Study On Water-salt Dynamic Of Saline Land Under Different Irrigation Quota And Plant Disposition

Depending on the problems of drought and rainless in Jingyuan,Gansu,the severity of salt accumulation in saline soils,and difficulty of improving,under the basic of applying organic manure and yellow sand,studying on the influence of water and salt changes in different saline-alkali-tolerant plant species and plant configurations under different irrigation quotas reveals the changing rules of water and salt in saline-alkali soil.The main results as follows:(1)The main effects of Irisensata Thunb and 9901 Willow on soil pH range from 0-60 cm soil layer,the main influence about Amorpha fruticosa L.to soil pH in 0-40 cm soil layer.Under the same irrigation amount condition had little effect on soil pH on different plant.(2)The main influence range of Irisensata Thunb,Amorpha fruticosa L.and 9901 Willow on soil salinity range from 0-60 cm,0-40 cm and 0-80 cm respectively,and contracted with the original decline 57%-76%,40%-76%,23%-61%.Low salinity areas is 9901 Willow>Amorpha fruticosa L.>Irisensata Thunb,with the increase of irrigation amount,the low salt area of three plants will be gradually enlarged.It shows high irrigation amount contribute to reducing soil salinity,conduciving to plant growth and increasing crown cover of plant.When the irrigation amount exceeds 780 m3/hm2,there is no significant change in the soil salinity decreasing between Irisensata Thunb and Amorpha fruticosa L,on 9901 Willow,while the irrigation amount exceeds 780 m3/hm2 and the soil salinity is about 3.0 g/kg,it will not affect plant growth.So the best irrigation amount is 780 m3/hm2.(3)Four kinds of the same allocation modes reduced the salinity of soil in 0-60 cm from 64%-69%,and the accumulation of soil salinity in 80-100 cm soil layer.The effect of M1 configuration(Amorpha fruticosa L.+ Irisensata Thunb)on salinity reduction was obvious in 0-40 cm soil layer.The effect of M2(9901 Willow+ Irisensata Thunb)on salinity reduction was obvious in 40-60 cm soil layer.The fluctuation of Ca2+,Mgt+,Na+ and Cl-in 0-100 cm soil layer was larger.The four ions of 0-60 cm soil layer decreased by 44.44%-85.35%,and accumulated in the soil layer of 60-100 cm.Considering the soil pH,salinity and plant growth index of 0-100 cm soil layer,M2 has the best configuration effect.