Simulation Investigations on Mass/Energy Transports in SPAC System and Their Applications in China

Plants make use of mass and energy which are transported in the Soil-Plant-Atmosphere continuum, known as SPAC system. Previous quantitative investigations on the mass/energy transports in the SPAC system and their gover-ing equations are dealt with in this paper as: water, solutes and heat (or temperature) transports. Some new concerns, such as heat-water coupled transport, simultaneous water-solute transport and coupled water-heat-solute transport, of research in China are given. The advances in experimental and theoretical studies of SPAC system in China are as:successful application of Regulated Deficit Irrigation; solving salinity problem with better, quantitative soil water management; dynamical estimate of water extraction by plants; application of SPAC system simulation to irrigation timing. Several difficult aspects concerning SPAC system research are listed as: appropriate models for the descriptions of transport processes; determination of reasonable boundary conditions; measurement techniques for physical parameters of soils; treatments of soil variations; effective methods for the solution of different processes; combination of computational and experimental, both indoor and in the field, methods.