Health risk assessment of trace metal(loid)s in agricultural soils based on Monte Carlo simulation coupled with positive matrix factorization model in Chongqing, southwest China

This study aimed to investigate the pollution characteristics, source apportionment, and health risks associated with trace metal(loid)s(TMs) in the major agricultural producing areas in Chongqing, China. We analyzed the source apportionment and assessed the health risk of TMs in agricultural soils by using positive matrix factorization(PMF) model and health risk assessment(HRA) model based on Monte Carlo simulation. Meanwhile, we combined PMF and HRA models to explore the health risks of TMs in agricultural soils by different pollution sources to determine the priority control factors. Results showed that the average contents of cadmium(Cd), arsenic (As), lead(Pb), chromium(Cr), copper(Cu), nickel(Ni), and zinc(Zn) in the soil were found to be 0.26, 5.93, 27.14, 61.32, 23.81, 32.45, and 78.65 mg/kg, respectively. Spatial analysis and source apportionment analysis revealed that urban and industrial sources, agricultural sources, and natural sources accounted for 33.0%, 27.7%, and 39.3% of TM accumulation in the soil, respectively. In the HRA model based on Monte Carlo simulation, noncarcinogenic risks were deemed negligible(hazard index <1), the carcinogenic risks were at acceptable level(10^(-6)<total carcinogenic risk ≤ 10^(-4)), with higher risks observed for children compared to adults. The relationship between TMs, their sources, and health risks indicated that urban and industrial sources were primarily associated with As, contributing to 75.1% of carcinogenic risks and 55.7% of non-carcinogenic risks, making them the primary control factors. Meanwhile, agricultural sources were primarily linked to Cd and Pb, contributing to 13.1% of carcinogenic risks and 21.8% of non-carcinogenic risks, designating them as secondary control factors.

STUDY ON THE FRAMEWORK SYSTEM OF DIGITAL AGRICULTURE

China is a great agricultural country with large population, limited soilresources and traditional farming mode, so the central government has been attaching greatimportance to the development of agriculture and put forward a new agricultural technologyrevolution ― the transformation from traditional agriculture to modern agriculture and fromextensive farming to intensive farming. Digital agriculture is the core of agriculturalinformatization. The enforcement of digital agriculture will greatly promote agricultural technologyrevolution, two agricultural transformations and its rapid development, and enhance China'scompetitive power after the entrance of WTO. To carry out digital agriculture, the frame system ofdigital agriculture is required to be studied in the first place. In accordance with the theory andtechnology of digital earth and in combination with the agricultural reality of China, this articleoutlines the frame system of digital agriculture and its main content arid technology support.

Evolution Characteristics of Government-Industry-University-Research Cooperative Innovation Network for China＇s Agriculture and Influ- encing Factors： Illustrated According to Agricultural Patent Case

Under the special background of China, the cooperative innovation between different government-industry-university-research institutes plays an increasingly important role in the agricultural field. However, the existing literature has paid little attention to it. Considering the cooperation patents, published in the agriculture field stemming from the Full-text Database of China Patents as the study object, the spatial and institutional attribute of the authors as the data source, and by combining the social network and spatial econometrics analysis, this paper analyzes the structure evolution characteristics of cooperative innovation networks of agricultural government-industry-university-research institute in the city level of China in 1985–2014, based on the triple helix theory, with the influence factors discussed. This shows that, 1) since 1985, China's agricultural innovation level has been substantially increased, but the development degree of the cooperative innovation network is low, and the patent cooperation mainly relies on authors in the same unit; 2) enterprises play a leading role in the agricultural cooperative innovation. The effect of the government and hybrid organizations driven by the government is not obvious; 3) the cooperative innovation in the province and city dominates, and a multi-pole pattern has been formed. The cooperative innovation network structure evolves from a single helix empty core and double helix multi core to a double helix hierarchical network; 4) the city's science, education funding and personnel investment are key factors determining the agricultural cooperative innovation, while the agricultural development of the city presents slight negative impacts on it. The spatial mismatch of supply and demand is present in the technical cooperative innovation of China's agriculture. Therefore, the science enhancement and education investment to big agricultural provinces should be promptly implemented.

The Main Content,Technical Support and Enforcement Strategy of Digital Agriculture

This paper deals with the content,purpose and significance of digital agriculture,and gives a brief introduction to digital earth,digital China and digital agriculture abroad.The main content of digital agriculture includes the construction of database,Metadata standard,monitoring system,forecasting and decision_making system,information_releasing system.The main technical supports of digital agriculture are 3S technology,Metadata management technology,fast_handling technology of remote sensing,the technology of computer wide_band network and virtual reality,intelligent agriculture machinery and field real_time information collecting technology.The advantages of implementing digital agriculture in China and the problems worthy of attention are pointed out as well.

Research on Supply Chain Operation of Connecting Agriculture with Supermarkets Based on Agricultural Brokers System

On the basis of expounding the research results of using relevant knowledge about Game Theory for supply chain of agricultural products at home and abroad,we use principal-agent model in Game Theory to research the new function that the supermarkets entrust supervision and control over quality of agricultural products to agricultural brokers in the circulation model of connecting agriculture with supermarkets;then design the optimal incentive contract and influencing factors between agricultural broker and supermarket,and explain the fundamental role of agricultural brokers in the process of circulation;finally in light of the role of government in promoting development and application of agricultural brokers,put forward corresponding policy suggestions:establish government support policy;set relevant standard of industry;establish cooperative organizations of agricultural brokers.

The Impact of China's Fiscal Expenditure in Agriculture on Farmer's Income

Based on the account of the vital role which the national finance played in supporting agriculture,the thesis presents the current situation of financial support for agriculture in China,in terms of the limited scale and irrational structure of financial support expenditure in agriculture.On the basis of the brief introduction of the current level of Chinese farmers' income,the thesis discusses the effects of scale and irrational structure of financial support expenditure in agriculture on the farmers' income,according to the related data of financial support expenditure in agriculture and rural per capita net income.The results indicate that the calculating regression equation has a remarkable explanation power,reflecting the positive role of financial support expenditure in agriculture played by national finance in increasing the farmers' income.As regards the structure of financial support expenditure in agriculture at present,according to the proportion from high to low,the expenditure primarily consists of three parts from high to low in sequence as follows:productive expenditure and funds for public undertakings,capital construction expenditure,and rural relief expenditure plus science and technology funds.Such sequence deviates from the marginal production effects of financial support expenditure in agriculture and the correlation of farmers' income,which demonstrates the severe irrationality of the structure of financial support expenditure in agriculture.Corresponding countermeasures are put forward as follows:on one hand,we should continue intensifying the efforts to support agriculture financially in order to form a regular increase mechanism;on the other hand,we should adjust and optimize the structure of financial support expenditure in agriculture,and further crystallize the investment flows.

Impact of Urban Agriculture on the Species Distribution and Insecticide Resistance Profile of <i>Anopheles gambiae s.s.</i>and <i>Anopheles coluzzii</i>in Accra Metropolis, Ghana

Malaria incidence in urban areas has generally been low compared to rural areas but recent data indicate that urban malaria remains a public health problem. It is therefore important to understand the factors that promote urban malaria to help formulate future vector control strategies. This study compared Anopheles gambiae s.l. (A. gambiae s.l.) species composition, distribution and insecticide resistance mechanisms between vegetable and non-vegetable growing areas in Accra Metropolis. Four sites were selected within the city of Accra which comprised of two vegetable-growing and two non-vegetable growing areas. WHO susceptibility tests were carried out on adults A. gambiae s.l. reared from larvae collected from the sites. Five insecticides were tested and the A. gambiae complex, resistance genotypes and enzyme activities of each population were characterized. All A. gambiae s.l. populations tested were resistant to all the insecticides, but relatively lower mortalities were observed in the vegetable growing areas. The mortality against 0.05% deltamethrin was 2.6% (Opeibea) and 12.5% (Korle-Bu) for the vegetable growing areas and 36.2% (Achimota) and 38.9% (Mataheko) in the non-vegetable growing areas. Anopheles gambiae s.s. (95% of Opeibea population) and Anopheles coluzzii, (98% of Korle-Bu population) were the dominant species in the vegetable growing areas. The voltage-gated sodium channel (Vgsc-1014F) frequencies of all the populations were similar but the acetylcholinesterase (ace-1) frequencies were significantly lower (p A. gambiae s.l. from Opeibea than from the other areas. The contribution of urban agriculture in the development of insecticide resistance needs to be considered in the formulation of future vector control strategies alongside other domestic usages.

Orientation of Government's Role in Building the Technology System of Circular Agriculture

This article expounds the economic characteristics of circular agricultural technology.Since the circular agricultural technology has characteristics and externality of public goods,the government participation is necessary in building the technology system of circular agriculture,in order to avoid "free rider" behavior in the consumption of public goods and internalize externality.We analyze the orientation of government's role in building the technology system of circular agriculture:the government is the leader,designer,organizer and regulator in building the technology system of circular agriculture;the government orientates the four roles precisely in building the technology system of circular agriculture,to ensure that they do not cross the line,but be indispensable all the while.

The Ecological Service Function Development of Urban Modern Agriculture in Tianjin City and Corresponding Countermeasures

Based on the current situation of ecological environment of agriculture in Tianjin City,we divide the ecological service function of urban modern agriculture in Tianjin City into seven types: air regulation,climate regulation,water conservation,soil formation and protection, waste disposal,biodiversity conservation,and ecological entertainment. According to the method for assessing the value of natural ecosystem, coupled with the ecological service value equivalency factor table of China's ecosystem formulated by domestic scholars,we estimate the ecological value in Tianjin City. The results show that the actual ecological value of agriculture in Tianjin City was 30. 752 billion yuan in 2010,close to the agricultural economic value ( 31. 733 billion yuan) in 2010. Finally we put forth the following countermeasures for the ecological function development of urban modern agriculture in Tianjin City: strictly protecting arable land,and raising the standards of compensation for agricultural land requisition; actively and prudently developing facility agriculture,and preventing the blind scale expansion of facility agriculture to better give play to its ecological function; strengthening the construction of ecological agriculture,and promoting the market conversion of the ecological service value of agriculture; improving the environment,to form relatively complete agro-ecological system.

SUIXI'S AGRICULTURE

Suixi, located in the northern part ofAnhui Province, covers 2,381 squarekilometres and has a population of 1.06million. It is wellknown as the home of wineand coal. Its traffic network connects it withthe Longhai Line of the Euroasia ContinentalBridge to the north, the Jinhpu Railway tothe east and the Jingjiu Line to the west.Program-controlled telecommunicationsextends over the county. Enjoying rich powersupply and plentiful coal resources, Suixiachieved GNP of RMB2.5 billion, RMB 142million of financial income and RMB1,320of per capita income for peasants in 1995. Inthe past five years, the county’s comprehensiveeconomic strength has ranked among the topten counties for best economic returns inAnhui Province. Suixi is appointed by the World Bankfor irrigation enforcement transformationand as the Huanghuaihai harnessing zone.After several years of effort, the county

China's Agriculture Calling for Foreign Investment

At the recently-convened meetings of the National People’sCongress and the Chinese People’s Political ConsultativeCoference, agriculture has once again become a hot topicattracting attentions of deputies. Speeding up the opening up ofagricultural sector and properly resolving the thorny financial andtechnological problems confronting it become a highlighted issuein the State’s plan to utilize foreign investment in the coming fewyears.

基于DRAINMOD-S和-NⅡ模型的黄河三角洲盐碱地玉米施氮策略

玉米是黄河三角洲(简称黄三角)滨海盐碱区主要粮食作物之一,氮肥合理施用对于促进该地区玉米产量提升、养分资源高效利用以及生态环境改善至关重要。为了明确该地区玉米的适宜施氮量和施氮制度,该研究基于2 a(2019—2020年)玉米栽培田间滴灌施肥试验,校验和评估DRAINMOD-S和DRAINMOD-NⅡ模型在该地区的适用性和可靠性,从而确定田间排水沟/管间距和建立玉米适宜施氮量估算模型与施氮制度。结果表明:1)DRAINMOD-S和-NⅡ模型可较准确地模拟黄三角滨海盐碱农田地下水埋深、土壤含盐量和硝态氮含量分布的动态变化,其模拟值与实测值之间的决定系数R2均大于0.80,标准化均方根误差(normalized root mean squared error,NRMSE)均低于25%;2)通过分析排水间距与土壤渍水和盐分胁迫减产效应间的关系,推荐该地区排水间距可设为17 m;3)在兼顾作物氮素需求(即吸氮量满足玉米自身需求)、土壤持续供氮能力(收获后土壤无机氮储量与播种时大抵相近)及养分淋失风险可控(氮淋失量尽量小)等目标的前提下,基于数值模拟确定了不同气候和初始土壤无机氮含量条件下的玉米适宜施氮量,并建立了其与主要环境变量如降雨量、降雨强度和初始土壤无机氮含量之间的定量关系(R^(2)=0.70,P<0.01);4)评估了典型枯水年、平水年、丰水年施肥1~3次下不同施肥时期组合的影响,表明不同水文年里都可选择在玉米拔节期-抽雄期(或拔节期-抽雄期-灌浆期)追施氮肥2(3)次。研究结果可为黄河三角洲滨海盐碱农田玉米氮素管理提供参考。

Aiding Africa’s Agriculture

WH EN 58-year-old Jiang Heping set his foot on African soil for the first time in 2006. he dreamed that one day rice and golden corn would boost the continent＇s food security, saving people from starvation and comforting crying children.

Agriculture Key to Nigeria’s Growth

THERE are two growing schools of thought when it comes to developing the agricultural sector of Africa, a continent which holds about 60 percent of global uncultivated land. Both have the same goal, to ensure that the small farmer is part of the sector＇s growth. The first, headed by the Africa Progress Panel （APP）, believes that the sector will succeed and grow if it is developed from the ground up - in other words by raising the productivity of small- holder farmers. This is particularly supported by Kofi Annan and requires government action.

Remote Sensing Dynamic Monitoring System for Agricultural Disaster in Henan Province Based on Multi-source Satellite Data

Using 3S technology, relying on earth-space three-dimensional agriculture disaster monitoring network, remote sensing monitoring model for agricultural disaster in Henan Province was established, and agricultural disaster monitoring system plat- form of Henan Province based on multi-souroe satellite data was further constructed, which realizes dynamic monitoring of agricultural disasters in Henan Province （drought, flood, snow cover and straw burning）.

Assessment and mapping of environmental quality in agricultural soils of Zhejiang Province, China

Heavy metal concentrations in agricultural soils of Zhejiang Province were monitored to indicate the status of heavy metal contamination and assess environmental quality of agricultural soils. A total of 908 soil samples were collected from 38 counties in Zbejiang Province and eight heavy metal （Cd, Cr, Pb, Hg, Cu, Zn, Ni and As） concentrations had been evaluated in agricultural soil. It was found 775 samples were unpolluted and 133 samples were slightly polluted and more respectively, that is approximately 14.65% agricultural soil samples had the heavy metal concentration above the threshold level in this province by means of Nemerow＇s synthetical pollution index method according to the second grade of Standards for Soil Environmental Quality of China （GB15618- 1995）. Contamination of Cd was the highest, followed by Ni, As and Zn were lower correspondingly. Moreover, Inverse Distance Weighted （IDW） interpolation method was used to make an assessment map of soil environmental quality based on the Nemerow＇s pollution index and the soil environmental quality was categorized into five grades. Moreover, ten indices were calculated as input parameters for principal component analysis （PCA） and the principal components （PCs） were created to compare environmental quality of different soils and regions. The results revealed that environmental quality of tea soils was better than that of paddy soils, vegetable soils and fruit soils. This study indicated that GIS combined with multivariate statistical approaches proved to be effective and powerful tool in the mapping of soil contamination distribution and the assessment of soil environmental quality on provincial scale, which is beneficial to environmental protection and management decision-making by local government.

基于STM32和S算法的微电脑鼠的设计与实现

采用STM32F405微处理器作为主控制器,设计了一款新型智能微电脑鼠,不仅满足了迷宫探索的各项要求,而且显著提高了微电脑鼠行走的稳定性,减少了微电脑鼠的迷宫探索时间。重点介绍了硬件系统的设计,包括微处理器、电源电路、传感器电路、电机驱动电路等组成部分。在软件设计部分,采用了“S转法”,通过6段法则来设计转弯运行。实验表明,基于STM32F405微控制器和S转法,微电脑鼠可以有效缩短探索路径并减少到达终点的时间。

Current Situations and Problems of Logistics for Guangxi Fresh Agricultural Products in the New Period and Recommendations

In recent years,Guangxi realized consecutive bumper harvests in fresh agricultural products,leading increase of logistics demand;logistics infrastructure begins to take shape,and logistics of fresh agricultural products takes on diversified development form with wholesale market as main form. However,traditional fresh agricultural products are not selling well and it lacks construction of supply chain; the construction of logistics information system for fresh agricultural products lags behind; organizational level of production and operation of fresh agricultural products is low. Through analyzing current situations and existing problems of logistics of Guangxi fresh agricultural products in the new period( 21 st century),this paper came up with recommendations for developing logistics of fresh agricultural products of Guangxi. Government should increase policy and financial support,build and manage supply chain of fresh agricultural products,accelerate construction of logistics information system for agricultural products,and improve organizational level of logistics of fresh agricultural products,to ensure healthy development of logistics of fresh agricultural products in Guangxi.