果蔬品质劣变传感检测与监测技术研究进展

果蔬在采后贮藏和运输过程中极易发生品质劣变,食用价值降低且造成巨大的经济损失。为保障果蔬品质,减少产后劣变导致的资源浪费,本文综述了果蔬品质劣变传感检测与监测技术最新研究现状,分析了各类检测技术的原理、特点及优缺点。其中,机器视觉可检测果蔬外部品质和表面缺陷,电子鼻可监测果蔬的劣变气味,近红外光谱可检测果蔬内部品质和隐性缺陷,高光谱成像能实现可视化检测果蔬内外品质、监测劣变过程,拉曼光谱可检测果蔬腐败菌及其代谢产物,多技术联用和多信息融合能综合评价果蔬劣变。以各种传感器为感知节点构建物联网监测系统,进而实现果蔬品质劣变信息的智能化实时监测,为解决果蔬加工过程中品质劣变控制技术难题提供参考,对降低果蔬产后的经济损失,推进果蔬产业可持续发展具有重要意义。     

A methodology for the management of quality in horticultural distribution

This paper presents a comprehensive methodology for the post-harvest management of quality in the distribution of horticultural produce. The methodology consists of three connected subsystems—quality prediction, price prediction and management decision making. The theoretical frameworks developed have been tested experimentally and the methodology is now available as an aid to decision making.The three main forms of deterioration—mechanical damage, physiological deterioration and pathological decay—are modelled and quality out turn is predicted from input quality and environment-event-time histories in each case. Price prediction is based on price-supply-quality relationships developed from studies of prices on wholesale markets. The price of a particular consignment is calculated from a quality index using quality-price functions. A management decision subsystem then evaluates alternative distribution strategies in terms of profit.A case study on water loss in spinach during distribution from harvest to markets shows how the methodology works.     

Fruit packaging and handling distribution systems: An evaluation method

Fruit and vegetable distribution systems vary in efficiency according to the inherent characteristics of the produce and the packaging and the handling procedures adopted. The maintenance of quality depends on the interrelationships of these components.It is proposed that performance prediction should be used to obtain maximum benefits from the distribution system. To evaluate the performance of a system requires that its elemen be identified and linked so that the interrelationships can be quantified. It is also necessary to establish acceptable limits for quality and losses.A method for predicting system performance is outlined and, for apples, an eight-step procedure for predicting bruising is given. The method is based on energy concepts and energy absorbed by packaged apples serves as the link between fruit, package and handling.The basic approach should be applicable to a wide range of products.     

A hard systems approach to the management of quality in apple distribution

The management of quality in the distribution of produce which exhibits significant and inevitable deterioration with time and event is a neglected but essential component of physical distribution management. This paper concentrates on horticultural produce and, in particular, on apples.Horticultural distribution is described as a system and systems thinking is employed to develop a ‘hard systems’ methodology for the management of quality. A management system is defined in terms of quality-price, quality-cost and quality-happening relations. An example from apple distribution demonstrates the methodology and is used to emphasize the central importance of quantitative models of price, cost, quality and of their interactions with time and happening.     

Water management in raised bed systems: a case study from the Chao Phraya delta,Thailand

Agricultural diversification is a major trend in Asian rice-based systems. In lowlands, however, soil and water conditions are mostly suitable for rice cultivation and the development of raised beds is often required to accommodate vegetables or fruit trees. Raised bed systems go together with specific techniques of water management, both at the polder level (between the plots and the canals) and at the plot level (bed irrigation). Details of this management in the Chao Phraya Delta are given for three different crops: mango, grapes and asparagus and differences are explained. The water balance over 1 year is specified, showing the impact of seepage and estimating water requirements. Water quality is shown to be a major issue.     

果蔬贮藏保鲜业的现状与展望

研究开发、推广应用果蔬保鲜技术,改变我国果蔬保鲜技术落后现状,推进果蔬贮藏保鲜业发展,拉长果蔬产业链,既是农业增效农民增收的有效途径和繁荣市场的需要,也是各级农机化部门面临的新任务。本文在调研基础上,结合宁波市北仑区农机总站承担的果蔬贮藏保鲜项目实施情况,分析了果蔬贮藏保鲜业发展现状与趋势,提出了发展果蔬贮藏保鲜业对策措施。     

浅谈计算机视觉技术在果蔬外观品质检测中的应用

果蔬的外观品质是评估其市场价值、被消费者选择的依据之一,而且在某种程度上也会影响它们的内部品质。本文分析了计算机视觉系统对果蔬外部品质检测的发展现状,提出了计算机视觉技术在南疆果蔬外观品质检测中存在的问题及建议,旨在为新疆南疆地区水果和蔬菜品质检测技术的研究和发展提供参考。     

果蔬包装机智控系统的设计与研究——基于嵌入式ARM

果蔬产业在我国农产品中占据着重要的市场地位,对我国经济发展起着积极的促进作用。随着我国经济的发展,出于对健康的考虑,人们对果蔬产品的质量、新鲜程度和食用安全的要求也在提高,逐渐开始看重果蔬类产品的外形包装。为了实现果蔬产品的快速包装及减少果蔬产品因与机械直接接触引起的二次污染,设计和研发可以独立自主包装果蔬的机械设备显得尤为重要。为此,基于嵌入式ARM中的AT91SAM9263处理器,设计了果蔬包装机的智控系统,其集机械电子、智能测试和光电传感等多种学科于一体,具有自动化程度高、精度优、稳定性强及可靠性高等特点,能较大程度地提高包装质量,且可以完成对不同种类产品的包装,提高了包装作业的效率,为果农降低了经济成本。     

基于可见-近红外光谱技术的果蔬品质检测方法

可见-近红外光谱技术利用波长在380～2 500 nm的电磁波获取果蔬中有机分子含氢基团的特征信息,根据样品对不同波长光的吸收信息,实现果蔬的外部、内部缺陷及营养成分定性、定量分析,是目前主流的果蔬内外部品质快速无损检测技术。综述了目前基于吸光度谱和能量谱对果蔬营养物质含量定量分析及缺陷定性分析,所使用的检测模型和变量筛选模型及其检测准确性,为相关研究人员选择高效准确的检测模型提供技术支撑。     

Sustainability of conjunctive water use for salinity control in irrigation areas: theory and application to the Shepparton region,Australia

The long term sustainability of conjunctive water use for controlling irrigation salinity is affected by increase in groundwater salinity over time. This paper uses mass conservation of salt and water to assess groundwater degradation over long time scales. Management options which affect this rate of degradation are also examined. The groundwater model developed is illustrated using data from the Shepparton Irrigation Region in the Murray Basin, Australia. The model predicts rapid groundwater deterioration when conjunctive use is conducted over only a fraction of the area of influence of a groundwater pump. Where the pumped aquifer is underlain by deeper groundwaters, the rate of groundwater degradation is also affected by leakage into or out of the conjunctive use system. Surface redistribution of groundwater from pumps installed in zones of regional groundwater discharge to areas recharging the regional groundwaters, reduces excessive degradation in the zones of discharge. With optimal surface distribution of groundwater, the rate of degradation is low. The rate of groundwater degradation also depends on salt inputs from irrigation water and rainfall, and the average depth from the soil surface to the base of the aquifer. The rate of degradation resulting from applied salts in surface water and rainfall is typically about 0.01 dSm^-1 per year for shallow aquifers in the Shepparton region, but the rate is lower where deeper aquifers are pumped. Partial irrigation also reduces the rate of degradation because of the reduced rate of salt inputs. Where poorer quality groundwater lies within the area of influence of the groundwater pump, a greater rate of deterioration in the quality of pumped groundwater can be expected from groundwater mixing. In some irrigation regions limited export of groundwater through surface water conveyance structures to a river is possible, so that a regional surface salt balance could be maintained. However, salt exports made equal to the rate of surface imports into the irrigated area will only significantly impact groundwater salinity in the very long term, or where only shallow aquifers can be pumped. In addition, this export can be costly for downstream water users, or if construction of additional conveyance infrastructure is extensive; export can have a detrimental impact on riverine ecosystems. Other management options such as the depth of pump installation and the spatial distribution of irrigation water and pumped groundwater, which affect the redistribution of salts within the groundwater system, have the potential to have a much greater impact on local groundwater salinity.     

Mechanical damage in agricultural products: A basis for management

This paper proposes that mechanical damage in solid agricultural commodities needs to be managed and that such management should be based on a trade-off between the costs of damage and the costs of prevention. In turn, prevention strategies need to be based on the prediction of damage and this demands a clear understanding of the mechanics of failure of agricultural materials.Mechanical failure in selected horticultural materials is classified as shear (slip and bruising), or cleavage (cracking, splitting). It is shown that the intensity and nature of loading controls the mode and onset of failure. Once failure has begun, the amount of damage is a function of the amount of energy absorbed. The relationship between damage and energy absorbed for the most likely mode of failure provides a basis for the prediction of damage.A framework for the management of mechanical damage is developed and its application is proposed for fruit and vegetables, eggs, seed and grain.     

保护地蔬菜连作障碍特点及控制措施

保护地蔬菜栽培对于保障蔬菜供应、促进农村经济发展具有重要的作用，但由于缺乏科学管理与化学投入品的滥用，保护地蔬菜连作障碍问题日益严重，影响了蔬菜产业的健康发展。以江苏省射阳县沿海地区保护地蔬菜种植为例，介绍了蔬菜连作障碍的特点及控制措施。      

Bio-resource flow in integrated agriculture–aquaculture systems in a tropical monsoonal climate: a case study in Northeast Thailand

The degree of integration and intensification in integrated agriculture–aquaculture systems (IAAS) varies with the variation in the pattern of bio-resource flow among various enterprises. Bio-resource flow in IAAS in Northeast Thailand was studied across four different agroecologies, one irrigated and three rainfed (drought-prone, rainfed lowland and rolling land). Only the irrigated and one rainfed (drought-prone) agroecology had easy market accessibility. Patterns of bio-resource flow clearly varied between IAAS as most enterprises in the irrigated agroecology functioned independently with a low degree of integration based on bio-resource flow among the enterprises compared with a high degree of integration among enterprises in the rainfed agroecologies. However, market accessibility played a crucial role in intensification of IAAS regardless of agroecology. Households with integrated systems in irrigated and drought-prone agroecologies applied adequate chemical fertilisers to fruit and vegetables to realize high gross incomes from these enterprises. In contrast, households in rainfed lowland and rolling land agroecologies operated subsistence IAAS as they relied more on organic manure from on- or off-farm sources with corresponding low gross income. Fish culture in farm ponds was a low-input system in all agroecologies but resource-use efficiency based on assessment of total N in pond inputs and N removed in fish harvest appeared to be relatively high. A combination of resource base and market accessibility can be envisaged to play the key role in the development of viable IAAS in Northeast Thailand.     

Estimating field-measured, plant extractable water from soil properties: beyond statistical models

For effective irrigation management we need to know the water storage capacity of the soil reservoir. Though plant extractable water is best measured in the field, sometimes it is useful to estimate it. Laboratory-derived retention curves do not necessarily reflect field conditions. Statistical models to estimate plant extractable water from other soil properties are restricted by assumptions that are difficult to check, and they can look very complicated. We propose to test a physical-based model that exploits the similarity between the particle size distribution curve and the soil water retention curve. A large data set of soil properties from the USA was used. Detailed particle size fraction data enabled the construction of simulated soil water retention curves for 388 samples. The physical-based model was compared against a statistical model that was derived from a subset of the data base. The statistical model fit the data better than the physical-based model. On the other hand, the statistical model overpredicted the soil water limits of those soils that were not used in the derivation of the statistical model. The strength of the physical model is that it represents a cause and effect relationship between particle size distribution and soil water retention. Also, it is conceptually simple and requires few inputs. The physical model may be improved by considering soil structure and type of clay.     

农村生活污水一级处理水灌溉对青菜生长品质影响

通过3种水质对生长中的青菜进行灌溉,探讨利用农村生活污水一级处理水对青菜植株生长发育的品质影响.研究表明,相比较自来水和50%的农村生活污水,经过一级处理的农村生活污水对生长期的青菜灌溉,对青菜植株维生素C和硝酸盐质量比有一定的影响,维生素C质量比下降10%左右,硝酸盐质量比增长6%左右,对青菜株高、叶面积、地上部分鲜质量均没有明显差异.通过与国标蔬菜中硝酸盐质量比的限值比较,经过污水灌溉的青菜在安全食用范围内,不会影响到人类身体健康.因此,农村污水作为农作物灌溉的另一个重要水源,具有一定技术可行性和经济合理性.     

农业供给侧改革背景下的乌鲁木齐市果蔬消费需求

为适应人民日益增长的美好生活需要和不平衡不充分发展之间的矛盾变化，农业发展由总量扩张转向质量提升。通过从宏观层面统计分析消费者主要食品边际消费倾向，采用一次指数平滑法对果蔬消费量预测；从微观层面依据对乌鲁木齐市476户城镇家庭调研的数据，利用有序多分类logistic模型分析消费需求的影响因素。从消费者角度发现果蔬供给过程中现存的问题，并对此提出建议，从而为地方政府制定蔬菜供应保障策略与规划提供科学依据，并为农产品消费方面的研究提供参考。      

Interpretation of commercial production information: A case study of lulo (Solanum quitoense), an under-researched Andean fruit

Every time a farmer plants and harvests a crop represents a unique event or experiment. Our premise is that if it were possible to characterize the production system in terms of management and the environmental conditions, and if information on the harvested product were collected from a large number of harvesting events under varied conditions, it should be possible to develop data-driven models that describe the production system. These models can then be used to identify appropriate growing conditions and improved management practices for crops that have received little attention from researchers. The analysis and interpretation of commercial production data in the context of naturally occurring variation in environmental and management, as opposed to controlled experimental data, requires novel approaches. Information was available on both variation in commercial production of the tropical fruit, lulo (Solanum quitoense), and the associated environmental conditions in Colombia. This information was used to develop and evaluate procedures for the interpretation of the variation in commercial production of lulo. The most effective procedures depended on expert guidance: it was not possible to develop a simple effective one step procedure, but rather an iterative approach was required. The most effective procedure was based on the following steps. First, highly correlated independent variables were evaluated and those that were effectively duplicates were eliminated. Second, regression models identified those environmental factors most closely associated with the dependent variable of fruit yield. The environmental factors associated with variation in fruit yield were then used for more in depth analysis, and those environmental variables not associated with yield were excluded from further analysis. Linear regression and multilayer perceptron regression models explained 65-70% of the total variation in yield. Both models identified three of the same factors but the multilayer perceptron based on a neural network identified one location as an additional factor. Third, the three environmental factors common to both regression models were used to define three Homogeneous Environmental Conditions (HECs) using Self-Organizing Maps (SOM). Fourth, yield was analyzed with a mixed model with the categorical variables of HEC, location, as a proxy for cultural factors associated with a geographic region, and farm as proxy for management skills. The mixed model explained more than 80% of the total variation in yield with 61% associated with the HECs and 19% with farm. Location had minimal effects. The results of this model can be used to determine the appropriate environmental conditions for obtaining high yields for crops where only commercial data are available, and also to identify those farms that have superior management practices for given environmental conditions.     

Relationship between salinity and efficient water use

The relationship between salinity and water use efficiency is highly dependent upon which definition of water use efficiency is used. The two common definitions, yield per unit evapotranspiration and yield per unit applied water, both have significant deficiencies and can lead to erroneous conclusions. Thus, the analysis of efficient use of saline waters invokes a broader analysis than merely computing water use efficiency. An array of models is available to simulate the effects of various irrigation management strategies with saline waters. Based on results computed from these models, which consider the osmotic and matric potential effects on plant growth, strategies can be developed to effectively use saline waters in crop production. The cyclic strategy of using waters of different salinities can effectively be used in maintaining crop rotations which include both salt-sensitive and salt-tolerant crops. The major deficiency of the models is that they do not account for the effects of water quality on soil physical conditions with consequent effects on crop production. Indeed, the most limiting factor in use of saline waters on soils may be deterioration of soil physical conditions. The deterioration of soil physical conditions does not result from using the high-salinity waters per se but from subsequent rainfall or low salinity waters. Thus far the emphasis on using saline waters on crop production has centered on yields and less attention has been given to the long-term consequences on soil physical conditions. This factor requires further research and should be a focus of attention in future experiments. Relatively high saline water tables can be maintained without drainage if a non-saline source of water is available, and irrigation amounts can be controlled. This strategy might invoke the necessity for shifting irrigation systems from surface to pressurized systems. Eventually, some salt must be removed from the system. It is probably more efficient to allow it to become very concentrated and remove small volumes to be disposed of in some manner rather than apply it to productive land.     

基于神经网络的黄瓜等级判别

在瓜果的等级判别中尚存在机器人挑选与人挑选结果不一致的问题。作者基于图像处理技术和神经网络理论开发了一种适用于长型瓜果的判别系统,该系统通过对各对象标准样本的学习即可实现对学习工型瓜果的等级判别,达到一机多用的目的。     

基于残差块与注意力机制的果蔬自动识别方法

针对果蔬识别中识别效率低、成本高等问题,本文提出了基于残差块和注意力机制的果蔬识别模型,并成功部署于果蔬智能识别设备。果蔬自动识别装置由Raspberry Pi、STM32F103ZET6、摄像头、称量传感器、处理器、显示屏、微型打印机、扎口机以及电源等部分组成。中央控制器与显示屏进行交互实时显示各种参数,通过摄像头与称量传感器采集待测物体图像与待测物体质量,由部署于Raspberry Pi的果蔬自动识别模型对果蔬进行精准识别,同时协同单片机STM32F103ZET6将果蔬相关信息打印并控制扎口机进行封口打包。本文以YOLO v5网络为基础,通过增加残差块与注意力机制构建果蔬自动识别模型RB+CBAM-YOLO v5。以自制的数据集训练网络,将6种网络进行对比试验,并选择最优网络进行设备端检测试验。试验结果表明,RB+CBAM-YOLO v5的精确率、召回率与mAP0.5分别为83.55%、96.08%、96.20%,较YOLO v5提升4.47、1.10、0.90个百分点。将RB+CBAM-YOLO v5模型部署于嵌入式设备Raspberry Pi中,设备可实现精准识别、自动称量、打印凭条以及快速打包等功能,可满足果蔬识别以及无人售卖装置的需求。