The impact of fertilization on the health of paddy soil: pathways and prospects for fertility regulation based on microbial communities

Fertilization is crucial for enhancing soil fertility and crop yields, primarily by modifying soil physicochemical properties and microbial communities, which subsequently influence soil carbon storage. Due to the unique flooded conditions of rice cultivation, paddy soils exhibit distinct microbial compositions and carbon storage mechanisms compared to upland soils. However, indiscriminate fertilization, without a thorough understanding of the underlying soil carbon pool storage and turnover mechanisms, not only yields suboptimal results but also poses environmental risks. Currently, a comprehensive literature review exploring the impacts of fertilization on crop growth and soil fertility accumulation mechanisms within rice cultivation systems remains lacking. This review summarizes the nutrient characteristics and turnover mechanisms in paddy soils, revealing slower organic matter turnover and stable soil organic carbon due to the unique paddy soil anaerobic environment. Microbial mineralization and organic matter accumulation vary with the planting cycle. We discuss the impacts of fertilization on soil fertility and microbial communities, highlighting the superior and more environmentally friendly effects of organic fertilizers. Importantly, a saturation threshold exists for soil carbon storage; exceeding this limit renders fertilization ineffective. Appropriate fertilizer application positively impacts microbial communities by modifying soil pH and physicochemical properties. Furthermore, this paper elaborates on the mechanisms of microbial-mediated carbon sequestration and its influencing factors. Future research leveraging a clear understanding of paddy soil nutrient mechanisms should integrate synthetic biology, materials engineering, and data-driven intelligent decision-making systems. This approach promises to be an effective pathway toward achieving intelligent, green, and high-yielding rice cultivation.