Effent Of Different Monovement Measures On Eco-phyelogy Chiaractericties Of On Sunflower In Sodie Soil

In order to determine a optimal improvement technology integration pattern,which is suitable for inland arid region sodic soil ecological exploitation and utilization.The researche taked typical takir and oil sunflower (saline-alkali land pioneer crops)as the study object in Ningxia Xidatan,we adopted the methods of pot simulated experiments,in-depth study on effect mechanisms of soil alkalization to eco-physiology of sunflower and effects of different synthetical improvement technology integration measures on eco-physiology of sunflower in sodic soil,we finded out the relationships between differ-ent technology integration measures and alkali-resistant physiological mechanisms of oil sunflower, determined a optimal ecological improvement technology integration measure in sodic soil in inland arid regions.the main conclusions were as follows:1.Effect mechanisms of soil alkalization to eco-physiology of oil sunflower.Soil alkalization destroyed soil granular structure,reduced noncapillary poropsity and soil aeration and permeability,promoted soil fungi growth and reproduction,inhibited the growth of soil actinomy-cete and bacteria etal other aerobic microorganisms,thereby reduced soil urease activity,inhibited the converting soil organic nutrients into inorganic matters,because of the lack of nutrients,its inhibitd the activity of antioxidant enzymes and enhanced H2O2 and O2- contents,destroyed membrane structure and photosynthetic pigment in order to decrease yields of oil sunflower;Soil alkalization depended on increasing LCP、Rd and reducing LSP、 Pnmax to decrease the range of PAR,leading to photoinhibition in advance to reduce yields of oil sunflower.2. Eco-physiological responses of sunflower to different sodic soil improvement measures.(1)The performance of improvement effects of different improved technology integration measures to takir was T2>T3>T5>T4>T1>CK.under T2 treatment,the utilization efficiency of rapidly-available P and K elements were maximum,the range of PAR was widest(60.49-2441.43μmol·m-2 ·s-1),Pnmax was maximum (49.24μmol CO2·m-2·s-1),yield of sunflower was maximum (588.8kg·hm-2),whileT5 could significantly increase soil fertility and enzyme activity.When contents of Ca2+ were insufficient,soil depended primarily on Mg+ to replace exchangeable Na+, When Ca+ was sufficient,Mg2+ and Ca2+ worked together to Na+, Ca2+ occupied the dominant position.(2) Soil alkalization resulted in stomates smaller,its increased CO2 flux by increasing stomates density to supplement its alkali-resistant energy,while improved technology integration measures enha-nced its alkali-resistance by increasing stomatal conductance of oil sunflower.(3) Variance and multiple regression analysis between endogenous hormone content of oil sunflow er root and plant height were showed that IAA and GA contents of oil sunflower root of T2 were maxim-um,while ABA content was minimum,and the relationship was negative correlation between ABA content and plant height significantly(R2=0.9558);Therefore the increase of ABA content was primary reason to restrict stem elongation of oil sunflower in sodic soil.(4) The multiple regression analysis of Pn-PAR curve mathematical model fitting and photosynthe-tic physiological parameters and yield of oil sunflower were showed that,under different improvement measures,Pn-PAR curves were"S"shape,rectangular hyperbola correction model is optimal mathematical fitting model of Pn-PAR curves of sunflower;Different improvement technology integration measures depended primarily on increasing LSP and Pnmax and PAR range to avoid photoinhibition phenomenon to increase yield of oil sunflower.(5)Correlation and principal component analysis between soil alkalization property and physiology of oil sunflower were showed that soil exchangeable Na+ was main limiting factor to affect the normal growth and development of oil sunflower,and along with the growth period of oil sunflower,sulfate etal leaded to soil salinization and salt stress highlighted;Sunflower relied mainly on K+ to balance Na+ osmotic stress in the preliminary,with the advance of growth period,oil sunflower depended on synthesi-zing soluble protein to balance inorganic osmotic stress.In summary,through the comparative analysis the relationships between different sodic soil impr-ovement technology integration measures and alkali-resistant physiological mechanisms of sunflower were showed that T2 (desulfurization gypsum:2t·666.7m-2,biochar:1t·666.7m-2,irrigation:200m3·666.7 m-2)was optimal ecological improvement technology integration measure in severe sodic soil.