摘要:为探究烟秆炭基肥对薏苡土壤有机碳组分及微生物群落结构和丰度的影响, 以烟秆生物炭基肥为试验材料, 通过大田试验, 设置不施肥(CK)、常规施化肥(F)、施低量烟秆炭基肥(LBF)、施高量烟秆炭基肥(HBF) 4个处理, 测定土壤pH、有机碳组分及土壤细菌群落结构和丰度, 同时研究与土壤碳循环和微生物活性有关的4种酶活性变化特征, 分析土壤pH、土壤有机碳组分、土壤酶和土壤细菌丰度之间关系。结果表明: 1)施用烟秆炭基肥显著提高土壤pH及土壤有机碳(SOC)、可溶性有机碳(DOC)、颗粒有机碳(POC)和微生物量碳(MBC)含量, 其中MBC提升效果最明显, 与常规施化肥相比提高41.09%~76.04% (P<0.05)。2)施用烟秆炭基肥显著提高土壤淀粉酶、脱氢酶活性, 与常规施化肥相比分别平均提高44.28%和57.54% (P<0.05), 而对土壤蔗糖酶影响不显著。3)施用烟秆炭基肥提高土壤细菌群落Chao1指数和Shannon指数, 提高土壤细菌丰度及多样性。4)施用烟秆炭基肥影响土壤细菌群落组成结构, 提高放线菌门和拟杆菌门相对丰度, 降低变形菌门和绿弯菌门相对丰度; 显著提高硝化螺旋菌属、布氏杆菌属等细菌属丰度(P<0.05), 降低酸土单胞菌属、泉发菌属丰度(P<0.05)。5)通过RDA分析, 土壤pH、碳组分、土壤酶活性和土壤细菌门群落丰度在烟秆炭基肥施用后存在一定相关关系, 其中土壤pH、SOC、POC、DOC和MBC含量与土壤各种酶活性均呈显著正相关关系(P<0.05), 而与变形菌门呈显著负相关(P<0.05)。综上, 烟秆炭基肥可以提高土壤pH、增加土壤有机碳组分含量、提高土壤酶活性和土壤细菌丰度, 进而改善土壤细菌群落结构, 改良薏苡种植土壤, 优化土壤生态。该研究可为烟秆废弃物资源化利用、土壤肥力提升提供参考依据。
关键词:烟秆炭基肥/
薏苡/
土壤有机碳组分/
酶活性/
微生物
Abstract:Long-term continuous cropping of adlay ( Coix lacryma-jobi L.) and the indiscriminate application of chemical fertilizers have led to soil fertility declines and acidification. To explore the effects of tobacco stalk biochar-based fertilizer on the soil organic carbon (SOC) fractions and microbial community structure and abundance, tobacco stalk biochar-based fertilizer was used in a field experiment with four treatments: no fertilizer, conventional fertilizer, low tobacco stalk biochar-based fertilizer, and high tobacco stalk biochar-based fertilizer. Changes in the activities of four enzymes related to soil carbon cycling and microbial activity were evaluated, and the relationships between the soil pH, SOC fractions, soil enzymes, and soil bacterial abundance were analyzed. The results showed that: 1) The application of tobacco stalk carbon-based fertilizer significantly increased the soil pH and the contents of SOC, dissolved organic carbon (DOC), particulate organic carbon (POC), and microbial biomass carbon (MBC) (P<0.05). The MBC was most affected, increasing by 41.09%?76.04% compared to conventional fertilizer application. 2) The application of tobacco stalk biochar-based fertilizer significantly increased the activities of soil amylase and dehydrogenase (P<0.05). Compared to conventional chemical fertilizers, amylase and dehydrogenase activities increased by 44.28% and 57.54%, respectively, whereas the soil invertase activity was unaffected when tobacco stalk biochar-based fertilizer was applied. 3) The application of tobacco stalk biochar-based fertilizer increased the Chao1 and Shannon indexes, abundance and diversity of the soil bacterial communities. 4) The application of tobacco stalk biochar-based fertilizer affected the composition and structure of the soil bacterial community, increased the relative abundance of Actinomycetes and Bacteroides, and reduced the relative abundance of Proteobacteria and Chloroflexus. It also significantly increased the abundance of Nitrospira, Bryobacter, and other bacterial genera, and significantly reduced the abundance of Aciditerrimonas and Crenothrix. 5) Redundancy anaylsis showed that soil pH, carbon fraction, soil enzymes activities, and soil bacterial community abundance were correlated each other after the application of tobacco stalk biochar-based fertilizer; soil pH, SOC, POC, DOC, MBC were significantly positively correlated with the activities of various soil enzymes (P<0.05), but were significantly negatively correlated with Proteobacteria (P<0.05). In summary, tobacco stalk biochar-based fertilizer increased the soil pH, SOC fractions, soil enzymes activities, and soil bacterial abundance, which improved the soil bacterial community structure and the adlay planting soil and optimized the soil ecology. This study provides a reference for the resource utilization of tobacco stalk and improvements in soil fertility.
Key words:Tobacco stalk biochar-based fertilizer/
Adlay/
Soil organic carbon fractions/
Enzyme activity/
Microorganism
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