Greenhouse gas emissions of rice straw return varies with return depth and soil type in paddy systems of Northeast China

ABSTRACT

A two-year field experiment was performed to investigate greenhouse gas emissions from rice straw return to different return depths and soil types. The experiment comprised of six treatments: without straw return (silty clay loam, SC; sandy loam, SL); straw return to topsoil (SCT, SLT); and straw return to subsoil (SCS, SLS). SCT and SLT released 2402.18 and 2494.01 kg ha⁻¹ more CO₂ than SC and SL in total, respectively. Straw return to topsoil and subsoil in both soil textures significantly increased CH₄ emissions. Compared to the total cumulative CH₄ fluxes in SC and SL, those of SCT and SLT increased by 239.62 and 131.34 kg ha⁻¹, and those of SCS and SLS increased by 125.07 and 89.93 kg ha⁻¹, respectively. SCT and SCS emitted 389.06 and 168.94 g ha⁻¹ less N₂O than SC in total, respectively. SL released 146.28 and 72.06 g ha⁻¹ more N₂O than SLT and SLS in total, respectively. The variations in the ratio of the total cumulative fluxes of CO₂ and CH₄, indicate that rice straw return to silty clay loam and subsoil tend to release more carbon in the form of CH₄ compared to sandy loam and topsoil, respectively.

KEYWORDS:

• Greenhouse gases
• rice straw return
• paddy soil
• soil depth
• soil type

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Science and Technology Planning Project of Ministry of Housing and Urban-Rural Development of the People’s Republic of China [2018-K6-003]; Science and Technology Planning Project of Jilin Province in China [20180520100JH]