Scholarship & Research
Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/1
Browse
11 results
Search Results
Item Ventenata (Ventenata dubia) control treatments on the Crow Reservation(Montana State University - Bozeman, College of Agriculture, 2023) Fighter, Zachariah Zachary Zane; Chairperson, Graduate Committee: Jane M. Mangold; Scott Powell (co-chair)Ventenata (Ventenata dubia) is a non-native winter annual grass that has been of increasing concern in southeastern Montana. Research has shown that ventenata can increase rapidly, lower forage production, and reduce biodiversity. This project is located in southeastern Montana, in Bighorn County on the Crow Reservation. Two studies were conducted to understand control options and monitoring of those treatments post-treatment. A field study tested two herbicides and a soil amendment for the management of ventenata. At four sites, indaziflam and imazapic at two water carrier rates and two rates of an organic soil nutrient amendment were tested using a split-plot randomized block design. The water carrier rates were meant to mimic aerial and ground applications. Herbicides were applied using a hand-held boom sprayer pressurized by CO 2. Soil amendment was hand-broadcasted. In late June 2022 (first growing season post-treatment), sampling consisted of randomly placing 3, 20 cm x 50 cm frames in each split-plot and estimating cover by species along with litter and bare ground. Imazapic and indaziflam provided the highest reduction of ventenata, regardless of water carrier rate. Across the four sites, imazapic reduced ventenata cover to <1% while indaziflam reduced cover to 4%, compared to the control which was 38%. The soil amendment reduced ventenata to 25% at two sites, suggesting it may not be as promising of a control method as the herbicides. Application rates for all treatments did not differ, suggesting that aerial application of the herbicides may provide just as good of control as ground application. This is encouraging for the prospect of managing ventenata aerially. At one of the sites, a remote sensing time series study using an Unmanned Aerial Vehicle (UAV) with a multispectral sensor was used to understand differences in the Normalized Difference Vegetation Index (NDVI) between herbicide sprayed and non-sprayed plots. Findings indicate that there is a shift in NDVI in late June where sprayed plots peak in NDVI and remain green longer into the season than non-sprayed plots. This study provides control options that land managers in southeastern Montana can consider using for ventenata management.Item Restoring semi-arid lands with microtopography(Montana State University - Bozeman, College of Agriculture, 2019) Dillard, Shannon Leigh; Chairperson, Graduate Committee: Anthony HartshornWater is often limiting to plant establishment in semi-arid lands, and this limitation can be especially pronounced in restoration contexts where human legacy impacts and/or non-native plants are present. The application of herbicide and mulch can help retain soil moisture by killing unwanted plant species or lowering evaporative losses, respectively. Creation of microtopography, or soil surface variation, is a third technique that could alleviate growing-season water shortages. Here we report findings from a study that explored the effects of these three techniques combined with broadcast seeding a mix of four native grasses, one native shrub, and one native forb for increasing plant canopy cover and density at three sites in northern Yellowstone National Park. One year after treatment, plant cover in control plots averaged 60%. Across plots treated singly with 1.5% glyphosate herbicide, 3 cm of red cedar mulch, or hand-dug microtopography, only mulch and microtopography increased canopy cover relative to control plots, although the increase consisted mostly of non-native species (>97%). Herbicide, not surprisingly, decreased canopy cover, and that decrease also consisted mostly of non-native species. The herbicide treatment was the most effective in encouraging native species canopy cover and density while simultaneously reducing the same measures of non-native species. Microtopography treatments encouraged growth of all plants (native and non-native), particularly in the micro-lows, but for this to be an effective restoration strategy, non-native species must first be controlled. Although herbicide was quite effective at reducing non-native species populations, particularly at the Cinnabar site, spraying must be timed with the phenology of the existing non-native plant community. We learned that reducing competition with non-native plants does not necessarily encourage native plant growth, which may indicate that growing conditions need to be improved at this site before restoration can be successful. Taken together, our results suggest that soil amendments like microtopography and mulch may have beneficial restoration applications in semi-arid lands but may also show little benefit on a short time-scale in a highly disturbed system. Areas plagued by non-native species invasions and legacy agricultural and grazing impacts are likely to require careful planning of restoration approaches in order to claim long-term success.Item A computerized automated rapid weathering apparatus for determining total lime requirements for acid minesoils(Montana State University - Bozeman, College of Agriculture, 1985) Harvey, K. C.Item Evaluation of amendments for a topsoil substitute at the Stillwater Mine(Montana State University - Bozeman, College of Agriculture, 1995) Kaiser, Heidi JillItem Effect of irrigation water quality, amendment and crop on salt leaching and sodium displacement(Montana State University - Bozeman, College of Agriculture, 1991) Brock, Teresa AnnItem Decomposition rates of residual crude oil in soil : a comparison of soil amendments(Montana State University - Bozeman, College of Agriculture, 1989) Cormier, Michael FrancisItem Concentrated iron pyrite mine waste as an amendment for alkaline soils(Montana State University - Bozeman, College of Agriculture, 1994) Smith, Troy C.Item Effects of precipitated calcium carbonate from sugar purification on crusting soils(Montana State University - Bozeman, College of Agriculture, 1996) Inkret, John MatthewPrecipitated calcium carbonate (PCC), a by-product of the sugar industry, results from a sucrose juice purification technique. This material has several properties that distinguish it from geological calcite. These properties include an organic load, high water-holding capacity, small particle size, high surface area, and uniformity. A large stockpile of PCC is located at the Holly Sugar refinery in Sidney, Montana. This study was initiated at the request of Holly Sugar to investigate potential PCC application as a soil amendment to local agricultural soils that exhibit surface crusting. Soil surface crusts, initiated by precipitation events, are common in Eastern Montana. These crusts can significantly inhibit crop seedling emergence. This study was designed to evaluate the potential of PCC to ameliorate crust formation in eastern Montana agricultural soils. Bulk soil samples from four different sites and stockpile PCC samples were collected for evaluation. Amendment (PCC) and the four soils were then physically and chemically characterized. Soil crust formation and strength of amended and control soils were evaluated in the laboratory and greenhouse by inducing crust formation and then measuring and analyzing specific soil crust properties and parameters. Soil areal extensibilities from saturated to dry moisture conditions were measured and evaluated. Outdoor trials evaluated seedling emergence success and surface crust strength. Greenhouse trials evaluated seedling emergence and the areal extent of soil surface fractures by a photographic quantification technique. The addition of PCC, at the rates tested, did not ameliorate the problematic physical characteristic of the soils. Soil crusting was not reduced by the amendments used in this study.Item Deep tillage of amendments using specialized equipment in land reclamation(Montana State University - Bozeman, College of Agriculture, 1994) Marsh, Matthew LukeItem Characterization of rangeland and cropland Natrargids(Montana State University - Bozeman, College of Agriculture, 1994) Sieler, David James