The Research Of Tomato Growth Model And Greenhouse Microclimate Modelling

Greenhouse is to create the most suitable environment for crops cultivated inside such that the goal of high-yield,high-quantity,low-cost,best-benefit,environment friendly at harvest can be reached,so it has attracted attention.Modern greenhouse is the main of China's facilities agricultural production,playing an important role in our off-season vegetable production and having good prospects for development.The control of the greenhouse microclimate is one of the key techniques in modern greenhouse and becoming increasingly important.On the basis of conducting effective test observation,the main contents of this paper include follows:(1)Temperature,humidity,light,carbon dioxide concentration are the major environmental factor having important impacts on crop growths in energy-saving solar greenhouse.In the use of the method that is applied of neural network and based on the environmental factors,the tomato leaf area index model of the effective temperature,the horizontal and longitudinal diameter model of tomato fruits,and dry matter accumulation and distribution exponential model of tomato are established.This method is simple,rapid,economic,and does not damage the leaves of tomato saving a lot of trouble.Thus the model has practical application.(2)Farmland evapotranspiration(Evapotranspiration,ET) is the fundamental basis to researchthe regional water balance and to plan to develop irrigation water requirement,and the accuracy of it have direct impact on crop water demand forecasting,so it has become the key link to monitor agricultural drought and to improve the regional water use efficiency.This paper established the water evaporation models based on environmental factors.The models show the relationship of environmental factors and water evaporation,soil evaporation,crop transpiration between the number,not only reveal the environmental factors of water evaporation,evaporation of soil moisture changes,and environmental factors on plant physiological changes of water,but also can be used to forecast crop transpiration water consumption with meteorological parameters,then based on predictive value to supply water plants timely and adequately,so as to achieve water-saving,high-yielding,high-quality purposes.In water evaporation and soil evaporation models,in the moment of change climatic factors,soil moisture and evaporation is also affected,if the model can predict the minimum evaporation,so that the growth of plants not only is beneficial,but also can save water.Genetic algorithm,referred to in recent years develop a new self-adaptive search algorithm for global optimization.It is more programming,and adaptable than the traditional method of convergence of nonlinear,you can reach the global optimum,so the applications prospects is a wide range.The application of genetic algorithm optimization model can predict the minimum evaporation model,this paper use genetic algorithm to optimize the water evaporation model.This models are of great significance for establishing a reasonable greenhouse moisture management technology system to reduce the frequency of disease,as well as to establish a reasonable irrigation system,in a timely manner to ensure adequate water supply of crops based on a large number of irrigation water conservation. (3)Modeling of greenhouse environment is not only the key to control the greenhouse environment,but also a problem of the achievement of greenhouse environmental controling. Greenhouse for such a non-linear,coupled multivariable complex system,whether it is used only data or only information on the use of language are difficult to adequately describe it.Modeling the mechanism of both the experimental model or are unable to establish a generic model of the greenhouse,and to greenhouse systems these models have simplifly and linearization ability.Whether it is the mechanism modeling or the experimental modeling we are unable to establish a common model of the greenhouse,and have ability to simplifly and linear models.Adaptive fuzzy neural network is a fuzzy logic system of learning function,by learning automatically correcting the fuzzy rules and with two types of utilization data and linguistic information,and it can identify nonlinear time-varying object suitablely.This paper established models of the greenhouse based on adaptive fuzzy neural network,according to the experimental datas adjusting the parameters of the models and the parameters converged to some final determined value in order to be adaptive fuzzy neural network models.From the simulated results that inside the greenhouse established microclimate models with adaptive fuzzy neural network,the models has higher precision,using the model in different seasons within the greenhouse temperature,humidity,light to carry out the forecast,then the forecast value and actual value also has a good fitting relationship.This shows that using adaptive fuzzy neural network model to simulate microclimate in the greenhouse and different seasons, it meet precision that the physical models may be unable to meet,and the performance of the internal simulation humidity is particularly evident.If the qualitative description of the greenhouse are more comprehensive,then the models will have better adaptability, overcoming these limitations that the general linear models have.(4)According to the establishment greenhouse microclimate models,the views are bring forward that the use of computer simulation to predict temperature,humidity,light and analyzed the characteristics of the greenhouse microclimate control facilities as well as ability to regulate and control in conjunction with the actual operation of the greenhouse.For spring, summer,fall,winter,indoor temperature,indoor humidity,indoor lighting,outdoor temperature, outdoor humidity,outdoor illumination of the different characteristics,different control measures are taken to create a suitable environment for crop growth,and characteristics and control facilities abilities are analyzed.It is fixed the premise conditions and the foundation for the control of greenhouse microclimate.(5)Based on environmental comprehensive datas for greenhouse tomato growth for many years,a set of successive anniversary temperature humidity solar radiation database is established,known as the universal database.Accoring to the establishment of the environmental databases light primarily on the basis of the record of temperature and humidity combined with the occurrence of common diseases of greenhouse conditions,used in greenhouse tomato disease forecasting expert system module,it predict the occurrence of diseases.The purpose is solving disease hazards in view of prevention.This will reduce the number of spraying and amount of application.At present the system only from the perspective of environmental factors predict,can not quantify.It proved an important data support for management of modern greenhouse,especially provide important data to support for the newly established greenhouse,and is helpful to automatization and intelligentized management for modern greenhouse environment.