蔗鸭共生对红壤蔗地土壤养分、酶活性及细菌多样性的影响

【目的】分析红壤地土壤养分和微生物群落对蔗鸭共生的响应,揭示蔗鸭共生促进甘蔗生长及改良土壤的微生态机制,为蔗鸭共生在红壤蔗区的应用提供理论依据。【方法】采用大田原位试验设3个处理:甘蔗单作、蔗鸭共生和肉鸭纯养,于甘蔗成熟期采集甘蔗单作和蔗鸭共生处理0~20 cm根际土壤及肉鸭纯养处理0~20 cm土层土壤,测定并对比分析不同处理的土壤养分、酶活性及细菌群落多样性。【结果】与甘蔗单作相比,蔗鸭共生极显著降低了土壤铵态氮含量(P<0.01,下同),极显著增加了土壤蔗糖酶活性。Alpha多样性分析结果显示,土壤细菌群落多样性Chao1指数和Shannon指数均表现为甘蔗单作>蔗鸭共生>肉鸭纯养。样本检测到的细菌类群隶属于44门1079属。物种群落组成分析表明,放线菌门(Actinobacteriota)、变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteria)、拟杆菌门(Bacteroidota)、粘球菌门(Myxococcota)是广西红壤地土壤细菌相对丰度较高的优势菌群。在属水平上,Gaiellales、JG30-KF-CM45、Gaiella、黄色杆菌属(Xanthobacteraceae)、67-14、Vicinamibacterales、JG30-KF-AS9、Roseiflexaceae、芽单胞菌属(Gemmatimonadaceae)、芽孢杆菌属(Bacillus)、TK10、Sandaracinus、Vicinamibacteraceae、Rokubacteriales、小单孢菌属(Micromonosporaceae)为优势菌群。与甘蔗单作相比,蔗鸭共生明显提高了JG30-KF-AS9相对丰度。【结论】蔗鸭共生改变了土壤有效氮养分,显著增加土壤蔗糖酶活性,但短期内其根际土壤细菌群落结构无明显改变。

Effects of sugarcane-duck symbiosis on soil nutrients,enzyme activity and bacteria diversity of sugarcane in red soil

【Objective】To analyze response of soil nutrient of red soil and microbial community to sugarcane-duck symbiosis,and to reveal micro-ecological mechanism of sugarcane-duck symbiosis on sugarcane growth and soil improvement by analyzing soil nutrition and microbial diversity,so as to provide theoretical basis on application of sugarcane-duck symbiosis in red soil sugarcane planting areas.【Method】Three treatments were set up in a field in situ experiment:sugarcane monoculture,sugarcane-duck symbiosis and meat duck rearing. Soil was collected from 0-20 cm of rhizospheric soil of the sugarcane monoculture and sugarcane-duck symbiosis treatments and from 0-20 cm of the meat duck pure rearing at the sugarcane maturing stage. Then soil nutrients,enzyme activities and bacterial community diversity of different treatments were measured and compared. 【Result】Sugarcane-duck symbiosis reduced ammonium nitrogen content in soil and increased invertase activity in soil highly significantly(P<0.01,the same below)compared with sugarcane monoculture.Alpha diversity analysis showed that the Chao1 index and Shannon index of soil bacterial community diversity were sugarcane monoculture>sugarcane-duck symbiosis>meat duck rearing. Bacterial groups detected in each sample belonged to 44phyla and 1079 genus. Species community composition analysis showed that Actinobacteri,Proteobacteria,Chloroflexi,Acidobacteriota,Bacteroidota and Myxococcota were dominant bacterial communities in the red soil sugarcane planting areas of Guangxi,enjoying high relative abundance. Gaiellales,JG30-KF-CM45,Gaiella,Xanthobacteraceae,67-14,Vicinamibacterales,JG30-KF-AS9,Roseiflexaceae,Gemmatimonadaceae,Bacillus,TK10,Sandaracinus,Vicinamibacteraceae,Rokubacteriales,Micromonosporaceae were dominant bacterial groups at genus level. Sugarcane-duck symbiosis increased the relative abundance of JG30-KF-AS9 significantly compared with sugarcane monoculture.【Conclusion】Sugarcane-duck symbiosis not only changes available nitrogen nutrients,but also increases soil invertase activity significantly. However,it does not change inter-rhizosphere soil bacterial community significantly in the short term.