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The Contrasting Effects of Alum‐Treated Chicken Manures and KH 2 PO 4 on Phosphorus Behavior in Soils
Author(s) -
Huang Lidong,
Yang Junming,
Xu Yuting,
Lei Jiayan,
Luo Xiaoshan,
CadeMenun Barbara J.
Publication year - 2018
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/jeq2017.08.0314
Subject(s) - alum , chemistry , manure , soil water , phosphorus , chicken manure , amendment , fractionation , zoology , solubility , environmental chemistry , agronomy , chromatography , ecology , biology , organic chemistry , political science , law
Alum [KAl(SO 4 ) 2 ⋅12H 2 O] is often added to chicken manure to limit P solubility after land application. This is generally ascribed to the formation of Al‐PO 4 complexes. However, Al‐PO 4 complex formation could be affected by the matrix of chicken manure, which varies with animal diet. Alum was added to KH 2 PO 4 (as a reference material) and two manures from typical chicken farms in China, one from an intensive farm (CMIF) and another from free‐ranging chickens (CMFR). These were subsequently incubated with soils for 100 d to investigate P transformations. Alum reduced water‐soluble colorimetrically reactive phosphorus (RP) from soils amended with manure more effectively than in soils amended with KH 2 PO 4 . Alum addition lowered Mehlich‐3 RP in soils with CMFR but had no influence on Mehlich‐3 RP in CMIF‐ or KH 2 PO 4 –amended soils. A comparison of P in digested Mehlich‐3 extracts with RP in undigested samples showed significantly increased P in digests of alum‐treated CMFR only. Fractionation data indicated that alum treatment increased P in the NH 4 F‐RP (Al‐P) fraction only in soils with KH 2 PO 4 , but not in soils with manure treatments. Furthermore, NaOH‐extracted nonreactive P was markedly higher in soil with alum‐treated CMFR relative to normal CMFR. The CMFR manure was assumed to contain higher concentrations of organic P because these chickens were fed grains only. These results suggest that the formation of alum‐organic P complexes may reduce P solubility. By comparing alum‐treated KH 2 PO 4 and manures, it appears that organic matter in manure could interfere with the formation of Al‐PO 4 complexes. Core Ideas Alum reduced WSP from soils amended with manure more effectively than KH 2 PO4. Alum treatment increased P in the Al‐P fraction only in soils with KH 2 PO4. Alum could stabilize alum‐organic P complexes in chicken manure to resist degradation.