accomplished by means of tractors. 



The quickest way to rid land of Johnson grass is to overgraze with 

 sheep, meanwhile irrigating frequently. The most effective way, as 

 well as the most economical, is the frequent cultivation of a late summer 

 crop, such as corn, followed by another crop demanding much tillage, 

 such as cotton. The exact crops to be chosen should depend upon the 

 market outlook and the probable price which can be realized. The 

 method demanding the least labor and outlay of cash is dry fallow in 

 summer followed by winter grains. This system may be very profitable 

 when grain prices are high. 



It is rarely feasible to attempt to rid a place of Johnson grass by 

 following one method alone ; but a combination of methods which prop- 

 erly distributes the labor, keeps up the fertility of the soil, and returns 

 a steady income, should be adopted. 



To control Johnson grass successfully provision must be made for 

 carrying on the desired operations as soon as the need is manifest. A 

 delay of one week may overcome the good effects of several weeks of 

 careful and consistent work. 



A method including dry fallow is reasonably effective and econom- 

 ical, but a heavy rain or an accidental leakage of irrigation water may 

 undo a great deal of work. 



If Johnson grass is to be eradicated by grazing with sheep more 

 animals must be pastured than the land will satisfactorily maintain, and 

 additional feed must be supplied since the effectiveness of this method 

 depends upon the grass being grazed as closely as possible. Further- 

 more, the growth of the Johnson grass must be encouraged in every 

 feasible way, particularly by supplying plenty of moisture, in order to 

 more quickly exhaust the stored up food in the rootstocks. 



When Johnson grass is to be killed by the tillage of ordinary farm 

 crops some provision must be made to take care of the seed which is 

 brought in by irrigating water during late summer. In the absence of 

 a suitable seed trap or screen, hand hoeing is usually necessary. John- 

 son grass does not form a rootstock until about the boot stage, which 

 is the time the head is appearing from its enclosing sheath. Prior to 



