Effect Of Different Irrigation Volume On Growth Of Turfgrass In Beijing Areas

The monthly rainfall from April to December of 2004 in Beijing area was measured in the study, and on the base of rainfall materials of past years, the characteristics of rainfall in Beijing area were summarized. And also the effect of different irrigation on apparent quality, growth and metabolism of Tall fescue (Festuca arundinacea), Kentucky bluegrass (Poa pratensis) and Zoysiagrass (Zoysia japonica) was analysed. The befitting monthly irrigation volume was conluded from June to November. Moreover, the evapotranspiration(ET) rates of the three species turfgrass were measured from June to December.The conclusions reached include the following:1. the characteristics of rainfall in Beijing areas are as followed: The average of yearly rainfall volume in Beijing areas is very low, and it was keeping decline in recent years. The rainfall in each season was quite different, mainly concentrating during June to August with hard intensity. Rainfall of different areas was various, the high value was distributed on the facing-wind slope in front of mountains.2. With the increasing of irrigation volume, the apparent quality of three turfgrass raised, the relation between irrigation volume and apparent quality is positive correlation.3. The stem growth rates, aboveground biomass and underground biomass were all increasing ,with the enhancement of irrigation volume, but with irrigation volume increasing to some degree, they would decline. The optimal ratio between root and stem is 1.0.4. Drought stress in some degree would contribute to the growth of roots, with the increasing of irrigation volume each growth indices would go up . The sequence of the number of root-tip under GV treatment: ZY>TF>KB. And suitable drought stress would promote the growth of turfgrass roots into deep soil, on the other hand over-irrigation would lead to short roots.5. With the increasing of irrigation , chlorophyl 1 content of three turfgrasswould go up , but to some degree,over-irrigation would also result in the decline of chlorophyll content. Under GV treatment, the sequence of total chlorophyll content (Ct) of three turfgrass is ZY>TF>KB.6. The total roots absorbing area was increasing with the enhance of irrigation., having maximum under GV treatment.7. With enhancement of irrigation, the net photosynthesis rates(NPR) were increasing, then to some degree, they would go down, the same to ET, Cs, LSP (Light saturation point), absolute value of DDR (Dark respiratory rate) and AQY(Apparent quantum yield) . But LCP (Light compensation point) was on the opposition. The LSP of TF, KB and ZY was 1184,975 and 1453 μ mol/s.m2 respectively, and LCP was 38.237,45.319 and 25.649 μ mol/s.m2.8. The ET of three turfgrass goes up with the increasing of irrigation, the relation between ET and irrigation volume was significant positive correlation. The ET sequence is TF>KB>ZY.