Premium
Reducing Soil Phosphorus Solubility with Coal Combustion By‐Products
Author(s) -
Stout William L.,
Sharpley Andrew N.,
Pionke Harry B.
Publication year - 1998
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1998.00472425002700010016x
Subject(s) - chemistry , soil water , coal combustion products , fly ash , phosphorus , lime , environmental chemistry , solubility , coal , flue gas desulfurization , surface runoff , environmental science , soil science , metallurgy , ecology , materials science , organic chemistry , biology
In the northeast USA, most soil samples analyzed for soil test P (STP) in 1990 exceeded P levels needed for plant production. Converting soil P to less soluble forms with applications of materials containing lime or Ca may reduce the release of soil P to runoff. We investigated the effect of several coal combustion by‐products on STP (Bray‐1 and Mehlich‐III), water extractable P, and equilibrium P concentration (EPC 0 ) of high P soils. Three widely available by‐products were used: fluidized bed combustion fly ash (FBC), flue gas desulfurization by‐product (FGD), and pulverized coal flyash (PC). In a by‐product type and rate experiment, a Berks soil with high STP was incubated for 21 d with each by‐product (0, 10, 20, 40, and 80 g kg soil −1 ). The highest rates of FBC and FGD reduced Mehlich‐III P (45%), Bray‐I P (50%), water extractable P (72%) and EPC 0 (37%). The PC had no effect on soil P solubility due to the addition of P with this by‐product. For eight soils ranging in physical and chemical properties, FBC at 10 g kg soil −1 reduced Mehlich‐III P 13%, and water‐extractable P 71%, while FGD reduced Mehlich‐III P 8% and water‐extractable P 48%. These reductions resulted from the conversion of readily desorbable soil P to less soluble Ca‐bound or Al‐ and Fe‐bound pools. Amending high P soils with FBC or FGD by‐products has the potential to reduce P enrichment of runoff by decreasing the solubility of soil P without reducing STP below optimum levels for plant growth.