Author
Wilson, Glenn | |
McGregor, Keith | |
Boykin, Deborah |
Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/3/2008 Publication Date: 6/1/2008 Citation: Wilson, G.V., Mcgregor, K.C., Boykin, D.L. 2008. Corn Residue Impacts on Runoff and Soil Erosion for Different Plant Populations. J. Soil & Tillage Research. 99(2): 300-307, doi.org/10.1016/j.still.2008.04.001. Interpretive Summary: The effects on runoff and erosion of add plant residue some years and not others is unclear. The objective of this study was to quantify the impact of different plant populations grown every other year on runoff and erosion. The residue management system involved shredding of corn stalks after harvest, tilling the residue into the soil the following spring, and leaving the land fallow until it was no-till planted the next spring. Runoff and soil losses were measured on 18 runoff plots with plots arranged in two areas with each having three treatments (0%, 50%, and 100% plant population) with three replications. The two areas were managed as a fallow/no-till corn rotation in two cycles of alternating years. Surface residue cover changed with time with significant changes between cycles and seasons in response to the management practices. In response to these changes in residue cover, the erosion index (an measure of rainfall intensity) was a better predictor of runoff than soil losses. The annual soil losses were reduced by 47% and 54% for the 50 and 100% plant populations, respectively compared to the control (0 plant population). The normal erosion protection afforded by no-till practices was lost by the incorporation of residue the previous year. Technical Abstract: The year to year carry-over effects of biomass additions under different plant populations on runoff and erosion is unclear. The objective of this study was to quantify the impact of different plant populations on residue cover to elucidate the effects of residue cover on runoff and erosion. The residue management system involved shredding of corn biomass after harvest, incorporating the residue the subsequent spring, and leaving the land fallow until it was no-till planted the following spring. Runoff and soil losses were measured on 18 runoff plots with plots arranged in two areas with each having three randomized treatments (0%, 50%, and 100% plant population) with three replications. The two areas were managed as a fallow/no-till corn rotation in two cycles of alternating years. Surface residue cover was highly dynamic with significant changes between cycles and seasons in response to the management practices. In response to these changes in residue cover, the erosion index (EI) was a better predictor of runoff than soil losses. The annual soil losses were reduced by 47% and 54% for the 50 and 100% plant populations, respectively compared to the control. However, the annual soil loss even for the 100% plant population was still nearly seven times the tolerable soil loss limit of 7 T/ha. The normal erosion protection afforded by no-till practices was lost by the incorporation of residue the previous year. |