g CIRCULAR 491, U. S. DEPARTMENT OF AGRICULTURE 



Under ideal moisture conditions Sudan grass may be drilled in 

 late summer on fallow land. The objectives of this plan are to seed 

 the Sudan grass early enough to provide the required cover and late 

 enough not to exhaust the subsoil moisture provided by summer 

 tillage. This condition is extremely difficult to attain. Often the 

 late summer rains are not sufficient to promote prompt germination 

 and growth of the Sudan grass. Occasionally an early frost kills 

 it before growth is sufficient for the purpose intended. Furthermore, 

 a late frost may enable the fall-grown grass to continue growth and 

 leave the soil nearly as dry as if it had been sown in the spring. 



PKEPAEATION FOK FALL SEEDING 



The foregoing suggestions are based largely on the assumption 

 that the pasture grasses are to be sown in the spring. It is more 

 difficult to suggest methods of preparing weed-free seedbeds con- 

 taining noncompetitive stubble material for fall seedings. Stubble 

 fields of small grains are usually lacking in subsoil moisture and 

 usually become infested with weeds and volunteer growth which 

 offer detrimental competition to fall-sown grasses. Summer-fallowed 

 land is less apt to blow in late summer and early fall than in the 

 spring, but the danger of blowing is usually too great to risk this 

 method at any season of the year, although it has been successful 

 at Woodward when the land was listed at intervals of 7 feet to 

 control blowing. Seeding winter wheat or winter rye late in the 

 spring may offer some possibilities as a preparation for fall-sown 

 grasses. These preparatory crops, when sown after frosts in the 

 spring, usually grow in a rather dense, prostrate manner and die 

 before late summer, leaving a cover more conducive to the control 

 of wind erosion and the conservation of subsoil moisture than if 

 sown the previous fall. 



Surface tillage may be necessary to control weeds in advance of 

 seeding. This operation should be performed at shallow depths suf- 

 ficient to subdue the weeds but not to destroy the surface mulch of 

 stubble and other crop residue. 



METHODS OF SEEDING 



Preliminary results obtained at Hays, Kans., and Woodward, 

 Okla., indicate that grasses may be seeded without nurse crops more 

 successfully than with nurse crops of oats, barley, Sudan grass, or 

 rye. Alfalfa and sweetclover, except when sown under especially 

 favorable conditions, resulted in consistently poorer stands when 

 seeded with companion crops of oats and barley than when seeded 

 alone. Similar results were obtained in limited trials with grasses. 

 Four strips of thickly and thinly seeded oats were made across 70 

 strains of grass seeded alone and with mixtures of three other grasses 

 at Woodward in the spring of 1937. The season after seeding was 

 extremely dry until late in the summer. The oats made rapid early 

 growth but produced very little forage. In every instance the stands 

 of grass were consistently poorer among the oats than on adjacent 

 weed-infested areas, especially where the weeds were thin. 



Results of similar significance were obtained where blue grama 

 was broadcast alone and with Sudan grass planted in rows spaced 



