川西低山丘陵区植茶土壤团聚体矿质氮分布特征

研究植茶对土壤团聚体全氮和矿质氮的影响可为茶园土壤合理施用氮肥提供理论依据。通过野外调查和室内分析,研究不同茶树品种(福鼎大白、川茶3号、川农黄芽早和川沐217)对土壤团聚体中全氮和矿质氮含量的影响。结果表明:(1)各植茶品种土壤团聚体含量随粒径减小呈先减小后增大的变化趋势,>2 mm粒径团聚体含量显著高于其他粒径团聚体,其含量约占总量的38.32%~66.26%。(2)各植茶品种土壤全氮含量均随团聚体粒径的减小呈先减小后平稳的趋势,而铵态氮和硝态氮的变化趋势则相反。(3)种植福鼎大白土壤各氮组分含量高于其他品种,2个土层矿质氮含量的变化趋势相似。(4)全氮、铵态氮和硝态氮储量均在>2 mm粒径团聚体最高,分别为6.25~11.44 kg/hm²,13.09~42.66 g/hm²,14.38~51.03 g/hm²。(5)种植川农黄芽早土壤全氮、铵态氮和硝态氮的储量均高于其他品种。研究结果可为川西低山丘陵区植茶土壤氮肥合理施用提供理论依据。

Distribution of Mineral Nitrogen in Soil Aggregates of Tea-planting Hilly Region in Western Sichuan

It is meaningful to clarify the effects of tea planting on total nitrogen and mineral nitrogen in soil aggregates for providing a theoretical basis of applying nitrogen fertilizer. The effects of different tea cultivars (Fuding Dabaicha, Chuancha No. 3, Chuannong Huangyazao and Chuanmu No. 217) on total nitrogen and mineral nitrogen content in soil aggregates were studied by field investigation and indoor analysis. The results showed that: (1) As the decrease of particle size, the content of aggregates in each tea planting soil decreased firstly and then increased. The content of >2 mm aggregate was significantly higher than that of other aggregates, accounting for about 38.32%~66.26% of the total content. (2) With the decrease of aggregate particle size, the total nitrogen content of the soil of each tea cultivar decreased firstly and then stabilized, while the contents of ammonium nitrogen and nitrate nitrogen showed the opposite trend. (3) The contents of each nitrogen component in the soil of planting Fuding Dabaicha were higher than those of other cultivars. The trend of mineral nitrogen content in different soil layers was similar. (4) The reserves of each nitrogen component were the highest in > 2 mm aggregates, which were 6.25~11.44 kg/hm², 13.09~42.66, 14.38~51.03 g/hm², respectively. (5) The reserves of total nitrogen, ammonium nitrogen and nitrate nitrogen of the soil planted with Chuannong Huangyazao were higher than other cultivars. These research results provide a theoretical basis for the rational application of nitrogen fertilizer in tea-planting soils in the hilly areas of western Sichuan.