Submitted to: ASA-CSSA-SSSA Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 11/6/2005
Publication Date: 11/6/2005
Citation: Baumhardt, R.L., Greene, L.W., Schwartz, R.C. 2005. Cattle grazing effects on dryland cropping system productivity and soil properties [abstract]. Agronomy Abstracts, ASA-CSSA-SSSA Annual Meeting, Salt Lake City, Utah. 2005 CDROM. Interpretive Summary:
Technical Abstract: On the southern Great Plains, dryland wheat (Triticum aestivum L.) and grain sorghum [Sorghum bicolor (L.) Moench] are grown in a wheat-sorghum-fallow (WSF) rotation that consistently produces two crops in a three year cycle using precipitation stored in the soil. Integration of cattle grazing on wheat forage and sorghum stubble to intensifies dryland production and increases profitability of the WSF rotation. Grazing, however, may result in soil compaction and decreased residue cover that decreases water conservation and crop yield. Our objective was to quantify the effect of grazing on crop grain and residue yield and system productivity, soil properties like aggregation, and soil water storage in a dryland WSF rotation. All phases of the WSF rotation were duplicated for grazed or ungrazed plots on a 16 ha area that was divided into three blocks (replicates). Cattle weight gain, forage and grain yield, residue production, precipitation, and soil water contents were measured for each rotation phase in a study initiated in 1998. Typically, sufficient wheat forage was produced for 32 days grazing, at approximately 1.8 Mg ha-1 wheat pasture, with a mean 140 kg ha-1 gain and no significant reduction of mean wheat yield. Where wheat was grazed-out in 2001, cattle gained 130 kg ha-1 and decreased wheat residue by 90%. Without this residue, soil water storage during fallow was negligible and the subsequent sorghum crop failed. In other years, timely removal of grazing cattle from wheat did not decrease residue amounts or the subsequent sorghum crop. Grazing dryland wheat may successfully increase overall productivity of the WSF cropping system provided wheat residue production is protected from graze-out.