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ABSTRACT: Black soil samples were collected from Lishu (43 degrees 20' N, 124 degrees 28' E), Dehui (44 degrees 12' N, 125 degrees 33' E), Hailun (47 degrees 26' N, 126 degrees 38' E), and Bei' an (48 degrees 17' N, 127 degrees 15' E), and an incubation test was conducted to study their microbial respiration and Biolog metabolic functional diversity at 4 degrees C, 15 degrees C, and 28 degrees C. The soil microbial respiration rate was in the order of Bei' an > Hailun > Dehui > Lishu, irrespective of incubation temperature, but the sensitivity of the respiration to the temperature, i. e., Q10 value, differed. The average value of the Q10 for the soils from Lishu, Dehui, Hailun, and Bei'an was 2.72, 3.26, 3.21, and 3.74 in the range of 4 degrees C-15 degrees C, and was 3.29, 2.36, 2.11, and 1.79 in the range of 15 degrees C to 28 degrees C, respectively. The metabolic quotient (qCO2) also differed with incubation temperature, which was in the order of Lishu > Dehui > Bei' an > Hailun at 28 degrees C and of Bei' an > Dehui > Hailun > Lishu at 15 degrees C, but no significant difference was observed at 4 degrees C. Biolog test showed that the substrate richness and metabolic Shannon diversity index of microbial community were higher for the soils from Hailun and Bei' an at 4 degrees C, but higher for those from Lishu and Dehui at 15 degrees C and 28 degrees C. Principal component analysis with Biolog data suggested that the metabolic function of soil microbial community was similar between Bei' an and Hailun, and between Dehui and Lishu. In sum, the responses of black soil's microbial respiration and community functional diversity to temperature varied with latitude, i. e., more sensitive to low temperature in high latitude region, but more sensitive to high temperature in low latitude region.
Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban 06/2010; 21(6):1485-91.
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ABSTRACT: Light intensity intercepted by the soybean canopy during the reproductive period is an important environmental factor determining soybean yield components and grain yield. A 2-year field experiment was conducted to investigate the effects of light enrichment and its interaction with planting density on yield formation of soybean cultivars. Light enrichment increased seed yield per plant and yield per unit area dramatically ranging from 26-94% (P<0.05) regardless of density and cultivars at lower and moderate density however the yield increase effect was not observed in H339 and HN35 at the high density in 2007. Seed yield and pod number per plant declined with the increased density in 2007 for all cultivars but remained unchanged in 2008 for KN18. There was significant light enrichment-by-density (P<0.05) on yield per plant and pod number per plant, but not on seed number per pod and seed size across the two years. Yield sensitivity to light enrichment differed among soybean cultivars. Adjustments to light enrichment imposed at the early flowering R1 stage increased pod number. Pod number per plant increased 20-119% over the two-years. Seed size in this study was unchanged or reduced slightly by light enrichment. Our data suggest that clarification of mechanisms induced the greatest yields in high population as demonstrated under light enriched conditions may provide insights for crop management and phenotypic improvement.
International Journal of Plant Production 02/2010; 4:1735-6814. · 1.10 Impact Factor
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ABSTRACT: A pot experiment was conducted with two soybean varieties (Di2003-1 and Hefeng25) and two main soil types (alfisol and mollisol) in Heilongjiang Province to study the interactive effects of variety and soil type on the root morphology and nodule traits of soybean plants. Root samples were collected at the fifth trifoliolate stage, bloom-beginning stage, pod-beginning stage, full pod stage, seed-beginning stage, full seed stage, and full maturity stage for the analysis of root dry mass, root length, root surface area, average root diameter, nodule number, nodule fresh mass, and mass per nodule. The results showed that soil type had significant effects on the root morphology and nodule traits of test varieties. In alfisol, the root dry mass, root length, and root surface area of test varieties were greater at the fifth trifoliolate stage and bloom-beginning stages while smaller after seed-beginning stage, compared with those in mollisol, and the average root diameter after seed-beginning stage was higher in alfisol than that in mollisol. Soil type did not affect root-shoot ratio. The nodule number after seed-beginning stage was much smaller in alfisol than in mollisol, while the nodule fresh mass and the mass per nodule were in adverse. The root traits in the two soil types varied with soybean variety. Compared with that of Hefeng25, the response of root traits of Di2003-1 to soil type was more sensitive. The interactive effects of variety and soil type on the root morphology and nodule traits of soybean plants were more significant at full seed stage.
Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban 09/2008; 19(8):1747-53.
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ABSTRACT: In a long-term experimental plot at the Hailun Agricultural Ecology Station of Chinese Academy of Sciences in Heilongjiang Province, Northeast China, the effects of three land management practices including natural restoration, fallowing and cropping on black soil microbial biomass C and enzyme activities at the depths of 0-10, 20-30 and 40-50 cm were investigated. The results showed that at 0-10 cm, soil microbial biomass C and soil urease, phosphatase, catalase and invertase activities were in the sequence of natural restoration > cropping > fallowing, while at 20-30 cm and 40-50 cm, they had less significant differences as those at 0-10 cm. Under natural restoration and cropping, soil microbial biomass C and soil urease, phosphatase and catalase activities decreased with increasing soil depth, while under fallowing, they were higher at 20-30 cm. Correlation analysis showed that there existed significant positive correlations between soil total C and total N, soil total C and microbial biomass C, and soil microbial biomass C and test enzyme activities. The indices soil microbial biomass C and soil enzyme activities showed that black soil under long-term natural restoration had better soil quality.
Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban 07/2007; 18(6):1275-80.
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ABSTRACT: Several soil samples were used to study how the characteristics of natural organic matter (NOM) affect sorption of organic compounds. These soils contains different amounts and types of NOM. Aromaticity of NOM (percentage of aromatic carbons) was determined from solid-state CPMAS 13C NMR spectra and the soil effective polarity was computed from the equation developed by Xing et al. Naphthalene was used to examine the sorption characteristics of NOM. Both aromaticity and polarity of NOM strongly affected sorption of naphthalene. Old NOM showed higher affinity than that in the surface, young soils. Sorption increased with increasing aromaticity and decreasing polarity. Thus, the sorption coefficients of organic contaminants cannot be accurately predicted without some consideration of NOM characteristics.
Journal of Environmental Sciences 08/2002; 14(3):351-6. · 1.66 Impact Factor
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ABSTRACT: AbstractSoil microbial biomass and community structures are commonly used as indicators for soil quality and fertility. A investigation was performed to study the effects of long-term natural restoration, cropping, and bare fallow managements on the soil microbial biomass and bacterial community structures in depths of 0–10, 20–30, and 40–50 cm in a black soil (Mollisol). Microbial biomass was estimated from chloroform fumigation-extraction, and bacterial community structures were determined by analysis of 16S rDNA using polymerase chain reaction-denaturing gradient gel electrophoresis (PCRDGGE). Experimental results showed that microbial biomass significantly declined with soil depth in the managements of restoration and cropping, but not in the bare fallow. DGGE profiles indicated that the band number in top 0–10 cm soils was less than that in depth of 20–30 or 40–50 cm. These suggested that the microbial population was high but the bacterial community structure was simple in the topsoil. Cluster and principle component analysis based on DGGE banding patterns showed that the bacterial community structure was affected by soil depth more primarily than by managements, and the succession of bacterial community as increase of soil depth has a similar tendency in the three managements. Fourteen predominating DGGE bands were excised and sequenced, in which 6 bands were identified as the taxa of Verrucomicrobia, 2 bands as Actinobacteria, 2 bands as α-Proteobacteria, and the other 4 bands as δ-Proteobacteria, Acidobacteria, Nitrospira, and unclassified bacteria. In addition, the sequences of 11 DGGE bands were closely related to uncultured bacteria. Thus, the bacterial community structure in black soil was stable, and the predominating bacterial groups were uncultured.
Pedosphere.
