Crop cultivars have an influence on greenhouse gas (GHG) emissions, and there is variation between varieties. However, there are few reports available on the differences in GHG emissions and their driving factors among vegetable varieties. In this study, we conducted a field experiment to examine the variances in GHG emissions and their contributing factors among eight flowering Chinese cabbage varieties (considering growth period, leaf shape, and colour). The results showed significant differences in GHG emissions within varieties; early-maturing varieties exhibited GHG by 25.6

Biochar was popularly used for reducing greenhouse gas (GHG) emissions in vegetable production, but using biochar does not necessarily guarantee a reduction in GHG emissions. Herein, it's meaningful to elucidate the intricate interplay among biochar properties, soil characteristics, and GHG emissions in vegetable production to provide valuable insights for informed and effective mitigation strategies. Therefore, in current research, a meta-analysis of 43 publications was employed to address these issues. The boost-regression analysis results indicated that the performance of biochar in inhibiting N2O emissions was most affected by the N application rate both in high and low N application conditions. Besides, biochar had dual roles and showed well performance in reducing GHG emissions under low N input (≤300 kg N ha-1), while having the opposite effect during high N input (>300 kg N ha-1). Specifically, applying biochar under low N fertilization input could obviously reduce soil N2O emissions, CO2 emissions, and CH4 emissions by 18.7 %, 17.9 %, and 16.9 %, respectively. However, the biochar application under high N fertilization input significantly (P < 0.05) increased soil N2O emissions, CO2 emissions, and CH4 emissions by 39.7 %, 43.0 %, and 27.7 %, respectively. Except for the N application rate, the soil pH, SOC, biochar C/N ratio, biochar pH, and biochar pyrolysis temperature are also the key factors affecting the control of GHG emissions in biochar-amended soils. The findings of this study will contribute to deeper insights into the potential application of biochar in regulating GHG under consideration of N input, offering scientific evidence and guidance for sustainable agriculture management.

Biochar is widely used to maintain crop yields and the sustainability of agroecosystems due to its characteristics. However, its effect on vegetable yield and quality in southern acidic soils has not been fully elucidated. The effects of two kinds of biochar application rates (3 t ha−1 and 12 t ha−1) on the nutrient availability, nutrient absorption, yield, and fruit quality of sandy acid oxide soil in South China were studied in a 2-year field experiment using two varieties of wax gourd (Tiezhu No. 2 and Dadao). The results showed that optimized fertilization (OPT, nitrogen, phosphorus, and potassium were reduced by 20.0%, 20.6%, and 21.1%, respectively) did not reduce the yield of the different varieties of wax gourd compared to FP (farmer practice). On the basis of the OPT treatment, the application of biochar increased the yield of Tiezhu No. 2 and Dadao wax gourd by 16.0–27.3% and 7.7–13.3%, respectively. The increase in yield was attributed to the improvement in soil organic carbon content which increased by 4.5–19.7%, nutrient effectiveness (NO3−-N and Olsen-P content enhanced by 23.7–27.0% and 15.3–23.4% in Tiezhu No. 2), and nutrient uptake (N, P, K, Ca, and Mg accumulation increased significantly by 21.1%, 46.1%, 36.8%, 25.7%, and 31.9%, respectively) by the plant after the biochar application. Different types of biochar also have some differences in these three aspects. Specifically, under the same dosage, rice biochar has a more significant effect on increasing the yield of winter melon, and has a better effect on the improvement of soil physical and chemical properties, while sawdust biochar has a more significant effect on nutrient absorption. In addition, the commercial quality, namely hardness and glossiness, and the nutritional quality, namely soluble sugar, soluble protein, VC content, and sugar–acid ratio of wax gourd fruits, were significantly improved after the biochar application. In summary, biochar application on acidic soils in South China could achieve a win–win situation in terms of increasing soil nutrient effectiveness to improve vegetable yield and quality while reducing chemical fertilizer.

本文利用2000、2005、2010和2015年中国人口普查(抽样调查)微观数据及1999-2018年的城市层面指标,基于中国加入WTO中美确立永久性正常贸易关系的准自然实验,采用Bartik方法构建城市层面贸易政策不确定性,详细考察了贸易政策不确定性下降对区域劳动力市场技能偏向的影响.研究发现,贸易政策不确定性下降显著提高了劳动力市场高中及以上学历的就业占比,加剧了就业技能偏向,且其长期影响大于短期影响.同时,贸易政策不确定性不仅对制造业部门就业技能偏向的影响存在动态演变特征,还对服务业部门形成一定的正向溢出效应,且出口升级在其中发挥了正向调节作用.进一步分析发现,贸易政策不确定性下降显著促进了劳动力市场的工资增长,且该影响具有长期效应.

"稳就业"是中国实施大规模减税降费政策的重要目标,科学评估每就业岗位增加需要付出的减税成本具有重要意义.本文基于区域劳动力市场的视角,借助2015年固定资产加速折旧政策,理论分析并经验考察了投资税收激励的地区就业效应和作用机制.研究发现,固定资产加速折旧政策的实施显著促进了地区总就业,而高房价与户籍摩擦会阻碍减税稳就业效应的发挥.本文表明,这一政策引致的资本投资上升并未在地区加总层面导致资本对劳动要素的替代,反而通过促进企业进入与行业间溢出提高了当地劳动力需求.此外,成本收益的量化分析表明,政府每增加1个就业岗位需付出约15 689元的减税成本.

In the "Action Plan for 10,000 Firms to Save Energy and Lower Carbon Emissions," China assigns responsibility for achieving the overall goal of achieving energy conservation and emissions reduction (ECER) to firms, which strengthens monitoring of ECER and pollution control. Based on the data on Chinese industrial firms and customs during 2010 and 2013, this paper analyzes the effect of ECER policy on employment adjustment with a difference-in-difference (DID) model and a mediating effect model. The results indicate that ECER policy significantly promotes net job growth by increasing firms' job creation effect and weakening the job destruction effect. For every 1% increase in ECER policy intensity, net job growth increases by 8.04%. The heterogeneity analysis shows that ECER policy weakens net job growth at firms with high export intensity, high market concentration, and high pollution and increases net job growth at firms in regions that are highly market based. ECER policy promotes job growth through the mediating mechanism of the productivity effect and adjustment in the scope of exports. Our results are helpful for assessing the shock to employment from Chinese environmental policy and provides feasible policy suggestions for adjusting existing laws and regulations to achieve higher social welfare.

工业机器人的使用对我国制造业升级和经济结构转型具有重要影响,“机器换人”成为当前学界和社会广泛关注的时代命题.面对工业机器人使用的冲击,区域劳动力市场的就业和工资将会如何进行调整?基于2012-2016年中国劳动力动态调查数据和工具变量法进行的实证研究表明:第一,城市工业机器人的使用并没有造成当地劳动力市场整体就业岗位的减少,但导致了劳动力在不同部门之间的重新配置,即制造业部门就业概率下降,服务业部门就业概率上升,这一效应主要体现在低技能水平的劳动力群体;第二,在就业的集约边际方面,城市工业机器人的使用显著提高了当地劳动力的工作时长,这主要源于服务业部门工作时长的增加;第三,城市工业机器人的使用对当地劳动力的整体工资增长影响较小,但部门工资结构随之调整,其中制造业部门的工资和技能溢价增长较快,服务业部门的工资增长较慢,而技能溢价无显著变化.有鉴于此,政府在制定工业智能化发展的产业政策时需考虑其与劳动力市场就业和工资的关系,尤其要考虑制造业部门和低技能劳动力群体的利益,辅以相应的就业和收入再分配政策,以减少工业机器人使用所带来的调整成本.

Historically, cooperative medical insurance and village doctors are considered two powerful factors in protecting rural residents’ health. However, with the central government of China’s implementation of new economic policies in the 1980s, cooperative medical insurance collapsed and rural residents fell into poverty because of sickness. In 2009, the New Rural Cooperative Medical Insurance (NRCMI) was implemented to provide healthcare for rural residents. Moreover, the National Basic Drug System was implemented in the same year to protect rural residents’ right to basic drugs. In 2013, a village doctor contract service was implemented after the publication of the Guidance on Pilot Contract Services for Rural Doctors. This contract service aimed to retain patients in rural primary healthcare systems and change private practice village doctors into general practitioners (GPs) under government management. Objectives: This study investigates the factors associated with rural residents’ contract behavior toward village doctors. Further, we explore the relationships between trust, NRCMI reimbursement rate, and drug treatment effect. We used a qualitative approach, and twenty-five village clinics were chosen from three counties as our study sites using a random sampling method. A total of 625 villagers participated in the investigation. Descriptive analysis, chi-squared test, t-test, and hierarchical logistic analyses were used to analyze the data. Results: The chi-squared test showed no significant difference in demographic characteristics, and the t-test showed a significant difference between signed and unsigned contract services. The results of the hierarchical logistic analysis showed that trust significantly influenced patients’ willingness to contract services, and the drug treatment effect and NRCMI reimbursement rate moderated the influence of trust. Conclusion: Our findings suggest that the government should aim to strengthen trust in the doctor–patient relationship in rural areas and increase the NRCMI reimbursement rate. Moreover, health officers should perfect the contract service package by offering tailored contract services or expanding service packages.