不同营养液对温室土壤盐渍化的影响

以种植年限3年的盐渍化土壤为研究对象,采用模拟土柱淋溶法,研究了不同用量和配比的KCl和MgCl2营养液对土壤盐渍化离子的影响,以期为盐渍化土壤的修复提供参考依据.结果表明:随着营养液施用量的增加,土壤中K+、Mg2+、Cl-含量提高,Na+、Ca2+、HC03-的含量降低,土壤中总盐分增高.与原土壤相比,土壤中K+、Na+、Ca2+、Mg2+、Cl-和土壤盐分总量下降,HCO3-和SO42-较原土壤有所提高.从土壤盐分离子总电荷变化来看,在1∶1型的营养液配方中各处理间差异较小,而在2∶1型营养液配方中,随施钾用量的增加使土壤阳离子的存留量降低.表明次生盐渍化土壤中,平衡及低浓度的施用量可缓解土壤盐渍化,降低养分的淋溶作用,促进离子间平衡,而过量施肥会加速阴阳离子的不均衡.

Effect of Different K+/Mg2+ Ration Nutrient Solutions on Soil Salinity

Using simulated soil column experiments,the effects of different dosages and ratios of KCI and MgCl2 mixture on salinization nutrient ions in the secondary salinization soil which had 3 years of planting were studied,with the aim to provide the theory basis for the remediation of secondary salinization soil.Results showed that the content of soil K-,Mg2+,Cl-and the total salinity were increased,with the increasing concentrations of nutrient solution,while Na+,Ca2+ and HCO3-contents were reduced.Compared with originals oil,soil K+,Na+,Ca2+,Mg2+,Cl-and total soil salinity were decreased,and HCO3-and SO42-were increased.In terms of the variation of soil total charge,the change ranges in 1∶1 treatment varied small,but the residual of soil cationic decreased with increasing application of K+ in the 2:1 treatment.It could be concluded that balanced and low application fertilizer could alleviate the soil saline,decrease the soil nutrition leaching and improve the balance among ions,while excess fertilization could accelerate the imbalance of zwitterions.