Development and application of albic soil subsoil cultivation technology and future trends

Albic soil is a typical problematic soil in the black soil region. Its main constraints include a thin black soil layer, the presence of a hardpan, low nutrient contents in the albic horizon, and a shallow effective plow layer. This leads to a decline in farmland quality, low crop yields, and limits the improvement of farmland productivity. Subsoil fertilization technology has emerged as an effective measure to overcome these limitations. This review systematically summarized the background, technical characteristics, refinement process, implementation methods, and field application outcomes of subsoil fertilization in albic soils. The analysis showed that this technology can: 1) improve the poor physical properties of the albic layer, break through the hardpan layer, reduce soil hardness and the solid phase ratio; regulate soil chemical indicators, enhance soil fertility in the albic layer, and adjust soil pH; create a soil environment suited for crop growth and development, and increase crop yields with continuous effects lasting over five years. 2) When applied, the technology is tailored based on the thickness of the black soil layer and the physical and chemical characteristics of the subsoil layer, with continuous refinement and expanding application scenarios. It proves particularly effective in barren soils with thin black soil layers. Future development trends are also discussed: 1) emphasize the flexibility of subsoil fertilization technology application, determining tillage depth and fertilization position according to the thickness of the black soil or humus layer and the location of obstacle layers; 2) strengthen the adaptability of subsoil fertilization technology, varying the types and amounts of applied materials based on the subsoil’s properties in different regions, taking into full consideration issues such as soil compaction, acidification, alkalization, low organic matter, nutrient deficiencies, and combined problems, in order to select appropriate fertilization materials and determine quantities; 3) improve the efficiency and stability of subsoil fertilization machinery, optimize the design of plowshares and related components to boost performance and efficiency, and promote machinery toward precision, intelligence, multifunctional integration, and green development; 4) establish an integrated technology system with subsoil fertilization as the core. The focus of subsoil fertilization technology should shift from a single technique to building a comprehensive technology system, not only emphasizing the integration and adjustment of agricultural machinery, agronomy, and products, but also assembling with other single technologies to enhance overall effectiveness.This technology has broad applicability and promising potential, providing a technical pathway for improving low-yield albic soils, alleviating soil constraints, and enhancing farmland fertility in the black soil region.