Can Cover Crop Improve Soil Hydraulic Properties after Corn Stover Removal?.

Corn (Zea mays L.) stover is being removed as feedstock for cattle and as a cellulosic biomass for biofuel production. High rates of corn stover removal may, however, have a negative impact on soil hydraulic properties. Addition of cover crops after stover removal may supplant the potential negative effects of stover removal on soil physical and hydraulic properties. We studied the effects of corn stover removal with and without winter cereal rye (Secale cereale L) cover crop on soil hydraulic properties such as water infiltration, water retention, plant available water, and pore-size distribution for three years on an ongoing irrigated no-till continuous corn experiment established in 2010 in south central Nebraska. The experimental treatments were: 1) no stover removal with cover crop, 2) stover removal with cover crop, 3) stover removal without cover crop, and 4) control (no stover removal without cover crop). Data are being analyzed and will be interpreted before the meetings. We expect corn stover removal will reduce water retention capacity and plant available water. The addition of a cover crop after stover removal may also have an effect on reducing the negative effect of residue removal on water retention capacity and plant available water. Water infiltration is being measured and will be presented to assess if stover removal and cover crop has a significant effect on water infiltration. Data on wet soil aggregate stability from this experiment show that residue removal can reduce aggregate stability but cover crops have limited effects. The increased soil aggregate stability may improve soil hydraulic properties. Results, in general, are expected to suggest that stover removal can reduce water infiltration, water retention, plant available water, and pore size, but addition of cover crops could ameliorate such negative effects.