Predicting soil wind erosion potential under different corn residue management scenarios in the central Great Plains

Authors: RAKKAR, MANBIR - University Of Minnesota; BLANCO-CANQUI, HUMBERTO - University Of Nebraska; Tatarko, John

Submitted to: Geoderma
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/26/2019
Publication Date: 6/15/2019
Citation: Rakkar, M.K., Blanco-Canqui, H., Tatarko, J. 2019. Predicting soil wind erosion potential under different corn residue management scenarios in the central Great Plains. Geoderma. 353:25-34. https://doi.org/10.1016/j.geoderma.2019.05.040.
DOI: https://doi.org/10.1016/j.geoderma.2019.05.040

Interpretive Summary: Various computer models and simplified equations are available to predict wind erosion potential from farm fields. However, their accuracy can often vary between sites, depending on soil properties and farming practices, requiring specific data for each site. Thus, in this study, we 1) validated two existing equations that predict the fraction of wind erodible size in the soil and 2) estimated the total soil loss with the Single-event Wind Erosion Evaluation Program (SWEEP) using 3-yr measured data from six experiments located across a rainfall gradient in the central Great Plains. Each site had three types of corn residue removal: no removal, grazed, and baled. Measured and predicted amounts of wind erodible size material were significantly correlated for Nebraska soils. However, there was uncertainty in the prediction along with under-estimation of wind erodible material using one equation. Therefore, a new equation for the wind erodible portion of the soil was developed for Nebraska soils, which performed similar to existing prediction equations. This suggested the need for further refinement of the equations for the region. Total soil loss predicted by the SWEEP computer model indicated that corn residue baling may increase soil loss if residue cover drops below 20% in the study region. Overall, results indicate that the existing equations for erodible material require site specific validation whereas the SWEEP output indicated the critical importance of keeping enough residue cover to protect soil from wind erosion.

Technical Abstract: Various models and simplified equations are available to predict wind erosion potential. However, their performance can be often site-specific, depending on soil characteristics and agronomic practices, warranting site-specific model validations. Thus, in this study, we 1) validated the wind erodible fraction (WEF) predictive equations by Fryrear et al. (1994) and Lopez et al. (2007) and 2) estimated the total soil loss with the Single-event Wind Erosion Evaluation Program (SWEEP) using 3-yr measured data from six experiments located across a precipitation gradient in the central Great Plains. Each site had three corn (Zea mays L.) residue removal treatments: control (no removal), grazed, and baled. The measured and predicted WEF were significantly correlated. While the Fryrear et al. (1994) equation performed better than the Lopez et al. (2007) equation, it underestimated WEF with 59% uncertainty across site-years. To reduce this underestimation and uncertainty, we developed a new statistical equation (WEF% = 84.3+2.64 × % silt%-0.30 × % clay-7.43 × % organic matter-0.15 × % residue cover; r2 = 0.56). The predictive ability of the new equation was, however, no better than that of the existing predictive equations, suggesting the need for further refinement of WEF equations for the region. Simulated total soil loss by wind using the SWEEP model indicated that corn residue baling may increase soil loss if residue cover drops below 20% in the study region. Overall, the existing WEF equations may under-estimate WEF in the region, warranting further model refinement and site-specific validation, whereas the SWEEP estimated soil loss corroborates the critical importance of maintaining sufficient residue cover (>20%) to reduce wind erosion.