Effects of corn crop residue grazing on soil physical properties and subsequent soybean production in a corn-soybean crop rotation

High winter feed costs associated with stored feeds are detrimental to the profitability of Midwest beef cattle enterprises. Therefore, many producers graze corn crop residues as an alternative to feeding hay. However, there is concern that grazing corn crop residue fields will cause compaction resulting in lower crop yields the following year. Therefore, two locations in Iowa (Chariton and Atlantic) were used to study the effects of corn crop residue grazing by beef cows on soil characteristics and subsequent soybean yields. After two years of study at both locations, organic matter yield of crop residue decreased at a faster rate in grazed fields than ungrazed fields, but corn crop residue composition did not differ between grazed and ungrazed fields, pre-, mid- and post-grazing. Corn crop-residue cover and soil roughness were greatly affected by the interaction of grazing and weather conditions. When soils temperatures were above freezing and precipitation was adequate, cattle traffic increased surface roughness, while reducing residue cover. Corn crop residue grazing increased the ratio of penetration resistance measured 15 feet outside to inside grazing exclosures by an average of 40% because of paddocks grazed when soils were unfrozen and at an adequate moisture content. But CR grazing did not cause any increase in bulk density measurements or differences in soybean yields in the subsequent growing season.