Dynamic Simulation Of Coupled Water And Heat Transfer In Soil-Plant-Environment Continuum (SPEC) In Greenhouses

This experiment has been done to research on the water and heat transfer and the root and shoot growth in solar greenhouses, and detail conclusions are drawn as follows:First, the concept of SPEC (Soil-Plant-Environment Continuum) is firstly approved in this paper based on lack of systematic researches in greenhouses, which makes it possible to control the greenhouses in real-time way.Second, film mulch can significantly improve the soil temperature by 3-4?, and the heat storage layer is the top 40cm in the soil depth, which is heated by solar radiation from 8:00 to 17:00, and the heat in the layer is discharged in the left time.Third, the muskmelon and watermelon grow unsteadily as "S" curve, and enough water should be given in the rapid growth stage when the diameters of muskmelon and watermelon reach to 9mm and 18mm.Forth, stomata resistance is different from different part of muskmelon leaves, and the resistance of the fore bottom of the leaves can represent the stomata resistance as a whole. Stomata resistance is close related with environment factors of solar radiation and VPD. and the stomata resistance model based on the up two factors is made by SPSS software, which makes it possible to regulate the behavior of stomata by regulating the environment factors to optimize the enviroment control.Fifth, the effective density of root length is represented by the comparative density of root length in the Mole-Remson model to make the model more useful.Sixth, the dynamic simulation of coupled water and heat transfer in SPEC in greenhouses shows good results that the simulation values of soil moisture and temperature is very closed to the measured values and the calculation of the sub-energy values in the energy balance equation make the transfer and changes of the energy in greenhouses very clear to be benefit for greenhouse production and management.