Soil biochemical properties in brown and gray mine soils with and without hydroseeding

Abstract

Abstract. Surface coal mining in the eastern USA disturbs hundreds of hectares of land every year and removes valuable and ecologically diverse eastern deciduous forests. Reclamation involves restoring the landscape to approximate original contour, replacing the topsoil, and revegetating the site with trees and herbaceous species to a designated post-mining land use. Re-establishing an ecosystem of ecological and economic value as well as restoring soil quality on disturbed sites are the goals of land reclamation, and microbial properties of mine soils can be indicators of restoration success. Reforestation plots were constructed in 2007 using weathered brown sandstone or unweathered gray sandstone as topsoil substitutes to evaluate tree growth and soil properties at Arch Coal's Birch River mine in West Virginia, USA. All plots were planted with 12 hardwood tree species and subplots were hydroseeded with a herbaceous seed mix and fertilizer. After 6 years, the average tree volume index was nearly 10 times greater for trees grown in brown (3853 cm 3 ) compared to gray mine soils (407 cm 3 ). Average pH of brown mine soils increased from 4.7 to 5.0, while gray mine soils declined from 7.9 to 7.0. Hydroseeding doubled tree volume index and ground cover on both mine soils. Hydroseeding doubled microbial biomass carbon (MBC) on brown mine soils (8.7 vs. 17.5 mg kg −1 ), but showed no effect on gray mine soils (13.3 vs. 12.8 mg kg −1 ). Hydroseeding also increased the ratio of MBC to soil organic C in both soils and more than tripled the ratio for potentially mineralizable nitrogen (PMN) to total N. Brown mine soils were a better growth medium than gray mine soils and hydroseeding was an important component of reclamation due to improved biochemical properties and microbial activity in mine soils.

CO<sub>2</sub> emission and structural characteristics of two calcareous soils amended with municipal solid waste and plant residue

“…In contrast, Strong et al (2004) found a faster decomposition rate of carbon in a soil with relatively larger pore sizes. Overall, our result are conditioned by the chemical composition of amendment, the rate of application and the soil texture and aggregate size distribution, which have been supported by other studies (Tejada and González, 2003;Ferreras et al, 2006;Mahmoodabadi and Heydarpour, 2014). The addition of organic amendments to the soils also improved the aggregate stability and consequently increased the soils' total porosity, especially macropore fraction.…”

“…For instance, a positive relationship was found between soil porosity and microbial respiration (Marinari et al, 2000). In general, the application of organic amendments can stimulate soil microbial respiration (Ferreras et al, 2006;Thomas et al, 2015), in order that a higher respiration occurs in those treatments applied at a higher rate (Marinari et al, 2000;González et al, 2010). An increase in the microbial respiration of an amended soil may cause the improvement of soil aggregate stability and porosity (Balashov et al, 2010).…”

“…Therefore, organic amendment has been widely used to increase the content of SOC (Fernández et al, 2009;Benbouali et al, 2013;. In this regard, the application of crop residues and manure has been suggested to improve soil quality and to support the sustainable production in agricultural land (Yu and Jia, 2014;Kaleeem Abbasi et al, 2015;Musinguzi et al, 2015;Turgut, 2015). Because the amount of livestock manure as a traditional organic product is limited, crop residue, as an exogenous source of organic matter, has been widely used for the remediation of soil (Benbouali et al, 2013;Mahmoodabadi and Heydarpour, 2014;Novara et al, 2015).…”

“…In this issue, the carbon sequestration is of importance for the earth system (Jaiarree et al, 2014;ParrasAlcántara and Lozano-García, 2014;Brevik et al, 2015;Bruun et al, 2015;de Graaff et al, 2015). Because most soils of arid and semiarid regions are poor in organic carbon (Tejada and González, 2003), the application of organic amendments is a management strategy to improve soil properties with relevant economic benefits for farmers (Bronick and Lal, 2005;González et al, 2010;Alexander et al, 2015). Therefore, organic amendment has been widely used to increase the content of SOC (Fernández et al, 2009;Benbouali et al, 2013;.…”

“…Soil application of organic amendments, such as animal manure, crop residue and MSW compost provides management strategies to compensate the removal of organic carbon from the soils. Besides, the use of organic amendments in the soils reduces the serious environmental problems caused by residue accumulation (Tejada and González, 2003;Ferreras et al, 2006).…”