70 CULTIVATION METHODS AND ROTATIONS FOB GREAT PLAINS. 



amounted to $6.32 per acre. This was closely followed by North 

 Platte, Nebr., in 1909, and Dickinson, N. Dak., in 1908, where it 

 amounted to $5.24 and $5.17, respectively. Highmore and Belle- 

 fourche, S. Dak., are the only stations showing markedly better 

 results from the corn-oats- wheat sequence. The effects of the 

 sequence seem to be less marked where the corn stubble is disked and 

 the other plats fall plowed than where all plats are spring plowed. 

 (See Tables XXIX and XXX.) 



(14) Wherever a perennial meadow grass, like brome-grass (Bro- . 

 mus inermis), can be profitably grown it should enter into the 

 rotation, which should be not less than five years in duration. The 

 following has given good results: Corn; wheat, winter or spring; 

 brome-grass, two or three years; oats, barley, emmer, or wheat (win- 

 ter or spring). 



Flax may be sown on the brome-grass sod as a catch crop after the 

 hay crop has been harvested. Where this practice is adopted it will 

 of course be impracticable to follow the flax with fall-sown grain, 

 but spring-sown grain can be substituted. 



(15) Where it is impracticable to secure a catch of brome-grass 

 or other meadow grass sown with the wheat crop, the grass should 

 be sown separately on carefully prepared ground in May or June. 

 This will require a rotation of at least six years' duration. There 

 will be one year (the year of seeding to grass) during which one field 

 will yield no crop return, but if flax is grown on the meadow sod 

 after the hay has been cut two crops will be obtained from this field 

 in one year. In this way as many crops will be grown as there are 

 fields in the rotation system. 



(16) Wherever alfalfa can be profitably grown it may be substi- 

 tuted in whole or in part for the brome-grass without interfering 

 with the general plan of the rotation. 



(17) Wherever clover can be profitably grown it can be sown with 

 the brome-grass without changing the general plan of the rotation; 

 or it can be sown separately, either with the wheat in a 4-year rota- 

 tion or without a nurse crop in a 5-year rotation. 



(18) Where neither perennial grasses nor perennial legumes or 

 clovers can be profitably raised, rye, peas, or sweet clover should be 

 raised every fourth year and plowed under for green manure. Rye 

 has so far given better average results than peas, sweet clover, or 

 summer tillage. This seeming superiority may be due to the fact 

 that the quantity of organic matter is greater in the rye and that it 

 can be turned under earlier in the season, thus allowing the rains of 

 June and July to be conserved in the soil instead of being consumed 

 in the growth of the green-manure crop. It seems quite probable 

 that the greater quantity of nitrogen gathered and restored to the 



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