Linear anionic polyacrylamide as an effective post-fire soil treatment: Understanding the chemistry and physical science

Abstract

Controlling erosion, reestablishing vegetation, and overcoming the negative effects of hydrophobic soils has long been a challenge following catastrophic wildfire on forested lands and rangelands. A three-year controlled study was recently completed to compare polyacrylamide soil treatment to the traditional cover method using agricultural straw on high severity burned soils of the Red Bull Fire, which burned through the Uinta National Forest near Provo, Utah, in July and August of 2004. Weed free, recycled paper pellets containing polyacrylamide were found to be an effective Burn Area Emergency Rehabilitation treatment option on clay rich soils containing divalent cations (i.e., Ca²⁺) within the soil matrix. This study showed aerial application of the granular polyacrylamide pellets resulted in an even distribution of the polymer-based product on the soil surface. Through water activation, a blend of water-soluble linear anionic polyacrylamide copolymers are slowly released, which bind with the soil particles, structurally stabilizing the soil. When compared to agricultural straw, polyacrylamide results show improved revegetation, reduced soil hydrophobicity, and reduced soil erosion.