PDF(Pubmed)
Abstract：
Pitaya (Hylocereus undulatus) is a significant cash crop in the karst region of Southwest China. Ecological stoichiometry is an essential method to research biogeochemical cycles and limiting elements. The purpose of this study was to explore the stoichiometric characteristics of C, N, and P in Karst pitaya orchards and fruit quality and to elucidate the mechanism and process of nutrient cycling. The results showed that: (1) Fruit quality was highest under the combination of chemical and organic fertilizers. Compared to the control, the contents of per-fruit weight, vitamin C, and soluble sugar increased significantly by 55.5%, 60.7%, and 23.0%, respectively, while the content of titratable acidity decreased significantly by 22.0%. (2) The content of soil nutrients under fertilization stress showed a downward trend in general, as did microbial biomass and extracellular enzyme activities. (3) Different fertilization treatments significantly affected the soil-microbial stoichiometry C:N ratio, C:P ratio, with research areas being significantly limited by C and P. (4) Spearman and PLS-SEM (partial least squares-structural equation model) analysis results showed that under the influence of fertilization, there was a significant positive effect between microorganisms and soil nutrients, but a significant negative effect between soil nutrients and quality. The results of this study offer an innovative perspective on pitaya quality research in Karst areas.
摘要：
火龙果（Hylocereusundulatus）是中国西南喀斯特地区的重要经济作物。生态化学计量学是研究生物地球化学循环和限制元素的重要方法。这项研究的目的是探索C的化学计量特征，N,和P在喀斯特火龙果果园和果实品质中的作用，并阐明养分循环的机理和过程。结果表明:(1)化肥和有机肥配施下果实品质最高。与对照相比，每个水果重量的含量，维生素C,可溶性糖显著增加了55.5%，60.7%,和23.0%，分别,而可滴定酸度的含量显著下降了22.0%。(2)施肥胁迫下土壤养分含量总体上呈下降趋势,微生物生物量和胞外酶活性也是如此。(3)不同施肥处理显著影响土壤微生物化学计量C:N比,C:P比率,(4)Spearman和PLS-SEM(偏最小二乘-结构方程模型)分析结果表明,在施肥的影响下,微生物与土壤养分之间存在显著的正效应,但土壤养分和质量之间存在显著的负面影响。本研究结果为喀斯特地区火龙果品质研究提供了创新的视角。
