不同灌溉方式对农田土壤微生物丰度及通透性的影响

Effects of Different Irrigation Methods on Soil Microbial Abundance and Permeability in Farmland

【目的】研究沟灌、滴灌、喷灌对农田土壤微生物丰度和土壤通透性的影响及不同灌溉处理下微生物丰度与环境因子的关系。【方法】采用大田控制试验,利用荧光定量PCR技术对微生物丰度进行了分析。【结果】土壤通透性受灌溉方式的影响显著,节水灌溉降低了土壤体积质量,提高了土壤的Eh和孔隙度。不同灌溉方式显著影响土壤微生物丰度,与沟灌处理相比,滴灌与喷灌处理下细菌丰度分别增加了17.8%与30.63%,真菌丰度分别增加了13.09%和21.68%,放线菌丰度分别增加了3.87%和59.72%。节水灌溉可以显著提高微生物丰度,具体表现为喷灌>滴灌>沟灌。RDA分析表明,微生物丰度与Eh、孔隙度、有机碳和pH值正相关,相关系数分别为0.856、0.718、0.445和0.443,与土壤体积质量、氨态氮和硝态氮负相关,相关系数分别为-0.892、-0.508和-0.361。【结论】节水灌溉能显著改善土壤通透性、提高土壤微生物丰度。土壤通透性、pH值、氨态氮与硝态氮是影响微生物丰度的主要因子,土壤通透性、pH值高,铵态氮、硝态氮量低的土壤微生物丰度高,有机碳、总氮与相对密度对微生物丰度影响不显著。

【Objective】Study the effects of furrow irrigation,drip irrigation and sprinkler irrigation on soil microbial abundance and soil permeability and the relationship between microbial abundance and environmental factors under different irrigation treatments.【Method】In this study,field control experiments were carried out,and the abundance of microorganisms was analyzed by fluorescence quantitative PCR.【Result】The results showed that,the soil permeability was significantly affected by irrigation method,water saving irrigation reduced soil bulk density and increased soil Eh and porosity.Soil microbial abundance were also significantly affected by different irrigation methods,compared with furrow irrigation,drip irrigation and sprinkler irrigation under bacterial abundance were increased by 17.8% and 30.63%,the abundance of fungi were increased by 13.09% and 21.68%,and the abundance of actinomycetes were increased by 3.87% and 59.72%.In general,the abundance of microbial abundance under water saving irrigation was significantly improved,performing as sprinkler irrigation drip irrigation furrow irrigation.RDA analysis showed that microbial abundance was positively correlated with Eh,porosity,organic carbon and p H,and the correlation coefficients were 0.856,0.718,0.445 and 0.443,respectivity.Microbial abundance was negatively correlated with soil bulk density,ammonia nitrogen and nitrate nitrogen,and the correlation coefficient was-0.892,-0.508 and-0.361,respectivity.【Conclusion】Water saving irrigation could significantly improve the soil permeability and soil microbial abundance.Soil permeability,p H value,ammonia nitrogen and nitrate nitrogen have significant effects on microbial abundance,when soil permeability and p H value are high,ammonium nitrogen and nitrate nitrogen content are low,that soil microbial biomass is high.organic carbon,total nitrogen and relative density have no significant influence on microbial abundance.