Research progress on the reduction of albic soil obstacles.

Albic soil is a typical low-yield soil with obstacles in the Northeast China Black Soil Region. It has a thin layer of black soil on the surface, low nutrient content in the soil body, and a compact and dense albic layer that hinders root penetration of crops and water infiltration. Those characteristics result in poor soil permeability and make the surface soil vulnerable to drought and flood disasters, which severely restricts grain yield. Eliminating the albic layer obstacle and increasing crop yield have become the main goals. We systematically summarized the research progress of albic soil obstacle reduction, discussed the advantages and disadvantages of current technologies from three aspects of chemical, biological, and mechanical improvement. We further analyzed the mechanism and improvement effect of each improvement technology on the physical properties of albic soil such as hardness, bulk density, soil pore structure and aggregates, as well as the chemical properties such as organic matter content, nutrient composition, and pH. In view of the problems existing in the research on albic soil obstacle reduction, we suggested that future research should focus on four directions: innovation and optimization of soil improvement machinery, policy support and assistance, promotion and application of modern soil improvement technologies, and response to obstacle reduction technologies under climate change and post-effect sustainability assessment, in order to provide a reference for the quality improvement of albic soil.