RANGE IMPROVEMENT BY DEFERRED GRAZING. 15 



SUMMARY. 



REQUIREMENTS OF PLANT GROWTH. 



1. The vigor of the vegetation determines the promptness with 

 which growth starts in the spring. 



2. Prompt spring growth and luxuriant herbage are necessary for 

 early and prolific production of flower stalks and for the develop- 

 ment of a large and fertile seed crop. 



3. Eepeated removal of the herbage during the growing period 

 weakens the plant and delays the resumption of growth the next 

 spring, retards the time of flower-stalk production, reduces the num- 

 ber of stalks produced, retards the time of seed maturity, and results 

 either in nonfertile or very few fertile seeds. 



4. Removal of the herbage after seed maturity in no way interferes 

 with plant growth, while seed production and viability are the same 

 as when the herbage is undisturbed year after year. 



5. Germination of the seed and establishment of seedlings very 

 largely depend upon the thoroughness with which the seed crop is 

 planted. Artificial stirring of the soil after the seed is dropped is 

 necessary to the permanent establishment of practically all seedling 

 plants. 



6. Even when a fertile seed crop is well planted, there is a heavy 

 loss in seedlings from freezing and drought during the first year. 

 After this, however, there is no loss from this cause. 



THE MAINTENANCE OF A MAXIMUM FORAGE CROP. 



YEARLONG GRAZING. 



1. Continued removal of the herbage year after year seriously in- 

 terferes with the growth and seed production of the forage plants. 



2. The vegetation is soon weakened, and in the absence of repro- 

 duction the range steadily loses its carrying capacity and finally 

 becomes depleted. 



YEARLONG PROTECTION. 



1. Yearlong protection is favorable to the growth of the vegeta- 

 tion, and under it weakened plants readily recuperate. 



2. Practically no reproduction from seed is obtained, however, re- 

 gardless of whether or not a fertile seed crop is produced, because the 

 seed is not planted. Only the species whose seeds are provided with 

 barbs or awns revegetate under yearlong protection. 



3. Economical yearlong protection is not practicable, since the for- 

 age crop is lost during the long revegetation period. In addition, 

 the accumulation of inflammable material increases the fire danger. 



