Index System Of Water-saving Irrigation For Garden Plants In Tianjin Economic Development Area

In situ field dynamic monitoring results of soil moisture of three types of greenbelt in Tianjin economic development area, including bentgrass, tall fescue and paulownia, showed that the seasonal and vertical dynamics of soil water is the basis of water-saving irrigation.According to velocity of soil water consumption, the seasonal dynamics of soil water can be divided into different stages. Bentgrass greenbelt soil can be divided into slow consumption stage, quickest consumption stage, quicker consumption stage and slower consumption stage. Tall fescue greenbelt soil can be divided into slow consumption stage, quickest consumption stage and slower consumption stage. Paulownia greenbelt soil can be divided into quicker consumption stage, quickest consumption stage and slower consumption stage.In term of soil water coefficient of variation, the soil water profile in 0-100cm can be divided into 3 layers, i.e., hypoactive layer, hypoactive layer and correspondingly stable layer. These soil water layers varied along with soil water consumption seasons alternating. Different greenbelt types were distinguished from one another in different soil water consumption seasons.Soil water irrigation maximum was decided by soil physical properties. For bentgrass greenbelt soil, its soil water irrigation maximum was 35.1%-38.4% at 0-100cm depth. For tall fescue greenbelt soil, its soil water irrigation maximum was 35.2%-37.9% at 0-80cm depth, 30.2% at 100cm depth. For paulownia greenbelt soil, its soil water irrigation maximum was 32.8%-34.0%, 3at 0-100cm depth, 24.6% at 100cm depth.Soil water irrigation minimum and scheming wetted soil layer depth were decided by soil physical properties and plant physiological property. According to the correlativity between stomatal conductance and soil moisture, root system distribution and soil water profile, these greenbelt should irrigate when soil moisture is high, and their scheming wetted soil layer depth is shallow in slow consumption stage; irrigate when soil moisture is low, and their scheming wetted soil layer depth is deep in quickest consumption stage; irrigate when soil moisture is higher, and their scheming wetted soil layer depth is deeper hi slower consumption stage.Irrigation water requirement per time=(soil water irrigation maximum- soil water irrigation minimum) ?scheming wetted soil layer depth.Irrigation cycle and irrigation times were decided by soil water irrigation maximum, minimum and consumption velocity.Irrigation quota can be calculated by irrigation water requirement per time and irrigation times.Soil salt didn't excess 3g kg-1 when experiments were finished, but paulownia greenbelt soil salt increased.Index system was made sure and will provide gist for intelligentlizing water-saving irrigation.