Investigating the effects of herbaceous root systems on the soil detachment process at the species level

Jian-Fang Wang; Yan-Fen Yang; Guo-Bin Liu; Bing Wang; Feng-Bao Zhang; Nu-Fang Fang

doi:10.1016/j.scitotenv.2022.160196

Investigating the effects of herbaceous root systems on the soil detachment process at the species level

Sci Total Environ. 2023 Feb 10;859(Pt 1):160196. doi: 10.1016/j.scitotenv.2022.160196. Epub 2022 Nov 17.

Authors

Jian-Fang Wang¹, Yan-Fen Yang², Guo-Bin Liu³, Bing Wang⁴, Feng-Bao Zhang², Nu-Fang Fang²

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 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 712100, PR China; University of Chinese Academy of Sciences, Beijing 100049, China.
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 712100, PR China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: gbliu@ms.iswc.ac.cn.
⁴ 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 712100, PR China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: bwang@ms.iswc.ac.cn.

PMID: 36403841
DOI: 10.1016/j.scitotenv.2022.160196

Abstract

Plant root growth significantly affect soil detachment process, whereas the mechanism of how roots affect the soil detachment process by overland flow at species level is not fully understood. This study was conducted to investigate the soil detachment rate responds to plant-induce soil properties and root traits at species level. Two typical herbaceous plants, Bothriochloa ischcemum (Linn.). Keng (BI; fibrous root system) and Artemisia vestita Wall. ex Bess (AG; tap root system), from the Loess Plateau were studies for one year under six planted densities of 5 plants m^-2, 10 plants m^-2, 15 plants m^-2, 20 plants m^-2, 25 plants m^-2, and 30 plants m^-2. In total, 24 steel tanks were planted, and two plots were used as bare soil controls. Their soil detachment rates were tested under a constant overland flow (1.5 l s^-1) on a 26.2 % slope. The results showed that soil detachment rate under the six planted densities ranged from 0.034 kg m² s^-1 to 0.112 kg m² s^-1 for BI and was ranged from 0.053 kg m² s^-1 to 0.132 kg m² s^-1 for AG, which all greatly reduced soil detachment rate and were 68.17 % to 92.33 % and 69.20 % to 87.27 % less than that of the control. In general, BI was more effective in reducing soil detachment rate than AG, achieving a mean soil detachment rate that was 23.75 % lower. With increasing plant density, soil detachment rate decreased as a power function. The overland flow hydraulic characteristics, soil properties and root traits influenced by plant density were positively or negatively correlated with soil detachment rate. Specifically, soil detachment rate decreased with velocity, bulk density, root length density, and increased with shear stress and Darcy-Weisbach friction factor as power or exponential functions. On this basis, the soil detachment rate (Dr) can be satisfactorily estimated by overland flow velocity (v), soil bulk density (BD) and root length density (RLD) as a power function (Dr = 63.03v^0.174 × BD^-20.712 × RLD^-0.233R² = 0.65; NSE = 0.60; p < 0.01).

Keywords: Fibrous root system; Loess Plateau; Plant density; Plant species; Root length density; Tap root system.

MeSH terms

Plant Roots*
Plants
Poaceae
Soil*

Substances

Soil