Impacts of biochar application rates and particle sizes on runoff and soil loss in small cultivated loess plots under simulated rainfall

Yuanyuan Li; Fengbao Zhang; Mingyi Yang; Jiaqiong Zhang; Yingge Xie

doi:10.1016/j.scitotenv.2018.08.415

Impacts of biochar application rates and particle sizes on runoff and soil loss in small cultivated loess plots under simulated rainfall

Sci Total Environ. 2019 Feb 1:649:1403-1413. doi: 10.1016/j.scitotenv.2018.08.415. Epub 2018 Aug 30.

Authors

Yuanyuan Li¹, Fengbao Zhang², Mingyi Yang³, Jiaqiong Zhang³, Yingge Xie⁴

Affiliations

¹ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China.
² State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China; Institute of Soil and Water Conservation, CAS and MWR, Yangling, Shaanxi Province 712100, PR China. Electronic address: fbzhang@nwsuaf.edu.cn.
³ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China; Institute of Soil and Water Conservation, CAS and MWR, Yangling, Shaanxi Province 712100, PR China.
⁴ College of Science, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China.

PMID: 30308909
DOI: 10.1016/j.scitotenv.2018.08.415

Abstract

Increasing literature suggests that biochar can be used to improve soil fertility and subsequently benefit crop yield. However, the effects of biochar application rates and particle sizes on soil erosion processes have yet to be fully identified. The objective of the present study was to evaluate the influence of biochar with different application rates and particle sizes on soil erosion. Addition of biochar to loess generally increased the mean time to runoff by 19.47% relative to the control. The time to runoff decreased with an increase in the biochar application rates and fluctuated with a decrease in biochar particle sizes. The combined 1% and <0.25 mm biochar treatment yielded the longest time to runoff (2.97 min) and the lowest runoff (36.23 kg m^-2 h^-1) and soil loss (1.33 kg m^-2 min^-1). Biochar addition decreased the total runoff volume by 12.21% and generally inhibited soil loss under lower application rates (1% and 3%) while promoting soil loss under higher application rates (5% and 7%). With a decrease in biochar particle size, total runoff volume increased under the 5% and 7% biochar, but no uniform trend was observed under the 1% and 3% biochar treatments. The total soil loss increased with increasing biochar application rates, whereas a negative trend was observed with decreasing biochar particle sizes. The contribution of biochar application rates to runoff and soil loss rates was distinctly greater than the biochar particle sizes. Additionally, biochar addition could increase >2 mm water-stable soil aggregates and saturated hydraulic conductivity (K_sat) in this study. We inferred that the positive effects on soil and water loss were potentially due to the improvement in >2 mm water-stable soil aggregates and K_sat. The results implied that soil-biochar additions could be a potential measure for conserving soil and water in the Loess Plateau.

Keywords: Apple branch byproduct; Erosion mitigation; Interaction; Soil improvement; Soil physical properties.