不同灌水处理下滨海盐碱地土壤-玉米阳离子变化规律及相关关系研究

Irrigation Affects the Translocation of Cations from Soil to Maize Roots in Saline-alkaline Soil

【目的】探讨不同灌水处理下滨海盐碱地土壤-玉米系统阳离子变化规律及相关关系。【方法】采用田间试验研究了滨海盐碱地不同滴灌方式对根系层土壤K^(+)、Ca^(2+)、Na^(+)和作物体内K^(+)/Na^(+)的影响,共设计4个处理,每个处理3次重复,分别为灌水定额10 mm常规滴灌处理(LI10)、灌水定额20 mm常规滴灌处理(LI20)、灌水定额10 mm膜下滴灌处理(FI10)、灌水定额20 mm膜下滴灌处理(FI20)。分别建立作物K^(+)/Na^(+)、Ca^(2+)和根系层土壤K^(+)、Ca^(2+)、Na^(+)的回归模型。【结果】灌水后膜下滴灌处理土壤Na^(+)相对量降幅远大于常规滴灌处理;膜下滴灌较大灌水量处理全生育期茎中K^(+)/Na^(+)均较大,生育前期膜下滴灌处理叶片K^(+)/Na^(+)均较大;常规滴灌处理相对膜下滴灌处理根系层土壤K^(+)/Na^(+)和Ca^(2+)质量分数均对根系K^(+)/Na^(+)的影响较大;常规滴灌和膜下滴灌处理根系层土壤Ca^(2+)的增大通过抑制根系层土壤K^(+)/Na^(+)的增大从而抑制根系K^(+)/Na^(+)的增大。【结论】在滨海盐碱地使用滴灌技术可以有效改善土壤和玉米体内阳离子分布,其中膜下滴灌相比常规滴灌技术更有利于提高玉米抗盐碱性。

【Background and objective】Soil salinity is an abiotic stress hindering agricultural production worldwide,especially in coastal areas where the groundwater is usually shallow.The aim of this paper is to study experimentally how irrigation affects translocation of major cations from soil to the roots of maize in saline-alkaline soils.【Method】The experiments were conducted at a maize field in a coastal saline-alkali region.We compared four irrigation methods:conventional drip irrigation with irrigation amounts of 10 mm(LI20)and 20 mm(LI20)respectively,and mulched drip irritation with the same irrigation amounts(FI20and FI20).In each treatment,we measured the changes in K^(+),Ca^(2+)and Na^(+)in both the rhizosphere and roots,from which we derived regression models to analyze how the irrigation method and irrigation amount modulated the cations contents in soil and their translocation to the maize roots.【Result】Mulched drip irrigation reduced Na^(+)content in the rhizosphere more significantly than the conventional drip irrigation.Increasing irrigation amount in the mulched drip irrigation increased K^(+)/Na^(+)content in the maize stem in the whole growth season,but only increased their content in the leaves at early growth stage.Conventional drip irrigation affected the relationship between the concentrations of K^(+)/Na^(+)and Ca^(2+)in the rhizosphere and the K^(+)/Na^(+)content in the roots more than the mulched drip irrigation.The increase in Ca^(2+)in the rhizosphere due to irrigation was likely to have made K^(+)/Na^(+)less mobile in soil,thereby reducing their translocation from soil to roots and benefiting the crop growth as a result.【Conclusion】Drip-irrigating maize in coastal saline-alkali soil can effectively improve the translocation of cations from soil to crop roots,especially the mulched drip irrigation,thereby ameliorating salinity stress to the crop.It can thus be used as an improved irrigation technology for crop production in such regions.