Tillage and residue management effects on irrigated corn (zea mays) performance and water cycling in a semiarid cropping system of Eastern Colorado

Authors: SCHNEEKLOTH, JOEL - Colorado State University; Calderon, Francisco; FONTE, STEVEN - Colorado State University; Nielsen, David

Submitted to: Irrigation Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2020
Publication Date: 10/20/2020
Citation: Schneekloth, J., Calderon, F.J., Fonte, S., Nielsen, D.C. 2020. Tillage and residue management effects on irrigated corn (zea mays) performance and water cycling in a semiarid cropping system of Eastern Colorado. Irrigation Science. 38:547-557. https://doi.org/10.1007/s00271-020-00702-2.
DOI: https://doi.org/10.1007/s00271-020-00702-2

Interpretive Summary: In this paper we detail the effects of tillage and residue removal on soil water conservation under limited irrigation in a semiarid environment . Retaining the corn residues in the field was associated with higher corn yields, less evapotranspiration water losses, less soil compaction, and higher water infiltration. The effect of tillage on these variables was less marked than that of residue conservation. Our data indicates that the sale and export of the corn residues can negatively impact water conservation, erosion and corn yields, so the benefits of selling the residues need to be weighed against the negative impacts in yields and water conservation.

Technical Abstract: Residue removal from maize fields offers an opportunity to increase farmer profits, but potential trade-offs for water dynamics and crop performance merit further evaluation. This study compared the effects of two tillage practices (no-till and conventional) and two residue management practices (harvested vs. kept in place) on maize grain production, water infiltration, evapotranspiration, and soil physical attributes. On average, maize grain yields under limited irrigation were increased with residue retention by 1.1 Mg ha-1 yr-1 between 2016-2018, but tillage had no significant effect. Total 30 minute infiltration was higher, and evapotranspiration during the vegetative growing season was significantly reduced with residue retention, while tillage had no effect on either variable. Conversely, penetrometer resistance was significantly reduced by both tillage and residue retention. Volumetric water content in the soil profile at planting significantly increased with residue retention and no-till practices. These results suggest that residue removal plots would on average require 60 mm yr-1 of additional irrigation to attain the same yields of the residue retention treatment. In summary, our findings suggest that removing and exporting the crop residues under limited irrigation in a semiarid environment can negatively affect water conservation, erosion control and yields, and that trade-offs surrounding residue export need to be fully considered in land management and policy decisions.