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There is a global shortage of fresh water to meet the clean production of field crops. Water-saving irrigation can increase the production of field crops, but under certain conditions it can be overly water-saving and unsustainable, particularly in complex terrains in China where there is already a shortage of water resources. In light of the insufficient water resources and partial inequality in China, several investigators in China and abroad have researched irrigation nozzles and pumps, but there is little information on the impact of the environment on crop irrigation. The purpose of this study was to provide a fast and effective crop water demand prediction model to estimate the water requirement during the growth period of crops, to achieve the purpose of applying water according to the demand of the crops, and to optimize the irrigation network to determine the optimal network structure in order to reduce irrigation energy consumption in the process. Specifically, this study analyzed the environmental factors, namely, the soil moisture, soil electrical conductivity, air temperature, and light intensity, affecting the physiological water demand of field crops. Relevant sensors were used in the field, and environmental information was collected. This study used the collected environmental data to build a water demand prediction model based on the back propagation (BP) neural network. It also carried out optimized layout and hydrodynamic analyses of the drip irrigation network and identified the best pipe network arrangement. On the basis of the BP neural network, the remarkable R amount of 0.98963 was obtained for the water demand prediction model. The mean square error (MSE) value was 0.00857724. We also found that the drip irrigation pipe network in the H-shaped arrangement was more suitable for field crop irrigation than the comb-shaped and fish bone-shaped arrangements. This study employed the common field crops in China as the research object, used the wireless sensing technology to obtain the field environment information quickly, and constructed a water demand prediction model with high prediction accuracy. Finally, this study realized the precise control of field crop irrigation, reduced the waste of agricultural water, and achieved sustainable field crop production.

Against the background of the depletion of fossil fuel energy sources and environmental degradation, solar greenhouses represent an efficient and sustainable agricultural production method in China. The precise measurement and control of the position of the rolling shutter and rolling film is not only one of the core issues in the modification of the greenhouse environment in actual production but also the basis for improving the cleaner production efficiency of solar greenhouses. In this study, a mathematical algorithm for the control of a rolling shutter and rolling film was developed and is based on the simplification of the circular arc of the greenhouse surface. The “Liaoshen-IV” solar greenhouse was used as an example to illustrate the calculation steps of the algorithm. Any position on the light surface can be determined by calculating the angle at the bottom of the back wall of the greenhouse so that the position of the rolling shutter and the rolling film can be measured accurately by the angle sensor. Experiments using a scale model with one or two surface segments were conducted to demonstrate the advantages of the control algorithm with regard to the accuracy and stability compared with the existing control method of a time-delay relay. The relative errors of the control algorithm were stable and less than 1%. The use of the algorithm improved the control accuracy of the rolling shutter and rolling film and the average relative error was reduced by 6.37% in the first stage and by 3.40% in the second stage compared with the time-delay relay. The precise measurement and control of the position of the rolling shutter and rolling film in a solar greenhouse demonstrated in this study has great significance for practical applications. The proposed method may result in a reduction in energy consumption and greenhouse gas (GHG) emissions in greenhouse environments, thereby contributing to the improvement of resource efficiency and a cleaner production. The study also provides application examples and theoretical references for the automation of rolling shutters and rolling film in greenhouses worldwide.

Toxic and hazardous sulfur dioxide (SO2) residue reduction is not only one of the core issues in the preservation process with SO2 solid antistaling agents in actual table grapes cold chain, but also one of the important ways to improve the cleaner production efficiency of the table grapes. The aim of this paper is to propose an improved preservation process for the table grapes in cold chain by combining the fumigation treatment with the slow-release SO2 solid antistaling agent. The process was performed to reduce the toxic and hazardous SO2 residue of the table grapes, improve the cleaner production efficiency of the cold chain, guarantee the quality and safety of the table grapes, and finally enhance the human health. The slow-release SO2 solid antistaling agent was developed with no pricking holes and relatively stable release rate of the SO2. According to the comprehensive analysis of the fumigation treatment condition determination, the slow-release SO2 solid antistaling agent performance, the table grapes quality performance, the SO2 residue performance and the evaluation on improved preservation process, the proposed improved preservation process with SO2 residue reduction could effectively reduce the bleaching injury, the decay rate, the threshing rate and the toxic and hazardous SO2 residue of the table grapes. There was no bleaching injury after the fumigation treatment at the optimal fumigation treatment conditions with 5000 ppm fumigation concentration and 20 min fumigation time. The maximization reduction range of the average decay rate and the average threshing rate of the table grapes was about 91.3% and 44.8%, while the maximization reduction range of the average SO2 residue in table grapes peels was about 44.7%. The proposed improved preservation process could be extended for other cold chain applications to reduce their SO2 residue and improve their cleaner production efficiency.

Safe food is healthy, nutritious and environmentally friendly by green, sustainable and clean production. The objectives of this study were to examine factors influencing the consumers' purchase intention and willingness to pay a premium price for safe vegetables. To achieve the objectives, this paper developed the model of consumers' purchase safe vegetables. Based on 840 valid questionnaires from Beijing of China, the model was confirmed by the logistic regression method. The results showed that food safety, strict production and processing, and healthy environment were the top three perceived advantages of safe vegetables for consumers. In addition, 93.0% and 87.1% of consumers were familiar with organic vegetables and green vegetables, respectively. Two-thirds of consumers identified safe vegetables via certification labels on vegetable packages. Furthermore, 67.6% of consumers were willing to buy safe vegetables and 65.8% would pay a premium price for safe vegetables. Meanwhile, consumers' purchase intentions for safe vegetables were positively affected by family food expenditure, children, familiarity, differential cognition, safety awareness, nutritional health, packaging, label trust, and online shopping experience but price level, safety status, and freshness had a negative effect. Consumers’ willingness to pay a premium price for safe vegetables was positively affected by family income, familiarity, differential cognition, safety awareness, nutritional health, packaging, label trust, and online shopping experience but family food expenditure, price level, price fluctuations, and safety status had a negative effect. The findings of this study have important implications to improve the consumption and guide cleaner production of safe vegetables. The findings obtained can also provide references for other similar studies in other areas.

Freshwater aquaculture is the main form of aquaculture in inland areas, and pollution is a significant challenge. The aim of this work was to propose an effective risk assessment method for aquaculture to predict pollutant bioaccumulation in fish tissue based on water environment variables. This method was designed to assess the risk of pollutant levels in fish tissue that exceed China’s food safety standards. Firstly, field observation and investigation were conducted to analyze the migration mechanisms of the main pollutants between fish tissue and the water environment. Secondly, a classification and regression tree (CART) and generalized additive model (GAM) nexus method was used to analyze the environmental variables related to pollutants in the water environment and establish prediction models. Finally, models of the bio-reaction kinetics were established to predict the pollutant bioaccumulation in fish tissue. The experimental results indicate that the GAM models could explain 73.7%, 84.4%, and 84.5% of the deviations for the three predicted pollutants. For 90% of the sample data, the accuracy of the bioaccumulation prediction was 93.44% for volatile phenol bioaccumulation, and 90.16% for Cu and coliform bioaccumulation. The proposed risk assessment method could be extended for aquaculture applications that require monitoring of additional parameters to safeguard aquaculture quality and facilitate effective safety risk management.

In the process of agricultural production, the yield of field crops is affected by the interaction of various factors. This relationship between soil nutrients, fertilization, and yield is very complicated. It has strongly non-linear and black box characteristics and is difficult to quantify with traditional analytic methods. This paper proposes a method for the precision fertilization of maize based on the wavelet-BP neural network. Firstly, the existing “3414″ experimental data was chosen and interpolated as the performing data for the modeling. Then, the general condition of low frequency and details of high-frequency of the yield were calculated via the wavelet decomposition and reconstruction method. After that, the wavelet-BP neural network was established. Three different BP neural sub-networks for each component of the yield after wavelet analysis were established, and the output of each sub-network was summed to obtain the predicted corn yield. The results show that the model that combines wavelet analysis with the BP neural network achieves better performance than the traditional BP neural network, Support Vector Machine (SVM), and Random Forest regarding accuracy and stability, which indicates the feasibility of this method. Finally, the best fertilizer amount that achieves the maximum yield or maximum profit is calculated based on nonlinear programming. The proposed method of the wavelet-BP neural network provides a new technique for precision fertilization research and enriches the existing fertilization system. The application of precision fertilization based on the wavelet-BP neural network has important practical significance that guides and increases maize production, while reducing production cost and agricultural pollution. At the same time, it also provides a way to solve similar problems in the entire field of cleaner agricultural production.