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用土壤溶液浓度ＮａＣｌ７５ ～３２５ ｍｍｏｌ／Ｌ的中性盐对苜蓿 进行胁迫处理，研究苜蓿在土壤脱湿过程中，盐胁迫对其生长及矿质元素吸收运输的影响． 结果表明，ＮａＣｌ胁迫浓度的增加和胁迫时间的延长均使苜蓿的相对生长速率、含水量、累积 蒸散量、水分利用效率、Ｋ含量和Ｋ／Ｎａ值下降，但土体中的剩余水量却呈上升趋势．苜蓿生长 受到水分与盐分胁迫双重胁迫的影响．随ＮａＣｌ胁迫的增加，苜蓿的Ｎ素含有率变化不大，但积 累量显著减少；Ｋ＋、Ｃａ２＋的比吸收率（ＳＡＲ）显著降低，植株Ｋ＋、Ｃａ２＋含 量减少，而植株Ｎａ＋、Ｃｌ－的比吸收率ＳＡＲ显著提高，牧草体内Ｎａ＋、Ｃｌ－含量不断积 累增加，植株Ｋ／Ｎａ值降低．对Ｐ、Ｍｇ２＋的吸收在不同水盐条件下变化不一致．苜蓿根系 吸收钾钠离子后，向茎叶运输钾的选择性随ＮａＣｌ胁迫的不同而呈现出不同的趋势．
Alfalfa was treated with NaCl75 ~ 325 mmol / L neutral salt in soil solution concentration to study the effects of salt stress on its growth and mineral elements absorption and transportation during soil desorption. The results showed that the relative growth rate, water content, evapotranspiration, water use efficiency, K and K / Na of alfalfa decreased with the increase of NaCl stress and the prolongation of stress time, but the residual water in soil was Upward trend. Medicago sativa growth is affected by double stresses of water and salt stress. With the increase of NaCl stress, the content of N in alfalfa changed little, but the accumulation decreased significantly. The SAR of K + and Ca2 + decreased significantly, while the content of K + and Ca2 + decreased, but the ratio of Na + and Cl- Absorption rate of SAR increased significantly, pasture body Na +, Cl-content increased continuously, plant K / Na value decreased. The absorption of P and Mg2 + changed inconsistently under different water and salt conditions. After potassium chloride and sodium ions were absorbed by the roots of alfalfa, the selectivity of potassium transport to stems and leaves showed different trends with different NaCl stress.