Rational times for anti-gadfly measures in Western Siberia     

P V Semenov 《Veterinariia》1967,44(3):49-50

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Short-term fluctuations of sugar beet damping-off by Pythium ultimum in relation to changes in bacterial communities after organic amendments to two soils     

He M  Tian G  Semenov AM  van Bruggen AH 《Phytopathology》2012,102(4):413-420

Previously, oscillations in beet seedling damping-off by Pythium ultimum, measured as area under the disease progress curve (AUDPC), were demonstrated after incorporation of organic materials into organic and conventional soils. These periodic fluctuations of P. ultimum infections were cross-correlated with oscillations of copiotrophic CFU at lags of 2 to 4 days. For this article, we investigated whether bacterial communities and microbial activities fluctuated after a disturbance from incorporation of organic materials, and whether these fluctuations were linked to the short-term oscillations in AUDPC of beet seedling damping-off and bacterial populations (CFU) in soil. Soil microbial communities studied by polymerase chain reaction-DGGE analysis of 16S DNA after isolation of total DNA from soil and microbial activities measured as CO(2) emission rates were monitored daily for 14 days after addition of grass-clover (GC) or composted manure (CM) into organic versus conventional soils. Similar to our previous findings, AUDPC and density of copiotrophic bacteria oscillated with time. Fluctuations in species richness (S), Shannon diversity index (H), and individual amplicons on DGGE gels were also detected. Oscillations in AUDPC were positively cross-correlated with copiotrophic CFU in all soils. Oscillations in AUDPC were also positively cross-correlated with 19 to 35% of the high-intensity DNA fragments in soils amended with GC but only 2 to 3% of these fragments in CM-amended soils. AUDPC values were negatively cross-correlated with 13 to 17% of the amplicons with low average intensities in CM-amended soils, which were not correlated with densities of copiotrophic CFU. CO(2) emission rates had remarkable variations in the initial 7 days after either of the soil amendments but were not associated with daily changes in AUDPC. The results suggest that infection by P. ultimum is hampered by competition from culturable copiotrophic bacteria and some high-intensity DGGE amplicons, because AUDPC is cross-correlated with these variables at lags of 1 to 4 days. However, negative cross-correlations with low-intensity DNA fragments indicate that P. ultimum infection could also be suppressed by antagonistic bacteria with low densities that may be nonculturable species, especially in CM amended soil. The organic soil generally had lower AUDPC values, higher bacterial diversity, and negative cross-correlations between AUDPC and low-intensity DNA fragments (after CM amendment), indicating that specific bacteria that do not attain high densities may contribute to P. ultimum suppression in organic soils.  相似文献   

Experimental determination of the active organic matter content in some soils of natural and agricultural ecosystems     

V. M. Semenov  I. K. Kravchenko  L. A. Ivannikova  T. V. Kuznetsova  N. A. Semenova  M. Gispert  J. Pardini 《Eurasian Soil Science》2006,39(3):251-260

In incubation experiments, the soil supply with carbon of mineralizable (C_min), potentially mineralizable (C_pm), and active (C_ac) organic matter, and of microbial mass (C_mb) in natural and agricultural ecosystems of Moscow region (gray forest soil) and Catalonia (Xerochrept) was assessed based on the measurements of the C-CO₂ emission. In the gray forest soil, the C_pm and C_ac contents decreased in the following sequence of ecosystems: forest > meadow > unfertilized agrocenosis; in the Xerochrept, forest > pasture > scrub > agrocenoses with organic fertilizer > unfertilized agrocenosis. A method for measurement of the C_mb according to the C-CO₂ emission during an 11-to 14-day incubation of previously dried soils is proposed.  相似文献   

Critical Loads of Acidity for Forest Ecosystems of North Asia     

Mikhail Semenov  Vladimir Bashkin  Harald Sverdrup 《Water, air, and soil pollution》2001,130(1-4):1193-1198

Critical loads of acidity were calculated using the PROFILE model to assess the forest ecosystem sensitivity to acid deposition in the Asian part of Russia — Siberia. The main input parameters and the output were mapped. At present atmospheric inputs of acid forming pollutants to the study territory are mainly related to transregional and transboundary pollution from Europe. It was shown that the most sensitive to acid loading are ecosystems of the Tundra zone and of the East Sayan mountains' coniferous forests with dystric cambisols and gleysoils, critical loads of actual acidity (CL(Ac)) = 0–0.3 keq/ha/yr. The most tolerant ecosystems are ecosystems of deciduous forests with podsoluvisols, luvisols and humic luvisols of South Taiga zone in West Siberia, CL(Ac) = 3.5–7.0 keq/ha/yr. Generally the values of critical loads are increasing from the North to the South and from the East to the West following the bioproductivity, annual soil temperature and alkalinity of deposition increases.  相似文献   

Impacts of climate change on wheat anthesis and fusarium ear blight in the UK     

James W. Madgwick  Jon S. West  Rodger P. White  Mikhail A. Semenov  James A. Townsend  Judith A. Turner  Bruce D. L. Fitt 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(1):117-131

Climate change will affect both growth of agricultural crops and diseases that attack them but there has been little work to study how its impacts on crop growth influence impacts on disease epidemics. This paper investigates how impacts of climate change on wheat anthesis date will influence impacts on fusarium ear blight in UK mainland arable areas. A wheat growth model was used for projections of anthesis dates, and a weather-based model was developed for use in projections of incidence of fusarium ear blight in the UK. Daily weather data, generated for 14 sites in arable areas of the UK for a baseline (1960–1990) scenario and for high and low CO₂ emissions in the 2020s and 2050s, were used to project wheat anthesis dates and fusarium ear blight incidence for each site for each climate change scenario. Incidence of fusarium ear blight was related to rainfall during anthesis and temperature during the preceding 6 weeks. It was projected that, with climate change, wheat anthesis dates will be earlier and fusarium ear blight epidemics will be more severe, especially in southern England, by the 2050s. These projections, made by combining crop and disease models for different climate change scenarios, suggest that improved control of fusarium ear blight should be a high priority in industry and government strategies for adaptation to climate change to ensure food security.  相似文献   

Erratum to: A Study of Soil Organic Matter Stability Using Derivatography and Long-Term Incubation Methods     

Sokolov  D. A.  Dmitrevskaya  I. I.  Pautova  N. B.  Lebedeva  T. N.  Chernikov  V. A.  Semenov  V. M. 《Eurasian Soil Science》2021,54(7):1130-1130

Eurasian Soil Science - An Erratum to this paper has been published: https://doi.org/10.1134/S1064229321770015  相似文献   

Use of an individual‐based simulation model to explore and evaluate potential insecticide resistance management strategies          下载免费PDF全文

Russell Slater  Pierre Stratonovitch  Jan Elias  Mikhail A Semenov  Ian Denholm 《Pest management science》2017,73(7):1364-1372

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Particulate Organic Matter in Noncultivated and Arable Soils     

Semenov  V. M.  Lebedeva  T. N.  Pautova  N. B. 《Eurasian Soil Science》2019,52(4):396-404

Eurasian Soil Science - Data on the contents of particulate organic matter (POM) in the humus horizons of different soil types were obtained. The influence of the land use system and fertilizers on...  相似文献   

Seasonal Dynamics of Microbial Biomass in Soddy-Podzolic Soil     

Nikitin  D. A.  Chernov  T. V.  Zhelezova  A. D.  Tkhakakhova  A. K.  Nikitina  S. A.  Semenov  M. V.  Xenofontova  N. A.  Kutovaya  O. V. 《Eurasian Soil Science》2019,52(11):1414-1421

Eurasian Soil Science - The seasonal dynamics of the structure of microbial biomass in a soddy-podzolic soil under fallow was assessed using luminescent microscopy. Samples from three soil horizons...  相似文献   

Experience in the training of specialists with middle level qualifications     

M Z Semenov 《Veterinariia》1966,43(4):113-115

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