福建省安溪县铁观音茶园土壤氮素状况

为了解福建省安溪县铁观音茶园土壤氮素供应能力,对安溪县77个铁观音茶园土壤(分0～20、20～40 cm两个土层)全氮、碱解氮含量及对应的铁观音茶叶氮含量进行了测试分析。结果表明:安溪县铁观音茶园0～20 cm土层土壤全氮含量属中上水平,平均值1.13 g/kg,Ⅱ级(尚可)及以上样点比例达90.9%;20～40 cm土层土壤全氮含量属中下水平,平均值0.81 g/kg,Ⅱ级(尚可)及以下样点比例占77.9%。黄壤、红壤、水稻土改植、赤红壤茶园土壤全氮含量较高,粗骨土、潮砂土茶园土壤全氮含量较低;土壤全氮与有机质含量呈显著的正相关关系。安溪县铁观音茶园土壤碱解氮总体含量较为丰富,0～20cm土层土壤碱解氮含量平均值105.42 mg/kg,Ⅱ级(尚可)及以上样点比例达到97.4%;20～40 cm土层平均值75.02 mg/kg,Ⅱ级(尚可)以上样点比例占84.4%。黄壤、红壤、赤红壤、水稻土改植茶园土壤碱解氮含量较高,粗骨土、潮砂土茶园土壤碱解氮含量较低;土壤碱解氮与全氮、有机质含量呈显著的正相关关系。供试铁观音茶叶氮含量与土壤全氮、碱解氮含量相关关系不显著,土壤碱解氮含量能否作为铁观音茶园土壤供氮能力的指标,以及在铁观音茶树的营养诊断时采摘鲜叶的氮素含量是否能作为茶树氮素缺素的诊断指标有待进一步研究。安溪县铁观音茶园土壤氮素管理时应注重氮肥深施,同时增施有机肥、降低速效氮肥的施用比例。

Study on Soil Nitrogen Status of Tieguanyin Tea Gardens in Anxi County of Fujian Province

The amount of nitrogen (N) in soils and the N content of the selected tea leaves of 77 Tieguanyin tea (Camellia sinensis (L.) O. Kuntze cv. Tieguanyin) plantations at Anxi county, Fujian province were investigated in this study. The aim of this project is to determine the soil N nutrition status of Tieguanyin tea plantations in Anxi county. The results showed that the soil total N content of the Tieguanyin tea plantations in 0-20 cm soil layer were above average, and the average was 1.13 g/kg, the proportion of class II (ordinary) and the higher level reached 90.9%. The soil total N content of the Tieguanyin tea plantations in 20-40 cm soil layer were below average, the average was0.81 g/kg, the proportion of class II (ordinary) and the lower level reached 77.9%. The total N content in yellow soils, red soils, paddy soils and latosolic red soils was high. In contrast, the total N content was low in the skeletal soils and fluvo-aquic soils. There was a significant positive correlation between total nitrogen and organic matter content in soil. The soil alkaline nitrogen content of the Tieguanyin tea plantations was abundant, the average was 105.42 mg/kg in 0-20 cm soil layer, the proportion of class II (ordinary) and the higher level was 97.4%, and the average of soil alkaline nitrogen content of the Tieguanyin tea plantations was in 20-40 cm soil layer was 75.02 mg/kg , the proportion of class II (ordinary) and the higher level was 84.4%. The soil alkaline nitrogen content of the Tieguanyin tea plantations in yellow soils, red soils, latosolic red soils and paddy soils was high, but oppositely the alkaline nitrogen content was low in the skeletal soils and fluvo-aquic soils, there was a significant positive correlation between the content of soil alkaline nitrogen and total nitrogen, organic matter. In this study, there was no significant correlation between the N concentrations of the tea leaves and the total N content, alkaline nitrogen content in soil. Further research is needed for if the concentration of alkaline nitrogen in tea leaves of Tieguanyin could be used as a diagnostic index of N supplying capacity in tea plantation, and for if the concentration of N in Tieguanyin tea plants leaves could be used as a nutrition diagnostic index at the picking moment. So, it should be paid more attention to the deep placement of N fertilizers application, the ratio of applying organic manure and reducing the application of nitrogen fertilizer.