氮磷肥对茶树锌硒等中微量元素吸收与分配的影响

Abstract

锌（Zn）和硒（Se）及其他中微量元素（铝Al，钙Ca，铁Fe，铜Cu，锰Mn）是茶叶品质的重要指标，但茶树吸收Zn、Se能力及氮（N）磷（P）肥影响中微量元素吸收与分配的过程尚不清楚。以红壤丘陵区福鼎大白茶树为研究对象，开展Zn+Se、Zn+Se+N、Zn+Se+P、Zn+Se+N+P和对照共5种处理3次重复随机化区组试验，处理第3年春季分茶叶、成熟叶、吸收根、运输根和储藏根采集植物样品，测定其元素含量。结果表明，茶树地上和地下器官Zn和Se及其他中微量元素对N、P、Zn、Se添加的响应具分异性。与对照相比，茶树地上和地下器官Zn和Se含量均显著增加，与Zn+Se相比，施N和/或P肥仅显著提高茶叶和成熟叶Se含量（P<0.05）；与对照相比，施肥处理均显著提高吸收根和运输根Al、Fe含量以及储藏根Cu含量；运输根Mn含量表现为Zn+Se+N、Zn+Se+P、Zn+Se+N+P显著高于对照，储藏根Mn含量为Zn+Se+N+P显著高于其他处理；茶树各器官Ca含量对施肥处理无显著响应。此外，茶叶和成熟叶的Zn含量与吸收根显著正相关，而Se含量则与储藏根显著正相关。茶树具有吸收和积累Zn和Se的能力，而施N、P肥有助于提高茶叶Se含量，研究结果为红壤丘陵区培育高品质锌硒茶及营建生态高值茶园提供了依据。;Zinc (Zn), selenium (Se), and other trace elements, such as aluminum (Al), calcium (Ca), iron (Fe), copper (Cu), and manganese (Mn), are important indexes of tea quality. In Camellia sinensis the uptake mechanism of Zn and Se and the internal cycles of trace elements in response to nitrogen (N) and phosphorus (P) fertilizers are unclear. The tea plant Fudingdabai, located in the red-soil hilly region of China, was selected for a randomized block experiment with three replications of five treatments: Zn+Se, Zn+Se+N, Zn+Se+P, Zn+Se+N+P, and a control (CK). After three years of fertilization, trace element concentrations were measured in the tea and mature leaves and the absorptive, transportive, and storative roots. The concentrations of Zn, Se, and other trace elements in the above- and below-ground organs exhibited divergent responses to the treatments. In all of the organs, Zn and Se were significantly elevated in the fertilized plots. In the tea and mature leaves, Se concentrations significantly increased in the Zn+Se treated plots with N and/or P. Al and Fe (in the absorptive and transportive roots) and Cu (in the storative roots) were significantly elevated in the fertilized plots. Mn was more prevalent in the transportive roots of the Zn+Se+N, Zn+Se+P, and Zn+Se+N+P treated plots. In the storative roots, Mn increased only in the Zn+Se+N+P treatment. Ca did not differ. There was a positive correlation between Zn in the tea and mature leaves and Zn in the absorptive roots, while Se in the tea and mature leaves was positively correlated with Se in the storative roots. These results suggest that tea plants can absorb and accumulate Zn and Se, and N and P fertilizers increase Se levels in tea leaves. This study provides a basis for cultivating high-quality tea with abundant Zn and Se and for establishing tea gardens in the red-soil hilly region of China.