[Differences and Relationship Between Rhizosphere Characteristics and Methane Emissions of Double-cropping Rice...

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Rice cultivation is a major source of methane (CH4) emissions, a potent greenhouse gas.
• Varietal differences in rice can influence CH4 emission rates and the associated environmental impact.
• Understanding these variations is crucial for developing mitigation strategies in agriculture.

Purpose of the Study:

• To investigate and quantify the differences in CH4 emissions among six field varieties of early and late rice.
• To compare the cumulative CH4 emissions and the greenhouse effect per unit yield for different rice varieties.
• To identify factors influencing CH4 emissions and explore potential reduction methods.

Main Methods:

• Field experiments were conducted using six rice varieties (early and late).
• Static Obscura-Gas Chromatography was employed to measure CH4 gas emissions.
• Data on CH4 flux, cumulative emissions, and greenhouse effect per yield were analyzed.

Main Results:

• Significant differences in CH4 emission flux were observed between early and late rice varieties.
• Late rice varieties exhibited higher cumulative CH4 emissions (291.93–388.28 kg·hm-2) compared to early rice (198.3–303.44 kg·hm-2).
• Varietal differences in CH4 emissions and greenhouse effect per unit yield were significant, with specific varieties showing highest and lowest emissions.

Conclusions:

• Rice varietal selection significantly impacts CH4 emissions and the greenhouse effect.
• Management practices, such as reducing rhizosphere carbon and nitrogen and increasing Eh values, can mitigate CH4 emissions.
• Targeted varietal selection and agronomic adjustments are key to reducing the climate footprint of rice production.