Tillage and Cattle Grazing Effects on Soil Properties and Grain Yields in a Dryland Wheat–Sorghum–Fallow Rotation

• Published in: Agronomy journal 2011-05, Vol.103 (3), p.914-922
• Main Authors: Baumhardt, R.L, Schwartz, R.C, MacDonald, J.C, Tolk, J.A
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Animal productions; Arid zones; Biological and medical sciences; cattle; clay loam soils; crop production; crop rotation; Cropping systems. Cultivation. Soil tillage; dryland farming; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Generalities. Cropping systems and patterns; grain sorghum; grain yield; grazing; integrated agricultural systems; liveweight gain; minimum tillage; no-tillage; pastures; semiarid zones; soil compaction; Soil properties; Soil tillage; soil water content; soil water storage; Sorghum bicolor; stubble mulching; Terrestrial animal productions; Tillage. Tending. Growth control; Triticum aestivum; Vertebrates; weed control; winter wheat
• ISSN: 0002-1962; 1435-0645
• DOI: 10.2134/agronj2010.0388

Cattle (Bos taurus) grazing intensifies production of the dryland wheat (Triticum aestivum L.)–sorghum [Sorghum bicolor (L.) Moench]–fallow (WSF) rotation in the U.S. Southern High Plains. Stubble-mulch (SM) tillage controls weeds and counteracts soil compaction. No-till (NT) increases soil water at planting and dryland crop yields, but added grazing effects are unknown. Our objectives were to quantify dryland winter wheat and sorghum yield responses to grazing and tillage practices. At the USDA-ARS Conservation and Production Research Laboratory, Bushland, TX, we established all WSF rotation phases in triplicate ungrazed and grazed paddocks beginning 1999 on a Pullman clay loam (fine, mixed, superactive, thermic Torrertic Paleustoll) using SM tillage. During spring 2004, NT or SM tillage were superimposed within grazing main plots. Cattle gain, soil water after fallow, and crop yield were compared during 2005 to 2009 using a split-plot randomized complete block design. Cattle, stocked at 1.8 Mg ha−1, grazed sorghum stover and growing wheat an average of 29 d for a mean gain of 147 kg ha−1 Soil water at planting was unaffected by grazing, but increased from 14 to 28 mm with NT. Although grazing seldom reduced yield of wheat or sorghum, NT in ungrazed plots increased crop yields sufficiently (0.96–2.6 Mg ha−1) in 2008 and 2009 to offset any value added by grazing. We conclude that cumulative grazing effects in NT plots reduced soil water storage and depressed yield. We recommend post-wheat-harvest SM tillage to disrupt soil compaction and restore grazed soil productivity.