Soil nitrate leaching of tea plantation and its responses to seasonal drought and wetness scenarios
Soil nitrate leaching of tea plantation and its responses to seasonal drought and wetness scenarios
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DOI：
10.1016/j.agwat.2021.107325
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发表时间：
2022-02
影响因子：
6.7
通讯作者：
Fei Liu;Q. Zhu;Zhiwen Zhou;K. Liao;X. Lai
中科院分区：
文献类型：
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作者：
Fei Liu;Q. Zhu;Zhiwen Zhou;K. Liao;X. Lai
尽管在气候变化背景下，季节性干旱和湿润的频率和强度都在增加，但其对土壤硝态氮（NO3--N）淋溶的影响尚不清楚。在这项研究中，验证了一个典型的茶园坡地，中国太湖流域的现场数据，分解反硝化（DNDC）模型来研究这些影响。将十年一遇的干旱、十年一遇的湿润和不同季节的正常情况结合起来，构建了31个情景。结果表明，季节性干旱使NO3--N年淋失量减少，与正常情景相比，一季干旱减少6.52%-18.70%、二季干旱减少18.62%-29.68%、三季干旱减少36.64%-43.99%、四季干旱减少51.44%。除春旱外，其他季节的干旱均具有一定的遗传效应，导致各季节NO3--N淋失量增加。夏旱的后遗症甚至一直延续到第二年夏天。季节性湿润增加了NO3--N的年淋失量，与正常情景相比，一季湿润增加了2.58%-11.39%，二季湿润增加了10.04%-22.31%，三季湿润增加了19.50%-29.39%，四季湿润增加了29.66%。秋季和冬季湿润减少了连续季节的NO3--N淋失，而春季和夏季湿润则没有这种影响。土壤NO3--N淋失与降水量（干旱情景：r = 0.74;湿润情景：r = 0.54）和土壤水分渗漏量（干旱情景：r = 0.62;湿润情景：r = 0.56）呈正相关。土壤NO3--N含量与NO3--N淋失量之间的相关性较弱，尤其是在春旱（r = 0.17）和夏旱（r = 0.14）条件下。但施基肥后土壤硝态氮淋失量不受土壤硝态氮含量的限制。施肥+干旱或湿润增加了土壤NO3--N淋失的风险。这些研究结果将有助于在气候变化背景下控制种植园氮素的非点源流失。
Although the frequency and intensity of seasonal drought and wetness are increasing under climate change background, their effects on soil nitrate nitrogen (NO3--N) leaching have remained unclear. In this study, validated by the field data on a typical tea garden hillslope in Taihu basin, China, the Decomposition-Denitrification (DNDC) model was used to investigate these effects. The decennial drought, decennial wetness, and normal conditions of different seasons were combined to construct 31 scenarios. Results showed that seasonal drought decreased annual NO3--N leaching, with a reduction of 6.52%−18.70% (one-season drought), 18.62%−29.68% (two-season drought), 36.64%−43.99% (three-season drought) and 51.44% (all-season drought) relative to the normal scenario. Except the spring drought, drought in other seasons had legacy effects that increased NO3--N leaching in their succession seasons. The legacy effect of summer drought even continued till the summer of next year. Seasonal wetness increased annual NO3--N leaching, with an increase of 2.58%−11.39% (one-season wetness), 10.04%−22.31% (two-season wetness), 19.50%−29.39% (three-season wetness), and 29.66% (all-season wetness) relative to the normal scenario. Autumn and winter wetness decreased the NO3--N leaching in their succession seasons, while spring and summer wetness had no such effect. Soil NO3--N leaching had positive correlations with precipitation (drought scenarios: r = 0.74; wetness scenarios: r = 0.54) and soil water seepage (drought scenarios: r = 0.62; wetness scenarios: r = 0.56). Weak correlation coefficients between soil NO3--N content and NO3--N leaching were also observed especially under spring drought (r = 0.17) and summer drought (r = 0.14). However, NO3--N leaching was not limited by soil NO3--N content after the application of basal fertilizer. Fertilization plus drought or wetness increased the risk of soil NO3--N leaching. These findings will be benefit for controlling the non-point N loss of tea plantation under the background of climate change.