Comparing rice production systems in China: Economic output and carbon footprint.

In recent years, many rotational and integrated rice production systems coupled with several greenhouse gas (GHG) emissions mitigation practices have been developed and adopted for demand of low carbon production. However, there have been only few studies about comparisons on the balance between high production and mitigation of GHG emissions in different rice production systems. We therefore aimed to evaluate economic output and carbon footprint of different rice production systems, based on several long-term experiments conducted by our lab. CH4 and N2O emission were measured by the same static chamber/gas chromatogram measurement procedure in different rice production systems, including rice-fallow, rice-rapeseed, rice-wheat, double rice, and integrated rice-crayfish production system. Then, we applied the DeNitrification DeComposition model to simulate CH4 and N2O emission over different years under the same condition for comparison. Carbon footprint was calculated following the process-based life cycle assessment (PLCA) methodology. The economic benefit of rice production systems was assessed by cost-benefit analysis. According to the analysis, the double-rice production system exhibited the highest intensity of carbon footprint (ICF = 4.14 kg CO2-eq yuan-1), rain-fed treatment in the rice-rapeseed system had the lowest (ICF = 0.68 kg CO2-eq yuan-1). The intensity of carbon footprint in different treatments in the integrated rice-crayfish production system was around 0.8 kg CO2-eq yuan-1. Overall, the results of this case study suggest: (1) the proposed practices in different rice production systems are no straw returning (rice-fallow), no-tillage without straw returning (rice-wheat), rain-fed farming (rice-rapeseed), no insect and no inoculation (double rice), and feeding with straw returning (rice-crayfish); (2) rotational and integrated systems can achieve high net output with low carbon emission; (3) reducing the amount of nitrogenous fertilizer application is the most important and effective GHG mitigation practice for rotational systems.

Clinical experience of minimally invasive spine surgery on treating lumbar disc herniation / 中国现代医生

Objective To explore the effect of minimally invasive spine surgery in the treatment of lumbar disc herniation and analyze its application value. Methods 76 patients with lumbar disc herniation treated in our hospital from August 2015 to September 2017 were selected as subjects. Patients were divided into control group and experimental group according to the order of admission. Each group contained 38 cases. Patients in the control group were treated with conventional open surgery, while patients in the experimental group were treated with minimally invasive spine surgery under diskoscope. The results of treatment were compared between the two groups. Results The results showed that all patients were cured completely after surgery. Intraoperative blood loss, operation time, and length of hospitalization in the experimental group were significantly better than those in the control group (P＜0. 05). The incidence of postoperative complications in the experimental group was less than that of the control group(P＜0. 05). Conclusion The minimally invasive spine surgery for the treatment of lumbar disc herniation can effectively reduced the operation time and hospitalization time of patients. It has a good application prospect and is worthy of promotion.