title: Transformations of nitrogen and carbon in entrenched biosolids at a reclaimed mineral sands mining site.
abstract: Biosolids deep-row incorporation (DRI) provides high levels of nutrients to the reclamation sites; however, additions of N in excess of the vegetation requirements can potentially impair water quality. The effects of anaerobically digested (AD) and lime stabilized (LS) DRI biosolids and inorganic N fertilizer were compared on C and N transformations and transport at a reclaimed mineral sands mining site. Biosolids were applied at 213 and 426 Mg AD biosolids ha(-1) and 328 and 656 Mg LS biosolids ha)(-1) (dry mass), and inorganic N fertilizer was applied at 0 (control) and 504 kg N ha-(-1) yr(-1). Zero tension lysimeters were installed to collect leachate for determination of vertical N transport, and the biosolids seams were analyzed for N and C transformations after 28 mo aging. The leachijng masses from the DRI biosolids treatments were 139 to 291 kg ha(-1) NO3-N, 61 to 243 kg ha(-1) NH4-N, and 61 to 269 kg ha(-1) organic N, while the fertilizer treatment did not differ from the control. Aged biosolids analysis showed that total N lost over the course of 2 yr was 15.2 Mg ha(-1) and 10.9 Mg ha(-1) for LS and AD biosolids, respectively, which was roughly 50% of the N applied. Organic C losses were 81 Mg ha(-1) and 33 Mg ha(-1) for LS and AD biosolids, respectively. Our results indicated that entrenchment of biosolids in coarse-textured media should not be used as a mined land reclamation technique because the anaerobic conditions required to limit mineralization and nitrification cannot be maintained in such permeable soils.
authors.affiliation: Texas AgriLife Research & Extension Center, 1509 Aggie Dr., Beaumont, TX 77713, USA. kkostya@vt.edu
authors.forename: K I
authors.initials: KI
authors.lastname: Kostyanovsky
authors.forename: G K
authors.initials: GK
authors.lastname: Evanylo
authors.forename: K K
authors.initials: KK
authors.lastname: Lasley
authors.forename: C
authors.initials: C
authors.lastname: Shang
authors.forename: B F
authors.initials: BF
authors.lastname: Sukkariyah
authors.forename: W L
authors.initials: WL
authors.lastname: Daniels
mesh_terms: D001673:Biodegradation, Environmental; D002244:Carbon / Q000737:chemistry / Q000378:metabolism*; D003247:Conservation of Natural Resources / Q000379:methods*; D004784:Environmental Monitoring; D005308:Fertilizers; D007220:Industrial Waste; D008906:Mining; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism*; D012722:Sewage / Q000032:analysis; D012822:Silicon Dioxide / Q000737:chemistry; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D005308:Fertilizers; D007220:Industrial Waste; D012722:Sewage; D014874:Water Pollutants, Chemical; D002244:Carbon; D012822:Silicon Dioxide; D009584:Nitrogen