| 引用本文: | 伍少福,石其伟,顾昊男,等.围垦时间和利用方式对浙东海涂土壤有机碳和磷素的影响[J].灌溉排水学报,2023,42(10):105-113. |
| WU Shaofu,SHI Qiwei,GU Haonan,et al.围垦时间和利用方式对浙东海涂土壤有机碳和磷素的影响[J].灌溉排水学报,2023,42(10):105-113. |
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| 摘要: |
| 【目的】研究围垦海涂土壤有机碳和磷素变化特点，为科学施肥提供理论基础和依据。【方法】在浙江东部的浙北-杭州湾和浙南-乐清湾滨海平原选择不同利用方式的代表性海涂土壤（蔬菜地、果园和水田），以荒地为对照（CK），分析了土壤有机碳和磷素组成与围垦时间和利用方式的关系。【结果】随着围垦时间的增加，海涂土壤pH值下降，土壤有机碳（TOC）、全磷（TOP）和有效磷量增加。围垦50 a后，浙北-杭州湾和浙南-乐清湾土壤pH值分别下降1.72~2.36和1.14~2.24，有机碳量分别增加126.46%~294.97%和130.37%~266.14%，全磷量分别增加17.66%~100.00%和39.31%~87.20%。土壤pH值从高到低表现形式为：荒地>水田>果园>蔬菜地；有机碳：水田>果园>蔬菜地>荒地；土壤全磷和有效磷：荒地<水田<果园<蔬菜地。海涂围垦利用明显增加了土壤各形态的有机碳。随着围垦利用时间的增加，游离态颗粒有机碳占有机碳的比值（fPOC/TOC）先明显下降后缓慢增加的变化特点，闭蓄态颗粒有机碳占有机碳的比值（oPOC/TOC）逐渐增加，而矿物结合态有机碳占有机碳的比值（MOC/TOC）先明显增加后又呈现缓慢下降。MOC/TOC比例：水田>果园>蔬菜地，表明水田环境更易形成相对稳定的有机碳（MOC）。颗粒态有机碳的占比（包括fPOC/TOC和oPOC/TOC）均为乐清湾低于杭州湾，而MOC/TOC表现为乐清湾高于杭州湾。TOC与所有形态有机碳之间均存在极显著相关性，但TOP与各形态磷均无相关性。【结论】海涂围垦后土壤有机碳量、磷素量和形态组成可发生持续变化，pH值呈下降趋势，有机碳和磷素逐渐积累，利用方式可影响海涂土壤有机碳和磷素的积累速度，种植水稻有利于有机碳固定，种植蔬菜将增强磷素积累。 |
| 关键词: 海涂；碳库；磷积累；形态组成；围垦时间；利用方式；变化规律 |
| DOI：10.13522/j.cnki.ggps.2023026 |
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| 基金项目: |
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| Effect of Reclaiming Duration and Land Usage on Organic Carbon and Phosphorus in Coastal Saline Soils in Eastern Zhejiang Province |
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WU Shaofu, SHI Qiwei, GU Haonan, ZHANG Mingkui
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1. Shaoxing Grain and Oil Crop Technology Extension Center, Shaoxing 312000, China;
2. Keqiao District Agricultural and Fishery Technology Extension Station of Shaoxing, Shaoxing 312030, China;
3. College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
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| Abstract: |
| 【Objective】Reclaiming the saline coastal soils in eastern China is crucial for ensuring food security. Given the significance of soil carbon in soil quality, this paper investigates the change in soil organic carbon and phosphorus in the soil following initiation of reclamation. 【Method】The experiment was conducted in the northern regions of Hangzhou Bay and Yueqing Bay in eastern Zhejiang province. Soil samples were collected from vegetable fields, orchards, and paddy fields to measure their organic carbon, phosphorus, and other soil properties, from which we analyzed the relationship between soil organic carbon, phosphorus composition, reclamation duration, and land usage. A non-reclaimed soil was taken as the control. 【Result】As reclamation time elapsed, soil pH decreased while total organic carbon (TOC), total phosphorus (TOP), and available phosphorus increased. Fifty years of reclamation led to a reduction in soil pH in Hangzhou Bay and Yueqing Bay by 1.72 to 2.36 and 1.14 to 2.24, respectively. This was accompanied by significant increases in organic carbon and TOP by 126.46% to 294.97% and 130.37% to 266.14%, and available phosphorus by 17.66% to 100.00% and 39.31% to 87.20%, respectively. The decrease in soil pH among different land usages was ranked in the order of wasteland > paddy field > orchard > vegetable field; the increase in soil organic carbon followed the order of paddy field > orchard > vegetable field > wasteland; and the increase in TOP and available phosphorus followed the order of wasteland < paddy field < orchard < vegetable land. Reclamation also significantly increased different forms of soil organic carbon. Over time, the ratio of free particulate organic carbon to organic carbon (fPOC/TOC) in micro-aggregates decreased initially and then gradually increased, while the ratio of occluded particulate organic carbon to organic carbon (oPOC/TOC) increased gradually. The ratio of mineral-associated organic carbon to organic carbon (MOC/TOC) initially increased significantly and then decreased slowly. Land usage had a notable impact on the MOC/TOC ratio, with paddy fields showing the highest influence, followed by orchards and vegetable fields. The impact of land usage on TOP and available phosphorus was more significant than reclamation time. Except for residual phosphorus and HCl-P, other forms of phosphorus increased with reclamation time. It was also found that with the increase in reclamation time, the fraction of residual phosphorus and HCl-P decreased, while the fraction of phosphorus in other forms increased. TOC and organic carbon in different forms exhibited a strong correlation, but no correlation was found between TOP and phosphorus. 【Conclusion】Reclamation of the coastal saline soils results in continuous changes in composition and content of organic carbon and phosphorus, characterized by decreasing pH, increasing organic carbon and phosphorus. Land usage has a more substantial impact on the change in organic carbon and phosphorus than reclamation history. Growing rice promotes organic carbon sequestration, whereas vegetable cultivation enhances phosphorus accumulation. |
| Key words: coastal saline; carbon pool; phosphorus accumulation; chemical forms; reclamation time; landuse patterns; change rule |
