The Coupling Effects of Using Coal Fly‐Ash and Bio‐Inoculant for Rehabilitation of Disturbed Biocrusts in Active Sand Dunes

Abstract

Active wind‐borne sand dunes, which lead to covering of fertile soils and agricultural fields, are one of the main problems in desertified lands worldwide, and stabilizing them poses a significant challenge. Such sand dunes may be naturally stabilized by biocrusts (biological soil crusts). One of the main restraints of biocrust development is the typical lack of fine particles in sand dunes. A possible artificial source of fine particles is coal fly‐ash, which is the by‐product of power stations and comprises of particles having a diameter of less than 100 µm. This study tested the influence of the coupling effects of coal fly‐ash and bio‐inoculant of filamentous cyanobacteria, isolated from natural stabilized sand dunes nearby, on the soil surface of active sands for increasing resistance to wind erosion. Boundary‐layer wind tunnel experiments were conducted in experimental plots within a greenhouse for examining the effects of adding coal fly‐ash and bio‐inoculant to active sands. The biocrust development was evaluated via several physical and bio‐physiological variables. In all the physical measurements and the bio‐physiological variables, the treatment of “sand + inoculum + coal fly‐ash” showed significant differences from the “sand‐control”. The combination led to the best results of surface stabilization in boundary‐layer wind tunnel experiments, with the lowest sand fluxes. The filamentous cyanobacteria use the fine particles of the coal fly‐ash as bridges for growing toward and adhering to the large sand particles. The cumulative effects of biocrusts and coal fly‐ash enhance soil surface stabilization and may allow long‐term sustainability. Copyright © 2016 John Wiley & Sons, Ltd.

Amendments fail to hasten biocrust recovery or soil stability at a disturbed dryland sandy site

“…Rozenstein et al () found more rapid growth of cyanobacteria on fine sand fractions (<125 um) than on the coarser fractions. Zaady et al () confirmed these results when they demonstrated greater growth of biocrusts when the inoculum was combined with coal fly ash. Likewise, Felde et al () showed that silt and clay content are the primary cementing agents responsible for stabilization of biocrusts in the Israeli Negev Desert.…”

“…We tested gypsum as an amendment because: (1) it has long been observed that gypsum soils support well‐developed lichen and moss communities (Martínez et al ); (2) recovery of biocrusts occurs more rapidly on finer‐textured soils (Belnap & Eldridge ; Rozenstein et al ; Felde et al ; Zaady et al ); and (3) gypsum forms a very stable soil surface. As with the other treatments, we did not observe any effect of gypsum on soil stability metrics or chlorophyll a concentrations.…”

Cyanobacteria Inoculation Improves Soil Stability and Fertility on Different Textured Soils: Gaining Insights for Applicability in Soil Restoration

“…However, studies on their application for biofertilizing and bioconditioning degraded arid soils are relatively few. Experiments under laboratory (Maqubela et al, 2009(Maqubela et al, , 2012Mugnai et al, 2018) and outdoor conditions (Wang et al, 2009;Wu et al, 2013;Lan et al, 2017;Park et al, 2017;Zaady et al, 2017) point to positive results in terms of soil stability and fertility.…”

Restoring soil functions by means of cyanobacteria inoculation: Importance of soil conditions and species selection

“…Soil texture is one of the soil properties described as a key driver affecting cyanobacterial colonization in natural (Williams, Buck, Soukup, & Merkler, ) and artificial biocrusts (Rozenstein et al, ). However, while a large body of literature has addressed the application of cyanobacteria for restoring biocrust functioning on sandy soils (Chen et al, ; Park, Li, Zhao, Jia, & Hur, ; Wang, Liu, Li, Hu, & Rao, ; Wu et al, ; Xie, Liu, Hu, Chen, & Li, ; Zaady et al, ), only a few researchers have focused on biocrust rehabilitation experiments involving fine‐textured soils (Ayuso, Silva, Nelson, Barger, & Garcia‐Pichel, ; Falchini, Sparvoli, & Tomaselli, ; Maqubela, Muchaonyerwa, & Mnkeni, ; Rogers & Burns, ). In addition, differences in soil conditions, such as different degrees of degradation or physicochemical properties might cause different responses to cyanobacterial application.…”