Recently, Hubei Academy of Agricultural Sciences has made new progress in the research of key technologies for carbon and nitrogen nutrient management in the rice-wheat rotation model. The "Innovation and Application of Key Technologies for Annual Carbon and Nitrogen Balance Nutrient Management in Rice-Wheat Rotation" led by the academy has been reviewed and identified by domestic and foreign academicians, reaching an internationally leading level overall.
Schematic diagram of research mechanism. Image provided by the interviewed unit.
This study, supported by the Key Laboratory of Agricultural Waste Fertilization and Utilization of the Ministry of Agriculture and Rural Affairs, is based on the long-term positioning experiment of rice-wheat rotation straw returning at the National Agricultural Environment Observation and Experiment Station in Qianjiang. It validates and analyzes data from the National Hongshan Experimental Observation Station over 43 years, uncovering the mechanism of carbon-nitrogen coordination regulating soil microbial metabolism to synergistically enhance soil organic matter and crop yield.
Under the practice of straw returning in rice-wheat rotation, the straw regulates microbial assembly, drives lipid and amino acid metabolic pathways, and increases the stable carbon abundance in the soil, such as lipids, organic acids, organic nitrogen compounds, and phenols. Proper straw returning combined with nitrogen fertilizer induces soil microbial synthetic metabolic pathways, increases soil microbial residue carbon, with a carbon sequestration contribution exceeding 50%. Soil aggregates play a crucial role in carbon sequestration, enhancing soil organic carbon content in aggregates of different particle sizes, with the 0.25-2 mm particle size aggregates contributing the highest to organic carbon (45-59%).
Straw returning combined with fertilization regulates soil microbial metabolism, enhances soil carbon, nitrogen, and phosphorus cycling-related extracellular enzyme activities, improves soil nutrient activity, enhances crop nutrient absorption capacity, and increases crop yield.
This technological achievement has achieved significant benefits in the rice-wheat rotation area of Hubei Province, with an annual average carbon sequestration and emission reduction of 2.24 million tons of CO2 equivalent, equivalent to a carbon trading value of 2.24 billion yuan, increasing rice and wheat production by 550,000 tons annually, generating additional benefits of 2.77 billion yuan, contributing to food security and environmental safety.
