Phosphorus adsorption and desorption in soil under different land use types in karst wetlands
-
摘要:
文章选取桂林会仙岩溶湿地的3种不同土地利用类型（农田、果园、荒地）的表层土(0~20 cm)和深层土(20~40 cm)及河流底泥作为研究对象，利用Langmuir等温吸附方程拟合不同磷浓度的吸附曲线，计算出磷最大吸附容量(Qm)、磷吸附能(K)、最大缓冲容量(MBC)，通过曲线拟合得到被吸附磷的解吸率(a)。结果表明：（1）荒地对外源磷吸附率高于农田、果园土壤及河流底泥；在中低浓度的磷添加下（≤2 500 mg·kg−1），深层土对磷的吸附率均大于表层土；（2）Langmuir模拟揭示：河流底泥的Qm 为4 961.61 mg·kg−1，但K很低(0.034 kJ·mol−1)，因此MBC较小(171.82)；荒地表层土的磷吸附特征则与前者正好相反，MBC较大(255.10)。农田和果园土壤的磷吸附特征值介于两者之间；（3） 土壤磷吸附主要受土壤质地及pH控制；河流底泥的a值(11.9%)高于其他土壤，表层土a值高于深层土，a值与土壤有效磷含量显著正相关。农田和果园对磷吸附量大，但固持能力弱，有较大的磷淋溶风险；荒地表层土则在湿地中起到固持磷、降低富营养化风险的作用；河流底泥的磷极易释放，是水体富营养化的长期磷源。
Abstract:The adsorption and desorption of phosphorus (P) in soil are the main factors controlling the P availability and leaching risk. Soils in karst wetlands are characterized as being rich in calcium with pH close to neutral. However, it still lacks a systematic evaluation on the characteristics of P adsorption and desorption in the soil under different land use types in karst wetlands. Meanwhile, exploring the main influencing factors of P adsorption and desorption can provide a scientific basis for the prevention and control of surface source pollution in karst wetlands. This study investigated the characteristics of P adsorption and desorption in surface soils (0-20 cm) and deep soils (20-40 cm) under different land use types, namely, farmland, orchard and barren land, as well as river sediment in Huixian karst wetland, Guilin, China. Langmuir adsorption isotherm equation was applied to reveal the maximum P adsorption capacity (Qm), energy of adsorption (K) and maximum buffering capacity (MBC). In addition, the desorption rate of adsorbed P was estimated through curve fitting. The relationship of the indices of P adsorption and desorption and soil physiochemical features were analyzed to reveal the impact of human activities.
The results are shown as follows, (1) The barren soils had greater P adsorption rate than the soils from farmland, orchard and river sediment. The P adsorption rates of deep soils were higher than those of surface soils when the low P concentration (below 2,500 mg·kg−1) was added.
(2) Langmuir equation showed good fits to the curves of soil adsorbed P contents and the corresponding P concentrations in the equilibrated solution of all soils (R2=0.91-0.98, p<0.01). The characteristics of P adsorption in soil varied greatly among different land use types. The river sediment had the largest Qm (4,961.61 mg·kg−1)) but very low K, resulting in a relatively low MBC. To the contrary, the surface soil of the barren land had the smallest Qm (359.71 mg·kg−1) but largest K, leading to the largest MBC among all soils. The indices of P desorption characteristics of the rice paddy land and orchard soil were in-between of the above two soils.
(3) The P desorption rate of river sediment (11.9%) was higher than those of the other soils. Among all surface soils, the barren land had the lowest desorption rate (4.5%). The desorption rates of all deep soils were lower than those of the surface soils, indicating a greater P sequestration capability of the deep soils in karst wetlands.
(4) In terms of the surface soil of farmlands and orchards, Qm increased by 286.11% and 1,025.80%; K decreased by 79.41% and 95.49%; desorption increased by 75.56% and 33.33% respectively, compared with the wasteland. This indicates that anthropogenic tillage raised the phosphorus adsorption sites in the soil. However, the binding energy between soils and the adsorbed P decreased. Therefore, the adsorbed P did not convert into a stable form. Under high external P load, it would enter into the phase of fast P desorption. In comparison, even though the river sediment had a great Qm, its K value was the lowest, leading to a small MBC and the greatest P desorption rate. This result indicates that the weakly bound iron/aluminum-P in the karst soil reduced and released P under anaerobic condition. Even though the barren soil had a low Qm value, but its P adsorption and buffering capability was the greatest; therefore, the potential risk of P leaching was the lowest in this kind of soil.
(5) The Pearson's correlation and principal component analysis (PCA) suggests that the indices of P desorption (Qm, K and MBC) were closely correlated with soil texture and pH, suggesting that land use change would affect the characteristics of P adsorption through changing soil physiochemical features. The P desorption rate was significantly correlated with soil available P, suggesting that the equilibrium of P desorption is the major control of available P content of soil. This study concludes that the characteristics of P adsorption and desorption are affected by different land uses in karst wetlands. The soils of farmland and orchards adsorb great amount of P, but with great potential risk for P leaching due to the weak retention strength. The barren soil retains P and plays an important role in reducing the risk for eutrophication owing to a high water connectivity in karst wetlands. The river sediment releases P easily, and therefore functions as a long-term P source for waterbody eutrophication.
-
Key words:
- karst wetland /
- phosphorus /
- adsorption /
- desorption /
- land use
-
-
表 1 供试土壤的基本理化性质
Table 1. Basic characteristics of soils
土地利用类型 pH 总磷（TP）/mg·kg−1 有效磷（AP）/mg·kg−1 总有机碳（TOC）/g·kg−1 总氮（TN）/g·kg−1 黏粒/% 粉粒/% 砂粒/% 农田表层土 7.64±0.05 591.93±64.03 63.11±6.79 35.54±4.55 3.56±0.27 66.42 27.45 6.13 果园表层土 7.37±0.10 389.73±26.09 12.27±1.28 13.38±1.75 1.44±0.15 61.23 36.53 2.25 荒地表层土 6.15±0.04 223.31±11.05 25.19±5.80 20.83±8.15 2.20±0.64 76.50 20.18 3.32 河流底泥 7.20±0.08 345.55±32.31 30.37±3.79 46.57±4.26 4.84±0.55 / / / 农田深层土 7.75±0.04 407.23±93.01 71.23±5.39 16.32±14.35 1.49±1.05 64.96 31.27 3.77 果园深层土 6.96±0.22 354.54±82.16 26.52±4.66 10.96±2.29 1.17±0.20 54.62 30.27 15.11 荒地深层土 7.48±0.18 315.25±86.20 7.95±0.88 7.30±2.31 0.97±0.18 66.11 29.22 4.68 注：表中数值为平均值±标准差。 
下载: 导出CSV
表 2 不同土地利用类型下土壤对磷的等温吸附参数
Table 2. Isothermal adsorption parameters of phosphorus in soils under different land use types
土地利用类型 R2 吸附能（K）/kJ·mol−1 最大吸附容量（Qm）/mg·kg−1 最大缓冲容量（MBC） 农田表层土 0.95** 0.146 1 388.89 202.84 果园表层土 0.97** 0.032 4 049.61 129.87 荒地表层土 0.91** 0.709 359.71 255.10 河流底泥 0.98** 0.034 4 961.61 171.82 农田深层土 0.93** 0.062 2 777.78 170.94 果园深层土 0.93** 0.119 1 923.08 228.83 荒地深层土 0.93** 0.086 2 325.58 200.40 注：** P < 0.01；MBC = K*Qm。
下载: 导出CSV
表 3 不同土地利用类型下土壤对磷的吸附量与解吸量的关系
Table 3. Relationship between P desorption and adsorption by soil under different land use types
土地利用类型 y=ax+b R2 a b 农田表层土 0.079 5.908 0.93* 果园表层土 0.060 6.910 0.95* 荒地表层土 0.045 2.627 0.96* 河流底泥 0.119 9.987 0.96* 农田深层土 0.028 3.159 0.95* 果园深层土 0.017 15.310 0.92* 荒地深层土 0.038 10.522 0.93* 注：* P < 0.05。
下载: 导出CSV
表 4 磷吸附和解吸参数与土壤理化性质的相关分析
Table 4. Correlation between the parameters of P adsorption/desorption and physical-chemical properties of soils
参数 pH 总磷 有效磷 总有机碳 总氮 黏粒 粉粒 砂粒 K −0.845* −0.525 −0.144 0.043 0.058 0.827* −0.889* −0.249 Qm 0.619 0.208 0.266 −0.285 −0.330 −0.577 0.821* −0.056 MBC −0.508 −0.388 −0.079 0.177 0.208 0.764 −0.917* −0.122 解吸率（a） 0.468 0.518 0.852* 0.124 0.043 0.102 0.189 −0.371 注：* P < 0.05。
下载: 导出CSV
-
[1] Ardón M, Montanari S, Morse J L, Doyle M W, Bernhardt E S. Phosphorus export from a restored wetland and ecosystem in response to natural and experimental hydrologic fluctuations[J]. Journal of Geophysical Research:Biogeosciences, 2010, 115(4):31-43.
[2] Nair V D, Reddy K R. Methods in Biogeochemistry of Wetlands[M].//Phosphorus sorption and desorption in wetland soils. Florida, America: Soil Science Society of America, 2013, 10: 667-681.
[3] Smolders E, Nawara S, De Cooman E, Merckx R, Martens S, Elsen A, Odeurs W, Vandendriessche H, Santner J, Amery F. The phosphate desorption rate in soil limits phosphorus bioavailability to crops[J]. European Journal of Soil Science, 2021, 72(1):221-233. doi: 10.1111/ejss.12978
[4] 崔虎, 王莉霞, 欧洋, 阎百兴, 韩露, 李迎新. 湿地生态系统磷迁移转化机制研究进展[J]. 水生态学杂志, 2020, 41(2):107-114.
CUI Hu, WANG Lixia, OU Yang, YAN Baixing, HAN Lu, LI Yingxin. Research progress on phosphorus migration and transformation in wetland ecosystem[J]. Journal of Hydroecology, 2020, 41(2):107-114.
[5] 孙军娜, 徐刚, 邵宏波. 黄河三角洲新生湿地磷分布特征及吸附解吸规律[J]. 地球化学, 2014, 43(4):346-351. doi: 10.19700/j.0379-1726.2014.04.004
SUN Junna, XU Gang, SHAO Hongbo. Fractionation and adsorption-desorption characteristics of phosphorus in newly formed wetland soils of Yellow River Delta, China[J]. Geochimica, 2014, 43(4):346-351. doi: 10.19700/j.0379-1726.2014.04.004
[6] 赵树成, 张展羽, 夏继红, 杨洁, 盛丽婷, 唐丹, 陈晓安. 鄱阳湖滨岸土壤磷素吸附特征研究[J]. 长江流域资源与环境, 2019, 28(1):166-174.
ZHAO Shucheng, ZHANG Zhanyu, XIA Jihong, YANG Jie, SHENG Liting, TANG Dan, CHEN Xiaoan. Phosphorus adsorption characteristics of riparian soils surrounding Poyang lake[J]. Resources and Environment in the Yangtze Basin, 2019, 28(1):166-174.
[7] Liu W Z, Liu G H, Li S Y, Zhang Q F. Phosphorus sorption and desorption characteristics of wetland soils from a subtropical reservoir[J]. Marine and Freshwater Research, 2010, 61(5):507-512. doi: 10.1071/MF09013
[8] 王翀, 方芳, 王超, 袁子越, 张蕊, 周小明, 郭劲松. 澎溪河不同高程消落带土壤磷的吸附特性[J]. 重庆大学学报, 2019, 42(12):92-101. doi: 10.11835/j.issn.1000-582X.2019.12.011
WANG Chong, FANG Fang, WANG Chao, YUAN Ziyue, ZHANG Rui, ZHOU Xiaoming, GUO Jinsong. Phosphorus adsorption characteristics of the soils at different altitudes in water-level-fluctuating zone of Pengxi river[J]. Journal of Chongqing University, 2019, 42(12):92-101. doi: 10.11835/j.issn.1000-582X.2019.12.011
[9] 罗玉红, 聂小倩, 胥焘, 王林泉, 黄应平. 香溪河库湾沉积物及库岸土壤对磷的吸附特征[J]. 三峡大学学报(自然科学版), 2017, 39(6):98-103.
LUO Yuhong, NIE Xiaoqian, XU Tao, WANG Linquan, HUANG Yingping. Dynamics of phosphorus adsorption in the sediments and soils in Xiangxi Bay[J]. Journal of China Three Gorges University (Natural Sciences), 2017, 39(6):98-103.
[10] 闫金龙, 吴文丽, 江韬, 魏世强. 土壤组分对磷形态和磷吸附—解吸的影响: 基于三峡库区消落带落干期土壤[J]. 中国环境科学, 2019, 39(3):1124-1131. doi: 10.3969/j.issn.1000-6923.2019.03.028
YAN Jinlong, WU Wenli, JIANG Tao, WEI Shiqiang. Effect of organic matter and iron oxides on phosphorus forms and adsorption-desorption on dry-period soils in the water-level-fluctuating zone of the Three Gorges Reservoir[J]. China Environmental Science, 2019, 39(3):1124-1131. doi: 10.3969/j.issn.1000-6923.2019.03.028
[11] Queiroz H M, Ferreira T O, Barcellos D, Nóbrega G N, Antelo J, Otero X L, Bernardino A F. From sinks to sources: The role of Fe oxyhydroxide transformations on phosphorus dynamics in estuarine soils[J]. Journal of Environmental Management, 2021, 278(15):111575.
[12] Gypser S, Hirsch F, Schleicher A M, Freese D. Impact of crystalline and amorphous iron- and aluminum hydroxides on mechanisms of phosphate adsorption and desorption[J]. Journal of Environmental Sciences, 2018, 70(8):175-189.
[13] Gérard F. Clay minerals, iron/aluminum oxides, and their contribution to phosphate sorption in soils-A myth revisited[J]. Geoderma, 2016, 262(15):213-226.
[14] Fink J R, Inda A V, Bavaresco J, Barrón V, Torrent J, Bayer C. Adsorption and desorption of phosphorus in subtropical soils as affected by management system and mineralogy[J]. Soil and Tillage Research, 2016, 155:62-68. doi: 10.1016/j.still.2015.07.017
[15] Jiang S, Lu H L, Liu J C, Lin Y S, Dai M Y, Yan C L. Influence of seasonal variation and anthropogenic activity on phosphorus cycling and retention in mangrove sediments: A case study in China[J]. Estuarine Coastal and Shelf Science, 2018, 202(5):134-144.
[16] 李菁, 杨程, 靳振江, 朱同彬, 曹建华. 断陷盆地区不同土地利用方式土壤钙形态分布特征[J]. 中国岩溶, 2019, 38(6):889-895.
LI Jing, YANG Cheng, JIN Zhenjiang, ZHU Tongbin, CAO Jianhua. Characteristics of calcium fraction distribution in soil under different land use types in karst fault-depression basins[J]. Carsologica Sinica, 2019, 38(6):889-895.
[17] Andersson K O, Tighe M K, Guppy C N, Milham P J, McLaren T I. The release of phosphorus in alkaline vertic soils as influenced by pH and by anion and cation sinks[J]. Geoderma, 2016, 264:17-27. doi: 10.1016/j.geoderma.2015.10.001
[18] 梁建宏, 曹建华, 杨慧, 黄芬. 钙、铁、铝形态对岩溶石灰土磷有效性的影响[J]. 中国岩溶, 2016, 35(2):211-217. doi: 10.11932/karst20160211
LIANG Jianhong, CAO Jianhua, YANG Hui, HUANG Fen. Effects of calcium, iron and aluminum fractions on the phosphorus bioavailability in limestone soil of karst region[J]. Carsologica Sinica, 2016, 35(2):211-217. doi: 10.11932/karst20160211
[19] Cámara J, Gómez-Miguel V, Martín M Á. Lithologic control on soil texture heterogeneity[J]. Geoderma, 2017, 287(1):157-163.
[20] 谷佳慧, 杨奇勇, 蒋忠诚, 罗为群, 曾红春, 覃星铭, 蓝芙宁. 广南县幅岩溶区与非岩溶区土壤碳氮磷生态化学计量比空间变异分析[J]. 中国岩溶, 2018, 37(5):761-769.
GU Jiahui, YANG Qiyong, JIANG Zhongcheng, LUO Weiqun, ZENG Hongchun, QIN Xingming, LAN Funing. Spatial variation analysis of soil carbon, nitrogen and phosphorus eco-stoichiometricratios in karst and non-karst areas of Guangnan county, Yunnan, China[J]. Carsologica Sinica, 2018, 37(5):761-769.
[21] 宋涛, 于晓英, 邹胜章, 张连凯, 刘朋雨, 赵一, 沈利娜. 岩溶湿地退化评价指标体系构建初探[J]. 中国岩溶, 2020, 39(5):673-681.
SONG Tao, YU Xiaoying, ZOU Shengzhang, ZHANG Liankai, LIU Pengyu, ZHAO Yi, SHEN Lina. Preliminary study on the construction of evaluation index system of karst wetland degradation[J]. Carsologica Sinica, 2020, 39(5):673-681.
[22] 李路祥, 李金城, 韦春满, 周姣, 张琴, 刘辉利, 王俊, 乔政皓. 广西会仙湿地水质现状分析与评价[J]. 桂林理工大学学报, 2019, 39(3):693-699.
LI Luxiang, LI Jincheng, WEI Chunman, ZHOU Jiao, ZHANG Qin, LIU Huili, WANG Jun, QIAO Zhenghao. Analysis and evaluation of water quality status in Huixian wetland of Guangxi[J]. Journal of Guilin University of Technology, 2019, 39(3):693-699.
[23] 陈作雄. 论广西土壤的垂直地带性分布规律[J]. 广西师范学院学报(自然科学版), 2003, 20(1):66-72.
CHEN Zuoxiong. A disputation on distributive laws of vertical zonality of soil in Guangxi[J]. Journal of Guangxi Teachers Education University (Natural Science Edition), 2003, 20(1):66-72.
[24] 鲁如坤. 土壤农业化学分析方法[M]. 北京: 中国农业科技出版社, 2000.
LU Rukun. Soil agrochemical analysis methods[M]. Beijing: China Agricultural Science and Technology Publishing House, 2000.
[25] Caroline van der Salm, Johannes Kros, Wim de Vries. Evaluation of different approaches to describe the sorption and desorption of phosphorus in soils on experimental data[J]. Science of the Total Environment, 2016, 571(15):292-306.
[26] 陈浏寰, 覃英凤, 王紫莹, 黄德周, 张苑, 梁建宏, 朱婧. 土地利用方式下岩溶湿地土壤无机磷形态特征及分析方法适用性探讨[J]. 中国岩溶, 2020, 39(6):845-853.
CHEN Liuhuan, QIN Yingfeng, WANG Ziying, HUANG Dezhou, ZHANG Yuan, LIANG Jianhong, ZHU Jing. Occurrence forms of inorganic phosphorus in soils of karst wetland under different land uses and comparison of two analysis methods[J]. Carsologica Sinica, 2020, 39(6):845-853.
[27] Sindelar H R, Brown M T, Boye T H. Effects of natural organic matter on calcium and phosphorus co-precipitation[J]. Chemosphere, 2015, 138:218-224. doi: 10.1016/j.chemosphere.2015.05.008
[28] Hou E Q, Tang S B, Chen C R, Kuang Y W, Lu X K, Henan M, Wen D Z. Solubility of phosphorus in subtropical forest soils as influenced by low-molecular organic acids and key soil properties[J]. Geoderma, 2018, 313:172-180. doi: 10.1016/j.geoderma.2017.10.039
[29] 赵一, 邹胜章, 申豪勇, 周长松, 樊连杰, 朱丹尼, 李军. 会仙湿地岩溶地下水系统水位动态特征与均衡分析[J]. 中国岩溶, 2021, 40(2):325-333.
ZHAO Yi, ZOU Shengzhang, SHEN Haoyong, ZHOU Changsong, FAN Lianjie, ZHU Danni, LI Jun. Dynamic characteristics and equilibrium of water level of the karst groundwater system beneath the Huixian wetland[J]. Carsologica Sinica, 2021, 40(2):325-333.
[30] 薄录吉, 王建国, 王岩, 李伟, 杨林章. 淹水时间对水稻土磷素形态转化及其有效性的影响[J]. 土壤, 2011, 43(6):930-934.
BO Luji, WANG Jianguo, WANG Yan, LI Wei, YANG Linzhang. Effect of flooding time on phosphorus transformation and availability in paddy soil[J]. Soils, 2011, 43(6):930-934.
[31] 夏瑶, 娄运生, 杨超光, 梁永超. 几种水稻土对磷的吸附与解吸特性研究[J]. 中国农业科学, 2002, 35(11):1369-1374. doi: 10.3321/j.issn:0578-1752.2002.11.012
XIA Yao, LOU Yunsheng, YANG Chaoguang, LIANG Yongchao. Characteristics of phosphate adsorption and desorption in paddy soils[J]. Scientia Aqricultura Sinica, 2002, 35(11):1369-1374. doi: 10.3321/j.issn:0578-1752.2002.11.012
[32] 梁博, 林田苗, 任德智, 聂晓刚, 万丹, 喻武, 赵薇. 土地利用方式对雅江中游土壤理化性质及颗粒分形特征的影响[J]. 土壤, 2018, 50(3):613-621.
LIANG Bo, LIN Tianmiao, REN Dezhi, NIE Xiaogang, WAN Dan, YU Wu, ZHAO Wei. Effects of land use types on soil physicochemical properties and fractal characteristics of soil particles in middle reaches of Yajiang river[J]. Soils, 2018, 50(3):613-621.
[33] 李银霞. 祁连山南坡不同土地利用方式下的土壤理化特征研究[D]. 青海: 青海师范大学, 2018.
LI Yinxia. Analysis of soil physicochemical characteristics of land utilization types in the south slope of Qilian Mountains[D]. Qinghai: Qinghai Normal University, 2018.
[34] 卢垟杰, 郭振. 渭南市不同土地利用方式对土壤颗粒组成的影响[J]. 绿色科技, 2019(18):129-131. doi: 10.3969/j.issn.1674-9944.2019.18.046
LU Yangjie, GUO Zhen. Effects of different land use patterns on particle composition of different types of soil[J]. Journal of Green Science and Technology, 2019(18):129-131. doi: 10.3969/j.issn.1674-9944.2019.18.046
[35] 宋春丽, 樊剑波, 何园球, 赵汝东, 屠人凤. 不同母质发育的红壤性水稻土磷素吸附特性及其影响因素的研究[J]. 土壤学报, 2012, 49(3):607-611. doi: 10.11766/trxb201104200142
SONG Chunli, FAN Jianbo, HE Yuanqiu, ZHAO Rudong, TU Renfeng. Phosphorous adsorption characteristics of red paddy soils derived from different parent materials and their influencing factors[J]. Acta Pedologica Sinica, 2012, 49(3):607-611. doi: 10.11766/trxb201104200142
[36] 徐敏, 宋春, 戴炜, 肖霞, 毛璐, 王小春, 杨文钰. 紫色丘陵区玉米−大豆套作系统土壤磷吸附−解吸动力学[J]. 应用生态学报, 2015, 26(7):1985-1991.
XU Min, SONG Chun, DAI Wei, XIAO Xia, MAO Lu, WANG Xiaochun, YANG Wenyu. Dynamics of soil phosphorus adsorption-desorption in maize/soybean relay intercropping system in purple hilly area[J]. Chinese Journal of Applied Ecology, 2015, 26(7):1985-1991.
[37] 熊际东, 林世奇, 陈倩婷, 吴华, 张杨珠, 廖育林, 许超. 江华国家烟草示范基地土壤磷的吸附与解吸特征[J]. 湖南农业科学, 2011(3):57-60. doi: 10.3969/j.issn.1006-060X.2011.03.018
XIONG Jidong, LIN Shiqi, CHEN Qianting, WU Hua, ZHANG Yangzhu, LIAO Yulin, XU Chao. Characteristics of sorption and desorption of phosphate by soil in Jianghua National Tobacco Demonstration Base[J]. Hunan Agricultural Sciences, 2011(3):57-60. doi: 10.3969/j.issn.1006-060X.2011.03.018
[38] 李志伟, 崔力拓, 耿世刚, 张艳萍. 影响土壤磷素解吸的环境因素研究[J]. 中国水土保持, 2007(6):33-34. doi: 10.3969/j.issn.1000-0941.2007.06.013
LI Zhiwei, CUI Lituo, GENG Shigang, ZHANG Yanping. Effects of environmental factors affecting soil phosphorus desorption[J]. Soil and Water Conservation in China, 2007(6):33-34. doi: 10.3969/j.issn.1000-0941.2007.06.013
-
图(4)
表(4)
计量
- 文章访问数: 1597
- PDF下载数: 46
- 施引文献: 0