摘要
利用根袋模拟实验方法,研究了古尔班通古特沙漠南缘5种常见植物梭梭(Haloxylon ammodendron)、白梭梭(Haloxylon persicum)、刺沙蓬(Salsola ruathenica)、骆驼蓬(Peganum harmala)和骆驼刺(Alhagi sparsifolia)的根际和非根际土壤的pH值及养分含量状况。结果表明:干旱区五种植物均可以通过根系调节降低根际土壤pH,且梭梭根际和非根际的pH值差异显著。有机质含量除梭梭和白梭梭外均在根际显著聚集,其根际聚集率分别为刺沙蓬110.27%,骆驼蓬113.08%,骆驼刺为126.73%。全氮含量在刺沙蓬和骆驼蓬的根际中亏缺显著,亏缺率分别达24.54%和18.75%,而在骆驼刺根际中却显著聚集,聚集率为120.43%。有效氮在根际和非根际中的含量与全氮相反,刺沙蓬和骆驼蓬根际中聚集率分别为178.16%和151.76%,而在骆驼刺根际中亏缺率为45.79%。全磷含量和全钾含量在根际和给根际间均无显著差异。有效磷含量在刺沙蓬和骆驼蓬根际中出现了显著亏缺。速效钾含量在梭梭根际中表现为亏缺,在骆驼刺中表现为富集,而在其余3种植物中差异不显著。总之,5种干旱区植物均表现出不同程度的根际效应,对降低根际土的pH值、提高根际有机质含量有积极作用,对5种不同生活型植物的对比表明梭梭和白梭梭两种荒漠灌木在1 a的盆栽实验中,其根际效应没有草本植物根际效应大。
Rhizosphere is commonly regarded as the volume of a thin layer of soil immediately surrounding the plant roots.Due to the microbe populations' interactions and the root activities in this region,the rhizosphere soil usually distinguishes significantly from the 'bulk' soil,which is not influenced directly by living roots.To determine the magnitude of rhizosphere effect on different plants in arid region,a rhizobag experiment on five xerophytic plants of Haloxylon ammodendron,Haloxylon persicum,Salsola ruathenica,Peganum harmala and Alhagi sparsifolia was carried out to investigate the difference of soil pH and nutrient content in rhizosphere and bulk soil at the south edge of Gurbantunggut Desert.The results show that pH values in rhizosphere of five xerophytic plants were lower than those in bulk soil,and it differentiated significantly between the rhizosphere and bulk soil for H.ammodendron.organic matter content in rhizosphere was higher than those in bulk soil of five xerophytic plants,especially for the three grass plants of S.ruathenica,P.harmala and A.sparsifolia,and the accumulation ratios for them were 110.27%,113.08% and 126.73% respectively.Total N content in the rhizosphere of S.ruathenica and P.harmala was smaller than in bulk soil,and the deficient ratios were 24.54% and 18.75% respectively,while total N was richly accumulated in the rhizosphere of A.sparsifolia,and its accumulated ratio reached 120.43% compared to bulk soil.Available N content in rhizosphere and bulk soil presented a opposite pattern with total N,accumulated in rhizosphere of S.ruathenica and P.harmala,and depleted in A.sparsifolia's rhizosphere.For total P and total K,there were no significant differences between the rhizosphere and bulk soil.Available P was also depleted in rhizosphere of S.ruathenica and P.harmala.While available K depleted in the rhizosphere of H.ammodendron,and accumulated in the rhizosphere of A.sparsifolia.All results documented five xerophytic plants presented different extent of rhizosphere effects actually
出处
《干旱区地理》
CSCD
北大核心
2011年第2期222-228,共7页
Arid Land Geography
基金
中国科学院"西部之光"人才培养计划"干旱区不同耐盐机制沙生植物根际土壤特征的对比研究"
关键词
根际效应
PH值
土壤养分
干旱区
Rhizosphere effect
pH
soil nutrition
arid region
