| How much water do the turfgrasses require per year, and is the turfgrass consume of water is more than the trees? Those are very important question . This study was carried out at the Experimental station (39° 34' , 116° 28' E; elevation 50m) of clover group, which is lacated in Chaoyang District, Beijing, with an accumulated temperature of 4200 ℃ ,above 10 ℃ and 600mm of an annual precipition.The research contents is including: (1)the leaf stoma characteristics and stomatal conductance of six specises of grasses; (2)phothosynthesis, Transpiration and WUE of TF, KB, PR, BG, LG and BF; (3)ETmax, ETmin and ETmax-min of six grasses under MLS and SPAC system; (4)Soil water dynamic during growing season and saving irrigation; (5)The effect of superabsonbent polymens on tunfgrass. The results obtained are as following:1. It was found that the form of stoma of BF, LG and BG was ring-shaped. The length of stoma is one time to the width. The stoma of BG and BF were covered with wax. The stoma of KB.PR and TF are ellipse. The length of stoma is as two times bigger as the width. The leaf stoma sizes of the three warm-season turfgrasses are smaller than the three cool-season turfgrasses, and the stoma densities of the warm-season turfgrases are larger than the cool-season turfgrasses.The stomated eanductance dynamic of cool-season turf-grasses occured two peaks during a day, but warm-season turf-grasses had only one. The stomatal conductance of KB and LG was lower than all of others. The more stomatal conductance of grasses leaves, the more water consumed was proved, because of stoma opening.2. The Pn, Tr and WUE of Six turfgrasses were measured with CID-301 PS and LD-640° portable photosynthesis system in 2002 and 2003 respectiyely. The results were shown that Pn (u mol CO2 m-2 s-1) of cool-season grasses during the Spring and Autumn periods was more than that of the warm-season grasses, but it was contrary that warm-season grasses were higher than the cool-season grasses except for PR in Summer. The Pn peak of the cool-season grasses occurred before 10 a.m, and the warm-season grasses occurred during 12-14 p.m.. Tr of both warm and cool-season turfgrasses during Summer is larger than in Spring and Autumn. The order of the Tr is TF>KB>PR among the cool-season grasses, and BG>LG>BF among the warm-season grasses . The Tr of turfgrasses except for LG in Autumn got up as the air temperature rose , and Tr peak of the turfgrass took place after the photosynthesis peak. It was obviously different that the peak time of Tr occurred for the different grasses during aday, Tr peak of the warm-season grasses in Summer occurred earlier than the cool-season grasses . The WUE of the cool-season grasses is higher than the warm-season grasses during the Spring and Autumn, and is contrary in Summer, especially, WUE of PR and LG is more than others.4. MLS and SPAC systems with equal rank at the some time were conducted in 2002 and 2003, in order to measure ET and ET/d of turfgrasses exactly . There were full and limited irrigation treatment in MLS with six grasses. SPAC used three turfgrasses (TF, KB, PR), and three soil moisture treatment (30-50% wf, 50-70% wf, 70-90% wf) and three replications were set up , the plot numbers were 27. ET of SPAC was calculated by the following equation : ET=P+I-(W2-W1), ET is evapotranspiration (mm), P is precipitation (mm), I is irrigation amount, W1 and W2 are stored water in 0-25cm soil layer from the begining to the last time.Table 1 shows a fine relationship and similar, with ETmax, ETmin and ETmax-min of TF were measured in 2002 and 2003, it can indicate the differences between MLS and SPAC.The ET from MLS is larger than SPAC except ETmax from SPAC in 2002Table 2 shows the ET max, ET min and ET max-min of six turfgrasses with MLSand SPAC in 2002 and 2003The stress coefficient of soil water (Ks) can indicate the ecological range of plants on water requarement, and the Ks is larger when the plant suffer more stress from water.It was shown that ETmax, ETmin and ETmax-min of the cool-seaso...
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