秸秆还田对植烟土壤养分及真菌群落多样性的影响

Effects of Straw Returning on Soil Nutrients and Fungal Diversity in Tobacco Planting Field

通过2009~2012年的秸秆还田定位试验,研究不同用量小麦及玉米秸秆还田对植烟土壤养分及真菌群落多样性的影响。研究结果表明:有机质及速效养分指标均随秸秆还田量的增加而增加,且等量玉米秸秆还田效果优于小麦秸秆。PCR-DGGE的检测结果显示秸秆还田能一定程度提高土壤真菌群落的多样性,其中真菌丰度和香浓多样性指数随着玉米秸秆还田量的增加而增加,而小麦秸秆在中量还田时(4500 kg hm^(-2))多样性最高,且等量玉米秸秆还田在提高真菌多样性的效果优于小麦秸秆。此外,秸秆还田各处理土壤的真菌群落结构相似性较高,真菌多样性相似系数均大于0.73。特异条带的测序显示,与对照相比,小麦秸秆1500 kg hm^(-2)还田处理中,隐囊菌属真菌(Apanoascus)及毛壳属真菌(Chaetomium)出现,玉米秸秆还田7500 kg hm^(-2)处理,两种特异性的真菌类群(Uncultured Eukaryote和Fungal sp.CRS567818T-1)出现。且土壤真菌多样性与土壤有机质、全钾及碱解氮呈显著正相关。可见,秸秆还田能够增加土壤养分含量,提高烟田土壤真菌群落多样性,这有助于烟草土传病害控制、烟田生态系统的健康维护及其可持续发展。

A field experiment from 2009 to 2012 was conducted to study the effect of different amount of wheat straw and maize straw returning on soil nutrients and fungal community diversities. The result indicated that soil organic matter and available nutrients were all increased with the increasing of the amount of straw returning. And the effect of maize straw returning was better than that of wheat straw. Furthermore, straw returningto an extentincreasedsoil fungal diversity, and fungal riches and Shannon diversity index were increased with the increasing of the amount of maize straw returning, but the diversity index was the highest in the middle amount of wheat straw retuning（4500 kg hm-2）from the result of PCR-DGGE. The effect of maize straw returning on fungal diversity was also better than that of wheat straw. Meanwhile, soil fungal community in all treatments had a high similarity coefficient more than 0.73. The results of some specific bands sequencing indicated that the species of Apanoascus and Chaetomium appeared in the treatment of wheat straw returning（1500kg hm-2）, and two species of Uncultured Eukaryote and Fungal sp.CRS567818T-1also appeared in the treatment of maize straw returning（7500kg hm-2）. And the Shannon diversity index of fungal diversity were positive correlation with soil organic matter, total K and alkaline hydrolyze N.All in all,either wheat or maize straw returning increased soil nutrients and fungal diversity, which would contribute to disease control, health maintain and sustainable development of the tobacco ecosystem.