【作者】 霍晓静；

【导师】 杨世凤；

【作者基本信息】 河北农业大学 ， 农业机械化工程， 2002， 硕士

【摘要】 干旱历来是农业生产的主要自然灾害之一，而灌溉是人类用来避免干旱，提高作物产量的基本手段。长期以来，如何准确判断作物水分亏缺程度、掌握生长对水分亏缺反应的规律，为实时精确灌溉提供依据，一直是众多学者致力于研究的课题，人们从不同方面入手，制订了相应的灌水指标。在已建立的灌溉自动控制系统中，土壤含水量或大气相对湿度是最常见的控制农作物灌溉的指标，但对作物缺水而言，这些都是反映作物生长环境的间接指标，对反映作物的缺水比较迟钝、滞后。而在土壤—植物—大气连续体(简称SPAC)中，植物才应该是是否需要灌溉的最优指示物，因为只有它们才能把控制植物水分平衡的土壤因子和大气因子综合起来。因此，从植物本身出发，本文在国内首次采用了以植株茎部声发射信号作为农作物需水信息的新方法，运用目前在测控领域国际流行的虚拟仪器技术，建立了对作物植株茎部声发射信息进行实时、快速测量的微机检测系统，并以温室盆栽番茄为对象，研究了声发射信息同植物蒸腾以及环境因子间的关系。试验结果表明，作物在水胁迫下产生的声发射信号与蒸腾量等水分指标的一致性较好，对水分亏缺反应敏感，是一个良好的灌水指标。为此，本文在监测系统的基础上扩展了系统功能，建立了基于植物生理需水信息的温室滴灌自动控制系统，并进行了灌溉控制效果实验。同定时灌溉相比，按声发射信息控制灌溉可节水34.02％，而作物生长几乎不受影响，节水效果与经济效益显著。在河北农业大学温室实际试用结果表明，该系统工作稳定可靠、操作方便灵活、测试结果准确，适应了现代化农业科学生产和自动化管理的需要，并为开展植物生理、生态研究提供了一个良好的研究手段，具有较高的实用价值和广阔的应用前景。更多还原

【Abstract】 To avoid drought, which is always the main natural disaster of agricultural production, and improve the yield of crops, irrigation is the basic method. For a long time, how to detect water stress levels in crops accurately and apply a real-time accurate irrigation, is a popular topic for many researchers. As a result of researches, several water indexes were brought up from different methods, such as soil moisture content and air relative humidity, which were most commonly used in the past irrigation control system. For crop water stress, however, those are all insensitive and indirect indexes that represent the environmental states of crops. In SPAC, it is the plant that should be optimum indicator for irrigation control, because the soil factor and air factor, which control the balance of water in crops, can but be integrated by plant. As result, a new method is presented by using the acoustic emission (AE) signal from stem of individual plant as its demand information. Based on virtual instruments technique, which is becoming a popular tool in measurement and automation fields international, a computer-based detecting system is developed for the fast, real-time measurement. Take tomato crops for testing example in greenhouse, the relation between AE and transpiration, environmental factors has been studied. It has shown that a good agreement between acoustic emission and transpiration, and the AE signal is a good water stress index for irrigation control. So, a real-time irrigation control system based on plant physiological water needing information was established, and the effect experiment of irrigation control was made. Compared with timing irrigation, 34.02 percent water can be saved by using acoustic emission technique for irrigation control and the growing state of tomato crops doesn’t be affected. The system works safely, operates easily and measures accurately, it is suitable to the need of scientific production and auto-manage of modern agriculture. A new research method for the physiological and ecological research of plant is applied by the system as well. In a word, it has great practical value and wide future of application.更多还原