GRASS CULTURE AND RANGE IMPROVEMENT 7 



tate the penetration of moisture. The Sudan grass may not germi- 

 nate quite so completely or so uniformly as on smooth land, but 

 should emerge sufficiently to provide satisfactory protection for 

 grasses sown the following year. This method may be modified and 

 further improved by sowing the Sudan grass or sorghum in strips, 

 leaving a lister furrow unseeded and undisturbed between drill 

 widths. The entire area may then be sown with grasses the follow- 

 ing year. On heavy soils, buffalo grass sods may be placed at inter- 

 vals in the furrows. The result would be a deep furrow with a series 

 of smaller intervening furrows, which would control run-off and 

 erosion under ordinary conditions. 



Where the land is level or very sandy and not inclined to lose 

 water readily by run-off, the blank listing operation may be dis- 

 pensed with and a series of smaller furrows obtained at less expense 

 by seeding the Sudan grass in 14- to 20-inch drill rows with one of 

 the new furrow-type grain drills. This operation, as well as the 

 blank listing just before drilling the Sudan grass, may require one 

 or more light cultivations in advance to control weeds and store 

 moisture. Planting the preparatory crop in wide-spaced lister rows 

 is not advisable, because the resultant stubble is seldom sufficient to 

 control soil blowing and retard surface evaporation while the grass 

 seedlings are becoming established the following spring. 



It appears essential to cut the Sudan grass or sorghum crop so as 

 to leave stubble about 8 to 12 inches high. If this is done before the 

 crop has approached maturity, the aftermath usually produces more 

 vigorous basal growth. This adds to the wind-resisting and evapo- 

 ration-reducing qualities of the surface residue the following spring. 

 In this region practically every rain is followed by high winds, 

 which often dry the surface soil before the shallow-seeded grasses 

 have time to emerge and become well established. High, dense 

 stubble helps to keep the surface soil moist a day or two longer than 

 on bare fallow land. This delay in evaporation often represents the 

 difference between success and failure in obtaining satisfactory initial 

 stands. 



Preliminary data indicate that to leave the Sudan grass or sor- 

 ghum crop unmowed not only wastes valuable forage but results in 

 the production of less basal growth than when the crop is mowed 

 early and high. Furthermore, unmowed plants often break off at 

 the base and blow away during the winter. When Sudan grass is 

 allowed to mature, volunteer plants often appear the following 

 spring and offer severe competition to the slower growing perennial 

 grasses. 



A few instances have occurred where small areas of high-cut 

 stubble, nearly or wholly surrounded by cultivated fields, have 

 become too deeply covered with wind-deposited silt to provide a sat- 

 isfactory seedbed. Close mowing of the stubble on isolated areas of 

 this kind would reduce the deposit of silt but leave a poor seedbed. 

 It is desirable, therefore, that surrounding areas be at least tempo- 

 rarily stabilized before an attempt is made to reestablish grass on 

 cultivated land. 



Close-drilled stubble has other advantages as preparation for grass. 

 The soil is usually firmer, cleaner, and freer of weeds than on land 

 without stubble. 



