Patch burning: implications on water erosion and soil properties

Area of Science:

• Ecology
• Soil Science
• Environmental Management

Background:

• Patch burning is a grassland management technique aimed at increasing habitat heterogeneity, forage production, and plant biodiversity.
• However, comprehensive data on the environmental impacts of patch burning, particularly on soil properties and water erosion, are limited.

Purpose of the Study:

• To investigate the effects of time after patch burning on vegetative cover, water erosion, and soil properties.
• To compare recently burned, older burned, and unburned grassland patches.

Main Methods:

• A patch-burn experiment was conducted on Yutan silty clay loam near Mead, NE, established in 2011.
• Measurements were taken in summer 2013, assessing vegetative cover, canopy cover, litter cover, bare ground, runoff depth, sediment loss, sediment-associated organic carbon loss, soil temperature, soil compaction, soil structure, dissolved nutrients, soil carbon, and total nitrogen concentration.

Main Results:

• Recently burned patches (4 months post-burn) exhibited significantly more bare ground and less canopy and litter cover compared to older burned (16 months post-burn) and unburned patches.
• Water runoff depth was 2.8 times greater in both recently and older burned patches than in unburned patches.
• Recently burned patches showed 4.5 times greater sediment loss and 3.8 times greater sediment-associated organic carbon loss than older burned and unburned patches.
• Increased daytime soil temperature was observed in recently burned patches, but soil compaction, structural properties, dissolved nutrients, soil carbon, and total nitrogen concentrations did not differ significantly across treatments.

Conclusions:

• Recently burned patches are characterized by reduced vegetation cover and increased water and sediment erosion, including associated organic carbon.
• Despite these surface-level changes, soil properties like compaction, structure, nutrient content, and carbon/nitrogen concentrations appear resilient to recent burning under the study conditions.
• Patch burning can create heterogeneity but requires careful consideration of potential increases in erosion and sediment loss in the short term.