The Different Water And Nitrogen On Physiological And Ecological Studies On Jatropha Curcas L. Sapling Under Salt Stress

Our country has a wide area of saline land,and has a high potential for development and utilization.As a biodiesel species,it received widely attention because of its high oil content and salt stress resistance.Although Jatropha curcas L.has strong ability to resist salt stress,the coupling effect of water and nitrogen on physiological and ecological characteristics conducive to the growth of Jatropha curcas L.is unclear.Therefore,in order to reveal the physiological and ecological mechanism of Jatropha curcas L.under salt stress effects of different water and nitrogen treatments and repair the ecological environment effectively,we combined pot and plot experiments.In this study,Jatropha curcas L.was used as a research material.We got the effect of different water and nitrogen on physiological and ecological studies on Jatropha curcas L.through the combined test method of pot and plot,three irrigation levels and four nitrogen levels were included.The following conclusions are obtFained:(1)With the same NaCl amount,comparing to the irrigation amount of 0.9L and 1.8L,the irrigation amount of 2.4L's plant height,dry mass,stem diameter,sound seedling index and water use efficiency increased observably.Compared with non NaCl amount,the dry mass and water use efficiency increased observably of 0.25g NaCl amount's of Jatropha curcas L.sapling,but there were little difference between 0.25 and 0.5g NaCl amount.(2)At non-nitrogen condition,compared with 0.8L treatment,1.6L's and 2.4L's the photosynthetic rate and transpiration rate,stomatal conductance,stomatal density,leaf water potential the biomass,root shoot ratio and irrigation increased.With the same irrigation amount,compared with the application of non-nitrogen treatment the photosynthetic rate,transpiration rate and stomatal conductance increased of salt stress.At the salt stress condition,with the increase of irrigation amount of soil water content of root zone rate of Jatropha curcas L.increased gradually and the high water amount promote the growth of height and stem diameter,significantly reduce the content of nitrate nitrogen and the Na+ in the soil root zone and the conductivity of the root soil.(3)Compared with T3NH's treatment,the photosynthetic rate,transpiration rate,stomatal conductance and leaf water potential of T3NM were significantly increased 5.15%,5.86%,8.81%and 23.25%respectively.Thus,under the salt stress of 0.5g NaCl/lkg dry soil,the optimal water and nitrogen control mode is T3NM that the irrigation is 9.6L and the nitrogen 30g of per plant of Jatropha curcas L.