Experimental Study On The Effects Of Soil Moisture And Chemical Agents To The Evapotranspiration And Growth Of Poa Pratensis

The main purpose of this paper was to investigate the effect of soil moisture and chemical agents (Super absorbent polymers, FA Handilong) on the evapotranspiration (ET) and the growth of Poa pratensis with the pot and field experiments.1 .The orthogonal experiments was conducted with the pot experiment, which consisted of three fators including soil moisture(SM) and the usage quantity of super absorbent polymers and FA Handilong, any one of which has three levels. The result show that: The lower limit soil moisture for Poa pratensis was 55%FC. The super absorbent polymers could effectively improve the growth of Poa pratensis, and reduced the evapotranspiration in the conditon of SM= (70~85%) or (40~55%) FC, but no significantly effect was observed when the soil moisture was about (55~70%)FC (α<0.1). FA handilong could control the stomatal conductance when sprayed on the Poa pratensis therefore reduce the evapotranspiration. It also had significantly influenced (α<0.1) on the LAI and the Biomass of Poa pratensis, but the vegetal rate, density, R/C, the average clipping yield per month had no significantly influenced(α<0.1).2. In this paper multiple indexes comprehensive evalution was used in the evalution of Poa pratensis, the comprehensive evalution function based on the water saving was educed. Clustering analysis result showed that the vegetal rate, density, LAI, cumulate clipping yield, above-ground and under-ground biomass can be substitute to one of them adding the width of the grass leaf and the R/C of the turfgrass can get the same evalution effect. Those gave a new scientific and impersonal way for turfgrass comprehensive evalution and evalution indexs filtrating in the further study.3. The best Poa pratensis quality was observed when 100g/m~2 super absorbent polymers and 3g/m~2 FA Handilong was applied in the condition of SM= (70~85 ) %FC. Based on the consideration of water saving and economic, when 3g/m~2 FA Handilong was sprayed in the condition of SM= (55~70) %FC without super absorbent polymers, the Poa pratensis could satisfied the view demand.4. A randomized trial was carried out in the Sujiatuo water saving demonstration distrct. The result showed that the chemical agents can increase the soil moisture and advanced the growth of the Poa pratensis. The concrete effect needs further study.