Paddy fields can gain high productivity with low net global warming potential by utilizing green manure

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Milk vetch is a common winter green manure in Southern China's paddy fields.
• The greenhouse gas impact of combining milk vetch and rice straw has not been previously studied.

Purpose of the Study:

• To investigate the net greenhouse gas emissions and environmental factors of co-utilizing milk vetch and rice straw in paddy fields.
• To assess the impact of milk vetch application on soil productivity and carbon sequestration.

Main Methods:

• A two-year long-term experiment was conducted.
• Net greenhouse gas emissions (CO2, N2O, CH4) and soil carbon sequestration rates were measured.
• Environmental factors and their relation to greenhouse gas emissions were analyzed.

Main Results:

• Milk vetch application increased rice yields and soil productivity, particularly when combined with rice straw.
• Annual soil carbon sequestration rates increased by 492 kg/ha (without straw) and 1115 kg/ha (with straw).
• Co-utilization of milk vetch and rice straw reduced net global warming potential and greenhouse gas emission intensity compared to rice straw alone.

Conclusions:

• Milk vetch application, especially with rice straw, mitigates net greenhouse gas emissions through enhanced soil carbon sequestration.
• This practice is an effective strategy for reducing agriculture's carbon footprint and supporting carbon neutrality goals.
• Utilizing milk vetch as green manure offers significant environmental benefits for paddy field management.