|Stavi, Ilan -|
|Lal, Rattan -|
Submitted to: Ecohydrology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 16, 2010
Publication Date: January 20, 2011
Citation: Stavi, I., Lal, R., Owens, L.B. 2011. Effects of cattle grazing during the dormant season on soil surface hydrology and physical quality in a moist-temperate region. Ecohydrology. 4(1):106-114. Interpretive Summary: Livestock grazing is a common agricultural practice, and there are many different management practices within the category of livestock grazing. The impacts of a variety of management practices have been studied in regards to several general parameters, such as forage sustainability, animal production and health, and water quality. Soil quality and various aspects of this have not received as much study as some of the other parameters. This article compares a variety of mechanical and hydrological characteristics of soils in a rotational, summer only grazing pasture with soils in an area that has dormant season grazing as well as rotational summer grazing. This comparison in eastern Ohio indicated that dormant season grazing with beef cows adversely affects soil quality. Penetration resistance and bulk density were greater with the dormant grazing; coarse root biomass, moisture capacity, and infiltration rate were lower with the dormant grazing than with the rotational summer only grazing. These are factors to be considered when deciding on dormant season management of livestock, but there is a need for more investigations with other management systems, types of grazing livestock, and topographies. This information is important to producers, university extension and NRCS personnel, and agricultural consultants, as well as other scientists.
Technical Abstract: Livestock grazing in paddocks of temperate regions during the dormant season adversely affects soil quality. The adverse effects stem from trampling action under wet soil conditions. Thus, the objective of this study was to evaluate the long-term effects of livestock grazing on soil quality, with special reference to some mechanical and hydrological characteristics of the soil. Soil properties were measured in a paddock under rotational grazing during the growing season only (GR) and compared with those under grazing during the dormant season and rotational grazing during the growing season (DO). Soil series in both paddocks is Coshocton (Aquultic Hapludalfs). Soil properties were studied for 3 depths (0-5, 5-10 and 10-15 cm). In comparison with GR, DO had a larger penetration resistance (0.93 vs. 1.42 MPa) and bulk density (1.24 vs. 1.44 g cm-3), and lower water stable aggregates (880 vs. 830 g kg-1, respectively), coarse root (> 1 mm) biomass (1.11 g / 86.7 cm3 vs. 0.62 g / 86.7 cm3), and field moisture capacity (364 vs. 326 g kg-1). Some indices of water infiltrability were higher in GR than in DO, including sorptivity (47.8 vs. 24.7 mm min-0.5), transmissivity (2.2 vs. -0.5 mm min-1), final equilibrium rate (4.8 vs. 1.4 mm min-1) and cumulative infiltration (865.6 vs. 260.0 mm). However, only small difference between the two grazing treatments was observed in vane shear strength (0.13 and 0.12 MPa for GR and DO, respectively), and no difference in aggregate’s mean weight diameter. Soil depth affected most of the soil properties. In general, the effect of grazing treatment decreased with increase in soil depth.