Effect of Interseeding and Spraying Soapstock and Molasses Mixtures on Little Bluestem Utilization

Introduction

In the 1870s, cattlemen brought large herds of livestock to the Northern Great Plains, including Richland County to graze the open prairies. From 1870 up until 1906, cattle, horses, and sheep grazed in the area. These domestic animals typically stayed on the lower ground where grazing was easier and close to water sources. This uneven distribution of grazing caused little bluestem to dominate in the plant communities. Traditional rangeland renovation practices such as chemical or mechanical treatments, burning, or reseeding are expensive and only serve to intensify the disturbance (causing soil erosion and irreversible ecological damage to the shallow soils).

Objectives

This project seeks to develop low-cost alternatives to renovate or to increase use of little bluestem plant communities in Richland County. One method addresses whether or not Medicago sativa, ssp falcata, a non-bloating alfalfa, can be interseeded successfully in little bluestem plant communities. The second phase of this project hopes to demonstrate that soapstock mixed with molasses can be sprayed onto standing dead little bluestem stalks to improve livestock utilization of the plants and stimulate new growth because of increased hoof action.

Study Area

Richland County is located on the boundary of the northern glaciated plains and the eastern sedimentary plains of northeastern Montana. In Richland County, 30 percent or approximately 400,000 acres is composed of the Lambert soil complexes. The Lambert complexes are characterized by steep slopes (8 – 45 percent) and shallow soils: 10 to 20 inches deep. Although cool season grasses dominate the composition, little bluestem (Schizachyrium scoparium) comprises up to 30 percent of the plant community.

The Panasuk Ranch grazing unit consists of 1,920 acres of native rangeland located approximately nine miles east of Richey, Montana, in the southwest corner of Richland County. Average annual precipitation is 14 to 16 inches. This range unit is located in the eastern sedimentary plains rangeland resource unit.

Methods

Phase One Treatment Area: Five 4.8 square-foot circular frames will randomly be clipped prior to interseeding. Species composition and total production weight will be recorded. “Before and after” photos will be taken. Prior to grazing treatment, five hoops will be clipped in the interseeded treatment to determine the grass, falcata alfalfa, and forb/shrub component. Another five hoops will be clipped in the mowed area for grass, forb, and shrub component. Utilization will be visually observed throughout the grazing period. This site will be monitored for five years to measure vegetation changes.

Phase Two Treatment Area: Two 100-foot transects will be set up. One will be in the acres treated with soapstock and molasses spray and one in the untreated little bluestem plant community. “Before and after” grazing photos will be taken each year. Each transect will be staked and recorded in the GPS unit. At one-foot intervals, little bluestem plants will be measured for utilization. Line measurements will be taken three times; once before grazing begins, in the middle of the grazing period, and right after cattle are moved from the treated pasture. Utilization will be measured by noting whether a little bluestem plant was grazed or ungrazed, the degree of grazing will be recorded, and the percent degree of use will be calculated. An exclosure will be set up in the untreated little bluestem. The little bluestem within the exclosure will be clipped and weighed at the end of the grazing period. Percent utilization will be calculated. The treatment acres, transects, and exclosures will change every year.

Results

Phase One Treatment Area: In 2005, the focus was on finding new growth of falcata alfalfa on the areas of little bluestem that were interseeded the previous year. During the season, the ranch had average or above average precipitation and there were no significant hail or wind events to negatively impact grass production. However, on the rangeland that was interseeded with falcata alfalfa, there were no seedlings or plants found on the site. With the favorable rainfall the past two years, an occasional plant should have been present.

Phase Two Treatment Area: In 2004, the soapstock spray did not appear to draw cattle into the area, as found by the pre- and post-spray evaluations. However, the molasses spray did draw cattle and horses into the area. Preliminary measurements show significant use of the treated plants, including the use of the old, top part of the plants.

In 2005, the focus was to return to the treated areas and monitor utilization of plants that were sprayed and grazed off last year. We had hoped to see the absence of the old top growth and the presence of succulent new growth emerging from the bases. As planned, additional soapstock or molasses was not sprayed on any more plots. However, this was not observed because the planned grazing system was no implemented. Fourteen horses grazed the 540-acre pasture rather than cow-calf pairs.

Valuable information was learned on how to handle and apply the molasses by-product and we are working on a cost effective formula. There are plans to move the project in the near future to a ranch that is willing to continue the project where grazing will be more representative for Richland County.

Contact Information

Jamie Selting
USDA-NRCS
HCR 90, Box 5165A
Sidney, MT 59270
(406) 433-2103 ext.117