Pteris vittata plantation decrease colloidal phosphorus contents by reducing degree of phosphorus saturation in manure amended soils.

The agricultural use of manure fertilizer increases the phosphorus (P) saturation of soils and the risk of colloidal P (P _coll ) release to aquatic ecosystems. Two experiments were conducted to identify whether Pteris vittata plantation can decrease P _coll contents in two soils (Cambisol and Anthrosol) amended with various manure P rates (0, 10, 25, and 50 mg P kg ^-1 of soil). The total P _coll contents in manured soil without P. vittata were 1.14-3.37 mg kg ^-1 (Cambisol), and 0.01-2.83 mg kg ^-1 (Anthrosol) across manure-P rates. The corresponding values with P. vittata were 0.97-2.33 mg kg ^-1 (Cambisol) and 0.005-1.6 mg kg ^-1 (Anthrosol). Experimentally determined colloidal minerals (Fe, Al, Ca), colloidal total organic carbon, Mehlich-3 nutrients (Fe, Al, and Ca), and the degree of P saturation were good predictors of P _coll concentrations in both soils with and without P. vittata plantation. In unplanted soils, P adsorption decreased and the degree of P saturation increased which released more P _coll . However, P. vittata plantation decreased the P _coll release and P loss risk due to the increase of P adsorption and reduced DPS in both soils. The P fractions (NaOH, NH ₄ F, and HCl-P) contributed to increase the P pool in planted soils which enhanced the bioavailability of P _coll and increased the P. vittata biomass. It suggested that P. vittata plantation was an effective approach to reduce P _coll release from manure amended soils.
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