Cover Crop Diversity in No-Till Systems

View the project final report

• 2013 annual report

Commodities

• Agronomic: corn, rye

Practices

• Crop Production: cover crops, no-till, nutrient cycling
• Education and Training: on-farm/ranch research
• Production Systems: general crop production

Fall plowed fields on clay soils in Vermont are a significant contributor to phosphorus pollution in Lake Champlain. Cover crops have been identified as a key Best Management Practice to prevent soil erosion and protect water quality. Although more farmers are using cover crops recently than they have in the past, most field crop growers use single species cover crops or two-species mixes, at most. The Champlain Valley Crop, Soil & Pasture Team would like to investigate the potential benefits of using cover crop mixes with at least three different species. Agronomy Outreach Professionals will collaborate with four different farms to perform field trials to collect data and demonstrate practices to farmers across the Lake Champlain region, with a particular focus on managing challenging clay soils. Trials will focus on the use of cover crop mixes, cover crops as pasture improvers, and reducing tillage. We will utilize sound research methods to collect data that is usable and applicable to farmers in the Champlain basin. Our team has had great success with a no-till project this summer and fall, and this project would enable us to capture that enthusiasm and momentum by offering yet another way to utilize those tools on their farms. It is well documented that cover crops reduce soil erosion. Also, research shows that properly managed cover crops can result in positive yield responses. The goal of this project is to show that cover crops are in fact a viable alternative to fall plowing in the Champlain Valley by demonstrating different methods and timing of establishing cover crops and let farmers choose the right system for their farm. The species mixes used in the trial will be composed of a grass, legume, and brassica, for biomass production, N fixation and deep taproot penetration/nutrient scavenging, respectively. Also, there will be a winter annual (winter hardy) and cool season annual (winterkill) formulation. This project will utilize a comprehensive outreach strategy to share the information with farmers that will include printed fact sheets, field days, presentations at farmer meetings, Facebook posts with photos, YouTube videos, television programming, and newsletter articles.

This project will evaluate planting times and rates of different cover crops and cover crop mixes for fall establishment, biomass production , nutrient scavenging, and overall effect on soil health. Mixing multiple species in one cover crop planting can result in of benefits of all included species. For example, compaction alleviation, N-fixation, and organic matter accumulation can be achieved with one well thought out mixed planting. These cover crop mixes have been gaining popularity across the country due to these advantages. They are being used increasingly not just to protect the soil from erosion, but also increase yields. Farmers in the Champlain Valley will be more receptive to cover cropping if these mixes can be shown to improve overall soil health, and increase crop yields in the long run. These trials will provide baseline data on seeding rates, timing, and species mixes that will provide a solid foundation for the continuing promotion of cover crops in the Champlain Valley.

Four cooperator farmers agree to provide land, equipment and labor to establish field trials on their farms for demonstration to other farmers and data collection on no-till cover crop growth. The no-till planting of seed mixtures will be supported by the use of Haybuster 107 no-till grain drills owned by UVM Extension as part of an on-going Ecosystem Restoration Grant to reduce soil and phosphorus loss into Lake Champlain. We used the grain drills in 2012 to seed 1,500 acres of seed mixtures on 49 individual farms for hay land renovation, pasture improvement and fall cover crop establishment after corn harvest. Our past experience working with these farmers provides a solid base for successful cover crop planting for this project.

For this project three farmers will identify a crop field suitable for a replicated field trial to plant two different cover crop mixtures at two different planting dates after wheat or corn silage production. One farmer will identify an improved pasture suitable for a replicated field trial to plant tillage radishes as a cover crop at two different planting dates with three different seeding rates. Three Extension Agronomy Outreach Professionals and a summer Field Technician will team up with the four cooperating farmers to support design, planting, monitoring and data collection of the field trials.

Data measurements include a pre-plant UVM Agricultural & Environmental Testing Lab soil test and a follow-up soil test after spring termination of the cover crops to determine changes in soil nutrient status of Phosphorus and related nutrients. Plant biomass yield checks will be taken with hand-harvested weighed samples and corrected for dry matter content to determine pounds per acre produced by November 1 in the fall and May 1 in the spring. Split samples will be submitted to Dairy One Forage Analysis Laboratory for a basic plus mineral wet chemistry analysis to determine dry matter content and nutrient content levels for both fall and spring sampling dates. Yield data plus forage analysis will be used to determine amount of nutrient uptake and retention of Nitrogen and Phosphorus by the cover crop that is retained and not lost to surface water runoff. Measurements using a beaded string method (NRCS) will be used to determine soil surface coverage provided by the growing or terminated cover crop. Each one acre trial on the four farms will be split into two sub-plots for the two different planting dates with each cover crop treatment replicated four times within the block for valid statistical analysis. Both mixes will be planted at high rate and a low rate to compare effects on soil cover.