Regional Assessment of Cattle Grazing and Baling of Corn Residues in Nebraska: Implications on Soil Ecosystem Services.

Response of soil ecosystem services to corn residue grazing and baling may vary across different soil types, tillage systems, irrigation regimes, and climates (i.e., precipitation). A regional assessment of the impact of corn residue grazing and baling on soil ecosystem services including water and wind erosion potential, compaction risks, soil structural quality, nutrient re-cycling, and crop production is being conducted on six on-farm experiments established across the precipitation gradient in Nebraska. The on-farm sites were established in fall 2013 with three treatments- corn residue: 1) baling, 2) grazing, and 3) control (no baling and no grazing) with two replications at Norfolk, Odessa, and Ainsworth, and three replications at Clay Center, Nebraska City, and Scottsbluff, NE. Field and laboratory measurements were performed in spring 2015 and 2016 to evaluate soil ecosystem services by determining bulk density and cone index (compaction parameters), dry and wet aggregate size distribution (soil structural quality), total organic C and N, and residue cover. Corn yield was determined each fall at crop maturity. In 2015, corn residue grazing (1.07±0.32 MPa) and baling (0.98±0.50 MPa) increased cone index at four sites compared to control (0.67±0.37 MPa). Grazing increased bulk density only at one site. In spring 2015, compared with control (10.30±2.97 Mg ha^-1), baling (3.94±1.45 Mg ha^-1) reduced corn residue amount at all sites and increased the proportion of erodible dry aggregates (<0.84 mm) at two sites. Corn residue baling and grazing had no effect on corn yield. Overall, cattle grazing and baling of corn residue may adversely affect some soil ecosystem services such as increased soil compaction risk and wind erosion potential in the short term.