Net ecosystem exchange of CO₂ (NEE) measurement was carried out in tropical lowland paddy at ICAR-National Rice Research Institute, Cuttack, Odisha, India, in 2015 using eddy covariance technique with the objective to assess the variation of NEE of CO₂ in lowland paddy and to find out the most suitable model for better partitioning of net ecosystem exchange of CO₂ in tropical lowland paddy. Paddy is grown twice (dry and wet season) a year in this region in the lowland, and the field is kept fallow during the remainder of the year. Two different flux partitioning models (FPMs)—the rectangular hyperbola (RH) and the Q10, were evaluated to assess NEE of CO₂, and its partitioning components—gross primary production (GPP) and ecosystem respiration (RE), and the resulting flux estimates were compared. The RH method assessed the effects of photosynthetically active radiation on the NEE, whereas the Q10 method utilized the relationship between ecosystem respiration and temperature in lowland paddy. The average NEE during the dry season and wet season was − 1.62 and − 1.83 g C m⁻² d⁻¹, respectively, whereas it varied from − 5.71 to 2.29 g C m⁻² d⁻¹ during the observation period covering both the cropping seasons and the fallow period. The mean difference between modeled GPP and RE from two FPMs was found significant in both the seasons. The maximum correlation for GPP estimation was found between two FPMs at the panicle initiation stage during both the dry season (R² = 0.767) and wet season (R² = 0.321). It was evident from the study that the Q10 method reliably produced the most realistic carbon flux estimates over the RH method, for the lowland paddy. The Q10 model which used nighttime flux and temperature data to estimate RE produced estimates that had lower prediction error (RMSE) as compared to the RH model. It can be concluded that in lowland paddy, the Q10 predicted better estimates of RE and GPP values than the RH method, suggesting that the Q10 model can be used for partitioning of NEE in tropical lowland paddy.

CO的净生态系统交换₂（NEE）测定是在热带低地稻谷在ICAR-水稻研究所，克塔克，奥里萨邦，印度，使用与所述目标涡动相关技术来评估CO的NEE的变化进行在2015年₂在低地稻田，并找到最合适的模型，以更好地划分热带低地稻田中CO ₂的净生态系统交换。稻田在低地的该地区每年种植两次（干旱和潮湿的季节），在其余年份，稻田保持休耕状态。评估了两种不同的通量分配模型（FPM）-矩形双曲线（RH）和Q10，以评估CO _2的NEE，以及其划分要素-总初级生产（GPP）和生态系统呼吸（RE），并比较了最终的通量估算值。RH方法评估了光合有效辐射对NEE的影响，而Q10方法利用了低地稻田生态系统呼吸与温度之间的关系。干旱季节和潮湿季节的平均NEE分别为-1.62和-1.83 g C m ^-2 d ^-1，而从-5.71到2.29 g C m ^-2 d ^-1在观测期涵盖耕种季节和休耕期。在两个季节中，从两个FPM建模的GPP和RE之间的平均差异均很明显。在干旱季节（R ²  = 0.767）和潮湿季节（R ²），在穗开始阶段的两个FPM之间发现了GPP估计的最大相关性。 = 0.321）。从研究中可以明显看出，对于低地稻田，Q10方法比RH方法可靠地产生了最现实的碳通量估算值。使用夜间通量和温度数据估算RE的Q10模型所产生的估算值与RH模型相比具有较低的预测误差（RMSE）。可以得出结论，在低地稻田中，Q10预测的RE和GPP值比RH方法更好，这表明Q10模型可用于热带低地稻田中NEE的划分。