Ensuring water resource security in China; the need for advances in evidence based policy to support sustainable management.

China currently faces a water resource sustainability problem which is likely to worsen into the future. The Chinese government is attempting to address this problem through legislative action, but faces severe challenges in delivering its high ambitions. The key challenges revolve around the need to balance water availability with the need to feed a growing population under a changing climate and its ambitions for increased economic development. This is further complicated by the complex and multi-layered government departments, often with overlapping jurisdictions, which are not always aligned in their policy implementation and delivery mechanisms. There remain opportunities for China to make further progress and this paper reports on the outcomes of a science-to-policy roundtable meeting involving scientists and policy-makers in China. It identifies, in an holistic manner, new opportunities for additional considerations for policy implementation, continued and new research requirements to ensure evidence-based policies are designed and implemented and identifies the needs and opportunities to effectively monitor their effectiveness. Other countries around the world can benefit from assessing this case study in China

The Effect of the Major-Grain-Producing-Areas Oriented Policy on Crop Production: Evidence from China

As a powerful actor in the global food system, China experienced a significant drop in crop production from 1998 to 2003, which posed a substantial threat to national food security and led to the establishment of 13 major grain-producing areas (MGPA). Although some qualitative research has found that the MGPA policy plays an important role in ensuring the national food security, quantitative evidence on the effect of the MGPA policy and its potential mechanism remains scarce. Based on China’s interprovincial panel data from 1998 to 2018, this study used a difference-in-differences (DD) estimation strategy to analyze the treatment effect of the MGPA policy by taking the assignment of 13 MGPA as a quasi-experiment. The results showed that the enforcement of the MGPA policy significantly increased crop production, especially in terms of grain, rice and wheat yields. The average grain yields were raised by 27.5%. The results of the event study analysis showed that the treatment effects were sustainable in the following years of the policy implementation. This study also explored alternative causal channels and found that the MGPA policy raised crop yields mainly by expanding planting areas, improving the level of mechanization and increasing transfer payments. These findings demonstrate the effectiveness of the MGPA policy in increasing crop production in a developing country setting, which could enlighten policymakers in some less well-developed countries on boosting crop production and maintaining food security

Technical Efficiency of Maize Production and Its Influencing Factors in the World’s Largest Groundwater Drop Funnel Area, China

Improving the efficiency of maize production is of great significance for global food security and the effective supply of agricultural products. Based on the survey data of 381 rural households, this study uses a stochastic frontier analysis to estimate the efficiency value and empirically analyze the factors affecting the technology efficiency of maize production in the Hengshui area of the North China Plain. First, higher costs were found to be related to extensive production methods of fertilization, pesticide application, and irrigation. Second, the results showed that there was an inverted U-shaped relationship between the irrigation cost and maize output. Specifically, when the irrigation cost was about 938 yuan/hectare, the maize output per unit area was optimal. Third, there was also an inverted U-shaped relationship between the fertilizer cost and maize output, and the loss of technical efficiency of maize output was minimal when the fertilizer cost is 2547 yuan/hectare. In addition, the findings of the inefficiency influencing factor model suggested that temperature and humidity were all positively associated with the non-efficiency of maize production. These findings can provide empirical support for improving the efficiency of maize production in North China or arid and semi-arid regions around the world

A Novel Knowledge Base Question Answering Method Based on Graph Convolutional Network and Optimized Search Space

Knowledge base question answering (KBQA) aims to provide answers to natural language questions from information in the knowledge base. Although many methods perform well when dealing with simple questions, there are still two challenges for complex questions: huge search space and information missing from the query graphs’ structure. To solve these problems, we propose a novel KBQA method based on a graph convolutional network and optimized search space. When generating the query graph, we rank the query graphs by both their semantic and structural similarities with the question. Then, we just use the top k for the next step. In this process, we specifically extract the structure information of the query graphs by a graph convolutional network while extracting semantic information by a pre-trained model. Thus, we can enhance the method’s ability to understand complex questions. We also introduce a constraint function to optimize the search space. Furthermore, we use the beam search algorithm to reduce the search space further. Experiments on the WebQuestionsSP dataset demonstrate that our method outperforms some baseline methods, showing that the structural information of the query graph has a significant impact on the KBQA task

Research Progress on the Polymeric Immunoglobulin Receptor (pIgR) in Fish

There are a large number of pathogens in the water where fish live, and the mucosal-associated lymphoid tissues (MALTs), such as skin, gill and intestine, are the first contact parts when pathogens infect fish. The secreted mucus of these tissues constitutes the first barrier for fish against the invasion of external pathogens. Mucosal immunity can identify and neutralize pathogens and induces immunocytes to devour pathogens and the like. As a key factor in the mucosal immune system, the polymeric immunoglobulin receptor (pIgR) is capable of mediating the transport and secretion of polymeric immunoglobulins towards mucus. The effective secretion of the pIgR is necessary for polymeric immunoglobulins (pIg) to exert mucosal defence and plays a significant role in fish immunity. With the deepening of research into fish immunoglobulins, the pIgR has become a research hotspot. The molecular structure, genetic structure and expression pattern of the pIgR and the important role it plays in mucosal immunity were summarized in this study, which contributed to a deeper understanding of fish mucosal immunity and laid a foundation for further exploration of the action mechanism and functions of the pIgR in fish

Ecological Security Patterns at Different Spatial Scales on the Loess Plateau

The study of ecological security patterns (ESPs) is of great significance for improving the value of ecosystem services and promoting both ecological protection and high-quality socio-economic development. As an important part of the “Loss Plateau-Sichuan-Yunnan Ecological Barrier” and “Northern Sand Control Belt” in the national security strategic pattern, there is an urgent need to study the ESPs on the Loess Plateau. Based on a remote sensing dataset, this study identified the ESPs at different spatial scales, and analyzed the similarities and differences of ecological sources, corridors, and key strategic points, so as to better inform the development and implantation of macro and micro ecological protection strategies. When taken as a whole unit, we identified 58 ecological sources (areas with higher levels of ecosystem services) on the Loess Plateau (total area of 57,948.48 km2), along with 134 corridors (total length of 14,094.32 km), 1325 pinch points (total area of 315.01 km2), and 2406 barrier points (total area of 382.50 km2). When splits into ecoregions, we identified 108 sources (total area of 67,892.51 km2), 226 corridors (total length of 13,403.49 km), 2801 pinch points (total area of 851.07 km2, and 3657 barrier points (total area of 800.70 km2). Human activities and land use types are the main factors influencing the number and spatial distribution of corridors, ecological pinch points, and barrier points. ESPs constructed at different spatial scales are broadly similar, but significant differences among details were identified. As such, when formulating ecological protection and restoration strategies, the spatial scale should be considered. Moreover, specific programs should be determined based on ESP characteristics to maximize the protection of biodiversity and ecosystem integrity from multiple perspectives and directions

Soil Respiration in different agricultural and natural ecosystems in an arid region

The variation of different ecosystems on the terrestrial carbon balance is predicted to be large. We investigated a typical arid region with widespread saline/alkaline soils, and evaluated soil respiration of different agricultural and natural ecosystems. Soil respiration for five ecosystems together with soil temperature, soil moisture, soil pH, soil electric conductivity and soil organic carbon content were investigated in the field. Comparing with the natural ecosystems, the mean seasonal soil respiration rates of the agricultural ecosystems were 96%–386% higher and agricultural ecosystems exhibited lower CO(2) absorption by the saline/alkaline soil. Soil temperature and moisture together explained 48%, 86%, 84%, 54% and 54% of the seasonal variations of soil respiration in the five ecosystems, respectively. There was a significant negative relationship between soil respiration and soil electrical conductivity, but a weak correlation between soil respiration and soil pH or soil organic carbon content. Our results showed that soil CO(2) emissions were significantly different among different agricultural and natural ecosystems, although we caution that this was an observational, not manipulative, study. Temperature at the soil surface and electric conductivity were the main driving factors of soil respiration across the five ecosystems. Care should be taken when converting native vegetation into cropland from the point of view of greenhouse gas emissions

Soil respiration in different agricultural and natural ecosystems in an arid region.

The variation of different ecosystems on the terrestrial carbon balance is predicted to be large. We investigated a typical arid region with widespread saline/alkaline soils, and evaluated soil respiration of different agricultural and natural ecosystems. Soil respiration for five ecosystems together with soil temperature, soil moisture, soil pH, soil electric conductivity and soil organic carbon content were investigated in the field. Comparing with the natural ecosystems, the mean seasonal soil respiration rates of the agricultural ecosystems were 96%-386% higher and agricultural ecosystems exhibited lower CO(2) absorption by the saline/alkaline soil. Soil temperature and moisture together explained 48%, 86%, 84%, 54% and 54% of the seasonal variations of soil respiration in the five ecosystems, respectively. There was a significant negative relationship between soil respiration and soil electrical conductivity, but a weak correlation between soil respiration and soil pH or soil organic carbon content. Our results showed that soil CO(2) emissions were significantly different among different agricultural and natural ecosystems, although we caution that this was an observational, not manipulative, study. Temperature at the soil surface and electric conductivity were the main driving factors of soil respiration across the five ecosystems. Care should be taken when converting native vegetation into cropland from the point of view of greenhouse gas emissions

Soil Respiration in Different Agricultural and Natural Ecosystems in an Arid Region

The variation of different ecosystems on the terrestrial carbon balance is predicted to be large. We investigated a typical arid region with widespread saline/alkaline soils, and evaluated soil respiration of different agricultural and natural ecosystems. Soil respiration for five ecosystems together with soil temperature, soil moisture, soil pH, soil electric conductivity and soil organic carbon content were investigated in the field. Comparing with the natural ecosystems, the mean seasonal soil respiration rates of the agricultural ecosystems were 96%–386% higher and agricultural ecosystems exhibited lower CO(2) absorption by the saline/alkaline soil. Soil temperature and moisture together explained 48%, 86%, 84%, 54% and 54% of the seasonal variations of soil respiration in the five ecosystems, respectively. There was a significant negative relationship between soil respiration and soil electrical conductivity, but a weak correlation between soil respiration and soil pH or soil organic carbon content. Our results showed that soil CO(2) emissions were significantly different among different agricultural and natural ecosystems, although we caution that this was an observational, not manipulative, study. Temperature at the soil surface and electric conductivity were the main driving factors of soil respiration across the five ecosystems. Care should be taken when converting native vegetation into cropland from the point of view of greenhouse gas emissions