中国农业科学 ›› 2016, Vol. 49 ›› Issue (4): 705-716.doi: 10.3864/j.issn.0578-1752.2016.04.010

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

脱硫副产物配合淋洗对碱化土壤团聚体含量的影响

谭煌,杨培岭,任树梅,俞昊良,王嘉航   

  1. 中国农业大学水利与土木工程学院,北京 100083
  • 收稿日期:2015-07-17 出版日期:2016-02-16 发布日期:2016-02-16
  • 通讯作者: 杨培岭,E-mail:yang-pl@163.com
  • 作者简介:谭煌,E-mail:tanhuang256@163.com
  • 基金资助:
    国家自然科学基金(51379210,51323001)、北京市科技计划(D151100004115003)

Effects of the Application of Flue Gas Desulphurized Gypsum and Water Leaching on Sodic Soil Aggregates

TAN Huang, YANG Pei-ling, REN Shu-mei, YU Hao-liang, WANG Jia-hang   

  1. College of Water Conservancy & Civil Engineering, China Agricultural University, Beijing 100083
  • Received:2015-07-17 Online:2016-02-16 Published:2016-02-16

摘要: 【目的】土壤团聚体特征是反映土壤结构好坏的重要指标。探究脱硫副产物配合淋洗对碱化土壤团聚体的影响,可为评价改良后土壤结构状况提供重要参考。【方法】本文基于内蒙古河套灌区长期碱化土壤改良田间试验,分析了3种脱硫副产物施用量和3种淋洗量共9组处理下0—10,10—20, 20—40和40—60 cm深度土层的土壤干、湿筛团聚体的平均质量直径(MWD)、几何均重直径(GMD)、分形维数D、0.25 mm的团聚体比重(DR0.25和WR0.25)等参数特征,以及土壤容重和饱和导水率。【结果】施用脱硫副产物配合淋洗的综合处理显著降低了0—60 cm土壤容重,并提高了饱和导水率Ksat以及机械稳定性团聚体的GMD 和MWD,其中高脱硫副产物施用量(14.5 t·hm-2)配合低水量淋洗处理(淋洗量为1.52×103 t·hm-2)的机械稳定性团聚体GMD和MWD显著高于其他处理。整体上,单一处理(仅施用脱硫副产物或仅淋洗)对团聚体的影响不显著,但仅淋洗处理下团聚体分形维数D显著高于仅施用脱硫副产物处理。综合处理中高脱硫副产物使用量处理在0—60 cm土壤剖面的分形维数D值均小于其他处理。改良后的碱化土壤中水稳性团聚体GMD和MWD远小于机械稳定性团聚体。多数碱化土壤团聚体参数与代换性钠含量、土壤碱化度(ESP)、土壤pH呈极显著负相关关系(P<0.01),而饱和导水率则与机械稳定性团聚体GMD,MWD和DR0.25呈极显著正相关关系(P<0.01)。【结论】施用脱硫副产物配合淋洗的改良对0—40 cm深度碱化土壤团聚体稳定性有明显的提升,土壤结构改善明显;仅施用脱硫副产物改良可以维持团粒结构稳定性,而仅淋洗改良则不利于团聚体的形成。

关键词: 土壤团聚体, 脱硫副产物, 淋洗, 盐碱土改良

Abstract: 【Objective】The characteristics of soil aggregates are important factors that are generally used for soil structure evaluation. The objective of this study was to investigate the influence of the application of flue gas desulphurized (FGD) gypsum and water leaching on sodic soil aggregates, which can help assess the enhancement of soil structure after reclamation.【Method】A field experiment with nine reclamation treatments (three levels of FGD gypsum amount × three levels of leaching water) was conducted in the Hetao irrigation district in northern China. Intact soil samples were collected at 0-10cm, 10-20cm, 20-40cm, and 40-60 cm soil depths after reclamation. The bulk density, saturated hydraulic conductivity (Ksat), and characteristic parameters of soil aggregates, including the mean weight diameter (MWD), geometric mean diameter (GMD), the aggregate fractal dimension D, and the proportion of aggregates with a diameter higher than 0.25mm (DR0.25 and WR0.25, respectively) obtained by the dry and wet sieving methods, were used for analysis.【Result】The results indicated that reclamation treatments with both FGD gypsum and leaching water significantly decreased the bulk density and increased Ksat and the MWD and GMD of mechanic-stable aggregates at a 0-40 cm soil depth. In addition, the combined treatment with a high level of FGD gypsum (14.5 t·hm-2) and a low level of leaching water (1.52×103 t·hm-2) G2W1 showed the highest MWD and GMD of mechanic-stable aggregates. In general, the single reclamation treatments didn’t show a significant impact on the characteristics of soil aggregates, while the single treatments with leaching water alone had a significant higher fractal dimension D than the ones with FGD gypsum alone. The fractal dimension D in all combined treatments with a high level of FGD gypsum was lower than that of other treatments at a 0-60 cm soil depth. The MWD and GMD of the water-stable aggregates were significantly lower than those of the mechanic-stable ones. Most parameters of the sodic soil aggregates showed significant negative relations with the content of exchangeable sodium, exchangeable sodium percentage (ESP), and pH. The Ksat was positively related to the GMD, MWD, and DR0.25 of the mechanic-stable aggregates.【Conclusion】The combined reclamation treatments with both FGD gypsum and leaching water significantly increased sodic soil aggregates’ stability at a 0-40cm soil depth, suggesting that the structure of sodic soil was improved after reclamation. The reclamation with FGD gypsum alone maintained the stability of soil aggregates, while the ones with leaching water alone may have a negative influence on the formation of aggregates.

Key words: soil aggregate, flue gas desulphurized gypsum, water leaching, sodic soil reclamation