Submitted to: Soil and Water Conservation Society
Publication Type: Abstract only
Publication Acceptance Date: 8/15/2006
Publication Date: 10/11/2006
Citation: Hively, W.D., Lang, M.W., McCarty, G.W., Keppler, J., McConnell, L.L. 2006. Remote sensing of cover crop performance on Maryland's Eastern Shore [abstract]. Soil and Water Conservation Society Meeting. 2006 CD-ROM. Interpretive Summary:
Technical Abstract: The use of cover crops on agricultural land has been identified as a desirable management practice with potential to positively impact Chesapeake Bay water quality. Accordingly, state cost share programs have been developed to promote cover crops. This project uses a combination of remote sensing and field sampling to evaluate the impact of cover crops on nutrient retention within the Choptank River watershed, a designated CEAP Special Emphasis research location on Maryland's Eastern Shore. The Maryland Department of Agriculture provides information on farmer enrollment in cover crop (winter grains with no fertilization) and commodity cover crop (winter grains with no fertilization before March 1st)cost share programs including location, planting date, species, and planting method. Satellite images (SPOT) are used to estimate aboveground biomass on cover cropped fields in winter and spring, with field sampling and hyperspectral sensing providing image calibration and nutrient concentration estimates. Winter 2006 results showed excellent correlation (r2=0.98) between SPOT-derived vegetation index and observed biomass. Planting date, planting method (aerial, drilled, broadcast), cover crop species (wheat, rye, barley), and previous crop (maize, soy) were all significantly correlated with biomass and nutrient accumulation, which ranged from 0 to 60 lb/acre. As might be expected, early planted crops produced the greatest biomass. Also, rye outpaced barley and wheat. Within species, the effect of seeding method was apparent (drilled outperformed broadcast), and aerial seeded wheat did not perform as well as might be expected from its early planting date, likely due to dry conditions following seeding. Several years of observation will be necessary to account for effects of climate. Spring 2006 results are forthcoming. The combination of remote sensing, field sampling, and access to farm program documents use in this project proved to be a successful and powerful method real-world real-time evaluation of cover crop performance on fields subsidized by the cover crop conservation cost share programs.