Mowing accelerates phosphorus cycling without depleting soil phosphorus pool.

Area of Science:

• Ecology
• Soil Science
• Biogeochemistry

Background:

• Grassland productivity is significantly influenced by phosphorus (P) cycling.
• Mowing, a common grassland management practice, involves biomass removal and can alter soil nutrient status.
• The specific impacts of mowing on P cycling in grassland ecosystems remain underexplored.

Purpose of the Study:

• To investigate the effects of different mowing regimes on soil P fractions and P accumulation in plants and litters.
• To elucidate the mechanisms by which mowing influences ecosystem P cycling by connecting aboveground communities with soil properties.

Main Methods:

• Investigated soil P fractions and P accumulation under various mowing regimes.
• Analyzed the relationship between aboveground community, soil properties, and P cycling.
• Examined microbial responses, including extracellular enzyme activity, microbial biomass, and community composition.

Main Results:

• Mowing increased soil dissolvable P concentrations, enhancing plant P absorption and accumulation.
• Mowing promoted grassland P cycling through plant-microbe interactions.
• Short-term mowing enhanced microbial extracellular enzyme activity via root exudation; long-term mowing boosted microbial metabolic activity through increased root carbon allocation.
• Organic P mineralization was stimulated by mowing for 15 years without causing soil P depletion.

Conclusions:

• Mowing enhances P cycling and accumulation in grasslands without necessarily leading to P limitation.
• Mowing stimulates P cycling through distinct short-term and long-term mechanisms involving plant-microbe-soil interactions.
• Findings contribute to understanding soil P dynamics under mowing and inform resource-efficient grassland management.