The hydrologic behavior of Loess and Marl soils in response to biochar and polyacrylamide mulching under laboratorial rainfall simulation conditions

• Published in: Journal of hydrology (Amsterdam) 2021-01, Vol.592, p.125620, Article 125620
• Main Authors: Sadeghi, Seyed Hamidreza, Hazbavi, Zeinab, Kiani-Harchegani, Mahboobeh, Younesi, Habibollah, Sadeghi, Padidehsadat, Angulo-Jaramillo, Rafael, Lassabatere, Laurent
• Format: Article
• Language: English
• Subjects: Biodiversity and Ecology; Environmental Sciences; Erosion flux; Hydrologic response; Pyrogenic carbon; Runoff mitigation, Soil management
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/j.jhydrol.2020.125620

•Biochar (BC) and polyacrylamide (PAM) were applied for soil and water conservation.•Effect of application of BC, PAM and BC + PAM on soil hydrology was dissimilar.•Marl and loess soils behaved differently in response to BC, PAM and BC + PAM.•PAM was the most effective treatment on runoff components changes.•BC treatment reported the maximum benefit for soil erosion components control.•BC and PAM can be appropriately used for hydrologic regulation of sensitive soils. Due to the high costs associated with the control of soil erosion, the precise selection of practical techniques towards this end is a prerequisite for sustainable land management. For the proper application of anti-erosion measures, a good knowledge of the behavior of soil erosion and hydrological properties is required. Research has indicated that biochar (BC) and polyacrylamide (PAM) are important soil amendments to enhance the physical and hydrological characteristics of soil. However, little is known about the response and mechanisms underlying the wearing away of Marl and Loess erosion-prone soils treated with individually and with a combination of BC and PAM. Therefore, we tested the effectiveness of these anti-erosion techniques on the variability of 1) hydrological components (i.e., time to runoff, the runoff coefficient, and infiltration), 2) runoff quality components (i.e., pH and electrical conductivity (EC)), and 3) erosion components (i.e., upward-splash, downward-splash, net-splash erosion, soil loss, and sediment concentration) at two locations with the Marl and Loess soils under rainfall simulation conditions. The study treatments consisted of control (200 ml water), BC (800 g m−2), PAM (2 g m−2), and BC (800 g m−2) + PAM (2 g m−2). The treatments were sprayed uniformly over the small plots (0.3 × 0.5 × 0.5 m in dimension; 0.25 m2 in area) with a slope of 20% using three replicates. Rainfall with an intensity of 50 mm h−1 for 0.5 h was applied. The results showed that (a) the use of PAM alone delayed the time to runoff with a rate of 41.4% compared to the control treatment in the Marl soil, and all treatments delayed the time to runoff for the Loess soil (BC = 37.1% and PAM = BC + PAM = 12.9%); (b) among the study treatments, PAM had the greatest effect as it decreased the runoff coefficient by 2.47% and 13.67%, and improved infiltration by 0.02% and 0.13% in Marl and Loess soils, respectively; (c) BC and BC + PAM increased the pH values of the runoff whereas the application o