Effects of Humic Acid from Weathered Coal on Water-Stable Aggregates and Pore Structure of a Reclaimed Cambisol

Abstract

To clarify the effects of weathered coal humic acid on water-stable aggregates and pore characteristics of reclaimed cambisol, this research analyzed the evolution characteristics of soil aggregates and pores. Effects of different humic acid dosages (0, 1%, 3%, and 5% by weight) and application period (1 year, 2 years, and 3 years) on soil aggregates and organic carbon components in soil water-stable aggregates were investigated. The results showed that it is advisable to have an addition of 5% weathered coal humic acid in reclaimed cambisol. The humic acid of weathered coal promoted the disintegration and transformation of water-stable aggregates and increased soil pore p > 75 μm. At 3 years, the structure of reclaimed soil was the most stable, with more robust connected pores, and the irregular pores increased. The humic acid of weathered coal has the potential to be used as an effective organic amendment for improving the quality of reclaimed cambisol.

Keywords

• reclaimed cambisol
• humic acid
• water-stable aggregate
• soil pore