Location: Rangeland Resources & Systems Research
Project Number: 3012-21500-001-016-I
Project Type: Interagency Reimbursable Agreement
Start Date: Sep 1, 2022
End Date: Aug 31, 2027
Objective:
This project will have three main objectives. They are 1) develop a predictive understanding of CRP restoration outcomes using a suite of experiments ranging from greenhouse to farm-scale, (2) generate innovative approaches to overcome abiotic and biotic barriers to establishment success; and (3) co-develop a decision support framework to support FSA and NRCS recommendations for CRP establishment in drylands
Approach:
To accomplish these objectives, the multi-disciplinary team will first synthesize existing data from FSA-ARS CRP experiments (i.e., native and exotic seedling recruitment, climate and soil covariates) and determine abiotic and biotic drivers of seeding success across CRP experiments using mixed effects meta-regression using the ‘metafor’ package in R. Also in Year 1, we will conduct intensive trait screening of seeded species from CRP Pollinator plantings tested in prior FSA-ARS CRP experiments at CO, MT, UT to develop a database of plant functional trait information for candidate CRP Pollinator seed mix species in a greenhouse setting. This information along with the synthesized information from previous experiments will be used to design two trait-based alternative seed mixes: (a) one to target increased competition with weeds, and (b) one targeting increased drought tolerance. We will test the restoration success of these two seed mixes relative to the NRCS business as usual (BAU) CRP Pollinator seed mix recommended for each site. In Montana, a series of plot level experiments will be used to determine the impact of residue, soil nutrient levels and seed placement and timing on soil water availability and weed competition. The effectiveness of herbicides on CRP establishment success will be determined by a series of field level treatments. To ensure our study includes a wide range of weed abundances, we will study 30 CRP fields that are seeded by managers over three years (10 fields per year × 3 years) in Colorado and Montana. Within each field, we will measure weed and seeded species densities shortly after they emerge in the first growing season. Then we will establish 12 plots [3 replications × (1 untreated control + 3 herbicide treatments)] and apply three herbicide treatments. The treatments will be two imidazolinone herbicides (imazethapyr, imazapic) and one grass-specific herbicide (fluazifop). Two weeks after applying herbicides, we will measure weed control and herbicide damage to seeded species. In the fifth and final growing season of the study, we will measure cover of all weeds and seeded plants by species. In collaboration with the Logan, UT site, information gathered at the plot and field level will be fed into existing weather forecasting tools to develop a smart weather forecast tool for use in CRP plantings. All the information will be gathered into a decision support framework for use by USDA-NRCS and FSA to use CRP establishment recommendations.
