title: Crop residue management and fertilization effects on soil organic matter and associated biological properties.
abstract: Returning crop residue may result in nutrient reduction in soil in the first few years. A two-year field experiment was conducted to assess whether this negative effect is alleviated by improved crop residue management (CRM). Nine treatments (3 CRM and 3 N fertilizer rates) were used. The CRM treatments were (1) R0: 100 % of the N using mineral fertilizer with no crop residues return; (2) R: crop residue plus mineral fertilizer as for the R0; and (3) Rc: crop residue plus 83 % of the N using mineral and 17 % manure fertilizer. Each CRM received N fertilizer rates at 270, 360, and 450 kg N ha(-1) year(-1). At the end of the experiment, soil NO3-N was reduced by 33 % from the R relative to the R0 treatment, while the Rc treatment resulted in a 21 to 44 % increase in occluded particulate organic C and N, and 80 °C extracted dissolved organic N, 19 to 32 % increase in microbial biomass C and protease activity, and higher monounsaturated phospholipid fatty acid (PLFA):saturated PLFA ratio from stimulating growth of indigenous bacteria when compared with the R treatment. Principal component analysis showed that the Biolog and PLFA profiles in the three CRM treatments were different from each other. Overall, these properties were not influenced by the used N fertilizer rates. Our results indicated that application of 17 % of the total N using manure in a field with crop residues return was effective for improving potential plant N availability and labile soil organic matter, primarily due to a shift in the dominant microorganisms.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, PO Box 821, 71 East Beijing Road, Nanjing, 210008, People's Republic of China. bzhao@issas.ac.cn.
authors.forename: Bingzi
authors.initials: B
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, PO Box 821, 71 East Beijing Road, Nanjing, 210008, People's Republic of China.
authors.forename: Jiabao
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, PO Box 821, 71 East Beijing Road, Nanjing, 210008, People's Republic of China.
authors.forename: Yueyue
authors.initials: Y
authors.lastname: Yu
authors.affiliation: USDA-ARS, National Laboratory for Agriculture and the Environment, 1015 N University Blvd., Ames, IA, 50011-3120, USA.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Karlen
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403 1st Ave S, Lethbridge, T1J 4B1, AB, Canada.
authors.forename: Xiying
authors.initials: X
authors.lastname: Hao
mesh_terms: D000383:Agriculture / Q000379:methods; D001419:Bacteria; D018533:Biomass; D018556:Crops, Agricultural / Q000737:chemistry*; D005308:Fertilizers / Q000032:analysis*; D008372:Manure / Q000032:analysis; D008903:Minerals / Q000032:analysis; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D005308:Fertilizers; D008372:Manure; D008903:Minerals; D012987:Soil
keywords: Biolog; Enzymatic activity; Fertilizer rate; PLFA; Soil organic matter