Zheng Shenghong, Ni Kang, Chai Hongling, Ning Qiuyan, Cheng Chen, Kang Huajing, Ruan Jianyun
Key Laboratory of Crop Breeding in South Zhejiang, Wenzhou Academy of Agricultural Sciences, Wenzhou, 325006, China.
Key Laboratory of Tea Biology and Resource Utilization of Tea (Ministry of Agriculture), Tea Research Institute, Chinese Academy of Agriculture Sciences, Hangzhou, 310008, China.
Sci Rep. 2024 Sep 5;14(1):20747. doi: 10.1038/s41598-024-71081-3.
Great concern has long been raised about nitrate leaching in cropland due to its possible environmental side effects in ground water contamination. Here we employed two common techniques to measure nitrate leaching in tea plantation soils in subtropical China. Using drainage lysimeter as a reference method, the adaptability of estimating drainage and nitrate leaching by combining the water balance equation with the suction cup technique was investigated. Results showed that the final cumulative leachate volume for the calculated and measured method was 721.43 mm and 729.92 mm respectively during the study period. However, nitrate concentration exerted great influence in the estimation of nitrate leaching from the suction cup-based method. The cumulative nitrate leaching loss from the lysimeter and suction cup-based method was 47.45 kg ha and 43.58 kg ha under lysimeter nitrate concentrations ranging from 7 mg L to 13 mg L, 156.28 kg ha and 79.95 kg ha under lysimeter nitrate concentrations exceeding 13 mg L. Therefore, the suction cup-based method could be an alternative way of monitoring nitrate leaching loss within a range of 7-13 mg L of nitrate concentrations in leachate. Besides, lower results occurred in suction cup samplers due to lack of representative samples which mainly leached via preferential flow when in strong leaching events. Thus, it is advisable to increase sampling frequency under such special conditions. The results of this experiment can serve as a reference and guidance for the application of ceramic cups in monitoring nitrogen and other nutrient-ion leaching in tea plantation soils.
长期以来，人们一直高度关注农田中的硝酸盐淋失问题，因为它可能对地下水污染产生环境副作用。在这里，我们采用了两种常用技术来测量中国亚热带茶园土壤中的硝酸盐淋失。以排水测渗仪作为参考方法，研究了将水平衡方程与吸盘技术相结合来估算排水量和硝酸盐淋失的适用性。结果表明，在研究期间，计算方法和测量方法的最终累积渗滤液体积分别为721.43毫米和729.92毫米。然而，硝酸盐浓度对基于吸盘法的硝酸盐淋失估算有很大影响。在测渗仪硝酸盐浓度为7毫克/升至13毫克/升的情况下，测渗仪和基于吸盘法的累积硝酸盐淋失量分别为47.45千克/公顷和43.58千克/公顷；在测渗仪硝酸盐浓度超过13毫克/升的情况下，分别为156.28千克/公顷和79.95千克/公顷。因此，基于吸盘法可能是监测渗滤液中硝酸盐浓度在7-13毫克/升范围内硝酸盐淋失量的一种替代方法。此外，由于缺乏代表性样本，吸盘采样器的结果较低，在强淋溶事件中，这些样本主要通过优先流淋失。因此，在这种特殊条件下增加采样频率是可取的。本实验结果可为陶瓷杯在监测茶园土壤氮素和其他养分离子淋失中的应用提供参考和指导。
