Journal of Integrative Agriculture ›› 2022, Vol. 21 ›› Issue (11): 3368-3381.DOI: 10.1016/j.jia.2022.08.065

• • 上一篇    下一篇

JIA-2021-1810 连续失水-复水中保水剂对土壤结构和水分物理特性的影响

  



  • 收稿日期:2021-10-14 接受日期:2021-11-25 出版日期:2022-11-01 发布日期:2021-11-25

Effects of super-absorbent polymers on the soil structure and hydro-physical properties following continuous wetting and drying cycles

JI Bing-yi1, 2, ZHAO Chi-peng1, WU Yue1, HAN Wei3, SONG Ji-qing1, BAI Wen-bo1   

  1. 1 Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China

    2 Liaoning Province Modern Agricultural Production Base and Construction Engineering Center, Shenyang 110033, P.R.China

    3 Shandong General Station of Agricultural Technology Extension, Jinan 250100, P.R.China

  • Received:2021-10-14 Accepted:2021-11-25 Online:2022-11-01 Published:2021-11-25
  • About author:JI Bing-yi, E-mail: jibingyi1991@163.com; Correspondence BAI Wen-bo, Tel/Fax: +86-10-82106005, E-mail: baiwenbo@caas.cn
  • Supported by:
    This study was supported by the National Natural Science Foundation of China (41601226) and the Agricultural Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences.

PDF

摘要： 保水剂（SAP）是一种应用较为广泛的化学节水材料，能够促进土壤水分增加，改善土壤结构，但 是在频繁干湿交替的环境中，保水剂的长效性及其有效性的影响因素尚不明确。本研究中，土壤中混施不 同用量的保水剂（0%，0.1%，0.2%和0.3%），研究在连续三次失水-复水条件下（T1、T2和T3），保 水剂对土壤结构和水分物理性质的影响效应。结果表明，当土壤处于轻度干旱（T2）和充分灌溉（T3）时， 用量为0.2%和0.3%的保水剂可以提高土壤的供水能力；但在重度干旱（T1）条件下，保水剂反而会降低 土壤的供水能力；且这种变化趋势与保水剂用量呈负相关。保水剂与土壤中的Si-O-Si键、-OH，以及不同 的结晶二氧化硅等矿物胶体之间的物理吸附和化学作用是直接导致干湿交替条件下保水剂持水性能降低的 重要因素之一。与对照相比，保水剂处理组的土壤液相比显著增加了8.8%~202.7%，T1和T2处理尤为明 显，引起土壤气相比显著降低。经历反复的干湿交替过程，尤其当保水剂用量较大时，保水剂处理组会显 著增加>0.25 mm的土壤团聚体和水稳性大团聚体（R0.25）的含量，减低<0.053 mm的土壤团聚体含量。 保水剂处理组平均重量直径（MWD）和几何平均直径（GMD）的增加，以及分形维数（D）和不稳定团粒 指数（ELT）数值的下降，说明保水剂可以大幅改善土壤结构的稳定性。综合分析认为，土壤团聚体的分 布和结构稳定性，以及土壤供水能力的改善与保水剂用量、土壤水分状况，以及保水剂和土壤颗粒之间的 相互作用密切相关。

Abstract:

Super-absorbent polymers (SAPs) are widely used chemical water-saving materials, which play an active role in the accumulation of soil water and the improvement of soil structure.  Little is known about their performance with repeated usage or about factors influencing their efficiency under alternate wetting and drying cycles.  In this study, various concentrations of SAP (0, 0.1, 0.2 and 0.3%) in soil following three continuous wetting and drying cycles (T1, T2 and T3), were studied to determine effects on soil structure stability and hydro-physical properties.  The results indicated that the SAP improved soil water supply capacity under conditions of mild drought (T2) and sufficient irrigation (T3) at concentrations of 0.2 and 0.3%, but a reduction was observed under severe drought conditions (T1), which was negatively correlated with the SAP concentration.  The physical adsorption of the SAP by soil and the chemical connection between the SAP and soil mineral colloids as Si-O-Si bonds, -OH bonds and different crystalline silica were the important factors that directly lead to the reduction of water retention capacities of the SAP with alternating wet and dry conditions.  Compared with the control, the soil liquid phase ratios of the SAP treatments were increased by 8.8–202.7% in the T1 and T2 cycles, which would have led to a decrease in the soil air phase ratios.  After repeated wetting and drying cycles, the SAP treatments increased the amount of >0.25 mm soil aggregates and the contents of water-stable macro-aggregate (R0.25), and decreased the amount of <0.053 mm soil aggregates, especially with higher concentrations of the SAP.  Increases in mean weight diameter (MWD) and geometric mean diameter (GMD), and declines in fractal dimension (D) and unstable aggregates index (ELT) were all observed with the SAP treatments, which indicated an improvement in soil stability and structure.  It was concluded that the distribution and stability of soil aggregates and soil water supply capacity was closely related to SAP concentration, soil moisture condition and the interaction between the SAP and soil particles

Key words: super-absorbent polymer(SAP) , soil water , soil structure , soil aggregate , soil colloid