不同暗沟间距对垂柳光谱和光合特性的影响

目的]通过评估不同处理的改良效果,为西北地区利用暗沟处理措施改良盐碱土提供理论依据,从而解决西北地区大面积的盐渍土现象,实现土地的高效利用。方法]以2年生垂柳为试验材料,对比分析了不同暗沟间距处理措施(CK为对照;T1为暗沟间距3m;T2为暗沟间距6m;T3为暗沟间距9m;T4为暗沟间距15m)对土壤理化性质、垂柳的生长和叶片光谱光合特性的影响。结果](1)4种处理的土壤含水率、pH值和土壤含盐量与对照相比均有所降低;除T4处理外,其余处理均与对照之间具有显著性差异(p0.05),T3处理的土壤含盐量下降最多。(2)通过处理垂柳的各项生长指标均比对照组有所提高,T1处理效果最好,T4处理效果最差,T1与T2,T3处理之间差异不显著(p0.05)。(3)4种暗沟间距处理都能显著提高垂柳的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度(Ci)和叶绿素含量,T1与T2,T3处理之间差异不显著(p0.05),T4处理效果不及另外3种处理。结论]在西北地区采用挖设暗沟排盐的方法可以有效排出盐分,综合考虑经济成本等因素,T3处理为最佳方案。

Effects of Blind Ditch Spacing on Spectral and Photosynthetic Characteristics of Salix Babylonica

Objective] The aim of the study was to provide theoretical basis for the improvement of saline soils by evaluating the improvements in different spacing treatments of blind ditch in the northwest area. Whereby, the salinization prevailed in the widespread area of Northwest China was expected to be restrain and the lands were expected to be use efficiently.Methods] Saline soil and Two years old Salix babylonica growing on it was used as the experimental materials. The effects of different blind ditch spacing (CK was control,T₁ was 3 m,T₂ was 6 m,T₃ was 9 m,T₄ was 15 m) on soil physical and chemical properties, the growth, leaf spectral photosynthetic characteristics of weeping willow were studied.Results] (1) Soil water content, pH value and soil salinity of the four treatments were all lower than the corresponding values of the control. The water content of 4 treatments were significantly different from the control (p<0.05) except T₄. The soil salinity of T₃ treatment decreased the most. (2) All the growth indexes of weeping willow were improved in comparison with those of the control treatment. The effect of T₁ ditch spacing treatment is the best and T₄ treatment is the worst. The differences among T₁ and T₂ and T₃ treatments were not significant(p>0.05).(3) Four kinds of ditch spacing treatment significantly increased the leaf photosynthetic rate(P_n), transpiration rate (T_r), stomata conductance (G_s) and chlorophyll content of weeping willows. The differences among T₁ and T₂ and T₃ treatments were not significant (p>0.05). The effect of T₄ spacing treatment is less than the ones of other three treatments.Conclusion] Therefore, the ditch spacing treatment can effectively discharge salt. When selecting the blind ditch spacing, T₃ ditch spacing treatment is the best solution for its low economic cost.