Winter cover crops in Illinois: Evaluation of ecophysiological characteristics of corn

Understanding ecophysiological characteristics of corn (Zea mays L.) under winter cover crops (WCCs) can improve management and farmers' acceptance by increasing the positive effects and decreasing the negative effects associated with their use. This study was conducted to quantify the effects of WCC on corn development, growth, and yield through the evaluation of ecophysiological characteristics. No-till corn planted after hairy vetch (Vicia villosa Roth), cereal rye (Secale cereale L.), and hairy vetch-cereal rye biculture and with four levels of N fertilizer (0, 90, 180, and 270 kg ha(-1)) was evaluated in 2002 and 2003 at Urbana, IL. Number of leaves, height, leaf area, chlorophyll meter readings (CMRs), light interception (LI), leaf carbon dioxide exchange rate (CER), grain yield, and yield components were measured. At 0 kg ha(-1), rye had significant detrimental effects on corn ecophysiological characteristics. However, most of the detrimental effects were overcome by adding 90 kg N ha(-1). Overall, hairy vetch provided benefits to corn that resulted in higher corn grain yield and was significantly better than all other treatments when no N fertilizer was used. Corn yield following hairy vetch-rye was intermediate between no cover and rye. As long as N rates are at least 90 kg ha(-1), incorporating WCC in a corn-soybean [Glycine max (L.) Merr.] rotation in Illinois does not affect corn ecophysiological characteristics and yield potential.