title: Winter effect on soil microorganisms under different tillage and phosphorus management practices in eastern Canada.
abstract: Determining how soil microorganisms respond to crop management systems during winter could further our understanding of soil phosphorus (P) transformations. This study assessed the effects of tillage (moldboard plowing or no-till) and P fertilization (0, 17.5, or 35 kg P·ha(-1)) on soil microbial biomass, enzymatic activity, and microbial community structure in winter, in a long-term (18 years) corn (Zea mays L.) and soybean (Glycine max L.) rotation established in 1992 in the province of Quebec, Canada. Soil samples were collected at 2 depths (0-10 and 10-20 cm) in February 2010 and 2011 after the soybean and the corn growing seasons, respectively. Winter conditions increased the amounts of soil microbial biomasses but reduced the overall enzymatic activity of the soil, as compared with fall levels after corn. P fertilization had a quadratic effect on the amounts of total, bacterial, arbuscular mycorrhizal fungi phospholipid fatty acid markers after corn but not after soybean. The soil microbial community following the soybean and the corn crops in winter had a different structure. These findings suggest that winter conditions and crop-year could be important factors affecting the characteristics of the soil microbial community under different tillage and mineral P fertilization.
authors.affiliation: Soils and Crops Research and Development Centre, Agriculture and Agri-Food Canada, 2560 Hochelaga Boulevard, Québec, QC G1V 2J3, Canada.
authors.forename: Yichao
authors.initials: Y
authors.lastname: Shi
authors.forename: Roger
authors.initials: R
authors.lastname: Lalande
authors.forename: Chantal
authors.initials: C
authors.lastname: Hamel
authors.forename: Noura
authors.initials: N
authors.lastname: Ziadi
mesh_terms: D000383:Agriculture; D018533:Biomass; D002170:Canada; D005308:Fertilizers; D010758:Phosphorus / Q000494:pharmacology*; D012621:Seasons; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D013025:Glycine max; D003313:Zea mays
chemical_list: D005308:Fertilizers; D012987:Soil; D010758:Phosphorus
keywords: P fertilization; biomasse microbienne du sol; community structure; fertilisation au P; hiver; soil microbial biomass; structure microbienne; tillage; travail du sol; winter