Guan'gai paishui xuebao (Feb 2023)

Change in Water Flow in Clay Soils Amended by Cotton Biochar

  • WANG Tao,
  • PU Shenghai,
  • YANG Guang,
  • LI Pan,
  • MA Xingwang,
  • MA Honghong,
  • WANG Zeyu,
  • NIU Xinxiang,
  • LIU Xiaoli

DOI
https://doi.org/10.13522/j.cnki.ggps.2022375
Journal volume & issue
Vol. 42, no. 2
pp. 24 – 31

Abstract

Read online

【Objective】 Biochar has been widely used to amend degraded soils to improve their quality and fertility. The aim of this paper is to investigate the change in hydraulic properties of clay soils after being amended by cotton biochar. 【Method】 The experiment was conducted in repacked columns, with soil in the top 20 cm being amended by biochar at weight ratio 0 (C0), 1% (C0), 2% (C2) and 4% (C4), respectively. Each biochar amendment was associated with three irrigation treatments: 4 200 (W1), 5 100 (W2) and 6 000 m3/hm2 (W3). For each treatment, we measured the advance of wetting front in the column, cumulative infiltration and infiltration rate, as well as water distribution in the soil. 【Result】 Biochar amendment enhanced water infiltration, with the enhancement increasing with biochar application amount. Compared with C0, C1, C2 and C3 increased initial infiltration rate, average infiltration rate, steady infiltration rate by 6.5%, 22.8% and 32.0%; 6.9%, 16.8% and 21.4%; and 1.4%, 38.6% and 40.9%, respectively. After the infiltration front crossed the top 20cm of soil layer, compared to C0, C1, C2 and C3 increased the cumulative infiltration by 5.0%, 6.0% and 9.8%, and soil water content at the column bottom by 1.2%, 4.5% and 6.3%, respectively. Overall, the cumulative infiltration increased with biochar application amount. On average, approximately 63.6%, 53.3% and 46.6% of the irrigated water in W1, W2 and W3 was stored in the soils, and the capacity the top 20 cm of soil layer to hold water increased with the biochar application amount. 【Conclusion】 Amending clay soil by cotton-stalk biochar improved its ability to store and infiltrate water. The improved ability of the amended top 20 cm soil layer was positively correlated with biochar application amount. Water percolation and evaporation was affected by irrigation amount more than by biochar amendment. Our results have implications for improving physical quality and productivity of clay soils.

Keywords