Comparing the variations and controlling factors of soil N2O emissions and NO3--N leaching on tea and bamboo hillslopes
Comparing the variations and controlling factors of soil N2O emissions and NO3--N leaching on tea and bamboo hillslopes
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茶竹山坡地土壤N2O排放和NO3--N淋溶变化及控制因素比较
DOI：
10.1016/j.catena.2020.104463
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发表时间：
2020
期刊：
影响因子：
6.2
通讯作者：
Liao Kaihua
中科院分区：
文献类型：
--
作者：
Zhou Zhiwen;Liu Ya;Zhu Qing;Lai Xiaoming;Liao Kaihua
由于经济利益的驱动，土地利用变化（如退耕还林还茶、种种植园）在我国东南部丘陵地区广泛发生。由于大量的化肥投入（约为常规稻麦轮作的1-2倍），这可能会刺激土壤氮（N）的严重损失。因此，我们研究了茶园（TG）和相邻的竹林（BF）山坡上的土壤N2 O通量和渗滤液NO3--N浓度及其对多因素的响应。TG坡地土壤N_2O通量和渗滤液NO_3 ~--N浓度分别是BF坡地的3.28倍和4.24倍。土壤N2 O通量春季最大，冬季最小。而渗滤液NO3--N浓度冬季最高，夏季最低。在两个山坡上，土壤温度（ST）和前7天降水量（API 7）与土壤N2 O通量呈正相关，与渗滤液NO3--N浓度呈负相关，而地下水位深度则相反。土壤含水量（SWC）和SWC/田间持水量（SWC/FC）的比值对两个山坡地淋滤液NO3--N浓度有负影响。土壤含水量和土壤含水量/土壤覆盖率对土壤N2 O通量的影响在TG坡面上表现为正效应，而在BF坡面上表现为二次效应。ST和API 7对两个坡面土壤N_2O通量和渗滤液NO_3 ~--N浓度空间变异的控制作用均存在显著差异。当ST> 9.5 °C时，两个坡面土壤N2 O通量的空间变异受地形、土壤性质和土壤水文参数的控制。当API 7 < 58.0 mm时，两个坡面渗滤液NO3--N浓度的空间变异也受这些因子的影响。本研究的结果将对茶园和竹林土壤N_2O排放和NO_3 ~--N淋溶的研究提供补充。
Due to the economic benefits, land use change (e.g. deforest to tea or fruit plantation) has been widely occurred in the south-eastern hilly area of China. This may stimulate serious soil nitrogen (N) losses due to large fertilizer inputs (about 1–2 times of that in regular rice-wheat rotation). Therefore, we investigated the soil N2O fluxes and leachate NO3–-N concentrations and their responses to multiple factors on a tea garden (TG) hillslope and an adjacent bamboo forest (BF) hillslope. Soil N2O fluxes and leachate NO3–-N concentrations on the TG hillslope were 3.28 and 4.24 times of those on the BF hillslope, respectively. Soil N2O fluxes measured in spring were the greatest while those measured in winter were the lowest. However, the measured leachate NO3–-N concentrations were the greatest in winter but the lowest in summer. On both hillslopes, soil temperature (ST) and precipitation during the previous seven days (API7) were positively related to soil N2O fluxes but negatively related to leachate NO3–-N concentrations, while the ground water table depth was opposite. Soil water content (SWC) and the ratio of SWC/field capacity (SWC/FC) negatively influenced leachate NO3–-N concentrations on both hillslopes. Positive influences of SWC and SWC/FC on soil N2O fluxes were observed on the TG hillslope, while quadratic relationships were observed on the BF hillslope. Thresholds of ST and API7 were existed in the controlling the spatial variations of soil N2O fluxes and leachate NO3–-N concentrations on both hillslopes. When ST was > 9.5 °C, spatial variations in soil N2O fluxes were controlled by topography, soil properties and soil hydrological parameters on both hillslopes. Similarly, when API7 were < 58.0 mm, the spatial variations in leachate NO3–-N concentrations were also influenced by these factors on both hillslopes. Finding of this study will supplement the knowledge of soil N2O emissions and NO3–-N leaching from the tea planation and bamboo forest.