Soil Thermal Properties under Prairies, Conservation Buffers, and Corn–Soybean Land Use Systems

Adhikari, P., et al., 2014. Soil Science Society of America Journal

Original research (primary data)
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Abstract

Although prairies and conservation buffers are becoming popular to improve soil properties and environmental quality, very little is known about their influence on soil thermal properties. This study compared and quantified thermal conductivity (l), thermal diffusivity (D), and volumetric heat capacity (C) of prairies (Tucker Prairie [TP] and Prairie Fork [PF]), conservation buffers (grass buffers [GB] and agroforestry buffers [AGF]), and corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation (COS) land uses in Missouri. Core and bulk soils were collected at 10-cm depth increments. Soil thermal properties and water characteristic curves were determined at 0, -33, -100, and -300 kPa pressures. Additionally, soil organic C (SOC) and bulk density (BD) were also determined. The results showed that SOC was negatively correlated with l and D and positively correlated with C. Significantly higher values of SOC and lower BD were observed for AGF, TP, GB, and PF than COS. Similarly, l and D were significantly higher and C was lower under COS than the prairies and conservation buffers. The results suggest that a greater amount of SOC decreases the thermal conductance due to the insulating characteristics of SOC and acts as a barrier to heat transport. Therefore, AGF, TP, GB, and PF had lower thermal conductance to deeper soil depths, which helps to conserve more moisture as well as assist in increasing the longevity of SOC in the soil matrix. Our results imply that buffers and perennial vegetation can help reduce heat flow by increasing the thermal capacity and thereby mitigating climate change.

Case studies

Basic information

  • Case ID: INT-171-1
  • Intervention type: Restoration
  • Intervention description:

    Restored prairie The PF land use system was restored in 1993 with native grasses and legumes such as little blue stem, side-oats grama [Bouteloua curti- pendula (Michx.) Torr. var. curtipendula] and Indian grass. [From Udawatta et al. 2008]: The Prairie Fork Conservation Area site was under row crop management for approximately 100 yr and was restored in 1993 with native grasses and legumes.

  • Landscape/sea scape ecosystem management: No
  • Climate change impacts Effect of Nbs on CCI Effect measures
    Reduced water availability  Positive Volumetric Moisture content at different depths (m3/m3) also look at soil quality properties - Soil organic C (SOC), bulk density (BD), thermal conductivity (l), and thermal properties - volumetric heat capacity (C), and thermal diffusivity (D) --> these properties are correlated to ability to retain moisture, by measuring these traits also determining ability of intervention to retain moisture (and how it is able to do so - i.e. by increasing (e.g.) SOC, able to decrease thermal conductivity and retain more moisture)
  • Approach implemented in the field: Yes
  • Specific location:

    Five study locations, GB, COS, AGF, Prairie Fork (PF, a restored prairie), and Tucker Prairie (TP, a natural prai- rie) land use systems were selected in central and northern Missouri.

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

Evidence

  • Notes on intervention effectivness: effectiveness determined by comparing outcome measures to those of the corn-soybean rotation which can be taken as the comparator. note that while they do measure volumetric moisture content, the bulk of their conclusions are drawn from correlations between soil quality properties and soil thermal properties --> soil thermal properties are considered an indicator of how the soil will be able to retain moisture and resist drought. by influencing soil quality properties, soil thermal properties are altered which in turn affects moisture Mitigation: they measure SOC and state "assist in increasing the longevity of SOC in the soil matrix."
  • 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?: Yes
  • Impacts on GHG: Positive
  • 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: