149-4 Soil Microbial Biomass, Activity, and Community Structure As Affected By Mineral P Fertilization in Two Grassland Soils.
Poster Number 950
See more from this Division: SSSA Division: Soil Biology & BiochemistrySee more from this Session: Soil Biology & Biochemistry: II
Monday, November 3, 2014
Long Beach Convention Center, Exhibit Hall ABC
Soil microorganisms response to mineral phosphorus (P) fertilization in forage stands is poorly understood. We assessed the effects of P fertilization on soil microbial biomass, activity, and community structure in timothy swards on a Kamouraska clay at Lévis (Qc), Canada and a Labarre clay loam at Normandin (Qc), Canada. Three P rates (0, 20, and 40 kg P ha-1) replicated three times have been applied in the spring of each year at the two sites since 2010. Soil samples (0-10 cm) were collected in June, August, and October during the growing season of 2013 to document soil microbial biomass C, N, and P (SMB-C, SMB-N, SMB-P), dehydrogenase and alkaline phosphomonoesterase activities, and phospholipids fatty acid markers of microbial community structure. All soil microbial parameters significantly varied with sampling time. Phosphorus fertilization increased SMB-P on the three sampling dates, but never affected SMB-C, SMB-N, dehydrogenase and alkaline phosphomonoesterase activities, or the microbial community structure. One year of data suggests that four years of P fertilization has limited effects on the composition and function of the soil microbial community of timothy swards in eastern Canada.
See more from this Division: SSSA Division: Soil Biology & BiochemistrySee more from this Session: Soil Biology & Biochemistry: II