不同养分条件下太子参根部土壤环境变化及综合评价

Dynamic Change and Comprehensive Evaluation of Soil Environment of Rhizosphere of Pseudostellaria Heterophylla Relative to Fertility

研究不同养分条件下太子参根部土壤环境变化的时间动态,探索太子参根部土壤环境的综合评价方法,可为指导太子参高效栽培提供理论基础。于3个不同土壤养分地块上分别种植太子参,定期监测其根部土壤化学性质、土壤酶活性及微生物种群结构变化,用主成分分析进行综合评价。结果表明:太子参整个生长时期,不同土壤养分条件下太子参根部土壤均以全磷、缓效钾、有效磷、速效钾含量以及土壤酸性转化酶(S-AI)和土壤过氧化氢酶(S-CAT)活性变异度最大;有机质及氮素含量、土壤酸性磷酸酶(S-ACP)、土壤脲酶(S-UE)及土壤多酚氧化酶(S-PPO)活性变异度较小;太子参成熟后,细菌和放线菌菌群数量显著增加,真菌菌群数量显著减少。测定的16个土壤环境指标中较多指标间显著相关,出现信息重叠,影响评价结果的客观性;以基本特征值大于1抽取5个成分,利用5个成分函数表达式进行综合评分,结果得出,各土壤养分含量越高,综合得分值越大,土壤环境越优。上述结果说明:太子参生育期内磷、钾素变化较大,及时补足磷、钾肥可能是改善太子参根部土壤环境的有效方法之一。利用主成分综合评分方法能客观、高效评价太子参根部土壤环境情况。

This study aims to explorate temporal variation of the soil environment in the rhizosphere of Pseudostellaria heterophylla as related to soil nutrient condition,in an attempt to find out a comprehensive method for evaluation of the soil environment in the rhizosphere of P.heterophylla,and to provide a theoretical basis for guiding efficient cultivation of P.heterophylla.In this study,P.heterophylla was planted in three plots different in soil nutrient condition,changes in soil chemical properties,soil enzyme activity and microbial population structure were monitored regularly,and multiple-factor comparisons done.Then principal component analysis of the data was performed for comprehensive evaluation.The results of the study show that during the whole growth period,total phosphorus,slowly available potassium,readily available phosphorus and readily available potassium varied the most significantly in content and S-AI（Soil acid invertase） and S-CAT（Soil catalase） did in activity in the rhizosphere soil of P.heterophylla in all the plots.However,organic matter,total nitrogen and alkalytic nitrogen did not vary much in content and S-ACP（Soil acid phosphatase）,S-UE（Soil urease） and S-PPO（Soil polyphenol oxidase） did neither in activity in the growing period as a whole.After the plant matured soil bacteria and actinomycetes increased significantly and fungus decreased significantly in population.Among the 16 soil environmental indices,significant correlations were found between some of them.In principal component analysis,five components were extracted with basic eigenvalue being higher than 1.Then comprehensive scoring was performed based on the function expressions of five components.The results show that the higher each soil nutrient in content,the higher the comprehensive score,the better the soil environment.During the growth period of P.heterophylla,soil phosphorus and soil potassium vary sharply,making it essential to supplement P and K fertilizers timely,which may be one of the effective measures to improve soil environment in the rhizosphere of P.heterophylla.It is,therefore,advisable to conduct comprehensive scoring based on principle component analysis to objectively and efficiently evaluate the soil environment in the rhizosphere of P.heterophylla.