|Todd, Richard - Rick|
Submitted to: American Water Resources Association Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/26/2002
Publication Date: 5/12/2003
Citation: Todd, R.W., Wenxuan, G., Stewart, B.A., Robinson, C. 2003. Vegetation and soil changes in shortgrass prairie near a beef cattle feedyard. In: American Water Resources Association 2003 Spring Specialty Conference Proceedings, May 12-14, 2003, Kansas City, Missouri. 2003 CDROM.
Technical Abstract: Shortgrass prairie downwind from a 25,000 head beef cattle feedyard near Bushland, Texas changed after stocking the feedyard in 1970. Objectives of the study were to determine pre 1970 vegetation, quantify current vegetation, and describe changes in vegetation, soil P and dust deposition with distance from the feedyard. Pre 1970 vegetation was documented with published measurements. In 2000, plant cover was quantified using 600 quadrats. Soil P, conserved in the local soil, was measured in soil samples from 119 locations. Dust was collected at 12 locations. Pre 1970 vegetation was predominantly blue grama [Bouteloua gracilis (H.B.K.) Lag. ex Griffiths] and buffalograss [Buchloe dactyloides (Nutt.) Engelm.]. From 1966 to 1972, cover was 18.8% blue grama and 7.4% buffalograss. In 2000, perennial grass (75-99% blue grama) cover averaged 3.7% at <150 m from the feedyard, and increased to 28% at >525 m from the feedyard. Conversely, annual grass (67% Hordeum pusillum Nutt.) and annual forb [72% Kochia scoparia (L.) Schrad.] covers were 49% and 35% nearest the feedyard and decreased to 9% and 1%, respectively, at >525 m. Over a similar distance, soil P decreased from 75 to 17 mg/kg. Dust deposition rate decreased with distance from the feedyard. Manure dust contribution to total dust ranged from negligible to 89%. It was estimated that 20-30 kg N/ha/yr were deposited over 30 years to areas nearest the feedyard. Changes in vegetation and soil P were greatest at <500 m from the feedyard. Vegetation and soil P were near values expected for shortgrass prairie at >500 m downwind from the feedyard.