植茶年龄对丘陵区茶园土壤和茶树养分含量的影响

Effects of Planting Year on Soil and Plant Nutrients in Hilly Tea Gardens

分析土壤养分供应和茶树养分含量之间的关联性可为茶园经营管理提供参考。以江西典型丘陵区不同植茶年龄(10年以下、10～20年、20～30年、30～40年、40～50年、50年以上和对照荒地)茶园为研究对象,开展土壤化学特性和茶树不同部位养分含量以及两者之间关联性的研究。结果表明,两层土壤的pH值均随植茶年龄的延长而下降,而阳离子交换量(CEC)、有机C、全N和全P均呈增加的趋势,且随植茶年龄增加表层(0～20 cm)和下层(20～40 cm)土壤化学特性的差异性减少(P<0.05)。除植茶年龄>50年的茶园外,其它茶园茶树根、茎、当年生枝、成熟叶和茶叶N和P含量均随植茶年龄增大而增加,且成熟叶和茶叶中的含量显著高于根、茎和当年生枝中的含量(P<0.05)。根、当年生枝、成熟叶和茶叶N、P含量与土壤pH、CEC、有机C有较强的相关性,但与土壤全N和全P含量相关性弱。成熟叶和茶叶C、N、P化学计量比与土壤全N含量显著相关,但与土壤全P含量不相关。可见,土壤特性与茶树体养分含量及其计量比的关联性因观测变量和植物体部位不同而各异;土壤有机质管理是茶园肥力维持的关键环节,土壤N、P供应失衡,N相对缺乏,而P相对富余,因此,增施富N有机肥是科学经营茶园的有效措施。

Understanding the linkage between soil nutrient supply and plant nutrient contents is helpful to improve the management of tea garden.The soil chemical properties at upper and lower depths,the nutrient traits in various plant modules and their relationships were studied in tea gardens of different planting years including less than 10 years,10-20 years,20-30 years,30-40 years,40-50 years and more than 50 years,with wasteland as control.The results showed that soil pH decreased,while soil cation exchange capacity（CEC）,organic C,total N and total P increased with increasing planting years of tea gardens（P0.05）,and the difference range between upper and lower soil depths of these indices decreased with increasing planting years.The N and P contents in various modules of tea plants increased with increasing planting years of tea gardens except the oldest garden,and the contents in mature leaves and tea leaves were much higher than those in roots,stems and annual shoots（P0.05）.The N and P contents in roots,annual shoots,mature leaves and tea leaves were significantly correlated with soil pH,CEC,organic C,but not with soil total N and total P.Additionally,the stoichiometric ratios of C,N and P in the mature and tea leaves were significantly correlated with soil total N,but not with total P.Clearly,the linkage between soil properties and nutrient contents of tea plants and its stoichiometric ratios varied with measured variables and plant modules.It might be concluded that the management of organic matter would be the key step,and there would be imbalance of N and P supply with relative richer N and poorer P in the tea gardens.Finally,the authors suggested that addition of the organic fertilizer with rich N should be the effective measure to scientifically manage the tea gardens in hilly red soil region.