【摘要】 选择红壤丘陵区典型柑橘园,设置清耕、自然生草和竹豆间种3种种植模式,研究不同种植模式下柑橘园土壤化学性质、微生物生物量、微生物碳源代谢特征变化,并探明主导碳源代谢特征变化的土壤环境因素。结果表明,相对于清耕和自然生草种植模式,竹豆间种模式下柑橘园土壤p H提高了24.03%和21.65%,有机碳、碱解氮、有效磷、速效钾分别提高了19.40%和25.14%、14.02%和18.61%、2.69和3.12倍、63.40%和1.14倍。柑橘园土壤微生物生物量碳受种植模式影响不显著,但是竹豆间种显著提高了土壤微生物碳源利用能力(Average well color development,AWCD)和均匀度指数。竹豆间种模式下土壤微生物对于酰胺、氨基酸、酚类和多聚物等多个大类碳源的代谢强度显著高于其他处理,清耕模式下土壤微生物对于糖类尤其是赤藓糖醇、葡萄糖-1-磷酸、D-纤维二糖的代谢强度显著高于其他处理。逐步回归分析结果表明,微生物的碳源利用能力和土壤有机碳密切相关,而p H是影响微生物功能多样性及多个特异性碳源代谢强度的首要因素。冗余分析结果表明,柑橘园土壤微生物碳源利用模式受土壤环境因素影响的大小顺序为:p H>有效磷>碱解氮>有机碳>速效钾。因此,竹豆间种能够缓解柑橘园土壤酸化,提高土壤养分含量,改善微生物群落结构和功能多样性,有利于柑橘园土壤生态健康和可持续利用。更多还原

【Abstract】 Choose a typical cirtus orchard in the red soil region and set up three planting patterns:clear tillage,natural grass growing and intercropping bamboo bean,were selected to study the changes of soil chemical properties,microbial biomass,and microbial carbon metabolic characteristics in citrus orchard. The critical soil factors affecting microbial carbon metabolic characteristics were also determined. The results showed that the pH of citrus orchard soil increased by 24.03% and 21.65%,and the organic carbon,alkaline nitrogen,available phosphorus,and available potassium increased by 19.40% and 25.14%,14.02% and 18.61%,2.69 and 3.12 times,63.40% and 1.14 times,respectively,under the intercropping bamboo bean pattern,compared to clear tillage and natural grass growing. Microbial biomass carbon was not significantly affected by planting patterns,but the average well color development(AWCD) and evenness index of soil microbe were significantly improved by intercropping bamboo bean.The microbial metabolic intensity of amides,amino acids,phenolic compounds and polymers in soils under intercropping bamboo bean pattern were significantly higher than those under other patterns. Microbial metabolic intensity of carbohydrates,especially Erythritol,Glucose-1-phosphate and D-cellobiose in soils under clear tillage pattern were significantly higher than those under other patterns. Stepwise regression analysis showed that the AWCD was closely related to soil organic carbon. But pH was the primary soil factor affecting microbial functional diversity and metabolically differential carbon source. Redundancy analysis showed that the order of soil factors affecting carbon utilization patterns was: pH > available phosphorus> alkaline nitrogen > soil organic carbon > available potassium. In conclusion,intercropping bamboo bean can alleviate the soil acidification,increase the soil nutrient content,and improve the microbial community structure and functional diversity,which is conducive to the health and sustainability of the soil ecosystem in citrus orchard.更多还原