Ability of No-till Practices to Protect Conservation Reserve Program (CRP) Land From Greenhouse Gas (GHG) Emissions on Conversion to Biofuel Crops.

The Conservation Reserve Program (CRP) is designed to reduce soil erosion, improve water and air quality, enhance wildlife populations, and sequester carbon in soil and biomass. Higher prices for corn and other biofuel crops are expected to induce farmers to take land out of CRP and return it into production. Conventional practices such as tillage will change greenhouse gas (GHG) balance of converted land as soil carbon is oxidized, N₂O fluxes are accelerated, and CH₄ oxidation is reduced. The objective of this study was to assess the ability of no-till (NT) practice to protect CRP land from GHG emissions on conversion to biofuel crops. The study was conducted at the the Great Lakes Bioenergy Research Consortium (GLBRC) Marshall Farm site in southwestern Michigan on sandy loam soils. The experimental design consisted of NT and conventional till (CT) treatments arranged in a randomized block design with 3 replications. Generally, annual CO2 fluxes in CT are significantly higher than in NT. Annual emissions of N₂O were significantly higher in CT treatments (averaged 6.69 kg N₂O-N ha^-1) than in NT treatments (averaged 2.72 kg N₂O-N ha^-1) (P<0.01). The N₂O flux was strongly correlated with precipitation. However, there is no significant difference of CH₄ fluxes between CT and NT treatments.