Reducing soil erosion and nitrogen leaching through sustainable cropping systems

Reducing soil erosion and nitrogen leaching through sustainable cropping systems

Summary

Cover crop species by nitrogen (N) rate plots were harvested May 1, 2006 with soil samples (0-3’) also at this time. Rye produced the most biomass. Over species, 2.7, 2.3, and 1.6 tons/ac DM were produced with early, middle, and late planting dates, respectively. Adding 30 lb N/ac in February resulted in 0.3 tons/ac more DM but increased N uptake only 8 lb/ac. Soil nitrate (0-3’) was reduced by 55 lb/ac from cover crop planting to termination with early planted rye. Average N uptake with 0 N was 90, 75, and 60 lb/ac for the early, mid, and late plantings, respectively.

Objectives/Performance Targets

Determine the winter cover crop species and planting date that provides the most vigorous winter soil cover, the greatest biomass return to the soil system, and the highest level of N uptake.
Determine the change in soil nitrate (NO3-) over the cover crop season.
Evaluate cover crop effects on subsequent crop weed control.
Educate producers and agricultural professionals on how to successfully implement cover crops to maximum environmental and economic advantage.

Accomplishments/Milestones

Plots were planted prior to grant initiation on September 30, October 20, and November 10, 2005. Soil samples (0-3’) were taken from a composite of the experimental area prior to planting, from each species by planting date plot in February and from each plot at cover crop termination. Aboveground biomass was harvested just prior to termination. All biomass and forage samples have been process and analyzed. Weed populations and shell quality of pumpkins were qualitatively ranked and photos of the plots were taken in late summer. Results from the 2005-06 season have been summarized.
Plots were planted on approximately the same dates in fall 2006. Species were barley, oats, crimson clover, rye, vetch, rye+vetch, and canola. Preplant soil samples (0-3’) were taken from a composite of the experimental area prior to planting.

Impacts and Contributions/Outcomes

Initial results from this research are being used to support the increased emphasis placed on cover crops by the Virginia Department of Conservation and Recreation cost share program. In fact, DCR received cost share applications for over 73,500 acres for fall 2006. Presentations have been made to over 400 growers at various county and regional meetings, at the annual meetings of the Virginia Small Grain Growers Association, the Virginia Crop Production Association, and the Shenandoah Valley Annual CCA Crop Management School. The plots, and cover crop education in general, were the focus of a Virginia NRCS in-service training on April 13, 2006 with over 150 attendees. An article reporting on this field day was published in the May 22, 2006 issue of the Southeast Farm Press (southeastfarmpress.com).
A fact sheet and/or other Cooperative Extension publications based upon the production management research conducted by the participants will be published. Cover crop systems will be highlighted as part of annual state-wide in-service training sessions. PowerPoint slide presentations will be developed and distributed to county agents at the in-service training for use in their educational programs pertaining to cover cropping systems.
Ultimately producers, NRCS workers, crop advisors, and others will have up-to-date and accurate local information about the most effective cover crop species and management practices.

Collaborators: