Modifying Soil Chemistry to Enhance Heathland Recreation: A Use for Sulphur Captured During Oil Refining

Abstract

The overall aim of this paper is to evaluate potential new modifications to methods for re-creating heathland habitats. Heathlands need acidic soils so the specific objectives are to evaluate the effectiveness of a new method for heathland re-creation by soil acidification using a sulphur soil amendment and to explore the benefits for re-creation of applying a soil stripping treatment in conjunction with soil acidification. A new source of sulphur was recovered from oil refinery towers and applied over agricultural sites covering a total of 13 ha on Trehill Farm, Marloes, Pembrokeshire, Wales, UK in 2004. In the summer of 2011 we compared soil chemistry and plant communities on sites subjected to different sulphur treatments (sulphur applied to the existing soil Green et al.; IJPSS, 6(5): 272-282, 2015; Article no.IJPSS.2015.117 273 surface and sulphur applied after top soil had been stripped) with those on an adjacent untreated control and on a nearby established heathland. Each of the four treatment sites and the control and heath site was surveyed using 10 random locations measuring 4 m x 4 m. The total above ground % cover was measured for each plant species and a bulk soil sample was taken in a 'W' shape from within each 4 m x 4 m quadrat. pH and all chemical parameters of the soil showed highly significant differences amongst the sampled sites (P>0.01 in all cases) and produced even greater abundance of ericaceous species on some of the treated sites than occurred in the established heath. However, soil stripping had no significant additional effect on either edaphic factors or plant species abundances. Sulphur recovered from oil refinery is a potentially useful tool in heathland recreation, but soil stripping prior to sulphur amendment did not enhance success. We propose that sulphur application drives success through increasing H + toxicity reducing the availability of base cations and creating Fe-induced Mn deficiency in plants. Short Research Article

Evaluating Heathland Restoration Belowground Using Different Quality Indices of Soil Chemical and Biological Properties

“…Application of elemental sulphur has resulted in the chemical conditions in the acidified pasture being significantly different to the control pasture, both in terms of multivariate analysis of similarity (ANOSIMchem) and Heathland Restoration Index (HRIchem). Soil pH and phosphorus have been found to drive aboveground floral community composition in heathland and grassland systems [69][70][71] and low pH and P concentrations are characteristic of the native heathland in this study [22] Table 8 summarizes the significant differences observed between the control pasture and the acidified pasture, and the acidified pasture and heathland. According to ANOSIM, regardless of the variables used (chemical, microbial faunal, or a combination), the acidified pasture treatment was significantly different to the control pasture.…”

Chronosequence of former kaolinite open cast mines suggests active intervention is required for the restoration of Atlantic heathland

“…Indeed, even after nearly 150 years (albeit with minimal additional management; i.e. grazing by livestock), soil chemistry failed to approach the levels of acidity, organic content, CEC, or key soil nutrients characteristic of, and important in, heathland soil (Clarke ; Green et al ). Similarly, although some species typical of established ALH were abundant in the 1868 site, the community was also characterized by species representative of acid or mesotrophic grasslands.…”

“…Moreover, low pH often results in loss of cations from soils; e.g. Green et al () reported a positive correlation between pH and concentrations of extractable K, Ca, and Mg, but a negative association with phosphate. In turn, soil concentrations of many elements affect the bioavailability of other key nutrients and also influence greatly the growth of species that might otherwise outcompete the target heathland species.…”

“…In turn, soil concentrations of many elements affect the bioavailability of other key nutrients and also influence greatly the growth of species that might otherwise outcompete the target heathland species. Green et al () describe how at higher pH (5 or above), the vegetation of restored heathland sites was dominated by Agrostis capillaris and note how control of this highly competitive species is key to Calluna and Erica cinerea establishment. Similarly, our results show how Agrostis capillaris , along with at least one other mesotrophic grass species, was dominant on the 1868, 1990, and 2013 sites where soil pH remained above 4.7.…”

“…Following reinstatement, further addition of organic matter to overburden is desirable for the same reasons (Smith & Read ; Muñoz‐Rojas et al ) and the potential enhancement of nitrogen cycling rates (Van Vuuren et al ), while fertilizer application can also encourage plant establishment and growth, and concomitant benefits to soil biota (Ngugi et al ). More specific to heathland restoration, soil pH is effectively reduced by the application of sulfur, with the additional benefit of increasing the bioavailability of phosphate without the need for fertilizer application (Green et al ). Heather establishment is also strongly dependent on symbiotic interactions with ericoid mycorrhizal fungi (ERM) that do not respond well to long‐term soil storage (Smith & Read ).…”