不同复配土比例对苜蓿幼苗光合特性的影响

Effects of Compound Soil Ratio on Photosynthesis of Medicago sativa Seedlings

为了高效利用风沙土,将风沙土和黄绵土以不同体积比例混合,形成复配土(复配土比例为0%、25%、50%、75%和100%),并对苜蓿幼苗光合特性进行分析。结果表明:黄绵土配比的增大使苜蓿幼苗的Pn、Gs、Ci以及WUE均呈现先升高后降低的趋势,而Tr表现为不断升高的趋势。Pn、Tr、Gs、Ci以及WUE与纯沙土(CK)处理相比,均达到显著水平。配土比例为25%时苜蓿的Pn、Gs、Ci和WUE最高,而Tr的最大值出现在配土比例为100%处理。利用隶属函数法对其进行综合评价表明,25%的配土比例综合评价指数最高,即风沙土与黄绵土配比为25%时苜蓿的光合作用效果最佳。

In order to efficiently use aeolian sandy soil, the aeolian sand and loess soil ratio was set as 0 %, 25 %, 50% ,75 % and 100% respectively for observation and analysis, the effect of different compound soil ratio on photosynthesis of Medicago sativa seedlings was studied. The results showed that photosynthetic rate （Pn）, stomatal conductance （Gs）,intercellular COz concentration （Ci） and water use efficiency （WUE） of Medicago sativawere increased at first and then decreased,while transpiration rate （Tr） showed a rising trend with the loess soil ratio increased gradually. Each index was at significant level compared with CK. The maximum photo- synthetic rate （ Pn）, stomatal conductance （ Gs ）, intercellular CO2 concentration （ Ci ） and water use efficiency（WUE） were occurred in 25 % treatment. However,transpiration rate（Tr） was at maximum in 100% treatment. Using subordinate function to evaluate comprehensively, it was showed that comprehensive evalua- tion index of Medicago sativa was at the highest in 25 % treatment,indicating that the aeolian sand and loess soil at 25% ratio was better to promote the growth of Medicago sativa seedlings.