Grazing management impacts on vegetation, soil biota and soil chemical, physical and hydrological properties in tall grass prairie

Teague, W. R., et al., 2011. Agriculture, Ecosystems and Environment

Original research (primary data)
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Abstract

To assess whether adaptive management using multi-paddock grazing is superior to continuous grazing regarding conservation and restoration of resources we evaluated the impact of multi-paddock (MP) grazing at a high stocking rate compared to light continuous (LC) and heavy continuous (HC) grazing on neighboring commercial ranches in each of three proximate counties in north Texas tall grass prairie. The same management had been conducted on all ranches for at least the previous 9 years. Impact on soils and vegetation was compared to ungrazed areas (EX) in two of the counties. MP grazing was managed using light to moderate defoliation during the growing season followed by adequate recovery before regrazing after approximately 40 days and 80 days during fast and slow growing conditions, respectively. The vegetation was dominated by high seral grasses with MP grazing and EX, and dominated by short grasses and forbs with HC grazing. LC grazing had a lower proportion of high seral grasses than MP grazing or EX. Bare ground was higher on HC than LC. MP and EX, while soil aggregate stability was higher with MP than HC grazing but not LC grazing and EX. Soil penetration resistance was lowest with MP grazing and EX and highest with HC grazing. Bulk density did not differ among grazing management categories. Infiltration rate did not differ among grazing management categories but sediment loss was higher with HC than the other grazing management categories. Soil organic matter and cation exchange capacity were higher with MP grazing and EX than both LC and HC grazing. The fungal/bacterial ratio was highest with MP grazing indicating superior water-holding capacity and nutrient availability and retention for MP grazing. This study documents the positive results for long-term maintenance of resources and economic viability by ranchers who use adaptive management and MP grazing relative to those who practice continuous season-long stocking.

Case studies

Basic information

  • Case ID: INT-126-1
  • Intervention type: Management
  • Intervention description:

    INT 1 – The general management on the ranches using multiple pad- docks per herd was to graze a pasture lightly to moderately for 1 or 3 days followed by a recovery period of approximately 30–50 days and 60–90 days during fast and slow growing conditions, respec- tively…. During drought periods animal numbers were adjusted to match forage amounts. In the winter, the goal was to graze and trample most of the standing forage to enhance litter cover and minimize self- shading that would limit plant growth in the following spring.

  • Landscape/sea scape ecosystem management: Yes
  • Climate change impacts Effect of Nbs on CCI Effect measures
    Reduced soil quality  Positive soil chemistry and microbiota
    Reduced water availability  Positive Soil moisture (Volumetric %)
    Soil erosion  Positive Sediment loss (g m−2 ), Aggregate stability (%), % bare ground (measure of erosion risk)
    Loss of food production  Positive biomass composition (%) and standing crop biomass (kg ha−1 ) per herbaceous functional group
  • Approach implemented in the field: Yes
  • Specific location:

    Fort Worth Prairie and West Cross Timbers vegetation regions of North Central Texas (98◦ 08′ N, 33◦ 16′ W) in Cooke, Parker and Jack counties

  • Country: United States of America
  • Habitat/Biome type: Temperate grasslands |
  • Issue specific term: Not applicable

Evidence

  • Notes on intervention effectivness: Effectiveness determined by comparing to non-adaptive management strategies (can act as controls as per our definition) There were two types of control management types (low and high intensity grazing). For erosion, the NBS was the same as one of them (no effect, for low intensity) but better than the other – coded positive overall
  • Is the assessment original?: Yes
  • Broadtype of intervention considered: Not applicable
  • Compare effectivness?: No
  • Compared to the non-NBS approach: Not applicable
  • Report greenhouse gas mitigation?: No
  • Impacts on GHG: Not applicable
  • Assess outcomes of the intervention on natural ecosystems: No
  • Impacts for the ecosystem: Not reported
  • Ecosystem measures:
  • Assess outcomes of the intervention on people: No
  • Impacts for people: Not reported
  • People measures:
  • Considers economic costs: No
  • Economic appraisal conducted: No
  • Economic appraisal described:
  • Economic costs of alternative considered: No
  • Compared to an alternative: Not reported

Evaluation methodology

  • Type of data: Quantitative
  • Is it experimental: Yes
  • Experimental evalution done: In-situ/field
  • Non-experimental evalution done: Not applicable
  • Study is systematic: