Soil CO₂ emissions from summer maize fields under deficit irrigation

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Irrigation significantly influences soil carbon dioxide (CO2) emissions from croplands, impacting global warming.
• Deficit irrigation, a water-saving technique, is crucial for summer maize cultivation facing water scarcity in Northwest China.

Purpose of the Study:

• To investigate the effects of deficit irrigation practices on soil CO2 emissions in summer maize fields.
• To evaluate the trade-offs between water conservation, CO2 reduction, and crop yield under different irrigation regimes.

Main Methods:

• A plot experiment was conducted with three irrigation treatments: full irrigation (T0), 20% deficit irrigation (T1), and 40% deficit irrigation (T2).
• Soil CO2 emissions and summer maize yields were measured under each treatment.
• Correlations between soil CO2 fluxes, soil moisture, and soil temperature were analyzed.

Main Results:

• Soil CO2 cumulative emissions decreased by 9.8% (T1) and 14.3% (T2) compared to full irrigation (T0).
• Summer maize yields were reduced by 4.9% (T1) and 30.9% (T2) relative to T0.
• Soil CO2 fluxes showed significant positive correlations with soil moisture and soil temperature.

Conclusions:

• Deficit irrigation (T1) effectively reduces soil CO2 emissions in summer maize fields by 9.8% without significantly compromising crop yield.
• This approach offers a viable strategy for sustainable agricultural management in water-limited regions like Northwest China.
• Optimizing irrigation regimes is key to mitigating greenhouse gas emissions while ensuring food security.