Abstract:

Soil biological characteristics play an important role in soil fertility and nutrient cycling, and are important biological indicators of soil fertility. However, few studies have been conducted on banana soil. In order to reveal the variation characteristics of soil nutrients and provide a theoretical basis for the soil effective management of soil nutrients, the variation rules of soil microbial biomass, soil urease, invertase and acid phosphatase activities in the rhizosphere soil at different growing stages of banana were investigated. The soil biomass and soil enzyme activities of the rhizosphere soil samples collected at the strong seedling stage, budding stage and late growth stage of banana were determined, and the dynamic changes and correlations were analyzed. The results indicate that the soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and soil urease activity in banana rhizosphere soil increased from the seedling to gestational bud stage, but gradually decreased after the gestational bud stage, with the maximum values of 271.64 mg∙kg^-1, 63.09 mg∙kg^-1 and 2.38 mg∙g^-1∙24 h^-1, respectively. Compared with other growth stages, the MBC value in the gestational bud stage was significantly higher (P<0.05). However, there were no differences (P<0.05) in MBN content and urease activity compared to the young seedling stage and late growing stage. Soil invertase activity showed an increasing tendency from planting to late growing stage of banana. It was consistent with the trend of control group. The acid phosphatase activity decreased from seedling to the gestational bud stage, and increased after the gestational bud stage, with the lowest value of 0.54 mg∙g^-1∙24 h^-1, but there was a decreasing tendency in the control group throughout growing stage. Correlation analysis showed that MBC and MBN were positively correlated with soil urease and invertase activities significantly, respectively. MBN were negatively correlated with acid phosphatase. In short, the bud formation stage is an important stage in which significant change of rhizosphere soil biological characteristics were observed. At the late growing stage of banana, changes in soil microbial biomass, soil urease and acid phosphatase activities in the rhizosphere soil indicated a decline of soil available nutrient related to microbial biomass, soil transformation of nitrogen and phosphorus.

Key words: banana, growing stages, soil microbial biomass, soil enzyme activity, correlation analysis

摘要：

土壤生物学特性对土壤肥力和土壤养分循环非常重要,是土壤肥力的重要生物学指标。然而,在香蕉（Musa spp.）土壤上开展的相关研究还很少。文章探讨了香蕉不同生育期根际土壤微生物生物量、脲酶、蔗糖酶和酸性磷酸酶活性的变化规律,以期揭示香蕉土壤养分变化特性,为有效管理土壤养分提供理论依据。在香蕉壮苗期、孕蕾期和生长后期采集根际土样,测定根际土壤生物量和土壤酶活,分析其动态变化及相关性。结果表明,随着生育期的延长,微生物生物量碳（MBC）、微生物生物量氮（MBN）值和土壤脲酶活性从种植到孕蕾期呈现升高趋势,最高值分别为271.64 mg∙kg^-1、63.09 mg∙kg^-1和2.38 mg∙g^-1∙24 h^-1。从孕蕾期到生长后期又降低。在孕蕾期,MBC值显著高于其他生育期（P<0.05）,然而MBN值和脲酶活性与壮苗期和生长后期均无显著差异。蔗糖酶活性从种植到生长后期一直上升,与对照变化趋势一致。酸性磷酸酶活性从种植到孕蕾期一直降低,最低值出现在孕蕾期,为0.54 mg∙g^-1∙24 h^-1,然后又升高;对照处理则呈持续降低趋势。相关性分析表明,MBC和MBN分别与土壤脲酶和蔗糖酶呈显著正相关。MBN与酸性磷酸酶呈显著负相关。结果表明,孕蕾期为根际土壤生物学特性出现显著变化的重要时期。在香蕉生长后期,根际土壤中微生物生物量、脲酶和酸性磷酸酶的变化预示和微生物生物量相关的土壤有效养分,以及土壤氮素和磷素转化能力的降低。

关键词: 香蕉, 生育期, 土壤微生物生物量, 土壤酶活, 相关性分析