| 引用本文: | 刘畅,齐伟,王策, 等.无机肥施用对农田干湿循环土壤收缩特性的影响[J].灌溉排水学报,2021,(11):44-50. |
| LIU Chang,QI Wei,WANG Ce, et al..无机肥施用对农田干湿循环土壤收缩特性的影响[J].灌溉排水学报,2021,(11):44-50. |
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| 摘要: |
| 【目的】研究无机肥施用对农田干湿循环土壤收缩特性的影响。【方法】选取南方地区粉壤土为试验土样，设置尿素、硫酸钾2种肥料配置浸润液（质量浓度设置为1、2、3 g/L），开展多级循环脱湿试验。【结果】①土壤收缩应变随着循环级数的推进而减小，且逐渐趋于稳定。无机肥的添加减少了土壤收缩应变，且随着循环级数的推进愈加明显。②VG-Peng模型拟合土壤收缩特性曲线效果较好，各处理均具有结构收缩、比例收缩、残余收缩、零收缩4个阶段，干湿循环使土壤结构收缩段增加，比例收缩段和残余收缩段减小。无机肥的添加使土壤比例收缩段孔隙比范围减少。③土壤收缩经历了从完全的纵向收缩-以纵向收缩为主-以横向收缩为主3个阶段，多次循环后土壤收缩各向异性减弱。【结论】无机肥添加和干湿循环条件不同程度减弱了土壤的收缩特性，多次循环后无机肥累积是土壤收缩能力下降的主要原因。 |
| 关键词: 干湿循环；无机肥；土壤；收缩特性曲线；几何因子 |
| DOI：10.13522/j.cnki.ggps.2021263 |
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| The Effects of Inorganic Fertilization on Soil Shrinkage in Wetting-drying Cycles |
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LIU Chang, QI Wei, WANG Ce, et al.
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1. College of Agricultural Science and Engineering, Hohai University, Nanjing 211100, China;
2. College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China
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| Abstract: |
| 【Objective】Swelling and shrinkage are important process reshaping soil structure. It is impacted by many factors, and the objective of this paper is to investigate how fertilization impacts this process.【Method】We used a silty loam in the experiment. The soil was fertilized using different inorganic N and K fertilizers at concentrations ranging from 1 g/L to 3 g/L. The emergence and development of the shrinkage during and following multiple wetting-drying cycles were measured in each treatment.【Result】① The shrinkage in the transverse and longitudinal directions both decreased asymptotically with the increase in the number of drying-wetting cycles. Adding inorganic fertilizer reduced the shrinkage in both transverse and longitudinal directions, and the reduction became more significant as the wetting-dying cycles increased. ② The VG-Peng model can fit the effects of the fertilization on soil shrinkage, and the shrinkages in each treatment can be classified into four types: structural shrinkage, proportional shrinkage, residual shrinkage and zero shrinkage. Increasing drying-wetting cycles increased the structural shrinkage at the expense of proportional shrinkage and residual shrinkage. The addition of the inorganic fertilizers reduced the void ratio of the soil in the shrunk region. ③ Soil shrinkage experienced three stages: complete longitudinal shrinkage, longitudinal-dominant shrinkage, and transverse-dominant shrinkage, with the anisotropy of the shrinkages decreasing after several drying-wetting cycles.【Conclusion】Applying inorganic fertilizers reduced soil shrinkage due to wetting-drying cycles, and the inorganic fertilizers accumulated after multiple wetting-drying cycles due to the decline in soil shrinkage. |
| Key words: wetting-drying cycle; inorganic fertilization; soil; contraction curve; geometric factors |
