Author
MELMAN, DANIEL - Colorado State University | |
SCHNEEKLOTH, JOEL - Colorado State University | |
COURTLAND, KELLY - Colorado State University | |
Calderon, Francisco | |
FONTE, STEVEN - Colorado State University |
Submitted to: Applied Soil Ecology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/24/2019 Publication Date: 11/20/2019 Citation: Melman, D.A., Schneekloth, J., Courtland, K., Calderon, F.J., Fonte, S.J. 2019. Tillage and residue management drive soil quality and functional changes in an irrigated cropping system of Eastern Colorado. Applied Soil Ecology. 143: 98-106. https://doi.org/10.1016/j.apsoil.2019.05.022. DOI: https://doi.org/10.1016/j.apsoil.2019.05.022 Interpretive Summary: In this multi year study at the Central Great Plains Research Station, we evaluated the effects of tillage and residue removal on the soil earthworm and insect abundance under irrigated corn. The combined practice of residue retention with no-tillage was associated with a five-fold increase in earthworm abundance, and enhanced soil structure. Our findings suggest that no-till and residue retention practices offer great promise for improving soil structure and water infiltration, and that these effects appear to be mediated by greater earthworm abundance when these two practices are combined. Technical Abstract: Tillage and stover harvest are common management practices in corn-based cropping systems around the globe. However, frequent soil disturbance and biomass export are likely to have negative long-term impacts on soil fertility, soil structure and belowground biological activity, and there is great concern surrounding the sustainability of these practices. To address this issue, experimental plots were established in April 2014 in Akron, Colorado to understand the impacts of conservation agriculture practices, no-tillage and residue retention, in a full factorial block design with the following treatments: no-till + residue retention (NT/R); no-till + residue harvest (NT/RH); conventional tillage + residue retention (CT/R); and conventional tillage + residue harvest (CT/RH). In year three of the experiment soil health parameters were assessed including: soil macrofauna communities, aggregate stability, potential infiltration, and chemical fertility measures. The combined practice of residue retention with no-tillage (NT/R) greatly enhanced macrofauna communities, including a five-fold increase in earthworm abundance and biomass. Greater earthworm populations were associated with an increase in aggregate stability under NT/R and a trend towards greater water infiltration. Soil chemical parameters indicated relatively less dramatic differences between treatments, but with some notable impacts of residue retention. Our findings suggest that no-till and residue retention practices offer great promise for improving soil structure and hydrologic function, and that these effects appear to be mediated by greater earthworm abundance when these two practices are combined. |