中文摘要：

水分和氮素是影响草坪草生长和成坪质量的关键因素。本试验研究目的是为了掌握最恰当和最节约的水氮条件,了解水分和氮素之间最有效的使用比例,这在草坪建植和养护过程中具有重要意义。本试验以草地早熟禾（Poa pratensis）为研究材料,设置了高、中、低3个浓度施氮量及适度水分、轻度水分胁迫和重度水分胁迫3个水分供给条件,对草地早熟禾的生长特性和坪用质量进行评价。结果表明：水氮互作条件下,轻度干旱时,高浓度氮素会促进地下部分的生长,同时也促进草地早熟禾叶长、叶宽、节间长度、分蘖数的增加;叶片绿色指数与根长、根冠比等相关性显著;适度水分或轻度水分胁迫时施氮量越高,越能促进地上和地下生物量的积累。重度干旱时,低浓度氮肥更有利于草地早熟禾的生长。因此我们得出结论：在不同的水分条件下,要因地制宜的控制氮素的使用,严重干旱条件下少量使用氮肥能得到更好的成坪效果。

英文摘要：

Water and nitrogen are the key factors in the growth of turfgrass and turf quality.In daily production and construction processing,lawn often limited by this two factors.Therefore,the study of how to regulate the ratio between water and nitrogen,and understand the most appropriate and economical water and nitrogen conditions in turf establishment process is of great significance.Three nitrogen supply levels and three water conditions were used in this experiment,to evaluate the growth characteristics and turf quality of Kentucky bluegrass（Poa pratensis）.The results showed：lighter water stress with high concentration of nitrogen,promoted the growth of the underground biomass,increased leaf length,leaf width,internode length,tillers.Leaf green color index is closely related to root length and root/shoot ratio.Moderate water and lighter water stress enhanced the biomass of underground and aboveground with the increased nitrogen supply,lower nitrogen concentration increased the growth of Kentucky bluegrass under serious water stress condition.Therefore,we could draw a conclusion that the nitrogen should be applied according to local conditions,including different water conditions;and the use of less amount of nitrogen can have a higher quality of turf under severe drought.