18 MISCELLANEOUS PUBLICATION 9 52, U.S. DEPT. OF AGRICULTURE 



Summary 



Green-manure fallow reduced the 

 yields of all small-grain crops below 

 those for ordinary fallow at Havre 

 and Huntley. At Moccasin, green- 

 manure fallow depressed the yield 

 of spring wheat but slightly in- 

 creased the yield of winter wheat. 

 The yield increase of winter wheat 

 was not enough to pay for the extra 

 cost of the green-manure crop. 

 Green-manure crops did not mate- 

 rially affect the nitrogen or carbon 

 content of the soil. 



Eight years of crested wheat- 

 grass in a 12-year rotation increased 

 spring wheat and oats yields to 

 some extent at Havre. Low hay 

 and flax yields more than offset 

 the wheat and oat yield increases. 



Wyoming 

 Yields 



Green-manure experiments were 

 started at Archer, Wyo., in 1913 

 (10, 61) and Sheridan, Wyo., in 

 1917. 5 Yields of several crops after 

 green-manure fallow, continuous 

 cropping, and ordinary fallow are 

 presented in table 11. 



In 1925, Towle (79) reported on 

 the work of the Sheridan Field 

 Station. Annual precipitation aver- 

 aged 15.1 inches. He discussed two 

 sod-crop rotations, one with alfalfa 

 and one with bromegrass. Both 

 were 6-year rotations with the sod 

 occupying the land half the time. 

 Yields of the other crops in these 

 two rotations did not differ from 

 those in other rotations that did 

 not include alfalfa or bromegrass. 



In 1931, Chilcott (10) found that 

 spring wheat on pea green-manure 

 fallow yielded the same as ordinary 

 fallow while rye green-manure fal- 

 low yielded less. Oats on pea green- 

 manure fallow outyielded ordinary 

 fallow by 2 bushels per acre. 



5 Barnes, O. K. effect of green 



MANURE AND BARNYARD MANURE ON 



soils and crops. Wyo. Agr. Expt. Sta. 

 [Unpublished Res. Rpt.] 1954. 



Nelson (61) reported yields of 

 winter wheat for the Archer station 

 for 1914-47. Annual precipitation 

 averaged 15.8 inches. Rye and 

 peas for green-manure fallow pro- 

 duced essentially the same yields as 

 ordinary fallow (table 11). 



At Sheridan, Barnes 5 found that 

 winter wheat on sweetclover green- 

 manure fallow and oats on rye 

 green-manure fallow produced es- 

 sentially the same yields as on 

 ordinary fallow (table 11). Wheat 

 yields on rye and pea green-manure 

 fallows were reduced. 



Summary 



Green-manure fallow decreased 

 or had no effect on yields of oats and 

 winter wheat at Sheridan and on 

 those of winter wheat and spring 

 wheat at Archer. 



Alfalfa and bromegrass, in a 6- 

 year rotation at Sheridan, did not 

 increase yields of other crops in 

 the rotation. 



Nebraska 



Yields 



Green-manure experiments were 

 initiated at North Platte, Nebr., 

 in 1907 and Scottsbluff, Nebr., in 

 1912 (85, 86). Yields of several 

 crops after green-manure fallow, 

 continuous cropping, ordinary fal- 

 low, alfalfa, and bromegrass are 

 presented (table 12). 



In 1923, Zook (85) summarized 

 the initial 10 years of data from 

 dryland crop rotations at Scotts- 

 bluff. Annual precipitation aver- 

 aged 14.0 inches. Pea and rye 

 green-manure fallows depressed 

 yields below those of ordinary 

 fallow (table 12). The author con- 

 cluded that there was no justifica- 

 tion for green manuring in the 

 Scottsbluff area. Green manuring 

 depressed yields and increased the 

 cost of seedbed preparation. 







