稻鸭共作系统中稻纵卷叶螟种群控制的模拟

为研究系统动力学方法在害虫种群的优化管理和预测等研究中的应用，以稻纵卷叶螟第二代种群为研究对象，分析了稻鸭共作系统中捕食性天敌蜘蛛及鸭对稻纵卷叶螟生长发育的影响，构建了相应的系统动力学框架模型，并利用STELLA软件对稻纵卷叶螟种群的数量动态进行了模拟和预测。结果表明，当第二代稻纵卷叶螟初始的百穴卵量为100粒，稻田蜘蛛密度为每百穴12.623头，如果同时考虑鸭对3龄幼虫期稻纵卷叶螟卷苞60%的捕食率，稻纵卷叶螟成虫的密度可降至每百穴9.129头，鸭的捕食可使稻纵卷叶螟第三代卵期末的百穴卵量减少约6.7%     

农作物苗期长势无损监测技术研究进展

农作物的苗期生长是一个复杂的生理生化及代谢过程,苗期的生长发育直接影响到作物的生物产量、经济产量、营养品质及其安全性。农作物苗期长势监测对于作物肥水管理、病虫害防治具有指导作用,是精细农业和数字农业的关键技术之一。该文从农作物苗期生长形态检测、营养组分检测和病虫害诊断3个方面,详细阐述了各种无损检测技术,如机器视觉技术、激光漫反射技术、荧光测量技术和反射光谱分析技术等在作物苗期长势监测中的应用进展。国内外学者对上述技术进行了较深入的理论方法研究,部分技术已在实践中得到广泛应用,但目前作物无损检测技术大多强调单一信息的获取及分析,随着数字农业和智慧农业的发展,未来将更加强调多源、多尺度数据的获取及形态、养分、病虫害综合信息的提取。作物苗期长势的监测数据将与精准农业的联系更加紧密,为农事操作提供传感信息,形成智能化的农业施工、调优栽培与管理决策系统。      

Aflaj irrigation and on-farm water management in northern Oman

This paper reports on results from a case study on water management within a traditional, falaj irrigation system in northern Oman. In the planning and design of regional irrigation development programs, generalized assumptions are frequently made as to the efficiency of traditional surface irrigation systems. Although qualitative accounts abound, very little quantitative research has been conducted on on-farm water management within falaj systems. Daily irrigation applications and crop water use was monitored during an 11-month period among 6 farm holdings at Falaj Hageer in Wilayat Al-Awabi. Contrary to the frequent assumptions that all surface irrigation systems incur unnecessarily high water losses, on-farm ratios of crop water demand to irrigation supply were found to be relatively high. Based on actual crop water use, irrigation demand/supply ratios among monitored farms varied from 0.60 to 0.98, with a mean of 0.79. Examination of the soil moisture budget indicates that during most irrigations of wheat (cultivated in the low evapotranspiration months of October–March) sufficient water is applied for the shallow root zone to attain field capacity. With the exception of temporary periods of high falaj delivery flows or periods of rainfall, field capacity is usually not attained during irrigations within the more extensive root zones of date palm farms. The data presented in this paper should provide a better understanding of water use performance by farmers within traditional falaj systems. Moreover, these data should also serve to facilitate more effective development planning for irrigation water conservation programs in the region.     

基于深度学习的害虫识别技术综述

在虫情监测和害虫防范治理过程中,准确识别害虫是有效解决农业领域虫害问题的重要前提。依靠专家知识和人工经验进行虫情诊断的方式效率较为低下,自动化和智能化水平较差,而采用深度学习、计算机视觉等智能化技术手段可以大幅度提升害虫识别过程的效率、准确度,并降低人工成本。概述了基于深度学习的害虫识别技术发展现状,分析深度学习技术在害虫图像识别领域的实现原理和优势,阐述国内外专家学者在基于深度学习的害虫识别技术领域的最新研究进展,提出该技术领域面临的挑战,并对发展方向进行预测。该文可为深入开展害虫识别和分类技术在智慧农业上的应用研究提供参考。      

Quantifying economic and environmental tradeoffs of walnut arthropod pest management

Many arthropod pesticides used by California walnut growers have been linked to water quality impairment. However lower risk alternatives are often associated with higher costs. The purpose of this paper was to: (1) identify currently practiced pest management strategies with probable high water quality impact, (2) quantify the importance of factors which affect economic tradeoffs associated with reducing water quality impact, and (3) identify pest management strategies that could potentially lower water quality impact with less economic consequence. An integrated analysis using environmental, economic and pesticide use data revealed that 96% of the pest management strategies analyzed were candidates for reducing the impact on water quality. Replacement of current pesticides by alternative pest controls lowered probable impact, but resulted in an economic tradeoff in the form of higher costs for the majority of growers. If biological control could eliminate the need for miticides and aphicides, this tradeoff could be replaced by savings for nearly half of the sample analyzed. This cost savings would most likely be realized by growers who currently have low numbers of pests that are not candidates for biological control, and relatively high use of organophosphates and miticides. The results indicated that if these pest management strategies had been replaced by alternative strategies and biological control, then total organophosphate, pyrethroid, and miticide active ingredient use would have been reduced by an average of 5 kg/hectare per year, while simultaneously lowering the grower’s pest management costs by an average of $128/hectare, thus contributing to both economic and environmental long-run sustainability.     

作物病虫害遥感监测研究进展与展望

病虫害是农业生产过程中影响粮食产量和质量的重要生物灾害。目前,我国的作物病虫害监测方式以点状的地面调查为主,无法大面积、快速获取作物病虫害发生状况和空间分布信息,难以满足作物病虫害的大尺度科学监测和防控的需求。近年来,随着国内外卫星光谱、时间和空间分辨率的不断提升,利用遥感手段开展高效、无损的病虫害监测成为有效提升我国病虫害测报水平的重要手段。与此同时,多平台、多种方式的作物病虫害遥感监测也为病虫害的有效防治和管理提供了重要科技支撑。本文从作物病虫害光谱特征、遥感监测方法和遥感监测系统等方面阐述了作物病虫害遥感监测研究的进展,分析了当前面临的挑战,并对未来发展趋势进行了展望。     

农作物病虫害遥感监测关键技术研究进展与展望

病虫害是影响农作物健康生长、产量和质量的制约因素之一,加强农作物病虫害的监测,对农作物病虫害进行精准防控,对保障粮食安全,提高农产品产量和质量具有重要意义。随着信息技术的发展,农作物病虫害监测由传统的人工监测逐渐向自动化、信息化和智能化方向发展。农作物病虫害监测平台、监测传感器技术以及相关的数据分析和处理技术是研究农作物病虫害遥感监测的关键技术,这些关键技术的发展水平,决定了农作物病虫害遥感监测技术的发展水平。本文从监测平台、监测传感器技术和相关数据分析与处理技术3方面对农作物病虫害监测技术研究进展进行综述。在监测平台方面,归纳总结了地面监测平台、航空监测平台和卫星监测平台的国内外研究现状,并分析了上述平台优缺点;在监测传感器技术方面,综述了雷达传感器、图像传感器、热成像传感器和光谱传感器等在作物病虫害领域的研究进展;在相关数据分析与处理技术方面,阐述了经典统计算法、计算机图像处理算法、机器学习算法和深度学习算法在农作物病虫害监测领域的研究成果。最后提出了监测平台、监测传感器技术和相关数据分析与处理技术的未来发展趋势,以期为进一步促进我国农作物病虫害监测平台及相关技术的发展提供参考。     

Measuring the technical efficiency and exploring the inefficiency determinants of vegetable farms in Samsun province,Turkey

The purposes of this research were to measure the technical efficiency of sample vegetable farms and subsequently to explore determinants of technical inefficiency in the Samsun province of Turkey. Stochastic Frontier Analysis was used to measure technical efficiency. Farm managers from 75 randomly selected farms were interviewed for farm level data in the 2002–2003 production periods. Research results revealed that the average output of vegetable farms in Samsun could increase by 18% under prevailing technology. The technical efficiency of the sample vegetable farms ranged from 0.56 to 0.95 (0.82 average). The variables of schooling, experience, credit use, participation by women and information score negatively affected technical inefficiency. However, age, family size, off-farm income and farm size showed a positive relationship with inefficiency. Therefore, this study proposes strategies such as providing better extension services and farmer training programs, integrating women into the training and extension programs, raising the educational level of farmers, and providing farmers with greater access to credit, to enhance technical efficiency.     

Application of unsteady flow hydraulic-model to a large and complex irrigation system

Canal hydraulic-models can be used to understand the hydraulic behavior of large and complex network, to evaluate their performance and to improve the operation and management of such systems at low cost. In this study, the canal hydraulic-model (CANALMAN) was applied to the right bank main canal (RBMC) of the Kangsabati irrigation project, West Bengal, India. The canal is 33.17 km in length and has eight distributaries. The model was calibrated for the irrigation period of 19 July–1 August 1997 and validated for 18–28 October 1997 and 23 July–5 August 1996. The observed and simulated inflow-rates were in close agreement with each other for both the calibration and validation periods. The calibration parameters, Manning’s roughness-coefficient and seepage-loss rate, were found to be 0.016 and 160 mm per day, respectively. The means of observed and simulated inflow-rates were not statistically different at 1% level of significance for both the calibration and validation periods. The calibrated model was subsequently used to study the adequacy of water supply during Kharif (rainy) season for the year 1996. Comparison between simulated (required) and observed (supplied) inflow-rates revealed that the supply of irrigation water was in excess most of the time. The average water supply during the entire Kharif season was about 13% higher than the model-simulated required flow-rate, which establishes the fact of over-irrigation in the head reach of the main canal system. The simulation results suggest that the CANALMAN-model can be successfully used for the operation and management of the RBMC of the Kangsabati irrigation project.     

基于YOLO v5和多源数据集的水稻主要害虫识别方法

针对水稻稻纵卷叶螟和二化螟成虫图像识别中自动化程度较低的问题,引入目标检测算法YOLO v5对监测设备和诱捕器上的稻纵卷叶螟和二化螟成虫进行识别与计数。依据稻纵卷叶螟和二化螟的生物习性,采用自主研发的水稻害虫诱集与拍摄监测装置,自动获取稻纵卷叶螟和二化螟成虫图像,并与三角形诱捕器和虫情测报灯诱捕拍摄的稻纵卷叶螟和二化螟成虫图像共同构建水稻害虫图像数据集;采用左右翻转、增加对比度、上下翻转的方式增强图像数据集;对比了不同训练模型对三角形诱捕器和监测设备诱捕拍摄的水稻害虫图像的检测性能,并对比稻纵卷叶螟成虫不同训练样本量对识别结果的影响,用精确率、召回率、F1值、平均精度评估各模型的差异。测试结果表明,测试集图像为三角形诱捕器和监测设备诱捕拍摄虫害图像时,稻纵卷叶螟识别的精确率和召回率分别达到91.67%和98.30%,F1值达到94.87%,二化螟识别的精确率和召回率分别达到93.39%和98.48%,F1值达到95.87%。不同采样背景、设备构建的多源水稻害虫图像数据集可以提高模型对水稻害虫识别的准确性。基于YOLO v5算法设计的水稻害虫识别计数模型能够达到较高的识别准确率,可以用于...     

Using crop and pest models for management applications

Models that simulate crop production systems are useful tools to aid in crop management. The manager can evaluate numerous management options quickly and select the options most suitable for his situation. The Florida Soybean growth model (SOYGRO) has been implemented with several user interfaces to meet specific management goals. These implementations include a gaming model (SOYGAME), a pest decision model (PESTDEC), an irrigation decision model (IRRDEC) and a strategy evaluation model (SICM). The crop model integrates the effects of weather conditions, crop management inputs and soil conditions on crop yield and the yield changes are reflected in the corresponding profit. Also described in the paper is an automated weather collection and reporting system for the acquisition and use of weather data.     

Relating long-term rainfall variability to cattle population dynamics in communal rangelands and a government ranch in southern Ethiopia

This study reconstructed 21 years of household cattle population data in key resource (tula wells) and non-key resource (pond-water) rangelands in southern Ethiopia, as well as 15 years of government cattle breed conservation ranch data, to analyze the relationship between long-term rainfall and cattle population dynamics. For the key-and-non-key resource rangelands, we assessed the reproductive life of cows and the number of calves. For both the communal and ranch systems, we analyzed impacts of multiple droughts on calving rates and herd die-offs. Relationships between pre-drought and post-drought cattle populations were used to evaluate evidence of density-dependence. Breeding females in the key resource tula well rangelands had a longer reproductive life than in the pond-water rangelands, and they produced more calves per reproductive life. Average calving rates were 55% for the communal and 52% for the ranch. Greater reductions in calving rates during droughts implied reduced herd growth potential. Breeding females and immature animals were influenced to a much greater degree by inter-annual rainfall variability than were mature males. The data showed a downward spiral for the total cattle holdings over a 21-year period, with a decline of 54%. The evidence of density-dependence was relatively important at the local land use level as compared with the regional level. Cattle population below carrying capacity under ranch management did not reduce herd die-offs, suggesting that rainfall variability, not density, had greater influence on cattle population dynamics. Long-term trends of cattle populations in the communal and ranch systems synchronized with mean deviations of rainfall. Our results indicate that rainfall variability under the different management systems strongly influenced the dynamics of cattle population, calving rates and mortality. The claim that ranching could be a superior model for range management in Borana over the communal system was not confirmed. The decline in cattle population in southern Ethiopia indicates a need for improved drought management policy. The evidence that droughts were more harmful to breeding females and immature animals than to mature males suggested that drought management needs to focus on herd recruitment potential. For the herders in southern Ethiopia, drought management involved herd mobility and accumulation of herds during periods of favourable rainfall. In the future, the importance of government ranch could be in breed conservation for the maintenance of the Borana cattle breed through distribution of bulls during the drought recovery phase.     

农田虫害远程自动监测系统设计

针对我国农田虫害频发、损失严重的特点以及信息网络技术在农村的发展现状,提出了用于农田虫害识别与虫情预报的自动监测系统。该系统采用ST公司的STM32F103微处理器和ZOGLAB公司的G3100 GPRS Mo-dem,由各种传感器采集虫害图像、现场温度、湿度、照度等数据,经GPRS网络发送至数据中心进行图像识别、虫害分析与预报。该设计方法对其他行业的数据采集与监控系统建设也有着积极的借鉴意义。     

我国稻田大螟发生规律与防治技术研究进展

自20世纪中叶以来,在长江中下游局部地区,稻田大螟的发生与危害呈逐年上升的趋势,并逐渐由常发性的次要害虫发展成为目前水稻上的主要害虫之一,在部分稻作田块的危害已接近或超过其他害虫。该文基于近几年国内有关稻田大螟发生与防治情况,就其种群变化、危害程度、发生规律、生物学特性、防治和测报技术等方面的研究进展进行了综述。      

低山丘陵区红壤水分的动态变化及影响因素

红壤分布区域是中国重要的粮食产地,但是降水时空分布的不均匀导致了季节性干旱的发生。因此,了解红壤中水分时空分布规律具有十分重要的意义。该文研究了低山丘陵区红壤旱地不同肥料配比长期试验小区土壤含水率的季节性变化状况及其与气象因素的关系,分析了典型红壤地区的土壤水分变化规律。结果表明：研究区1 a内的土壤含水率变化分为4个阶段：土壤水分充盈期、土壤水分亏缺期、土壤水分补充恢复期和土壤水分平稳期。空白小区土壤含水率变化较大;在施用肥料的试验小区中,蒸发对氮肥小区、氮磷小区和氮磷钾小区的影响逐渐降低;而降雨对氮肥小区、氮磷小区和氮磷钾小区的影响力逐渐增加。通过掌握典型红壤地区的土壤水分变化规律,对该地区水资源的调配管理、灌溉安排及干旱评估均可起到重要的指导作用。     

Combining an ecological model with remote sensing and GIS techniques to monitor soil water content of croplands with a monsoon climate

Soil water is an important factor affecting photosynthesis, transpiration, growth, and yield of crops. Accurate information on soil water content (SWC) is crucial for practical agricultural water management at various scales. In this study, remotely sensed parameters (leaf area index, land cover type, and albedo) and spatial data manipulated using the geographic information system (GIS) technique were assimilated into the boreal ecosystem productivity simulator (BEPS) model to monitor SWC dynamics of croplands in Jiangsu Province, China. The monsoon climate here is characterized by large interannual and seasonal variability of rainfall causing periods of high and low SWC. Model validation was conducted by comparing simulated SWC with measurements by a gravimetric method in the years 2005 and 2006 at nine agro-meteorological stations. The model-to-measurement R² values ranged from 0.40 to 0.82. Nash-Sutcliffe efficiency values were in the range from 0.10 to 0.80. Root mean square error (RMSE) values ranged from 0.028 to 0.056 m³ m⁻³. Simulated evapotranspiration (ET) was consistent with ET estimated from pan evaporation measurements. The BEPS model successfully tracked the dynamics and extent of the serious soil water deficit that occurred during September-November 2006. These results demonstrate the applicability of combining process-based models with remote sensing and GIS techniques in monitoring SWC of croplands and improving agricultural water management at regional scales in a monsoon climate.     

基于GPRS网络水位无线监控报警系统的设计

我国在水利、电力的监测中还没有普及应用自动化数据采集和传输设备,大部分地区仍通过人工方式进行数据采集和分析,存在数据测量准确度低、监测实时性不强等问题,为此设计一种基于GPRS网络的水位无线监控报警系统。该系统通过传感器采集水位信息,然后经终端数据中转站利用GPRS无线网络传输传送数据,实现后台集中式供水监控、失效报警以及水源井、蓄水池安全报警功能。     

利用无人机影像监测不同生育阶段玉米群体株高的精度差异分析

为明确利用无人机影像监测玉米群体株高的精度及其影响因素,本研究基于无人机搭载光学成像设备构建大田玉米群体数字高程模型（Digital Elevation Model,DEM）,研究不同生育时期下玉米群体株高监测的精度差异。针对3个玉米品种、8个播期处理构建的株高差异化群体,用多旋翼无人机搭载高清RGB相机和多光谱成像设备,采集试验区高清RGB和多光谱影像,获取玉米群体数字高程信息DEM和各处理区植株高度,分析不同品种和播期处理下基于无人机和人工测量株高间的相关关系。试验结果表明,高清RGB相机和多光谱成像设备获取的DEM均能反映玉米群体的高度差异。高清RGB相机的株高监测精度优于多光谱成像设备,但株高监测精度不足,难以反映玉米群体的较小株高差异。不同生育阶段对玉米株高监测精度具有较大影响,生育前期冠层尚未全部覆盖地表或生育后期植株衰老叶片枯黄下垂时,受裸露地表影响,群体株高被严重低估。本研究分析了影响无人机搭载成像设备监测玉米株高精度的因素,可为该方法应用于大田生产提供借鉴意义。     

Opportunities for yield increases and environmental benefits through site-specific nutrient management in rice systems of Zhejiang province,China

Environmental pollution by nitrogen (N) leaching or runoff from rice fields and high pesticide use has become a serious concern in China. Average N application is high and fertilizer-N use efficiency is low compared with other major rice growing countries. In Zhejiang, rice farmers apply 150–250 kg ha⁻¹ fertilizer N and 7–10 sprays of pesticides per season to maintain yield levels of 5.5–8.0 t ha⁻¹. Fertilizer and pest management strategies of farmers are not based on plant nutrient demand and pest control requirements. To provide farmers with options for high yielding, yet more resourceful management options, site-specific nutrient management (SSNM) was developed at Zhejiang University in collaboration with the International Rice Research Institute (IRRI). The approach comprises guidelines that allow farmers to adjust domain- and season-specific fertilizer recommendations to actual growing conditions in their fields taking into account plant nutrient demand, indigenous nutrient supply, nutrient use efficiency, as well as socio-economic factors. The main objective of this paper is to evaluate the agronomic performance of SSNM in farmers’ fields in the past seven years (1998–2004). With SSNM, average grain yield increased by about 0.5 t ha⁻¹ over the farmers’ practice, while N use efficiency increased significantly. About 30% of both fertilizer N could be reduced through adoption of SSNM, which would effectively eliminate an unnecessary source of pollution in the rice ecosystem. Larger scale dissemination of SSNM for rice is under way in Zhejiang province, but stronger institutional support is urgently required.