Variability of Factors Influencing Stand Establishment in Green Needlegrass Populations from Western South Dakota

In recent years, there has been an alarming conversion of rang-land to cropland in western South Dakota. More importantly, much of this increase in cropland has resulted in the plowing of large areas of land where the soils are unsuited or only marginally suited to continuous cultivation. During the period from 1967 to 1975, the extent of this trend represented a net increase of about 200,000 of class IV soils, which are used for the production of annual crops. Historically, such unwise expansions of cropland to land areas that are susceptable to severe wind and water erosion have resulted in costly and time consuming revegetation of these areas to perennial grasses. After the severe drought of the 1930’s, crested wheatgrass was used almost exclusively to revegetate the eroded croplands in western South Dakota. Attempts to use native species for revegetation of cropland in the 1930’s met with very little success. Seed of native species was not readily available, and the seedling vigor of widely distributed native such as green needlegrass and western wheatgrass was found to be greatly inferior to that of the crested wheatgrass. Green needlegrass is a cool season native species, which is well adapted to semi-arid regions of the northern Great Plains. Where range condition is good or excellent in western South Dakota, green needlegrass is a dominant species on medium to fine-textured soils. As a medium to fine-textured soils. As a mid-height species of grass, it is an important contributor to the total forage production of rangeland in western South Dakota. The objective of this study was to evaluate the variability of factors influencing stand establishment of green needlegrass and to determine the potential for selecting an improved variety from collections made at seven sites (representing 6 ecotypes) in western South Dakota. Variation of mature plant characteristics was also studied to determine of see and forage production could be improved through selection