Location: Rangeland Resources & Systems Research
Project Number: 3012-21610-003-017-I
Project Type: Interagency Reimbursable Agreement
Start Date: Aug 11, 2016
End Date: Aug 10, 2022
The objective of the Conservation Reserve Program (CRP), a cost-share program between farmers/ranchers and the US Government, is to reduce soil erosion, enhance water quality, and improve wildlife habitat by converting marginal or vulnerable cropland to perennial vegetative cover. Because much of the land enrolled is dryland cropland that can experience drought and high temperatures, many CRP plantings are unsuccessful, resulting in large tracts of land open to the invasion of weeds often with little to no ground cover. Lack of establishment success undercuts the conservation objectives of the program and increases costs as multiple establishment attempts are made. During the winter of 2016, FSA approached ARS rangeland scientists about the possibility of establishing experimental plots in relevant regions, specifically the northern Great Plains (NPA) Southern Plains (SP), and the Great Basin (GB) . The overall purpose of the proposed research is to increase establishment success and maintenance of native grasses, legumes, and forbs on CRP-enrolled fields by studying the plants, soil, and plant-soil interactions at experimental plots (sites) across a diversity of landscapes. Not only will this project increase the cost-effectiveness of the program in the short term, but it will enhance the ability of landowners to respond to a hotter and dryer future climate.
Four sites (fields) in the NGP and GB, and three sites in the SP will be selected from newly enrolled CRP land (i.e., current marginal cropland) where cover establishment will be measured beginning in 2017. All sites will have soil type and topography that are conducive to drill seeding ((not broadcast seeding). Each site will have between 48 and 64 acres available to cover both years of seeding. Site preparation will be done using a chemical fallow program that includes the application of non-selective herbicides (e.g., glyphosate) several times during the growing period to eliminate weed competition and conserve soil moisture prior to planting. Each site will have a single replication of each of four treatments in a randomized complete block (blocks = planting years) design. Of the four treatments, one will be the FSA recommended seed mix for each specific region which will provide common treatment metric between all three regions. The other three treatments will focus on regionally specific alternative seeding mixtures or seeding methods. However, some treatment commonality will be preserved between regions. Blocks will be randomly assigned to different planting years to evaluate the influence of weather variability on seeding establishment and plant persistence. Plots will be planted fall of 2016 (GB) and spring of 2017 (NGP, SP). The other half will be planted the following year, in 2017 and 2018. Each treatment will be replicated once per site (NGP, SP) or four times per site (GB) . Pre-planting data: Soil analysis - composite sample of ten cores per unit used to analyze soil texture, soil bulk density, and soil chemistry, including phospholipid fatty acids associated with soil organisms (PLFA); Vegetative cover - % vegetative cover by species and bare ground at 10 randomly selected sites per experimental unit. Post-planting (during growing season) : Soil analysis - soil texture , soil bulk density, and soil chemistry resampled in year 5 - Vegetative cover - seeding density and Postplanting (during growing season): Soil analysis - soil texture, soil bulk density, and soil chemistry resampled in year 5. Vegetative cover - seedling density and frequency of target species establishment, plant cover, weeds, basal cover, and basal and canopy gaps; Monthly pollinator sweeps per experimental unit with a minimum of three visits per year. Floral resources recorded at ten randomly sited quadrats. Samples will be frozen and sent to ARS entomologists for species identification. Throughout the duration of the project, conference calls will be used to make sure that data collection is being done uniform and to discuss questions that might arise.