|VAHYALA, IBRAHIM - South Dakota State University|
|SCHUMACHER, TOM - South Dakota State University|
Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/16/2018
Publication Date: 5/2/2018
Citation: Vahyala, I.E., Osborne, S.L., Schumacher, T.E., Riedell, W.E. 2018. Corn residue removal effects on hydraulically effective macropores. Communications in Soil Science and Plant Analysis. https://doi.org/10.1080/00103624.2018.1464187.
Interpretive Summary: The movement of air and water through soil is an important factor in evaluating soil health. The removal of crop residue from the soil surface has a significant impact on these properties. A field study was established by the USDA-ARS research laboratory located near Brookings, SD to evaluate how removing crop residue as a possible feedstock for ethanol production impacted surface pore structure. Removal of any above ground residue resulted lower water inflow into the soil surface compared to leaving all residue on the soil surface and only removing grain. Samples collected 9 months following residue removal found a decrease in pore size when residue was removed compared to leaving residue, but over time this decrease in pore size recovered and there was no difference in pore size for the different residue removal treatments 21 months following the removal or residue. Cover crops were not observed to have an impact on the measured soil properties within the time period of this experiment. This research contributes to the USDA-ARS-REAP project.
Technical Abstract: Enhanced understanding of biomass removal effects on soil quality could be achieved with greater knowledge of how corn stover removal and cover crops interact to affect surface pore structure. This study was conducted to evaluate the effects of corn stover removal on soil macropore characteristics and to assess the effectiveness of cover crops in mitigating the potential negative impacts of corn biomass removal on surface pore structure. Three different corn residue removal rates and the presence or absence of cover crops were evaluated in a no-till corn/soybean rotation near Brookings, SD. High (HRR) and medium (MRR) rates of residue removal reduced water inflow into the soil surface compared to the low (LRR) residue removal treatment. The representative mean pore radius (''') for both rotation phases of LRR approached the same value (˜ 235 µm). However, nine months after corn residue removal the ''' for HRR in the soybean phase of the rotation was significantly different than LRR at 161 µm. There was no significant difference in ''' between HRR (214 µm) and LRR treatments 21 months after residue removal during the corn phase of the rotation. The initial reduction in ''' following corn residue removal in HRR followed by a recovery the following year suggests that incorporation of decaying corn residue is critical in the maintenance of hydraulically functional macropores in this fine textured soil. Cover crops were not observed to mitigate these impacts of crop residue removal on surface soil structure within the time period of this experiment.