平衡减量施肥和行间配植对白茶园氮磷流失的影响

安吉白茶经济效益高,施肥量大,茶园氮磷流失已成为西苕溪流域农业面源污染的主要来源之一。通过2个生长周期的野外径流小区试验连续观测了减量施肥和行间配植乔木控制白茶园氮磷径流损失的效应。试验设置习惯施肥处理(CK)、减氮减磷处理(T1)、减磷+配植合欢处理(T2)和减氮减磷+配植合欢处理(T3)4个处理,各处理重复2次。结果表明:行间配植合欢处理(T2、T3)2个观测周期的径流水量、泥沙量显著小于无行间配植处理(CK、T1)(P0.05)。CK处理2个观测周期径流总氮及各形态氮的累积流失量均显著大于其他3个处理,泥沙氮素累积携出量显著大于T3处理(P0.05);CK处理2个观测周期径流总磷及无机磷的累积流失量均显著大于其他3个处理,泥沙磷素累积携出量显著大于T2和T3处理(P0.05)。白茶园氮素流失以径流水为主,磷素流失以径流泥沙为主。减施氮磷、行间配植和两者结合均能有效削减白茶园氮磷流失,减氮减磷与行间配植的组合措施效果更好,推荐的施肥和植被管理技术为N 270 kg/hm~2,P_2O_5 90 kg/hm~2,行间配植合欢密度200株/hm~2。

Effects of Balanced Reduced Fertilization and Inter-row Planting on Nitrogen and Phosphorus Loss in White Tea Garden

Anji white tea has high economic benefits, and large amount of chemical fertilizer has been applied in Anji white tea, while nitrogen and phosphorus loss in tea garden has been one of main sources of agricultural non-point pollution in the Xitiaoxi River Basin. This study continuously observed the effects of fertilization reduction and inter-row planting of trees on controlling nitrogen and phosphorus loss in the runoff of white tea garden through field runoff plot experiment with two growth cycles. The experiment included four treatments, which were conventional fertilization (CK), nitrogen and phosphorus reduction (T1), phosphorus reduction with inter-row planting of Albizia julibrissin (T2), and nitrogen and phosphorus reduction with inter-row planting of A. julibrissin (T3), and each treatment had two replicates. The results showed that the runoff and sediment amounts of inter-row planting treatments (T2, T3) were significantly less than those of the treatments with no inter-row planting (CK, T1) (P<0.05) in each growth cycle. During the two observation cycles, the cumulative losses of total nitrogen, all nitrogen fractions, total phosphorus and inorganic phosphorus in runoff water of treatment CK were all significantly higher than those of the other three treatments, the cumulative nitrogen outputs in sediment of treatment CK was significantly higher than those of treatment T3, and the cumulative phosphorus outputs in sediment of treatment CK was significantly higher than those of treatment T2 and T3 (P<0.05). Nitrogen loss in white tea garden was mainly with runoff water, and phosphorus loss was mainly with runoff sediment. Reduction of nitrogen and/or phosphorus application, inter-row planting and the combination of the two measures could effectively decrease the runoff loss of nitrogen and phosphorus in the white tea garden, and the combined measures of nitrogen and phosphorus reduction with inter-row planting were more effective. Thus, the fertilization doses of N 270 kg/hm², P₂O₅ 90 kg/hm², and inter-low planting density of 200 plants/hm² A. julibrissin were recommended for the local white tea culture.