title: Utilization of phosphate rock from Lisina for direct application: release of plant nutrients in the exchange-fertilizer mixtures.
abstract: This study examined the possibility of direct application of phosphate rock (PR) from Lisina deposit, in a mixture with natural clinoptilolite (Cp) and clinoptilolite partially saturated with ammonium ions (NH4-Cp). Solution P concentrations of the NH4-Cp/PR mixtures were sufficient for plant growth and ranged from 0.36 to 0.82 mg L(-1). The median NH4-Cp/PR ratio and the longest proposed mixing time had the most positive impact on the P concentration. Solution Ca concentrations of the NH4-Cp/PR mixtures were between 112.5 and 700.5 mg L(-1), indicating that use of the proposed NH4-Cp/PR mixtures solves the potential lack of Ca(2+) in the solution, which is typical for substrates of similar composition. Selected artificial neural networks (ANNs) were able to predict experimental variables for a broad range of the process parameters all through assay. Manifold effects of small changes in composition of the mixtures and time on the observed concentrations of nutrients were shown using the sensitivity analysis.
authors.affiliation: Institute for Technology of Nuclear and Other Mineral Raw Materials, 86 Franchet d'Esperey St., 11000 Belgrade, Serbia.
authors.forename: Marija
authors.initials: M
authors.lastname: Mihajlović
authors.forename: Nebojša
authors.initials: N
authors.lastname: Perišić
authors.forename: Lato
authors.initials: L
authors.lastname: Pezo
authors.forename: Mirjana
authors.initials: M
authors.lastname: Stojanović
authors.forename: Jelena
authors.initials: J
authors.lastname: Milojković
authors.forename: Zorica
authors.initials: Z
authors.lastname: Lopičić
authors.forename: Marija
authors.initials: M
authors.lastname: Petrović
mesh_terms: D064751:Ammonium Compounds / Q000032:analysis / Q000378:metabolism; D005308:Fertilizers / Q000032:analysis*; D005502:Food; D019015:Geologic Sediments / Q000737:chemistry*; D010710:Phosphates / Q000032:analysis* / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D055771:Serbia; D017641:Zeolites / Q000737:chemistry* / Q000378:metabolism
chemical_list: D064751:Ammonium Compounds; D005308:Fertilizers; D010710:Phosphates; C083175:clinoptilolite; D017641:Zeolites
keywords: Lisina; exchange fertilizer; multivariate analysis; phosphate rock; saturated clinoptilolite