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ARS Home » Southeast Area » Fayetteville, Arkansas » Poultry Production and Product Safety Research » Research » Publications at this Location » Publication #306701
Title: Microbial biomass and soil carbon after 8 and 9 years of field applications of alum-treated and untreated poultry litter and inorganic nitrogen

Author
item SAVIN, MARY - University Of Arkansas
item TOMLINSON, PETER - Kansas State University
item Moore, Philip

Submitted to: Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2015
Publication Date: 7/1/2015
Citation: Savin, M.C., Tomlinson, P.J., Moore Jr, P.A. 2015. Microbial biomass and soil carbon after 8 and 9 years of field applications of alum-treated and untreated poultry litter and inorganic nitrogen. Biology and Fertility of Soils. 180(1):21-27.

Interpretive Summary: Adding aluminum sulfate (alum) to poultry litter is considered a best management practice for its benefits in poultry production, reduced ammonia losses and reductions in phosphorus runoff. However, little is known about how long-term applications of alum-treated litter to soil will affect the microbial community and soil carbon (C). Soil from plots amended annually since 1995 with alum-treated or untreated poultry litter applied at 2.24 and 8.96 Mg litter ha-1, or ammonium nitrate (65 or 260 kg N ha-1), and an unamended control were taken prior to, 10 d, 1 mo, and 6 mo following application in 2003 and 2004. The samples were analyzed for dissolved organic C (DOC), total soil C, microbial biomass C and C:N, aerobic respiratory activity (dehydrogenase activities), pH, and Mehlich- III extractable aluminum. No short-term responses in soil C or microbial parameters were measured 10 d or 1 mo after fertilization. Total C was similar and significantly higher in soil receiving the high rate of alum-treated and untreated poultry litter compared to all other treatments, but DOC concentration was higher in the soil receiving the high rate of alum-treated compared to untreated poultry litter. Microbial biomass C was highest in soil receiving the high rate of alum-treated litter and lowest in soil receiving the high rate of ammonium nitrate. The high rate of ammonium nitrate also decreased dehydrogenase activities and pH compared to all other treatments but had the highest DOC concentration. The high rate of both poultry litters increased soil C, but the different DOC concentrations, microbial biomass, and pH indicate that the soil microbial community differs as a result of applications of alum-treated compared to untreated poultry litter.

Technical Abstract: Amendment with aluminum sulfate (alum) is considered a best management practice for its benefits in poultry production and increased retention of nutrients in the litter. However, little is known about how long-term applications of alum-treated litter to soil will affect the microbial community and soil carbon (C). Soil from grass plots amended annually since 1995 with alum-treated or untreated poultry litter applied at 2.24 and 8.96 Mg litter ha-1, or ammonium nitrate (65 or 260 kg N ha-1), and an unamended control were sampled prior to, 10 d, 1 mo, and 6 mo following application in 2003 and 2004 for dissolved organic C (DOC), total soil C, microbial biomass C and C:N, aerobic respiratory activity (dehydrogenase activities), pH, and Mehlich- III extractable aluminum. No short-term responses in soil C or microbial parameters were measured 10 d or 1 mo after amendment. Total C was similar and significantly higher in soil receiving the high rate of alum-treated and untreated poultry litter compared to all other treatments, but DOC concentration was higher in the soil receiving the high rate of alum-treated compared to untreated poultry litter. Microbial biomass C was numerically highest in soil receiving the high rate of alum-treated litter and lowest in soil receiving the high rate of ammonium nitrate. The high rate of ammonium nitrate also decreased dehydrogenase activities and pH compared to all other treatments but had the highest DOC concentration. The high rate of both poultry litters improved conditions to result in increased soil C, but the different DOC concentrations, microbial biomass, and pH indicate that the soil microbial community differs as a result of applications of alum-treated compared to untreated poultry litter.