土壤湿度对墨兰叶片生长和光合速率的影响

INFLUENCE OF MOISTURE ON LEAF GROWTH AND PHOTOSYNTHETIC RATE OF CYMBIDIUM SINENSE

将墨兰种植在不同土壤湿度的培养缸内５个月。从叶片生长速率和光合速率来衡量，得知最适宜于叶片生长的土壤保水力为７０％左右（即土壤含水量３６％）．当土壤保水力下降到５０％（即土壤含水量２７％）时，叶片生长和光合速率都下降，时间一长就会死亡，文中讨论土壤最适湿度与土壤保水力和通气状况有关．

In order to make clear the influence of soil moisture on leaf growth and photosynthetic rate inCymbidium sinense(Andr.)Wild,a series of pot experiments was carried out in which seedlingswere subjected to four levels of soil water-holding power ranging from 90 to 30%through fivemonths.Evaluated from growth rate and photosynthetic rate,the adaptable soil moisture is 70%soil water-holding power(namely 36%soil water content).When soil water moisture decreasedto 50%soil water-holding power(27%soil water content),the rates of both parametersdecreased sharply,and resulted in death if it lasted more than three months.The relationshipbetween optimum soil moisture and soil water-holding power as well as aeration condition arediscussed.