WorldWideScience

Sample records for arable soils effects

  1. Effect of vegetation manipulation of abandoned arable land on soil microbial properties

    NARCIS (Netherlands)

    Maly, S.; Korthals, G.W.; Van Dijk, C.; Van der Putten, W.H.; De Boer, W.

    2000-01-01

    The effect of vegetation composition on various soil microbial properties in abandoned arable land was investigated 2 years after agricultural practice had terminated. Microbial numbers and processes were determined in five replicate plots of each of the following treatments: continued agricultural

  2. Soil organic 14C dynamics: effects of pasture installation on arable land

    NARCIS (Netherlands)

    Römkens, P.F.A.M.; Plicht, van der J.; Hassink, J.

    1998-01-01

    In a study addressing composition and recovery of soil carbon following pasture installation on arable land, radiocarbon isotope ratios were measured in size-and density-separated soil organic matter (SOM) fractions in a pasture and maize plot. The average soil carbon age increased with depth from 4

  3. Soil organic (14)C dynamics : Effects of pasture installation on arable land

    NARCIS (Netherlands)

    Romkens, P.F A M; Hassink, J; van der Plicht, Johannes

    1998-01-01

    In a study addressing composition and recovery of soil carbon following pasture installation on arable land, radiocarbon isotope ratios were measured in size- and density-separated soil organic matter (SOM) fractions in a pasture and maize plot. The average soil carbon age increased with depth from

  4. The microbiology of arable soil surfaces

    OpenAIRE

    Jeffery, Simon

    2007-01-01

    Whilst much is known about the physics and erosion of soil surfaces on a millimetre scale, little is known about the associated microbiology, particularly in temperate arable systems. The vast majority of research regarding microbial interactions at soil surfaces has concerned microbiotic crusts. However, such surface crusts take many years to form and then only in relatively undisturbed soil systems. Arable soil surfaces are subject to relatively extreme environmental conditio...

  5. Occurrence of entomopathogenic fungi in arable soil

    Directory of Open Access Journals (Sweden)

    Ryszard Miętkiewski

    2014-08-01

    Full Text Available Samples of soil were taken from arable field and from balk. Larvae of Galleria mellonella and Ephestia kühniella were used as an "insect bait" for isolation of entomopathogenic fungi from soil. Metarhizium anisopliae and Paecilomyces fumosoroseus were isolated from both kind of soil. but Beauveria bassiana was present only in soil taken from balk.

  6. Assessment of cadmium (Cd) concentration in arable soil in China.

    Science.gov (United States)

    Zhang, Xiuying; Chen, Dongmei; Zhong, Taiyang; Zhang, Xiaomin; Cheng, Min; Li, Xinhui

    2015-04-01

    Cadmium (Cd) concentration in arable soil has drawn broad public attention due to its direct effect on Cd concentration in food. However, there have been few studies of surveying Cd accumulation on the national scale in China. This paper collected 486 studies of Cd concentrations in Chinese arable soil. The results showed that the average Cd concentration was 0.27 mg/kg, higher than its background value, indicating that Cd had been introduced into arable soil by human activity. The Cd concentrations in areas of mining and smelting, urban areas, and areas irrigated by wastewater were obviously higher than that in remote areas. Spatially, Cd concentrations were lower in the north than those in the south, and many hotspots existed throughout China due to mining and smelting activities. Most Cd in the arable soil were accumulated from external sources in all investigated provinces except Ningxia Hui Autonomous Region.

  7. Ecology of microarthropods in arable soil.

    NARCIS (Netherlands)

    Vreeken-Buijs, M.J.

    1998-01-01

    Soil microarthropods are all free-living mites and collembolans, living in the soil. The study presented in this thesis formed part of the Dutch Programme on Soil Ecology of Arable Farming Systems, an integrated multidisciplinary research programme, focused on the functioning of two differently mana

  8. Soil pH effect on phosphate induced cadmium precipitation in Arable soil.

    Science.gov (United States)

    Hong, Chang Oh; Owens, Vance N; Kim, Yong Gyun; Lee, Sang Mong; Park, Hyean Cheal; Kim, Keun Ki; Son, Hong Joo; Suh, Jeong Min; Kim, Pil Joo

    2014-07-01

    The objective of this study was to determine soil pH conditions that allow cadmium (Cd) to precipitate as Cd minerals in phosphate (P) amended soil. Cadmium immobilization could be attributed primarily to Cd adsorption due to increase in pH and negative charge. Soil pH might not affect Cd precipitation as Cd3(PO4)2 by direct reaction of Cd and P in the studied soil, even when soil pH increased up to 9.0. However, Cd might precipitate as CdCO3 with increasing pH up to 9.0 in P untreated soil and up to 8.0 in P treated soil depending on CO2 level.

  9. Emissions of nitrous oxide from Irish arable soils: effects of tillage and reduced N input

    DEFF Research Database (Denmark)

    Abdalla, M.; Jones, M.B.; Ambus, Per;

    2010-01-01

    . Reduced tillage had no significant effect on N2O fluxes from soils or crop grain yield. Multiple regression analysis revealed that soil moisture and an interaction between soil moisture and soil nitrate are the main significant factors affecting N2O flux. The derived emission factor was 0...

  10. Carbon Dioxide in Arable Soil Profiles

    DEFF Research Database (Denmark)

    Chirinda, Ngoni; Plauborg, Finn; Heckrath, Goswin Johann

    2014-01-01

    Carbon dioxide (CO2) concentrations in arable soil profiles are influenced by autotrophic and heterotrophic respiration as well as soil physical properties that regulate gas transport. Whereas different methods have been used to assess dynamics of soil CO2 concentrations, our understanding......). In a winter wheat field in Denmark, soil CO2 concentrations were measured from 29 November 2011 to 14 June 2012 at upslope and footslope positions of a short catena (25 m). Carbon dioxide was measured at 20 and 40 cm soil depths (i.e., within and below the nominal plough layer) using the two measurement...

  11. Effect of almond shell biochar addition on the hydro-physical properties of an arable Central Valley soil

    Science.gov (United States)

    Lopez, V.; Ghezzehei, T. A.

    2014-12-01

    Biochar is composed of any carbonaceous matter pyrolyzed under low oxygen exposure. Its use as a soil amendment to address soil infertility has been accelerated by studies reporting positive effects of enhanced nutrient retention, cation exchange capacity, microbial activity, and vegetative growth over time. Biochar has also been considered as a carbon sequestration method because of its reported environmental persistence. While the aforementioned effects are positive benefits of biochar's use, its impact on soil physical properties and water flow are equally important in maintaining soil fertility. This study aims to show how soil physical and hydraulic properties change over time with biochar addition. To address these aims, we conducted a 9 week microcosm incubation experiment with local arable loamy sand soils amended with biochar. Biochar was created from locally collected almond shells and differs by pyrolysis temperatures (350°C, 700°C) and size (determining content of water stable aggregates remaining after wet sieving. This series of experiments is expected to provide a greater understanding on the impact biochar addition on soil physical and hydraulic properties. Furthermore, it provides insight into whether or not converting local agricultural waste into biochar for soil use will be beneficial, especially in agricultural systems undergoing climate stress.

  12. Accumulation of cadmium and uranium in arable soils in Switzerland.

    Science.gov (United States)

    Bigalke, Moritz; Ulrich, Andrea; Rehmus, Agnes; Keller, Armin

    2017-02-01

    Mineral phosphorus (P) fertilizers contain contaminants that are potentially hazardous to humans and the environment. Frequent mineral P fertilizer applications can cause heavy metals to accumulate and reach undesirable concentrations in agricultural soils. There is particular concern about Cadmium (Cd) and Uranium (U) accumulation because these metals are toxic and can endanger soil fertility, leach into groundwater, and be taken up by crops. We determined total Cd and U concentrations in more than 400 topsoil and subsoil samples obtained from 216 agricultural sites across Switzerland. We also investigated temporal changes in Cd and U concentrations since 1985 in soil at six selected Swiss national soil monitoring network sites. The mean U concentrations were 16% higher in arable topsoil than in grassland topsoil. The Cd concentrations in arable and grassland soils did not differ, which we attribute to soil management practices and Cd sources other than mineral P fertilizers masking Cd inputs from mineral P fertilizers. The mean Cd and U concentrations were 58% and 9% higher, respectively, in arable topsoil than in arable subsoil, indicating that significant Cd and U inputs to arable soils occurred in the past. Geochemical mass balances confirmed this, indicating an accumulation of 52% for Cd and 6% for U. Only minor temporal changes were found in the Cd concentrations in topsoil from the six soil-monitoring sites, but U concentrations in topsoil from three sites had significantly increased since 1985. Sewage sludge and atmospheric deposition were previously important sources of Cd to agricultural soils, but today mineral P fertilizers are the dominant sources of Cd and U. Future Cd and U inputs to agricultural soils may be reduced by using optimized management practices, establishing U threshold values for mineral P fertilizers and soils, effectively enforcing threshold values, and developing and using clean recycled P fertilizers.

  13. Effects of a copper-tolerant grass (Agrostis capillaris) on the ecosystem of a copper-contaminated arable soil

    NARCIS (Netherlands)

    Boon, GT; Bouwman, LA; Bloem, J; Romkens, PFAM

    1998-01-01

    To test how a dysfunctioning ecosystem of a severely metal-polluted soil responds to renewed plant growth, a pot experiment was conducted with soil from an experimental arable field with pH and copper gradients imposed 13 years ago. In this experiment, four pH/copper combinations from this field wer

  14. Effects of a copper tolerant grass (Agrostis capillaris) on the ecosystem of a copper-contaminated arable soil

    NARCIS (Netherlands)

    Boon, G.T.; Bouwman, L.A.; Bloem, J.; Römkens, P.F.A.M.

    1998-01-01

    To test how a dysfunctioning ecosystem of a severely metal-polluted soil responds to renewed plant growth, a pot experiment was conducted with soil from an experimental arable field with pH and copper gradients imposed 13 years ago. In this experimentfour pH/copper combinations from this field were

  15. VARIABILITY OF ARABLE AND FOREST SOILS PROPERTIES ON ERODED SLOPES

    Directory of Open Access Journals (Sweden)

    Paweł Wiśniewski

    2014-10-01

    Full Text Available The basic method of reducing soil and land erosion is a change of land use, for example, from arable to forest. Particularly effective as a protective role – according to the Polish law – soil-protecting forests. The thesis presents differences in the deformation of the basic soil properties on moraine slopes, depending on land use. There has been presented the function and the efficiency of the soil-protecting forests in erosion control. The soil cross section transects and soil analysis displayed that soil-protecting forests are making an essential soil cover protection from degradation, inter alia, limiting the decrease of humus content, reduction of upper soil horizons and soil pedons layer. On the afforested slopes it was stated some clear changes of grain size and chemical properties of soils in relation to adjacent slopes agriculturally used.

  16. Effect of Phosphate Addition on Cadmium Precipitation and Adsorption in Contaminated Arable Soil with a Low Concentration of Cadmium.

    Science.gov (United States)

    Kim, Sung Un; Owens, Vance N; Kim, Yong Gyun; Lee, Sang Mong; Park, Hyean Cheal; Kim, Keun Ki; Son, Hong Joo; Hong, Chang Oh

    2015-11-01

    The objectives of this study were to determine (1) the phosphorus (P) level required to induce cadmium (Cd) precipitation in a contaminated arable soil with low concentrations of Cd and (2) the primary mechanism of Cd immobilization at different P levels. Phosphorus was added at levels of 0 800, 1600, and 16,000 mg P kg(-1) to a soil containing 5.57 mg Cd kg(-1). The concentration of 1 M NH4OAc extractable Cd decreased significantly with P levels up to 1600 mg kg(-1) due to an increase in soil pH and negative charge of soil (psoil containing low levels of this heavy metal.

  17. Soil Temperature Manipulation to Study Global Warming Effects in Arable Land

    DEFF Research Database (Denmark)

    Patil, R H; Laegdsmand, M; Olesen, Jørgen E

    2013-01-01

    in a plough layer. Temperature sensors were placed at 0.05, 0.1 and 0.25 m depths in soil, and 0.1 m above the soil surface in all plots, which were connected to an automated data logger. Soil-warming setup was able to maintain a mean seasonal temperature difference of 5.0 ± 0.005℃ between heated and control......-ground vegetation response as this method heats only the soil. Therefore, using infrared heaters seems to represent natural climate warming (both air and soil) much more closely and may be used for future climate manipulation field studies....

  18. Soil temperature manipulation to study global warming effects in arable land

    DEFF Research Database (Denmark)

    Patil, Raveendra H.; Laegdsmand, Mette; Olesen, Jørgen Eivind

    2013-01-01

    in a plough layer. Temperature sensors were placed at 0.05, 0.1 and 0.25 m depths in soil, and 0.1 m above the soil surface in all plots, which were connected to an automated data logger. Soil-warming setup was able to maintain a mean seasonal temperature difference of 5.0 ± 0.005 oC between heated...... that of above-ground vegetation response as this method heats only the soil. Therefore, using infrared heaters seems to represent natural climate warming (both air and soil) much more closely and may be used for future climate manipulation field studies....

  19. A RAINFALL SIMULATOR STUDY OF INFILTRATION INTO ARABLE SOILS

    NARCIS (Netherlands)

    WIERDA, A; VEEN, AWL

    1992-01-01

    Since Hortonian surface runoff is one possible mechanism for the fast transport of agricultural chemicals from arable soils to surface water, more information is needed on its significance in agricultural areas. The present study concerns the sandy soils of the Dutch Cover Sands area, and is based o

  20. Effects of long-term differential fertilization on eukaryotic microbial communities in an arable soil: a multiple barcoding approach.

    Science.gov (United States)

    Lentendu, Guillaume; Wubet, Tesfaye; Chatzinotas, Antonis; Wilhelm, Christian; Buscot, François; Schlegel, Martin

    2014-07-01

    To understand the fine-scale effects of changes in nutrient availability on eukaryotic soil microorganisms communities, a multiple barcoding approach was used to analyse soil samples from four different treatments in a long-term fertilization experiment. We performed PCR amplification on soil DNA with primer pairs specifically targeting the 18S rRNA genes of all eukaryotes and three protist groups (Cercozoa, Chrysophyceae-Synurophyceae and Kinetoplastida) as well as the ITS gene of fungi and the 23S plastid rRNA gene of photoautotrophic microorganisms. Amplicons were pyrosequenced, and a total of 88,706 quality filtered reads were clustered into 1232 operational taxonomic units (OTU) across the six data sets. Comparisons of the taxonomic coverage achieved based on overlapping assignment of OTUs revealed that half of the eukaryotic taxa identified were missed by the universal eukaryotic barcoding marker. There were only little differences in OTU richness observed between organic- (farmyard manure), mineral- and nonfertilized soils. However, the community compositions appeared to be strongly structured by organic fertilization in all data sets other than that generated using the universal eukaryotic 18S rRNA gene primers, whereas mineral fertilization had only a minor effect. In addition, a co-occurrence based network analysis revealed complex potential interaction patterns between OTUs from different trophic levels, for example between fungivorous flagellates and fungi. Our results demonstrate that changes in pH, moisture and organic nutrients availability caused shifts in the composition of eukaryotic microbial communities at multiple trophic levels.

  1. Remediation of degraded arable steppe soils in Moldova using vetch as green manure

    Science.gov (United States)

    Wiesmeier, M.; Lungu, M.; Hübner, R.; Cerbari, V.

    2015-05-01

    In the Republic of Moldova, non-sustainable arable farming led to severe degradation and erosion of fertile steppe soils (Chernozems). As a result, the Chernozems lost about 40% of their initial amounts of soil organic carbon (SOC). The aim of this study was to remediate degraded arable soils and promote carbon sequestration by implementation of cover cropping and green manuring in Moldova. Thereby, the suitability of the legume hairy vetch (Vicia sativa) as cover crop under the dry continental climate of Moldova was examined. At two experimental sites, the effect of cover cropping on chemical and physical soil properties as well as on yields of subsequent main crops was determined. The results showed a significant increase of SOC after incorporation of hairy vetch mainly due to increases of aggregate-occluded and mineral-associated OC. This was related to a high above- and belowground biomass production of hairy vetch associated with a high input of carbon and nitrogen into arable soils. A calculation of SOC stocks based on equivalent soil masses revealed a sequestration of around 3 t C ha-1yr-1 as a result of hairy vetch cover cropping. The buildup of SOC was associated with an improvement of the soil structure as indicated by a distinct decrease of bulk density and a relative increase of macroaggregates at the expense of microaggregates and clods. As a result, yields of subsequent main crops increased by around 20%. Our results indicated that hairy vetch is a promising cover crop to remediate degraded steppe soils, control soil erosion and sequester substantial amounts of atmospheric C in arable soils of Moldova.

  2. Spatial Distribution of Fungal Communities in an Arable Soil

    Science.gov (United States)

    Moll, Julia; Hoppe, Björn; König, Stephan; Wubet, Tesfaye; Buscot, François; Krüger, Dirk

    2016-01-01

    Fungi are prominent drivers of ecological processes in soils, so that fungal communities across different soil ecosystems have been well investigated. However, for arable soils taxonomically resolved fine-scale studies including vertical itemization of fungal communities are still missing. Here, we combined a cloning/Sanger sequencing approach of the ITS/LSU region as marker for general fungi and of the partial SSU region for arbuscular mycorrhizal fungi (AMF) to characterize the microbiome in different maize soil habitats. Four compartments were analyzed over two annual cycles 2009 and 2010: a) ploughed soil in 0–10 cm, b) rooted soil in 40–50 cm, c) root-free soil in 60–70 cm soil depth and d) maize roots. Ascomycota was the most dominant phylum across all compartments. Fungal communities including yeasts and AMF differed strongly between compartments. Inter alia, Tetracladium, the overall largest MOTU (molecular operational taxonomic unit), occurred in all compartments, whereas Trichosporon dominated all soil compartments. Sequences belonging to unclassified Helotiales were forming the most abundant MOTUs exclusively present in roots. This study gives new insights on spatial distribution of fungi and helps to link fungal communities to specific ecological properties such as varying resources, which characterize particular niches of the heterogeneous soil environment. PMID:26840453

  3. Spatial Distribution of Fungal Communities in an Arable Soil.

    Directory of Open Access Journals (Sweden)

    Julia Moll

    Full Text Available Fungi are prominent drivers of ecological processes in soils, so that fungal communities across different soil ecosystems have been well investigated. However, for arable soils taxonomically resolved fine-scale studies including vertical itemization of fungal communities are still missing. Here, we combined a cloning/Sanger sequencing approach of the ITS/LSU region as marker for general fungi and of the partial SSU region for arbuscular mycorrhizal fungi (AMF to characterize the microbiome in different maize soil habitats. Four compartments were analyzed over two annual cycles 2009 and 2010: a ploughed soil in 0-10 cm, b rooted soil in 40-50 cm, c root-free soil in 60-70 cm soil depth and d maize roots. Ascomycota was the most dominant phylum across all compartments. Fungal communities including yeasts and AMF differed strongly between compartments. Inter alia, Tetracladium, the overall largest MOTU (molecular operational taxonomic unit, occurred in all compartments, whereas Trichosporon dominated all soil compartments. Sequences belonging to unclassified Helotiales were forming the most abundant MOTUs exclusively present in roots. This study gives new insights on spatial distribution of fungi and helps to link fungal communities to specific ecological properties such as varying resources, which characterize particular niches of the heterogeneous soil environment.

  4. Effectiveness Of Miraba an Indigenous Soil and Water Conservation Measures On Reducing Runoff And Soil Loss In Arable Land Of Western Usambara Mountains

    Science.gov (United States)

    Msita, H. B.; Kimaro, D. N.; Mtakwa, P. W.; Msanya, B. M.; Dondyene, S.; Poesen, J.; Deckers, J.

    2012-04-01

    Soil erosion by water is rampant mainly in mountainous areas of Tanzania leading to environmental hazards, low land productivity, low income and increased poverty. Despite the severity of the soil erosion problem, there is not much quantitative data on the erosion effects and effectiveness of indigenous soil and water conservation (SWC) measures. The consequence is that indigenous knowledge in SWC planning is ignored. The on-farm field experiment was conducted for three years in Migambo village, Lushoto district in Tanzania, to determine the effectiveness of improved Miraba (IM) an indigenous soil erosion control measure on reducing runoff and soil loss. Management practices were tested viz: control that is without any soil conservation measure (C), Miraba alone (M), Miraba with farmyard manure and mulching (MFM) replicated three times in CRD setting. Maize (Zea mays) and beans (Phaseolus vulgaris) were used as test crops, due to their importance as food crops and the high erosion rates on fields with these crops. The crops were planted in rotation, maize and beans in short and long rains respectively. Gerlach troughs and runoff plots were used to evaluate the physical effectiveness. Results show significant effects of IM against control on crop yields, soil loss, surface runoff and moisture retention. MFM is the most effective measure in reducing soil and water losses followed by MF and M. The results further showed that these management practices can be implemented to reduce soil erosion and nutrient losses in the study area and areas with similar ecological setting. To facilitate adoption of these practices further research works is recommended for identifying economically feasible indigenous SWC measures under different biophysical and socio-economic conditions.

  5. Modelling soil organic carbon concentration of mineral soils in arable lands using legacy soil data

    DEFF Research Database (Denmark)

    Suuster, E; Ritz, Christian; Roostalu, H

    2012-01-01

    Soil organic carbon (SOC) concentration is an essential factor in biomass production and soil functioning. SOC concentration values are often obtained by prediction but the prediction accuracy depends much on the method used. Currently, there is a lack of evidence in the soil science literature...... as to the advantages and shortcomings of the different commonly used prediction methods. Therefore, we compared and evaluated the merits of the median approach, analysis of covariance, mixed models and random forests in the context of prediction of SOC concentrations of mineral soils under arable management in the A......-horizon. Three soil properties were used in all of the developed models: soil type, physical clay content (particle size

  6. Relationship between soil cellulolytic activity and suppression of seedling blight of barley in arable soils

    DEFF Research Database (Denmark)

    Rasmussen, Peter Have; Knudsen, I.; Elmholt, S.;

    2002-01-01

    the Hanes-Wolf transformation of the Michaelis-Menten equation. Soil samples from 6 to 13 cm depth were collected in the early spring as undisturbed blocks from 10 arable soils with different physico-chemical properties and cultivation history. Significant correlations were found between soil suppresiveness....... From the preliminary results obtained, it is proposed that the cellulolytic activity can be used as an enzymatic approach to study the microbial turnover of organic matter in soils and as indicator of seedling blight of barley caused by F. culmorum. (C) 2002 Elsevier Science B.V. All rights reserved....

  7. Humus form development of former arable soils under forest and fallow systems

    Science.gov (United States)

    Marcinkonis, Saulius

    2010-05-01

    Soil humus is a multi-component organic media and most dynamic part of soil, even humus amount itself under natural vegetation is relatively stable and predetermined by climatic conditions and landscape. Soil cultivation including common farming practices - mechanical soil tillage, use of mineral fertilizers (especially nitrogen) and ameliorants aimed to increase crop production. Agricultural soils beside many environmentally unfavorable more or less controlled processes of soil degradation (nutrient leaching, soil erosion) have unstable level and quality of soil humus (qualitative composition). These humus fluctuations are controlled through organic matter development processes - accelerating or inhabitation of mineralization and humification. During last decades economical drivers in Lithuania stimulated land uses changes (LUC) in less-favored farming areas with regions attributing to large proportions of low fertile soils, hilly landscape and ecological vulnerability. Prevailed types of LUC - arable land to grassland, land afforestration or land abandonment prompt agro ecosystems to return to land primeval state (under natural vegetation) and initial humus level through self-regulation. But listed transformations having own process drivers and prevailing soil humus development directions. Experimental field at the Voke branch of LIA was established (in 1995) and studies conducted with the aim to monitor soil properties transformation, to explore variation of soil quality under different stages of renaturalisation. The experiment was designed with four sites (treatments) on former arable land: 1) left as a cropland site (control) (I); 2) transformed to grassland (II); 3) uncultivated or transformed to fallow (III) and 4) pine afforested site (IV). Assuming 10 years of experimental results (1995-2004) it was concluded that transition of agricultural land characterized as complex of factors having strong effect on energy and nutrients turnover, however soil testing

  8. Anisotropy of Soil Hydraulic Properties Along Arable Slopes

    Institute of Scientific and Technical Information of China (English)

    JING Yuan-Shu; ZHANG Bin; A.THIMM; H.ZEPP

    2008-01-01

    The spatial variations of the soil hydraulic properties were mainly considered in vertical direction.The objectives of this study were to measure water-retention curves,θ(ψ),and unsaturated hydraulic conductivity functions,K(ψ),of the soils sampled at different slope positions in three directions,namely,in vertical direction,along the slope and along the contour,and to determine the effects of sampling direction and slope position of two soil catenas.At the upper slope positions,the surface soils (0-10 cm) sampled in the vertical direction had a lower soil water content,θ,at a certain soil water potential (-1500 kPa <ψ<-10 kPa) and had the greatest unsaturated hydraulic conductivity,K,at ψ> -10kPa.At the lower slope positions,K at ψ>-10 kPa was smaller in the vertical direction than in the direction along the slope.The deep soils (100-110 cm) had similar soil hydraulic properties in all the three directions.The anisotropic variations of the hydraulic properties of the surface soils were ascribed to the effects of natural wetting and drying cycles on the structural heterogeneity.These results suggested that the anisotropy of soil hydraulic properties might be significant in influencing soil water movement along the slope and need to be considered in modeling.

  9. Biochar decelerates soil organic nitrogen cycling but stimulates soil nitrification in a temperate arable field trial.

    Directory of Open Access Journals (Sweden)

    Judith Prommer

    Full Text Available Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50-80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies.

  10. In situ spatial patterns of soil bacterial populations, mapped at multiple scales, in an arable soil.

    Science.gov (United States)

    Nunan, N; Wu, K; Young, I M; Crawford, J W; Ritz, K

    2002-11-01

    Very little is known about the spatial organization of soil microbes across scales that are relevant both to microbial function and to field-based processes. The spatial distributions of microbes and microbially mediated activity have a high intrinsic variability. This can present problems when trying to quantify the effects of disturbance, management practices, or climate change on soil microbial systems and attendant function. A spatial sampling regime was implemented in an arable field. Cores of undisturbed soil were sampled from a 3 x 3 x 0.9 m volume of soil (topsoil and subsoil) and a biological thin section, in which the in situ distribution of bacteria could be quantified, prepared from each core. Geostatistical analysis was used to quantify the nature of spatial structure from micrometers to meters and spatial point pattern analysis to test for deviations from complete spatial randomness of mapped bacteria. Spatial structure in the topsoil was only found at the microscale (micrometers), whereas evidence for nested scales of spatial structure was found in the subsoil (at the microscale, and at the centimeter to meter scale). Geostatistical ranges of spatial structure at the micro scale were greater in the topsoil and tended to decrease with depth in the subsoil. Evidence for spatial aggregation in bacteria was stronger in the topsoil and also decreased with depth in the subsoil, though extremely high degrees of aggregation were found at very short distances in the deep subsoil. The data suggest that factors that regulate the distribution of bacteria in the subsoil operate at two scales, in contrast to one scale in the topsoil, and that bacterial patches are larger and more prevalent in the topsoil.

  11. Modeling the effects of different N fertilizer rates on N2O emissions and nitrate leaching from arable soils in Korea

    Science.gov (United States)

    Kim, Y.; Berger, S.; Tenhunen, J. D.; Gebauer, G.; Kiese, R.

    2012-12-01

    Process-based biogeochemical models can be used to predict the impact of various agricultural management practices on plant nitrogen use efficiency and nitrogen losses to the environment such as greenhouse gas emissions and nitrate leaching by analyzing the interactions between management practices, primary drivers such as climate, soil properties, crop types, etc., and biogeochemical reactions. In this study we applied the Landscape-DNDC model, which combines and uniforms functions of the agricultural-DNDC and the Forest-DNDC for simulation of C and N turnover, GHG emissions, nitrate leaching, and plant growth for a Korean arable field cultivated with radish (Raphanus sativus L.). The annual average temperature is app. 8.5°C and the annual precipitation is app. 1,500 mm. According to farmers practice the study field received a basal fertilizer application of app. 200 kg N ha-1 before setting up four fertilizer treatments i.e. additionally 50, 150, 250 and 350 kg N ha-1. All N treatment plots were tilled a week after application of specific N fertilizer in order to make row and interrow. Just before radish seeding rows were covered with black plastic mulch which was removed after harvest. In spite the widespread usage of black mulch in Korea or even Asia; so far biogeochemical models do not consider impacts of mulch on soil environmental conditions and soil biogeochemistry. Based on field measurements we adjusted input information and used only half of the annual precipitation and the maximum temperature for simulation of row conditions, whereas the actual weather data were used for the interrow simulations. Simulated N2O emissions agreed well with measurements; however peak emissions after fertilization were slightly underestimated in row and interrow. Annual N2O emissions of the fertilizer treatments increased with increasing fertilization rates from around 1.5 to 3 kg N ha-1 in the row and lower emissions of app. 1.5 kg N ha-1 (for all N treatments) in the

  12. Dynamics of organic carbon stock of Estonian arable and grassland peat soils

    Science.gov (United States)

    Kauer, Karin; Tammik, Kerttu; Penu, Priit

    2016-04-01

    Peat soils represent globally a major reserve of soil organic carbon (SOC). Estimation of changes in SOC stocks is important for understanding soil carbon sequestration and dynamics of greenhouse gas emissions. The aim of this study was to estimate the SOC stock of Estonian agricultural peat soils and SOC stock change depending on land use type (arable land and long-term grasslands (over 5 years)). The soils were classified as Histosols according to WRB classification. Generally the arable land was used for growing cereals, oilseed rape, legumes and used as ley in crop rotation. The main technique of soil cultivation was ploughing. During 2002-2015 the soil samples of 0-20 cm soil layer (one average soil sample per 1-5 ha) were collected. The SOC content was measured by NIRS method. The SOC stock was calculated by assuming that soil mean bulk density is 0.3 g cm-3. The SOC stock change in arable land was estimated during 3-13 years (N=91) and in grassland 4-13 year (N=163). The average SOC content of peat soils varied from 150.6 to 549.0 mg g-1. The initial SOC stock of arable land was 271.3 t ha-1 and of grassland 269.3 t ha-1. The SOC stock declined in arable peat soils faster (-2.57 t ha-1 y-1) compared to the changes in grassland peat soils (-0.67 t ha-1 y-1). According to the length of the study period the SOC stock change per year varied from -5.14 to 6.64 t ha-1 y-1 in grasslands and from -14.78 to 0.83 t ha-1 y-1 in arable land, although there was no clear relationship between the SOC stock change and the length of the study period. More detailed information about the properties of agricultural land and land use history is needed to analyse the causes of the SOC stock changes in agricultural peat soils. However, from the current research we can conclude that the SOC stock of arable and grassland peat soils is declining during the cultivation. These decreases are important to specify when considering the role of peat soils in atmospheric greenhouse gas

  13. Relationship between magnetic parameters and heavy element contents of arable soil around a steel company, Nanjing

    Institute of Scientific and Technical Information of China (English)

    BLAHA; U; ROESLER; W; APPEL; E

    2010-01-01

    Magnetic parameters and element contents were determined in core NJ008 collected from the uppermost ca. 40 cm in a steel company in southwest Nanjing. The results showed that magnetic susceptibility (χ), saturation isothermal remanent magnetization (SIRM) and anhysteretic remanent magnetization (ARM) were enhanced in the uppermost 20 cm, with a mean magnetic susceptibility value of 112.5×10-8 m3 kg-1. Below 20 cm, χ decreased sharply with a mean value of 27.8×10-8m3 kg-1. Low-coercivity minerals such as magnetite dominate in arable soils, while the relative content of antiferromagnetic minerals increases below 20 cm. Heavy metals (Ni, Cu, Fe, Pb, V, and Zn) have similar vertical trends as χ. Principal component analysis reveals common high loadings of the same factor for magnetic concentration parameters (χ, ARM, and SIRM) and elements (Ni, Cu, Fe, Pb, V, and Zn) with an excellent linear correlation (0.69≤R≤0.98) between them. Magnetic susceptibility of paddy soil core NJ013, which had the same parent material as NJ008 but was far from pollution sources, showed stable values of magnetic concentration parameters along the whole core. Absolute values correspond to the so-called magnetic background value (below 20 cm) of NJ008. This indicates that pesticide and fertilizer had little effect on magnetic signals of the upper part of core NJ008 and the extremely enhanced magnetic concentration parameters originate from the steel company emission. Although, the arable soil does not reveal the pollution history and transportation due to annual ploughing, the significant linear relationship between magnetic concentration parameters and heavy metal contents suggests that magnetic parameters can serve as a proxy for quickly detecting soil metallic pollution and estimating the extent of contamination.

  14. Soil organic matter dynamics after the conversion of arable land to pasture

    NARCIS (Netherlands)

    Römkens, Paul F.A.M.; Plicht, Johannes van der; Hassink, Jan

    1999-01-01

    Conversion of arable land (maize) to pasture will affect the soil organic matter (SOM) content. Changes in the SOM content were studied using a size- and density-fractionation method and C-13 analysis. Twenty-six years of maize cropping had resulted in a depletion of carbon stored in the macro-organ

  15. Soil organic matter dynamics after the conversion of arable land to pasture

    NARCIS (Netherlands)

    Römkens, P.F.A.M.; Plicht, van der J.; Hassink, J.

    1999-01-01

    Conversion of arable land (maize) to pasture will affect the soil organic matter (SOM) content. Changes in the SOM content were studied using a size- and density-fractionation method and 13C analysis. Twenty-six years of maize cropping had resulted in a depletion of carbon stored in the macro-organi

  16. Response of rhizosphere microbial community structure and diversity to heavy metal co-pollution in arable soil.

    Science.gov (United States)

    Deng, Linjing; Zeng, Guangming; Fan, Changzheng; Lu, Lunhui; Chen, Xunfeng; Chen, Ming; Wu, Haipeng; He, Xiaoxiao; He, Yan

    2015-10-01

    Due to the emerging environmental issues related to heavy metals, concern about the soil quality of farming lands near manufacturing district is increasing. Investigating the function of soil microorganisms exposed to long-term heavy metal contamination is meaningful and important for agricultural soil utilization. This article studied the potential influence of several heavy metals on microbial biomass, activity, abundance, and community composition in arable soil near industrial estate in Zhuzhou, Hunan province, China. The results showed that soil organic contents (SOC) were significantly positive correlated with heavy metals, whereas dehydrogenase activity (DHA) was greatly depressed by the heavy metal stress. Negative correlation was found between heavy metals and basal soil respiration (BSR), and no correlation was found between heavy metals and microbial biomass content (MBC). The quantitative PCR (QPCR) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis could suggest that heavy metal pollution has significantly decreased abundance of bacteria and fungi and also changed their community structure. The results could contribute to evaluate heavy metal pollution level in soil. By combining different environmental parameters, it would promote the better understanding of heavy metal effect on the size, structure, and activity of microbial community in arable soil.

  17. Soil Strength Characteristics Along an Arable Eroded Slope

    Institute of Scientific and Technical Information of China (English)

    PENG Xin-Hua; ZHANG Bin; ZHAO Qi-Guo; R. HORN

    2005-01-01

    Undisturbed soil cores were taken from different slope positions (upslope, backslope and footslope) and soil depths (0-15, 20-35 and 100-115 cm) in a soil catena derived from Quaternary red clay to determine the spatial changes in soil strength along the eroded slope and to evaluate an indicator to determine soil strength during compaction. Precompression stress, as an indicator of soil strength, significantly increased from topsoil layer to subsoil layer (P<0.05) and was affected by slope position. In the subsoil layer (20-35 cm), the precompression stress at the footslope position was significantly greater than at the backslope and upslope positions (P<0.05), while there were no significant differences at 0-15 and 100-115 cm. Precompression stress followed the spatial variation of soil clay content with soil depth and had a significant linear relationship with soil porosity (r2 = 0.40, P<0.01). Also, soil cohesion increased with increasing soil clay content.The precompression stress was significantly related to the applied stress corresponding to the highest change of pore water pressure (r2 = 0.69, P<0.01). These results suggested that soil strength induced by soil erosion and soil management varied spatially along the slope and the maximum change in pore water pressure during compaction could be an easy indicator to describe soil strength.

  18. Human Activity and Soil Fertility—Nutrients Depletion of Arable Soils in China

    Institute of Scientific and Technical Information of China (English)

    LURU-KUN

    1991-01-01

    The reserve of soil nutrients is limited.In case of irrational use of land,nutrients would be depleted sooner.Before the 1950s the low grain production in China was maintained only by expanding the cultivated area and by recycling of nutrients in agriculture.Calculation of nutrients balance showed that in the year of 1949 there were great deficits of N,P and K elements in agriculture of China.It revealed that there would have really been danger of soil nutrients exhaustion if such a situation had continued.Things have changed since the beginning of 1950s.The nutrients balance in agriculture has been getting better and better.In the year 1987 N and P balance got rid of their great deficits.But for K and deficit grew even larger.This resulted in a rapid expansion of soil area deficient in K in China since the mid 1970s.In spite of the fact that the P balance in the arable land of the whole country was positive,the field which did not receive P fertilizer had become deficient in P.So the area deficient in P also increased.It is stressed that great attention should be paid to the depletion of soil nutrients,especially K in the northern part of China where the soil is relatively rich in K.Of course,soil sulfur and microelements should be considered next.

  19. Assessment of arsenic (As) occurrence in arable soil and its related health risk in China.

    Science.gov (United States)

    Zhang, Xiuying; Zhong, Taiyang; Chen, Dongmei; Cheng, Min; Liu, Lei; Zhang, Xiaomin; Li, Xinhui

    2016-06-01

    Arsenic (As) is a major global environmental pollutant due to its high toxicity on human and animal health. This study collected 427 relevant papers to study As concentrations in Chinese arable soil and evaluate the health risk of exposure to As for humans. Results showed that the average of As concentration was 9.46 mg/kg in Chinese arable soil. Soil As concentrations in Hunan Province and Guangxi Zhuang Autonomous Region posed high carcinogenic and non-cancer risks on human health through diet, Yunnan, Guizhou, Guangdong, and Xinjiang provinces had relative high health risks, while As concentrations in the other provinces posed low health risks on humans. The physical factors controlled the spatial pattern of health risk on a provincial scale, but the As-related human activities introduced high health risk on people, particularly the agricultural activities such as sewage irrigation and fertilizer application should be given more attention due to its large area.

  20. Microbial response to increasing temperatures during winter in arable soils

    Science.gov (United States)

    Lukas, Stefan; Potthoff, Martin; Joergensen, Rainer Georg

    2014-05-01

    Climate scenarios predict increasing temperatures and higher precipitation rates in late fall to early spring, both holding the potential to modify carbon and nutrient dynamics in soils by altering snow pack thickness and soil frost events. When soils are frozen, a small amount of unfrozen water allows microorganisms to remain active at temperatures down to -10 °C. We carried out a field experiment on the microbial use of maize straw. We compared soils of two different clay contents and used latitude as a proxy for climate. Microcosms with sieved soil were mixed with chopped maize leaf straw (C/N 17) at a rate of 1 mg C g-1 dry soil, un-amended microcosms served as control. Results indicated that C-mineralization rates were independent from clay content. However, the microbial use of maize derived nitrogen was only increased in the soil with 13% clay compared to 33% clay in the other soil. Microbial responses to climate changes can be expected to be very specific due to characteristics of the soil and/or the location.

  1. Responses of plasmid-mediated quinolone resistance genes and bacterial taxa to (fluoro)quinolones-containing manure in arable soil.

    Science.gov (United States)

    Xiong, Wenguang; Sun, Yongxue; Ding, Xueyao; Zhang, Yiming; Zhong, Xiaoxia; Liang, Wenfei; Zeng, Zhenling

    2015-01-01

    The aim of the present study was to investigate the fate of plasmid-mediated quinolone resistance (PMQR) genes and the disturbance of soil bacterial communities posed by (fluoro)quinolones (FQNs)-containing manure in arable soil. Representative FQNs (enrofloxacin (ENR), ciprofloxacin (CIP) and norfloxacin (NOR)), PMQR genes (qepA, oqxA, oqxB, aac(6')-Ib-cr and qnrS) and bacterial communities in untreated soil, +manure and +manure+FQNs groups were analyzed using culture independent methods. The significantly higher abundance of oqxA, oqxB and aac(6')-Ib-cr, and significantly higher abundance of qnrS in +manure group than those in untreated soil disappeared at day 30 and day 60, respectively. All PMQR genes (oqxA, oqxB, aac(6')-Ib-cr and qnrS) dissipated 1.5-1.7 times faster in +manure group than those in +manure+FQNs group. The disturbance of soil bacterial communities posed by FQNs-containing manure was also found. The results indicated that significant effects of PMQR genes (oqxA, oqxB, aac(6')-Ib and qnrS) on arable soils introduced by manure disappeared 2 month after manure application. FQNs introduced by manure slowed down the dissipation of PMQR genes. The presence of high FQNs provided a selective advantage for species affiliated to the phylum including Acidobacteria, Verrucomicrobia and Planctomycetes while suppressing Proteobacteria and Actinobacteria.

  2. Topographic variability influences the carbon sequestration potential of arable soils

    DEFF Research Database (Denmark)

    Chirinda, Ngoni; Elsgaard, Lars; Thomsen, Ingrid Kaag

    2012-01-01

    cm soil depths. Concurrently, gas was sampled from 40, 50, and 80 cm depths using steel rods connected to a sampling port. Concentrations of CO2 in the gas samples were analyzed by gas chromatography. The results show that at the upslope position, soils from the topsoil horizon clearly had higher C...

  3. Molecular turnover time of soil organic matter in particle-size fractions of an arable soil.

    Science.gov (United States)

    Bol, Roland; Poirier, Natacha; Balesdent, Jérôme; Gleixner, Gerd

    2009-08-30

    The composition and molecular residence time of soil organic matter (SOM) in four particle-size fractions (POM >200 microm, POM 63-200 microm, silt and clay) were determined using Curie-point pyrolysis/gas chromatography coupled on-line to mass spectrometry. The fractions were isolated from soils, either continuously with a C(3) wheat (soil (13)C value = -26.4 per thousand), or transferred to a C(4) maize (soil (13)C value = -20.2 per thousand) cropping system 23 years ago. Pyrograms contained up to 45 different pyrolysis peaks; 37 (ca. 85%) were identifiable compounds. Lignins and carbohydrates dominated the POM fractions, proteins were abundant, but lignin was (nearly) absent in the silt and clay fractions. The mean turnover time (MRT) for the pyrolysis products in particulate organic matter (POM) was generally <15 years (fast C pool) and 20-300 years (medium or slow C pools) in silt and clay fractions. Methylcyclopentenone (carbohydrate) in the clay fraction and benzene (mixed source) in the silt fraction exhibited the longest MRTs, 297 and 159 years, respectively. Plant-derived organic matter was not stored in soils, but was transformed to microbial remains, mainly in the form of carbohydrates and proteins and held in soil by organo-mineral interactions. Selective preservation of plant-derived OM (i.e. lignin) based on chemical recalcitrance was not observed in these arable soils. Association/presence of C with silt or clays in soils clearly increased MRT values, but in an as yet unresolved manner (i.e. 'truly' stabilized, or potentially still 'labile' but just not accessible C).

  4. Geochemical background values for trace elements in arable soils developed from sedimentary rocks of glacial origin.

    Science.gov (United States)

    Czarnowska, K; Gworek, B

    1990-12-01

    The total content of trace elements was examined in some arable soils developed from boulder loam and silt formations of the Middle Poland and Baltic glaciations (62 profiles). Mean element concentrations calculated on the basis of chemical and statistical analyses were as follows: Mn = 322; Zn = 36; Cr = 30; Ni = 12.7; Pb = 10.3; Cu = 8.8; Co = 4.7; and Cd = 0.27 in mg kg(-1) of soil dry weight. The authors propose to accept these figures as the geochemical background values for soils derived from sedimentary rocks of glacial origin.

  5. Studies on mycoflora colonizing raw keratin wastes in arable soil

    Directory of Open Access Journals (Sweden)

    Teresa Korniłłowicz

    2014-08-01

    Full Text Available The present studies showed that feathers placed in soil demonstrated the succesion of physiologically differentiated communities of micromycetes. The first colonizers were sugar fungi. The second phase of feather colonization showed the prevalence of nutritively undeveloped polyphages and "root" celulolytic fungi. The final phase of colonization was dominated by keratinophilic fungi together with microflora that involved the forms known mainly for their strong proteolytic abilities. It was found that both the Chemical structure of substrate and soil properties with its pH determined the qualitative composition of fungal flora.

  6. Linking above- and below-ground biodiversity: abundance and trophic complexity in soil as a response to experimental plant communities on abandoned arable land

    NARCIS (Netherlands)

    Korthals, G.W.; Smilauer, P.; Van Dijk, C.; Van der Putten, W.H.

    2001-01-01

    1. This study investigates the effects of experimental plant communities on different trophic levels in the soil food web of abandoned arable land. 2. In April 1996, a biodiversity experiment commenced using a continuation of agricultural crop rotation (CCR), spontaneous succession with naturally co

  7. The impact of management and climate on soil nitric oxide fluxes from arable land in the Southern Ukraine

    Science.gov (United States)

    Medinets, Sergiy; Gasche, Rainer; Skiba, Ute; Medinets, Volodymyr; Butterbach-Bahl, Klaus

    2016-07-01

    NO fluxes from soils are a significant source for tropospheric NOx, though global and regional estimates of the soil source strength are constrained by the paucity of measurements. In a continuous 18 month effort (2012-2014) soil NO fluxes from an intensively managed arable site in the black soil region of the Southern Ukraine (Odessa region) were measured using an automated dynamic chamber system. Measurements revealed three periods of peak NO emissions (fertigation, re-wetting of soils, and to a lower extend during winter), with a pulse emission peak during soil re-wetting in summer of 88.4 μg N m-2 h-1. The mean annual NO flux was 5.1 ± 8.9 μg N m-2 h-1 and total annual NO emissions were 0.44 ± 0.78 kg N ha-1 yr-1. The fertilizer induced emission factor for NO was 0.63% under beetroot. The combined effect of soil temperature, soil moisture and soil DIN (NH4+ and NO3-) concentrations were identified as drivers of the temporal and spatial variability of soil NO fluxes. This work shows that long-term measurements are needed for estimating annual fluxes and the importance of soils as a source for tropospheric NOx as the contribution of different seasons and crop growing periods to the annual budget differed markedly.

  8. Ecotoxicological Impact of the Bioherbicide Leptospermone on the Microbial Community of Two Arable Soils

    Science.gov (United States)

    Romdhane, Sana; Devers-Lamrani, Marion; Barthelmebs, Lise; Calvayrac, Christophe; Bertrand, Cédric; Cooper, Jean-François; Dayan, Franck E.; Martin-Laurent, Fabrice

    2016-01-01

    The ecotoxicological impact of leptospermone, a β-triketone bioherbicide, on the bacterial community of two arable soils was investigated. Soil microcosms were exposed to 0 × (control), 1 × or 10 × recommended dose of leptospermone. The β-triketone was moderately adsorbed to both soils (i.e.,: Kfa ~ 1.2 and Koc ~ 140 mL g−1). Its dissipation was lower in sterilized than in unsterilized soils suggesting that it was mainly influenced by biotic factors. Within 45 days, leptospermone disappeared almost entirely from one of the two soils (i.e., DT50 < 10 days), while 25% remained in the other. The composition of the microbial community assessed by qPCR targeting 11 microbial groups was found to be significantly modified in soil microcosms exposed to leptospermone. Pyrosequencing of 16S rRNA gene amplicons showed a shift in the bacterial community structure and a significant impact of leptospermone on the diversity of the soil bacterial community. Changes in the composition, and in the α- and β-diversity of microbial community were transient in the soil able to fully dissipate the leptospermone, but were persistent in the soil where β-triketone remained. To conclude the bacterial community of the two soils was sensitive to leptospermone and its resilience was observed only when leptospermone was fully dissipated. PMID:27252691

  9. Use of the Regularities of Within-Field Variability of Arable Soil Fertility in Precision Agrotechnologies

    Directory of Open Access Journals (Sweden)

    Afanasyev Rafail Aleksandrovich

    2015-04-01

    Full Text Available The paper states the regularities of the within-field variation of soil fertility which are important for variable rate fertilizer application under conditions of precision agrotechnologies including the technologies which limit the agroeconomic efficiency. As it is well known, the usual (traditional fertilizer practice stipulates their application taking into account average indices of soil fertility: mobile plant food elements (N, P, K etc. content in the plow layer. At the same time, one part of the plants gets excess of mineral nutrition, and the other part – its deficiency. That results in shortage of agricultural products, their deterioration and also the pollution of the environment and the soil with the excesses of agrochemicals in overfertilized plots. In the last decades traditional technologies give place to high-precision agrotechnologies with differentiated fertilizer application taking into account within-field heterogeneity of soil fertility. There are several constraints for widespread adoption of high-precision agrotechnologies including the underestimation of the character of within-field variability of soil quality. Our investigations reveal eight regularities of the within-field variation of agrochemical indices, which characterize soil fertility in arable soils. These regularities would allow to more seriously estimate the efficiency of variable rate fertilizer application under conditions of precision agrotechnologies.

  10. Potential carbon sequestration of European arable soils estimated by modelling a comprehensive set of management practices.

    Science.gov (United States)

    Lugato, Emanuele; Bampa, Francesca; Panagos, Panos; Montanarella, Luca; Jones, Arwyn

    2014-11-01

    Bottom-up estimates from long-term field experiments and modelling are the most commonly used approaches to estimate the carbon (C) sequestration potential of the agricultural sector. However, when data are required at European level, important margins of uncertainty still exist due to the representativeness of local data at large scale or different assumptions and information utilized for running models. In this context, a pan-European (EU + Serbia, Bosnia and Herzegovina, Montenegro, Albania, Former Yugoslav Republic of Macedonia and Norway) simulation platform with high spatial resolution and harmonized data sets was developed to provide consistent scenarios in support of possible carbon sequestration policies. Using the CENTURY agroecosystem model, six alternative management practices (AMP) scenarios were assessed as alternatives to the business as usual situation (BAU). These consisted of the conversion of arable land to grassland (and vice versa), straw incorporation, reduced tillage, straw incorporation combined with reduced tillage, ley cropping system and cover crops. The conversion into grassland showed the highest soil organic carbon (SOC) sequestration rates, ranging between 0.4 and 0.8 t C ha(-1)  yr(-1) , while the opposite extreme scenario (100% of grassland conversion into arable) gave cumulated losses of up to 2 Gt of C by 2100. Among the other practices, ley cropping systems and cover crops gave better performances than straw incorporation and reduced tillage. The allocation of 12 to 28% of the European arable land to different AMP combinations resulted in a potential SOC sequestration of 101-336 Mt CO2 eq. by 2020 and 549-2141 Mt CO2 eq. by 2100. Modelled carbon sequestration rates compared with values from an ad hoc meta-analysis confirmed the robustness of these estimates.

  11. Assessment on the Impact of Arable Land Protection Policies in a Rapidly Developing Region

    Directory of Open Access Journals (Sweden)

    Jiadan Li

    2016-05-01

    Full Text Available To investigate the effect of arable land protection policies in China, a practical framework that integrates geographic information systems (GIS, soil quality assessment and landscape metrics analysis was employed to track and analyze arable land transformations and landscape changes in response to rampant urbanization within the Ningbo region (China from 2005 to 2013. The results showed that arable land loss and degradation have continued, despite the development of a comprehensive legal framework for arable land protection. The implementation of arable land protection policies is judged to be effective, but not entirely successful, because it guarantees the overall amount of arable land but does not consider soil quality and spatial distribution. In addition, there are distinct variations in arable land change dynamics between two temporal intervals. From 2005–2009, the transformation of arable land was diversified, with intensified conversion among arable land, built-up land, water and orchards. Moreover, many new arable land parcels were adjacent to built-up land, and are in danger of being occupied again through urban sprawl. By 2009–2013, most of the arable land was occupied by urban expansion, whereas a majority of newly increased arable land was reclaimed from coastal tideland. Although the newly increased arable land was contiguous and far from the urban area, it is of poor quality and has limited use. The permanent loss of high-quality arable land due to intensified urban sprawl may threaten sustainable development and food security on a larger scale.

  12. Thallium in French agrosystems--I. Thallium contents in arable soils.

    Science.gov (United States)

    Tremel, A; Masson, P; Sterckeman, T; Baize, D; Mench, M

    1997-01-01

    The thallium (Tl) content of the upper horizons of 244 French soils was determined as the first step towards the creation of a reference data bank for total Tl content of arable soils. Forty soil samples were collected in the vicinity of potential anthropogenic sources of Tl, but the remainder came from rural areas. The distribution of Tl concentrations in soils was characterized by a median value of 0.29 mg Tl kg(-1) and a 90th percentile value of 1.54 mg Tl kg(-1). Very high pedogeochemical contents were found (up to 55 mg Tl kg(-1)) but none could be attributed to obvious anthropogenic pollution. Areas of very high Tl concentration belong to an epihercynian transgression zone with a contact between a sedimentary basin and a crystalline massif. This contact is associated with stratified mineralizations (Zn, Pb, F, Sb, Ba, Tl and pyrites). High Tl concentrations were common in limestone, marl or granite derived soils, and the Tl in limestones or marls is probably concentrated in the sulfides contained in these rocks because Tl has a high affinity to S. In granites, Tl may be in the micas and feldspars because Tl+ can replace K+ in these minerals. Silty or clay-silty soils showed the highest concentrations. These granulometric fractions contain the majority of the minerals, which are supposed to be the major hosts of Tl in soils, i.e. clay minerals, oxides and micas. Tl in the soils was positively correlated with Ba, V, Pb, Fe, Ni, Cd, Zn, Co, As and especially Mn. A significant proportion of Tl may be in the Mn oxides: in oxidizing conditions, Tl(III) could enter the Mn oxides by sorption, or Tl(I) could replace K(I) in the oxide.

  13. Soil CO2 flux in relation to dissolved organic carbon, soil temperature and moisture in a subtropical arable soil of China

    Institute of Scientific and Technical Information of China (English)

    LOU Yun-sheng; LI Zhong-pei; ZHANG Tao-lin

    2003-01-01

    Soil CO2 emission from an arable soil was measured by closed chamber method to quantify year-round soil flux and to develop an equation to predict flux using soil temperature, dissolved organic carbon(DOC) and soil moisture content. Soil CO2 flux, soil temperature, DOC and soil moisture content were determined on selected days during the experiment from August 1999 to July 2000, at the Ecological Station of Red Soil, the Chinese Academy of Sciences, in a subtropical region of China. Soil CO2 fluxes were generally higher in summer and autumn than in winter and spring, and had a seasonal pattern more similar to soil temperature and DOC than soil moisture. The estimation was 2.23 kgCO2/(m2·a) for average annual soil CO2 flux. Regressed separately, the reasons for soil flux variability were 86.6% from soil temperature, 58.8% from DOC, and 26.3% from soil moisture, respectively. Regressed jointly, a multiple equation was developed by the above three variables that explained approximately 85.2% of the flux variance, however by stepwise regression, soil temperature was the dominant affecting soil flux. Based on the exponential equation developed from soil temperature, the predicted annual flux was 2.49 kgCO2/(m2·a), and essentially equal to the measured one. It is suggested the exponential relationship between soil flux and soil temperature could be used for accurately predicting soil CO2 flux from arable soil in subtropical regions of China.

  14. A compilation and meta-analysis of rainfall simulation data on arable soils

    Science.gov (United States)

    Fiener, P.; Seibert, S. P.; Auerswald, K.

    2011-10-01

    SummaryRainfall simulations are a useful and important tool in studying infiltration, surface runoff generation, soil erosion and nutrient as well as agro-chemical transport from arable land. Such simulations are time-consuming and costly and hence are usually only carried out under a limited variation of settings necessary to answer specific research questions. Therefore, it is difficult to use rainfall simulation data for hypothesis testing in a more general sense or to parameterize hydrological or erosion models applicable under a wider range of environmental conditions. To overcome these restrictions and to set-up a broader basis for following up studies, we analyzed, harmonized and filled gaps of a large set of existing rainfall simulations carried out by five different research groups in Germany. This covered 726 rainfall simulations (24,384 runoff measurements) carried out on 209 plots under a wide range of conditions for which 4 rain properties, 5 plot properties, 20 soil properties, 5 land use properties and 2 runoff properties were compiled. These data were quality controlled and made available for public use ( Seibert et al., 2011). The most important deficiencies were smoothed runoff measurements, missing time to ponding data, different soil descriptions including frequent gaps in stone content, inconsistent moisture measurements and sometimes rather rough measurements of surface cover. The calculation of the geometric mean particle diameter, time since tillage and the application of different site specific procedures supported harmonization and helped to overcome several of these deficiencies. A satisfying gap filling procedure was developed for time to ponding. The most important inconsistencies that could not be removed were different depths of moisture measurement. Hence, there is a need to define a set of basic variables that always should be measured and documented with defined standards to enable comparison between different studies, to assess

  15. Laccase activity is proportional to the abundance of bacterial laccase-like genes in soil from subtropical arable land.

    Science.gov (United States)

    Feng, Shuzhen; Su, Yirong; Dong, Mingzhe; He, Xunyang; Kumaresan, Deepak; O'Donnell, Anthony G; Wu, Jinshui; Chen, Xiangbi

    2015-12-01

    Laccase enzymes produced by both soil bacteria and fungi play important roles in refractory organic matter turnover in terrestrial ecosystems. We investigated the abundance and diversity of fungal laccase genes and bacterial laccase-like genes in soil from subtropical arable lands, and identified which microbial group was associated with laccase activity. Compared with fungal laccase genes, the bacterial laccase-like genes had greater abundance, richness and Shannon-Wiener diversity. More importantly, laccase activity can be explained almost exclusively by the bacterial laccase-like genes, and their abundance had significant linear relationship with laccase activity. Thus, bacterial laccase-like gene has great potential to be used as a sensitive indicator of laccase enzyme for refractory organic matter turnover in subtropical arable lands.

  16. Enantiomer signature and carbon isotope evidence for the migration and transformation of DDTs in arable soils across China

    Science.gov (United States)

    Niu, Lili; Xu, Chao; Zhu, Siyu; Bao, Huiming; Xu, Yang; Li, Hongyi; Zhang, Zhijian; Zhang, Xichang; Qiu, Jiguo; Liu, Weiping

    2016-12-01

    Due to the adverse impact of DDTs on ecosystems and humans, a full fate assessment deems a comprehensive study on their occurrence in soils over a large region. Through a sampling campaign across China, we measured the concentrations, enantiomeric fractions (EFs), compound-specific carbon isotope composition of DDT and its metabolites, and the microbial community in related arable soils. The geographically total DDT concentrations are higher in eastern than western China. The EFs and δ13C of o,p’-DDT in soils from western China show smaller deviations from those of racemic/standard compound, indicating the DDT residues there mainly result from atmospheric transport. However, the sources of DDT in eastern China are mainly from historic application of technical DDTs and dicofol. The inverse dependence of o,p’-DDT and p,p’-DDE on temperature evidences the transformation of parent DDT to its metabolites. Initial usage, abiotic parameters and microbial communities are found to be the main factors influencing the migration and transformation of DDT isomers and their metabolites in soils. In addition, a prediction equation of DDT concentrations in soils based on stepwise multiple regression analysis is developed. Results from this study offer insights into the migration and transformation pathways of DDTs in Chinese arable soils, which will allow data-based risk assessment on their use.

  17. Sensitive indicators of side-effects of pesticides on the epigeal fauna of arable land.

    NARCIS (Netherlands)

    Everts, J.W.

    1990-01-01

    The main objective of the present study was to evaluate the possible impact of pesticides on epigeal arthropods in arable land. It was also envisaged to develop a predictive model for possible undesirable effects of pesticides on the epigeal arthropod fauna using an indicator species from the field.

  18. Modeling greenhouse gas emissions and nutrient transport in managed arable soils with a fully coupled hydrology-biogeochemical modeling system

    Science.gov (United States)

    Haas, Edwin; Klatt, Steffen; Kiese, Ralf; Butterbach-Bahl, Klaus; Kraft, Philipp; Breuer, Lutz

    2015-04-01

    The use of mineral nitrogen fertilizer sustains the global food production and therefore the livelihood of human kind. The rise in world population will put pressure on the global agricultural system to increase its productivity leading most likely to an intensification of mineral nitrogen fertilizer use. The fate of excess nitrogen and its distribution within landscapes is manifold. Process knowledge on the site scale has rapidly grown in recent years and models have been developed to simulate carbon and nitrogen cycling in managed ecosystems on the site scale. Despite first regional studies, the carbon and nitrogen cycling on the landscape or catchment scale is not fully understood. In this study we present a newly developed modelling approach by coupling the fully distributed hydrology model CMF (catchment modelling framework) to the process based regional ecosystem model LandscapeDNDC for the investigation of hydrological processes and carbon and nitrogen transport and cycling, with a focus on nutrient displacement and resulting greenhouse gas emissions in various virtual landscapes / catchment to demonstrate the capabilities of the modelling system. The modelling system was applied to simulate water and nutrient transport at the at the Yanting Agro-ecological Experimental Station of Purple Soil, Sichuan province, China. The catchment hosts cypress forests on the outer regions, arable fields on the sloping croplands cultivated with wheat-maize rotations and paddy rice fields in the lowland. The catchment consists of 300 polygons vertically stratified into 10 soil layers. Ecosystem states (soil water content and nutrients) and fluxes (evapotranspiration) are exchanged between the models at high temporal scales (hourly to daily) forming a 3-dimensional model application. The water flux and nutrients transport in the soil is modelled using a 3D Richards/Darcy approach for subsurface fluxes with a kinematic wave approach for surface water runoff and the

  19. Dynamics of {sup 14}C-labeled glucose and ammonium in saline arable soils

    Energy Technology Data Exchange (ETDEWEB)

    Vuelvas-Solorzano, Alma; Hernandez-Matehuala, Rosalina [Instituto Tecnologico de Celaya, Celaya Gto. (Mexico). Dept. de Ing. Bioquimica. Lab. de Bioingenieria; Conde-Barajas, Eloy; Cardenas-Manriquez, Marcela [Instituto Tecnologico de Celaya, Celaya Gto. (Mexico). Dept. de Ing. Ambiental. Lab. de Bioingenieria], e-mail: marcela@itc.mx; Luna-Guido, Marco L.; Dendooven, Luc [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (Cinvestav), D.F. (Mexico). Dept. de Biotecnologia y Bioingenieria. Lab. de Ecologia de Suelos], e-mail: dendoove@cinvestav.mx

    2009-07-15

    Organic matter dynamics and nutrient availability in saline agricultural soils of the State of Guanajuato might provide information for remediation strategies. {sup 14}C labeled glucose with or without 200 mg kg{sup -}1 of NH{sub 4} {sup +}-N soil was added to two clayey agricultural soils with different electrolytic conductivity (EC), i.e. 0.94 dS m{sup -}1 (low EC; LEC) and 6.72 dS m{sup -}1 (high EC; HEC), to investigate the effect of N availability and salt content on organic material decomposition. Inorganic N dynamics and production of CO{sub 2} and {sup 14}CO{sub 2} were monitored. Approximately 60 % of the glucose-{sup 14}C added to LEC soil evolved as {sup 14}CO{sub 2}, but only 20 % in HEC soil after the incubation period of 21 days. After one day, < 200 mg {sup 14}C was extractable from LEC soil, but > 500 mg {sup 14}C from HEC soil. No N mineralization occurred in the LEC and HEC soils and glucose addition reduced the concentrations of inorganic N in unamended soil and soil amended with NH{sub 4}{sup +}-N. The NO{sub 2}{sup -} and NO{sub 3}{sup -} concentrations were on average higher in LEC than in HEC soil, with exception of NO{sub 2}{sup -} in HEC amended with NH{sub 4}{sup +}-N. It was concluded that increases in soil EC reduced mineralization of the easily decomposable C substrate and resulted in N-depleted soil. (author)

  20. Soil bacterial and fungal communities across a pH gradient in an arable soil.

    Science.gov (United States)

    Rousk, Johannes; Bååth, Erland; Brookes, Philip C; Lauber, Christian L; Lozupone, Catherine; Caporaso, J Gregory; Knight, Rob; Fierer, Noah

    2010-10-01

    Soils collected across a long-term liming experiment (pH 4.0-8.3), in which variation in factors other than pH have been minimized, were used to investigate the direct influence of pH on the abundance and composition of the two major soil microbial taxa, fungi and bacteria. We hypothesized that bacterial communities would be more strongly influenced by pH than fungal communities. To determine the relative abundance of bacteria and fungi, we used quantitative PCR (qPCR), and to analyze the composition and diversity of the bacterial and fungal communities, we used a bar-coded pyrosequencing technique. Both the relative abundance and diversity of bacteria were positively related to pH, the latter nearly doubling between pH 4 and 8. In contrast, the relative abundance of fungi was unaffected by pH and fungal diversity was only weakly related with pH. The composition of the bacterial communities was closely defined by soil pH; there was as much variability in bacterial community composition across the 180-m distance of this liming experiment as across soils collected from a wide range of biomes in North and South America, emphasizing the dominance of pH in structuring bacterial communities. The apparent direct influence of pH on bacterial community composition is probably due to the narrow pH ranges for optimal growth of bacteria. Fungal community composition was less strongly affected by pH, which is consistent with pure culture studies, demonstrating that fungi generally exhibit wider pH ranges for optimal growth.

  1. An examination of the biodiversity-ecosystem function relationship in arable soil microbial communities

    DEFF Research Database (Denmark)

    Griffiths, B.S.; Ritz, Karl; Wheatley, R.

    2001-01-01

    Microbial communities differing in biodiversity were established by inoculating sterile agricultural soil with serially diluted soil suspensions prepared from the parent soil. Three replicate communities of each dilution were allowed to establish an equivalent microbial biomass by incubation for 9...... relates to the numbers and proportions of different microbial species. Biodiversity decreased by ca. 15, 40 and 60% at each successive dilution step. There was no consistent effect of biodiversity on a range of soil processes measured (incorporation of thymidine and leucine, potential nitrification......, nitrate accumulation, respiratory growth response, community level physiological profile and decomposition). Neither was there a direct effect of biodiversity on the variability of the processes, nor on the stability of decomposition when the soils were perturbed by heat or copper. The biodiversity of...

  2. Biodiversity of soil biota and plants in abandoned arable fields and grasslands under restoration management

    NARCIS (Netherlands)

    Brussaard, L.; Bakker, J.P.; Olff, H.

    1996-01-01

    The currently widespread abandoning of agricultural land use in Western Europe offers new opportunities for ecological restoration and nature conservation. This is illustrated for abandoned arable fields and for permanent grasslands cut for hay after the cessation of fertilizer application. Although

  3. Structural properties of dissolved organic carbon in deep horizons of an arable soil.

    Science.gov (United States)

    Lavaud, A.; Croué, Jp; Berwick, L.; Steffens, M.; Chabbi, A.

    2010-05-01

    The objective of this work is to quantity the DOC that percolates in deep horizons of an arable soil, and to characterize the structural properties of the main fractions. The study was conducted on the long term observatory for environmental research- biogeochemical cycles and biodiversity Lusignan site-France. DOC collected using lysimeter plates inserted to a depth of 105 cm was fractionated into 3 fractions using the two column array of XAD-8 and XAD-4 resins. The HPO (hydrophobic) fraction (i.e. humic substances) isolated from the XAD-8 resin, the TPH (Transphilic) fraction from the XAD-4 resin and the HPI (hydrophilic) fraction which corresponds to the DOC that does not adsorbed onto the two resins under the acid condition used (pH 2). DOM adsorbed onto the resins is recovered with a 75%/25% acetonitrile/water mixture and lyophilized. The hydrophilic fraction is purified according the protocol proposed by Aiken and Leenheer (1993). The isolated fractions were subjected to several characterization tools: UV/Vis, fluorescence EEM, HPSEC/UV/DOC, 13C NMR, 14C dating, FT-IR, pyrolysis, thermochemolysis and MSSV GC/MS. The DOC content ranged from 1 to 2.5 mg / L between winter and the middle of spring and then to 4-5 mg / L in summer time. For all isolated fractions HPSEC analyses indicated the predominance of low molecular structures with a low aromatic character. Fluorescence EEM confirmed the non-humic character of the DOM. 13C-NMR spectra showed that the aromatic character decreased from HPO to TPH, and HPI character. Molecular size follows the same trend. HPI DOM was found to be strongly enriched in carboxyl groups. The 14C concentration of the HPO fraction corresponds to an apparent calibrated age around AD 1500. For the same fraction isolated from the 0 - 30 cm horizon, the measured 14C concentration 131.9 pMC corresponds to that in the atmosphere around AD 1978. Significant input of terpenoid derived organic matter was confirmed in the HPO fraction of DOC

  4. Application of δ13C and δ15N isotopic signatures of organic matter fractions sequentially separated from adjacent arable and forest soils to identify carbon stabilization mechanisms

    Directory of Open Access Journals (Sweden)

    M. Sommer

    2011-03-01

    Full Text Available Identifying the chemical mechanisms behind soil carbon bound in organo-mineral complexes is necessary to determine the degree to which soil organic carbon is stabilized belowground. We used the δ13C and δ15N isotopic signatures from two organic matter (OM fractions from soil to identify the likely binding mechanisms involved. We used OM fractions hypothesized to contain carbon stabilized through organo-mineral complexes: (1 OM separated chemically with sodium pyrophosphate (OM(PY and (2 OM stabilized in microstructures found in the chemical extraction residue (OM(ER. Furthermore, because the OM fractions were separated from five different soils with paired forest and arable land use histories, we could address the impact of land use change on carbon binding and processing mechanisms within these soils. We used partial least squares regression to analyze patterns in the isotopic signature of OM with established proxies of different binding mechanisms. Parsing soil OM into different fractions is a systematic method of dissection, however, we are primarily interested in how OM is bound in soil as a whole, requiring a means of re-assembly. Thus, we implemented the recent zonal framework described by Kleber et al. (2007 to relate our findings to undisturbed soil. The δ15N signature of OM fractions served as a reliable indicator for microbial processed carbon in both arable and forest land use types. The δ13C signature of OM fractions in arable sites did not correlate well with proxies of soil mineral properties while a consistent pattern of enrichment was seen in the δ13C of OM fractions in the forest sites. We found a significant difference in δ13C of pooled OM fractions between the forest and arable land use type although it was relatively small (<1‰. We found different binding mechanisms predominate in each land use type. The isotopic signatures of OM fractions from arable soils were highly related to the clay and silt size particles

  5. Soil types will alter the response of arable agroecosystems to future rainfall patterns

    Science.gov (United States)

    Zaller, J. G.; Schwarz, T.; Hall, R.; Ziss, E.; von Hohberg und Buchwald, C.; Hösch, J.; Baumgarten, A.

    2012-04-01

    Regional climate change scenarios for eastern Austria (pannonian region) predict fewer but heavier rains during the vegetation period without substantial changes in the total annual amount of rainfall. While many studies investigated the effects of rainfall patterns on ecosystem properties, very little is known on how different soil types might alter ecosystem responses. In order to test this, we conducted an experiment at the AGES lysimeter station using 18 3 m2 lysimeters where we simultaneously manipulated rainfall patterns according to regional climate scenarios (current vs. prognosticated rain) on the three main soil types of the region (sandy calcaric phaeozem, gleyic phaeozem and calcic chernozem). Lysimeters were cultivated according to good farming practice using crop varieties and crop rotations typically for the region. Here, we present results of the response of field peas (Pisum sativum) on important agricultural parameters. Lysimeters under progn. rain showed lower crop cover than under curr. rain while soil types had no effect. Total aboveground biomass production (comprising crops plus weeds) was significantly lower under progn. rain; sandy calcaric phaeozem showed the lowest plant biomass. Pea yields under progn. rain were substantially lower than under curr. rain; again, yields under sandy soils were lower than under the other two soil types. Root growth was significantly higher in progn. rain than in curr. rain; there was a trend towards less root growth in the gleyic soils. Mycorrhization of roots was not influenced by soil types, however under progn. rain colonization rates were lower than under curr. rain. Weed establishment and growth was increased under progn. rain in gleyic soils but decreased in the other soil types. Weed biomass was not affected by rainfall, however sandy soils had less weed biomass than the other soil types. Abundance of the insect pest pea moth (Cydia nigricana) was almost twice as high under progn. rain than under curr

  6. Sensitive indicators of side-effects of pesticides on the epigeal fauna of arable land.

    OpenAIRE

    1990-01-01

    The main objective of the present study was to evaluate the possible impact of pesticides on epigeal arthropods in arable land. It was also envisaged to develop a predictive model for possible undesirable effects of pesticides on the epigeal arthropod fauna using an indicator species from the field. The strategy was the following. In the field, species were identified that were (1) sensitive to a number of pesticides, (2) abundant, (3) regular in time and space and (4) easy to sample and iden...

  7. Combining a coupled FTIR-EGA system and in situ DRIFTS for studying soil organic matter in arable soils

    Directory of Open Access Journals (Sweden)

    M. S. Demyan

    2013-05-01

    Full Text Available An optimized spectroscopic method combining quantitative evolved gas analysis via Fourier transform infrared spectroscopy (FTIR-EGA in combination with a qualitative in situ thermal reaction monitoring via diffuse reflectance Fourier transform infrared spectroscopy (in situT DRIFTS is being proposed to rapidly characterize soil organic matter (SOM to study its dynamics and stability. A thermal reaction chamber coupled with an infrared gas cell was used to study the pattern of thermal evolution of carbon dioxide (CO2 in order to relate evolved gas (i.e., CO2 to different qualities of SOM. Soil samples were taken from three different arable sites in Germany: (i the Static Fertilization Experiment, Bad Lauchstädt (Chernozem, from treatments of farmyard manure (FYM, mineral fertilizer (NPK, their combination (FYM + NPK and control without fertilizer inputs; (ii Kraichgau; and (iii Swabian Alb (Cambisols areas, Southwest Germany. The two latter soils were further fractionated into particulate organic matter (POM, sand and stable aggregates (Sa + A, silt and clay (Si + C, and NaOCl oxidized Si + C (rSOC to gain OM of different inferred stabilities; respiration was measured from fresh soil samples incubated at 20 °C and 50% water holding capacity for 490 days. A variable long path length gas cell was used to record the mid-infrared absorbance intensity of CO2 (2400 to 2200 cm−1 being evolved during soil heating from 25 to 700 °C with a heating rate of 68 °C min−1 and holding time of 10 min at 700 °C. Separately, the heating chamber was placed in a diffuse reflectance chamber (DRIFTS for measuring the mid-infrared absorbance of the soil sample during heating. Thermal stability of the bulk soils and fractions was measured via the temperature of maximum CO2 evolution (CO2max. Results indicated that the FYM + NPK and FYM treatments of the Chernozem soils had a lower CO2max as compared to both NPK and CON treatments. On average, CO2max of the

  8. The Community Abundance and Diversity of Arable Soil Insect Community Following Different Fertilizer Treatments in Xinjiang,China

    Institute of Scientific and Technical Information of China (English)

    LIN Ying-hua; LIU Hua; ZHANG Shu-qing; ZHANG Fu-dao

    2008-01-01

    The soil insect community was studied in grey desert soil district in September 2004.90 soil samples and 100 pitfalls were collected from 10 treatments,i.e.,abandonment(Aband.),CK,N,NP,NK,PK,NPK,MNPK(fertilizer N:organic N=3:7),1.5MNPK,and SNPK.4 915 soil insects(128 unknown),as individuals belonging to 9 orders and 33 families,were obtained by pitfall traps and modified Tullgren methods.The results showed that,based on the number of individuals and groups,the macro fauna in total reached their peaks in abandonment,whereas meso and micro fauna in N and PK,respectively.Of the 10 treatments,the most dominant of soil insect composition was in MNPK and most evenness was N.The result by Kruskal-Wallis test indicated that the distribution of the arable soil insect was significantly impacted by different fertilizer treatments(X0.05(9)= 23.38,P <0.005),and soil insect group of the abandonment was significantly different from that of other fertilizer treatments.The soil insect community was divided into five groups by non-metricMDS analysis:(1)NPK,MNPK,1.5MNPK,CK,(2)NP and PK,(3)NK and N,(4)SNPK,and(5)abandonment,which indicated that distribution of soil insect was related to the character of the fertilizer.In the principal component analysis,two factors explained 98.51% of the total variation among the 10 treatments,and the factor one explained that N and SNPK positively affected soil insect community,whereas factor two explained that 1.5MNPK positively affected soil insect community,which showed that the diversified fertilizer did not evenly affect the soil insect community.

  9. Effect of rural-urban migrants’ remittances on arable crop production in Delta State, Nigeria

    Directory of Open Access Journals (Sweden)

    Ofuoku Albert U.

    2015-01-01

    Full Text Available This study was conducted in Delta State, Nigeria, to investigate the effect of rural-urban remittances on arable crop production. Twenty percent (20% of the registered arable crop farmers in Delta State were selected to arrive at 131 respondents for the study. Questionnaire and structured interview schedule were used to collect data from the respondents. Descriptive and inferential statistics and contingency tables were used to treat the collected data. It was discovered that most (69.5% of rural-urban migrants were in the 11-30 age bracket. The remittances from rural farm households were far higher than the remittances from rural-urban migrants. The little remittances from the rural-urban migrants were added to the funds of the rural farm household, farm labour and inputs. The remittances from rural-urban migrants did not make any meaningful contribution to arable crop production. It was recommended that governments should make the rural areas attractive to young school learners/graduates, embark on enlightenment programme to expose the youths to agriculture related self-employment opportunities in the rural areas; and create enabling environment for the youths to operate as self-employed individuals in the rural areas.

  10. Impact of manure-related DOM on sulfonamide transport in arable soils

    Science.gov (United States)

    Zhou, Dan; Thiele-Bruhn, Sören; Arenz-Leufen, Martina Gesine; Jacques, Diederik; Lichtner, Peter; Engelhardt, Irina

    2016-09-01

    Field application of livestock manure introduces colloids and veterinary antibiotics, e.g. sulfonamides (SAs), into farmland. The presence of manure colloids may potentially intensify the SAs-pollution to soils and groundwater by colloid-facilitated transport. Transport of three SAs, sulfadiazine (SDZ), sulfamethoxypyridazine (SMPD), and sulfamoxole (SMOX), was investigated in saturated soil columns with and without manure colloids from sows and farrows, weaners, and fattening pigs. Experimental results showed that colloid-facilitated transport of SMOX was significant in the presence of manure colloids from fattening pigs with low C/N ratio, high SUVA280 nm and protein C, while manure colloids from sows and farrows and weaners had little effect on SMOX transport. In contrast, only retardation was observed for SDZ and SMPD when manure colloids were present. Breakthrough curves (BTCs) of colloids and SAs were replicated well by a newly developed numerical model that considers colloid-filtration theory, competitive kinetic sorption, and co-transport processes. Model results demonstrate that mobile colloids act as carriers for SMOX, while immobile colloids block SMOX from sorbing onto the soil. The low affinity of SMOX to sorb on immobile colloids prevents aggregation and also promotes SMOX's colloid-facilitated transport. Conversely, the high affinity of SDZ and SMPD to sorb on all types of immobile colloids retarded their transport. Thus, manure properties play a fundamental role in increasing the leaching risk of hydrophobic sulfonamides.

  11. Net sulfur mineralization potential in Swedish arable soils in relation to long-term treatment history and soil properties

    DEFF Research Database (Denmark)

    Boye, Kristin; Nilsson, S Ingvar; Eriksen, Jørgen

    2009-01-01

    The long-term treatment effect (since 1957-1966) of farmyard manure (FYM) application compared with crop residue incorporation was investigated in five soils (sandy loam to silty clay) with regards to the net sulfur (S) mineralization potential. An open incubation technique was used to determine...... accumulated net S mineralization (SAccMin) and a number of soil physical and chemical properties were determined. Treatments and soil differences in SAccMin, as well as correlations with soil variables, were tested with single and multivariate analyses. Long-term FYM application resulted in a significantly (p...... = 0.012) higher net S mineralization potential, although total amounts of C, N, and S were not significantly (p mineralization differed significantly (p 

  12. Physical protection of mineralizable C in aggregates from long-term pasture and arable soil

    NARCIS (Netherlands)

    Pulleman, M.M.; Marinissen, J.C.Y.

    2004-01-01

    Depending on agricultural management, soil aggregation can provide physical protection of organic matter against rapid decomposition. Within a given soil series, farm management affects the quality and quantity of organic inputs, soil disturbance and biological activity, and thereby the processes of

  13. Prediction of the P-leaching potential of arable soils in areas with high livestock densities

    Institute of Scientific and Technical Information of China (English)

    WERNER Wilfried; TRIMBORN Manfred; PIHL Uwe

    2006-01-01

    Due to long-term positive P-balances many surface soils in areas with high livestock density in Germany are oversupplied with available P, creating a potential for vertical P losses by leaching. In extensive studies to characterize the endangering of ground water to P pollution by chemical soil parameters it is shown that the available P content and the P concentration of the soil solution in the deeper soil layers, as indicators of the P-leaching potential, cannot be satisfactorily predicted from the available P content of the topsoils. The P equilibrium concentration in the soil solution directly above ground water table or the pipe drainage system highly depends on the relative saturation of the P-sorption capacity in this layer. A saturation index of <20% normally corresponds with Pequilibrium concentrations of <0.2 mg P/L. Phytoremediation may reduce the P leaching potential of P-enriched soils only over a very long period.

  14. Long-term changes in organic matter of woodland soils cleared for arable cropping in Zimbabwe

    NARCIS (Netherlands)

    Zingore, S.; Manyame, C.; Nyamugafata, P.; Giller, K.E.

    2005-01-01

    Subsistence farmers in Africa depend largely on the soil organic matter to sustain crop productivity. Long-term changes in soil organic carbon and nitrogen were measured after woodland clearance for smallholder subsistence farming or for commercial farming. The contents of organic carbon and nitroge

  15. Speciation and distribution of P associated with Fe and Al oxides in aggregate-sized fraction of an arable soil

    Science.gov (United States)

    Jiang, X.; Bol, R.; Willbold, S.; Vereecken, H.; Klumpp, E.

    2015-11-01

    To maximize crop productivity fertilizer P is generally applied to arable soils, a significant proportion of which becomes stabilized by mineral components and in part subsequently becomes unavailable to plants. However, little is known about the relative contributions of the different organic and inorganic P bound to Fe/Al oxides in the smaller soil particles. Alkaline (NaOH-Na2EDTA) extraction with solution 31P-nuclear magnetic resonance (31P-NMR) spectroscopy is considered a reliable method for extracting and quantifying organic P and (some) inorganic P. However, any so-called residual P after the alkaline extraction has remained unidentified. Therefore, in the present study, the amorphous (a) and crystalline (c) Fe/Al oxide minerals and related P in soil aggregate-sized fractions (> 20, 2-20, 0.45-2 and citrate-bicarbonate (DCB, both a- and c-Fe/Al oxides). These soil aggregate-sized fractions with and without the oxalate and DCB pre-treatments were then sequentially extracted by alkaline extraction prior to solution 31P-NMR spectroscopy. This was done to quantify the P associated with a- and c-Fe/Al oxides in both alkaline extraction and the residual P of different soil aggregate-sized fractions. The results showed that overall P contents increased with decreasing size of the soil aggregate-sized fractions. However, the relative distribution and speciation of varying P forms were found to be independent of soil aggregate-size. The majority of alkaline-extractable P was in the a-Fe/Al oxide fraction (42-47 % of total P), most of which was ortho-phosphate (36-41 % of total P). Furthermore, still significant amounts of particularly monoester P were bound to these oxides. Intriguingly, however, Fe/Al oxides were not the main bonding sites for pyrophosphate. Residual P contained similar amounts of total P associated with both a- (11-15 % of total P) and c-Fe oxides (7-13 % of total P) in various aggregate-sized fractions, suggesting that it was likely occluded

  16. Emissions of nitrous oxide from arable organic and conventional cropping systems on two soil types

    DEFF Research Database (Denmark)

    Chirinda, N.; Carter, Mette Sustmann; Albert, Kristian Rost

    2010-01-01

    . The main objective of this study was to compare nitrous oxide (N2O) emissions from soil under winter wheat (Triticum aestivum L.) within three organic and one conventional cropping system that differed in type of fertilizer, presence of catch crops and proportion of N2-fixing crops. The study......Conventional cropping systems rely on targeted short-term fertility management, whereas organic systems depend, in part, on long-term increase in soil fertility as determined by crop rotation and management. Such differences influence soil nitrogen (N) cycling and availability through the year...... was replicated in two identical long-term crop rotation experiments on sandy loam soils under different climatic conditions in Denmark (Flakkebjerg—eastern Denmark and Foulum—western Denmark). The conventional rotation received 165–170 kg N ha−1 in the form of NH4NO3, while the organic rotations received 100...

  17. Carbon dynamics with prolonged arable cropping soils in the Dano district (Southwest Burkina-Faso)

    Science.gov (United States)

    Hounkpatin, Ozias; Welp, Gerhard; Amelung, Wulf

    2016-04-01

    The conversion of natural ecosystems into agricultural land affects the atmospheric CO2 concentration whose increase contributes to global warming. In the low activity clay soils (LAC) of the tropics, farming is largely dependent on the level of soil organic carbon (SOC) for sustainable crop production. In this study, we investigated the changes in SOC in Plinthosols along a cultivation chronosequence in the Dano district (Southwest Burkina-Faso). The chronosequence consisted of undisturbed savannah (Y0) and 11 agricultural fields with short and long histories of cultivation ranging from 1-year-old cropland to 29-year-old cropland (Y29). About 14 soil profiles were described and soil composite samples were taken per horizon. Particulate organic matter (POM) was fractionated according to particle size: fraction 2000 - 250 μm (POM1), 250 μm - 53 μm (POM2), 53 μm - 20 μm (POM3), and POM1 > POM3 > POM2 carbon no matter the duration of land use. However, SOC losses occurred not only in the labile C pools but also in the stabile nonPOM fraction with increasing duration of agricultural land use. Compared to the initial carbon content in the Y0 field, about 59% of carbon content loss occurred in the POM1 (> 250 μm), 53% in the POM2 (250 - 53 μm), 52 % in the POM3 (53 - 20 μm) and 47% in the nonPOM fraction (organo-mineral associations are a key parameter for carbon stabilization, its depletion with increasing cultivation intensity suggests that the destruction of aggregates in these fields increased the vulnerability of this pool to microbial degradation. Keywords: Soil organic carbon, Plinthosols, low activity clay soil, POM

  18. Relationship Between Soil Microbial Biomass C and N and Mineralizable Nitrogen in Some Arable Soils on Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHOUJIANBIN; LISHENGXIU

    1998-01-01

    The chloroform fumigation-incubation metho was used to measur the soil microbial biomass C(SMBC) and N(SMBN) in 16 loessial soils sampled from Ansai,Yongshou and Yangling in Shaanxi Province.The SMBC ontents in the soils ranged from 75.9 to 301.0μg C g-1 with an average of 206.μgCg-1,accounting for 1.36%-6.24% of the total soil organic C with an average of 3.07%,and the SMBN contents from 0.51 to 68.40μg Ng-1 with an average of 29.4μg N g-1,accounting for 0.20%-5.65% of the total N in the soils with an average of 3.36%.A close relationship was found between SMBC and SMBN,and they both were positively correlated with total organic C, total N,NaOH hydrolizable N and mineralizable N.These results confirmed tha soil microbial biomass had a comparative role in nutrient cycles of soils.

  19. Analysis of Multi-Scale Changes in Arable Land and Scale Effects of the Driving Factors in the Loess Areas in Northern Shaanxi, China

    Directory of Open Access Journals (Sweden)

    Lina Zhong

    2014-04-01

    Full Text Available In this study, statistical data on the national economic and social development, including the year-end actual area of arable land, the crop yield per unit area and 10 factors, were obtained for the period between 1980 and 2010 and used to analyze the factors driving changes in the arable land of the Loess Plateau in northern Shaanxi, China. The following areas of arable land, which represent different spatial scales, were investigated: the Baota District, the city of Yan’an, and the Northern Shaanxi region. The scale effects of the factors driving the changes to the arable land were analyzed using a canonical correlation analysis and a principal component analysis. Because it was difficult to quantify the impact of the national government policies on the arable land changes, the contributions of the national government policies to the changes in arable land were analyzed qualitatively. The primary conclusions of the study were as follows: between 1980 and 2010, the arable land area decreased. The trends of the year-end actual arable land proportion of the total area in the northern Shaanxi region and Yan’an City were broadly consistent, whereas the proportion in the Baota District had no obvious similarity with the northern Shaanxi region and Yan’an City. Remarkably different factors were shown to influence the changes in the arable land at different scales. Environmental factors exerted a greater effect for smaller scale arable land areas (the Baota District. The effect of socio-economic development was a major driving factor for the changes in the arable land area at the city and regional scales. At smaller scales, population change, urbanization and socio-economic development affected the crop yield per unit area either directly or indirectly. Socio-economic development and the modernization of agricultural technology had a greater effect on the crop yield per unit area at the large-scales. Furthermore, the qualitative analysis

  20. Combining a coupled FTIR-EGA system and in situ DRIFTS for studying soil organic matter in arable soils

    Directory of Open Access Journals (Sweden)

    M. S. Demyan

    2012-11-01

    Full Text Available An optimized spectroscopic method combining quantitative evolved gas analysis via Fourier transform infrared spectroscopy (FTIR-EGA and qualitative in situ thermal reaction monitoring via diffuse reflectance Fourier transform infrared spectroscopy (in situT DRIFTS is being proposed to rapidly characterize soil organic matter (SOM to study its dynamics and stability. A thermal reaction chamber coupled with an infrared gas cell was used to study the pattern of thermal evolution of carbon dioxide (CO2 in order to relate evolved gas to different qualities of soil organic matter (SOM. Soil samples were from three different sites, i.e. (i the Static Fertilization Experiment, Bad Lauchstädt (Chernozem from treatments of farmyard manure (FYM, mineral fertilizer (NPK, combination (FYM + NPK and control without fertilizer inputs, and cropped soils from the (ii Kraichgau and (iii Swabian Alb (Cambisols areas, Southwest Germany. Soils from Kraichgau and Swabian Alb were further fractionated into particulate organic matter (POM, sand and stable aggregates (Sa + A, silt and clay (Si + C, and NaOCl oxidized Si + C (rSOC to gain OM of different inferred stabilities. Fresh soil samples from the Kraichgau and Swabian Alb were incubated at 20 °C and 50% water holding capacity for 490 days in order to measure soil respiration under controlled conditions. A variable long path length gas cell was used to record the mid-infrared absorbance intensity of carbon dioxide (2400 to 2200 cm−1 being evolved during soil heating from 25 to 700 °C with a heating rate of 68 °C min−1 during an initial ramping time of 10 min and holding time of 10 min. Separately the heating chamber was placed in a diffuse reflectance chamber (DRIFTS for measuring the mid-infrared absorption of the soil sample during heating. Thermal stability of the bulk soils and fractions was measured via the temperature of maximum CO2 (2400

  1. Analysis, fate and effects of the antibiotic sulfadiazine in soil.

    NARCIS (Netherlands)

    Schauss, K.; Focks, A.; Heuer, H.; Kotzerke, A.; Schmitt, H.; Thiele-Bruhn, S.; Smalla, K.; Wilke, B.M.; Matthies, M.

    2009-01-01

    This review summarizes current knowledge about the interplay between fate and effects of the antibiotic sulfadiazine in soil ecosystems. In applying manure from antibiotic-treated animals to arable soils, sulfadiazine can reach the environment, but fate and transformation processes and the consequen

  2. Application of δ13C and δ15N isotopic signatures of organic matter fractions sequentially separated from adjacent arable and forest soils to identify carbon stabilization mechanisms

    Directory of Open Access Journals (Sweden)

    M. Sommer

    2011-10-01

    Full Text Available Identifying the chemical mechanisms behind soil carbon bound in organo-mineral complexes is necessary to determine the degree to which soil organic carbon is stabilized belowground. Analysis of δ13C and δ15N isotopic signatures of stabilized OM fractions along with soil mineral characteristics may yield important information about OM-mineral associations and their processing history. We anlayzed the δ13C and δ15N isotopic signatures from two organic matter (OM fractions along with soil mineral proxies to identify the likely binding mechanisms involved. We analyzed OM fractions hypothesized to contain carbon stabilized through organo-mineral complexes: (1 OM separated chemically with sodium pyrophosphate (OM(PY and (2 OM occluded in micro-structures found in the chemical extraction residue (OM(ER. Because the OM fractions were separated from five different soils with paired forest and arable land use histories, we could address the impact of land use change on carbon binding and processing mechanisms. We used partial least squares regression to analyze patterns in the isotopic signature of OM with established mineral and chemical proxies indicative for certain binding mechanisms. We found different mechanisms predominate in each land use type. For arable soils, the formation of OM(PY-Ca-mineral associations was identified as an important OM binding mechanism. Therefore, we hypothesize an increased stabilization of microbial processed OM(PY through Ca2+ interactions. In general, we found the forest soils to contain on average 10% more stabilized carbon relative to total carbon stocks, than the agricultural counter part. In forest soils, we found a positive relationship between isotopic signatures of OM(PY and the ratio of soil organic carbon content to soil surface area (SOC/SSA. This indicates that the OM(PY fractions of forest soils represent layers of slower exchange not directly attached to mineral surfaces. From the isotopic composition

  3. Plant litter decomposition and carbon sequestration for arable soils. Final report of works. April 2005; Biodegradation des litieres et sequestration du carbone dans les ecosystemes cultives et perennes. Rapport final des travaux Avril 2005

    Energy Technology Data Exchange (ETDEWEB)

    Recous, S.; Barrois, F.; Coppens, F.; Garnier, P.; Grehan, E. [Institut National de Recherches Agronomiques (INRA), Unite d' Agronomie Laon-Reims-Mons (France); Balesdent, J. [CNRS-CEA-Univ.de la Mediterranee, UMR 6191, Lab. d' Ecologie Microbienne de la Rhizosphere, 13 - Saint Paul lez Durance (France); Dambrine, E.; Zeller, B. [Institut National de Recherches Agronomiques (INRA), Unite Biogeochimie des Ecosystemes Forestiers, 54 - Nancy (France); Loiseau, P.; Personeni, E. [Institut National de Recherches Agronomiques (INRA), Unite d' Agronomie, 63 - Clermont-Ferrand (France)

    2002-07-01

    The general objective of this project was to contribute to the evaluation of land use and management impacts on C sequestration and nitrogen dynamics in soils. The land used through the presence/absence of crops and their species, and the land management through tillage, localisation of crop residues, fertilizer applications,... are important factors that affect the dynamics of organic matters in soils, particularly the mineralization of C and N, the losses to the atmosphere and hydrosphere, the retention of carbon into the soil. This project was conducted by four research groups, three of them having expertise in nutrient cycling of three major agro-ecosystems (arable crops, grasslands, forests) and the fourth one having expertise in modelling long term effects of land use on C storage into the soils. Within this common project one major objective was to better understand the fate of plant litter entering the soil either as above litter or as root litter. The focus was put on two factors that particularly affect decomposition: the initial biochemical quality of plant litter, and the location of the decomposing litter. One innovative aspect of the project was the use of stable isotope as {sup 13}C for carbon, based on the use of enriched or depleted {sup 13}C material, the only option to assess the dynamics of 'new' C entering the soil on the short term, in order to reveal the effects of decomposition factors. Another aspect was the simultaneous study of C and N. The project consisted in experiments relevant for each agro-ecosystem, in forest, grassland and arable soils for which interactions between residue quality and nitrogen availability on the one hand, residue quality and location on the other hand, was investigated. A common experiment was set up to investigate the potential degradability of the various residue used (beech leaf rape straw, young rye, Lolium and dactylic roots) in a their original soils and in a single soil was assessed. Based on

  4. Significant alteration of soil bacterial communities and organic carbon decomposition by different long-term fertilization management conditions of extremely low-productivity arable soil in South China.

    Science.gov (United States)

    Xun, Weibing; Zhao, Jun; Xue, Chao; Zhang, Guishan; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu

    2016-06-01

    Different fertilization managements of red soil, a kind of Ferralic Cambisol, strongly affected the soil properties and associated microbial communities. The association of the soil microbial community and functionality with long-term fertilization management in the unique low-productivity red soil ecosystem is important for both soil microbial ecology and agricultural production. Here, 454 pyrosequencing analysis of 16S recombinant ribonucleic acid genes and GeoChip4-NimbleGen-based functional gene analysis were used to study the soil bacterial community composition and functional genes involved in soil organic carbon degradation. Long-term nitrogen-containing chemical fertilization-induced soil acidification and fertility decline and significantly altered the soil bacterial community, whereas long-term organic fertilization and fallow management improved the soil quality and maintained the bacterial diversity. Short-term quicklime remediation of the acidified soils did not change the bacterial communities. Organic fertilization and fallow management supported eutrophic ecosystems, in which copiotrophic taxa increased in relative abundance and have a higher intensity of labile-C-degrading genes. However, long-term nitrogen-containing chemical fertilization treatments supported oligotrophic ecosystems, in which oligotrophic taxa increased in relative abundance and have a higher intensity of recalcitrant-C-degrading genes but a lower intensity of labile-C-degrading genes. Quicklime application increased the relative abundance of copiotrophic taxa and crop production, although these effects were utterly inadequate. This study provides insights into the interaction of soil bacterial communities, soil functionality and long-term fertilization management in the red soil ecosystem; these insights are important for improving the fertility of unique low-productivity red soil.

  5. Dynamics of mineral N, water-soluble carbon and potential nitrification in band-steamed arable soil

    DEFF Research Database (Denmark)

    Elsgaard, Lars

    2010-01-01

    mechanically with the band-steamer. In the steamed soil, ammonium concentrations increased from 1.1 to 20.3 μg NH4+-N g-1 dry weight during 28 days. This coincided with an immediate and persistent inhibition of potential nitrification (33-61% inhibition during 90 days). Assays of the temperature response...... of potential nitrification confirmed the temperature sensitivity and showed an optimum temperature of 27.1°C and a temperature coefficient (Q 10) of 1.9. The effects of band-steaming on concentrations of nitrate and water-soluble carbon were divergent and stimulatory, respectively, but generally...

  6. Linking an economic model for European agriculture with a mechanistic model to estimate nitrogen and carbon losses from arable soils in Europe

    Directory of Open Access Journals (Sweden)

    A. Leip

    2008-01-01

    Full Text Available A comprehensive assessment of policy impact on greenhouse gas (GHG emissions from agricultural soils requires careful consideration of both socio-economic aspects and the environmental heterogeneity of the landscape. We developed a modelling framework that links the large-scale economic model for agriculture CAPRI (Common Agricultural Policy Regional Impact assessment with the biogeochemistry model DNDC (DeNitrification DeComposition to simulate GHG fluxes, carbon stock changes and the nitrogen budget of agricultural soils in Europe. The framework allows the ex-ante simulation of agricultural or agri-environmental policy impacts on a wide range of environmental problems such as climate change (GHG emissions, air pollution and groundwater pollution. Those environmental impacts can be analyzed in the context of economic and social indicators as calculated by the economic model. The methodology consists of four steps: (i definition of appropriate calculation units that can be considered as homogeneous in terms of economic behaviour and environmental response; (ii downscaling of regional agricultural statistics and farm management information from a CAPRI simulation run into the spatial calculation units; (iii designing environmental model scenarios and model runs; and finally (iv aggregating results for interpretation. We show the first results of the nitrogen budget in croplands in fourteen countries of the European Union and discuss possibilities to improve the detailed assessment of nitrogen and carbon fluxes from European arable soils.

  7. Effects of organic versus conventional management on chemical and biological parameters in agricultural soils

    NARCIS (Netherlands)

    Diepeningen, van A.D.; Vos, de O.J.; Korthals, G.W.; Bruggen, van A.H.C.

    2006-01-01

    A comparative study of organic and conventional arable farming systems was conducted in The Netherlands to determine the effect of management practices on chemical and biological soil properties and soil health. Soils from thirteen accredited organic farms and conventionally managed neighboring farm

  8. Heavy metals and health risk assessment of arable soils and food crops around Pb-Zn mining localities in Enyigba, southeastern Nigeria

    Science.gov (United States)

    Obiora, Smart C.; Chukwu, Anthony; Davies, Theophilus C.

    2016-04-01

    This study determined the heavy metals concentration in arable soils and associated food crops around the Pb-Zn mines in Enyigba, Nigeria, and metal transfer factors were calculated. Air-dried samples of the soils and food crops were analyzed for 8 known nutritional and toxic heavy metals by Inductively Coupled Plasma - Mass Spectrometer (ICP-MS) method. Eighty seven percent of all the 20 sampled soils contain Pb in excess of the maximum allowable concentration (MAC) set by Canadian Environmental Quality Guideline (CCME) and European Union (EU) Standard, while Zn in thirty-one percent of the samples exceeded the CCME for MAC of 200 mg/kg. All the food crops, with the exception of yam tuber, contain Pb which exceeded the 0.43 mg/kg and 0.3 mg/kg MAC standards of EU and WHO/FAO respectively, with the leafy vegetables accumulating more Pb than the tubers. The metal transfer factors in the tubers and the leafy vegetables were in the order: Mo > Cu > Zn > Mn > As > Cd > Cr > Ni > Pb and Cd > Cu > Zn > Mn > Mo > As > Ni > Pb > Cr, respectively. Risk assessment studies revealed no health risk in surrounding populations for most of the heavy metals. However, Pb had a high health risk index (HRI) of 1.1 and 1.3, in adults and children, respectively for cassava tuber; Pb had HRI > 1 in lemon grass while Mn also had HRI > 1 in all the leafy vegetables for both adult and children. This high level of HRI for Pb and Mn is an indication that consumers of the food crops contaminated by these metals are at risk of health problems such as Alzheimers' disease and Manganism, associated with excessive intake of these metals. Further systematic monitoring of heavy metal fluxes in cultivable soils around the area of these mines is recommended.

  9. Soil properties, crop production and greenhouse gas emissions from organic and inorganic fertilizer-based arable cropping systems

    DEFF Research Database (Denmark)

    Chirinda, Ngonidzashe; Olesen, Jørgen Eivind; Porter, John Roy

    2010-01-01

    crops, respectively. Nevertheless, SOC levels in 2008 were similar across systems. The cumulative soil respiration for the period February to August 2008 ranged between 2 and 3 t CO2–C ha-1 and was correlated (r = 0.95) with average C inputs. In the organic cropping systems, pig slurry application......: total soil organic carbon (SOC), total N, microbial biomass N (MBN), potentially mineralizable N (PMN), and levels of potential ammonium oxidation (PAO) and denitrifying enzyme activity (DEA). In situ measurements of soil heterotrophic carbon dioxide (CO2) respiration and nitrous oxide emissions were...... and inclusion of catch crops generally increased soil respiration, PMN and PAO. At field capacity, relative gas diffusivity at 0–5 cm depth was >50% higher in the organic than the inorganic fertilizer-based system (P

  10. THE INFLUENCE OF MINIMUM TILLAGE SYSTEMS UPON THE SOIL PROPERTIES, YIELD AND ENERGY EFFICIENCY IN SOME ARABLE CROPS

    Directory of Open Access Journals (Sweden)

    Teodor RUSU

    2006-05-01

    Full Text Available The paper presents the influence of the conventional ploughing tillage technology in comparison with the minimum tillage, upon the soil properties, weed control, yield and energy efficiency in the case of maize (Zea mays L., soyabean (Glycine hispida L. and winter wheat (Triticum aestivum L. in a three years crop rotation. For all cultures within the crop rotation, the weed encroachment is maximum for the disc harrow and rotary harrow soil tillage, followed by the chisel and paraplow. The weed encroachment is minimum for the conventional ploughing tillage technology. The results of investigations showed that the yield is a conclusion soil tillage systems influence on soil properties, plant density assurance and on weed control.

  11. A method to assess ecosystem services developed from soil attributes with stakeholders and data of four arable farms

    NARCIS (Netherlands)

    Rutgers, M.; Wijnen, van H.J.; Schouten, A.J.; Mulder, C.; Kuiten, A.M.P.; Brussaard, L.; Breure, A.M.

    2012-01-01

    Ecosystem-service indicators and related accounting units are crucial for the development of decision frameworks for sustainable land management systems. With a management concept using ecosystem services, land-use expectations can be linked to quantifiable soil features in a defendable and transpar

  12. Modeling greenhouse gas emissions (CO2, N2O, CH4) from managed arable soils with a fully coupled hydrology-biogeochemical modeling system simulating water and nutrient transport and associated carbon and nitrogen cycling at catchment scale

    Science.gov (United States)

    Klatt, Steffen; Haas, Edwin; Kraus, David; Kiese, Ralf; Butterbach-Bahl, Klaus; Kraft, Philipp; Plesca, Ina; Breuer, Lutz; Zhu, Bo; Zhou, Minghua; Zhang, Wei; Zheng, Xunhua; Wlotzka, Martin; Heuveline, Vincent

    2014-05-01

    The use of mineral nitrogen fertilizer sustains the global food production and therefore the livelihood of human kind. The rise in world population will put pressure on the global agricultural system to increase its productivity leading most likely to an intensification of mineral nitrogen fertilizer use. The fate of excess nitrogen and its distribution within landscapes is manifold. Process knowledge on the site scale has rapidly grown in recent years and models have been developed to simulate carbon and nitrogen cycling in managed ecosystems on the site scale. Despite first regional studies, the carbon and nitrogen cycling on the landscape or catchment scale is not fully understood. In this study we present a newly developed modelling approach by coupling the fully distributed hydrology model CMF (catchment modelling framework) to the process based regional ecosystem model LandscapeDNDC for the investigation of hydrological processes and carbon and nitrogen transport and cycling, with a focus on nutrient displacement and resulting greenhouse gas emissions in a small catchment at the Yanting Agro-ecological Experimental Station of Purple Soil, Sichuan province, China. The catchment hosts cypress forests on the outer regions, arable fields on the sloping croplands cultivated with wheat-maize rotations and paddy rice fields in the lowland. The catchment consists of 300 polygons vertically stratified into 10 soil layers. Ecosystem states (soil water content and nutrients) and fluxes (evapotranspiration) are exchanged between the models at high temporal scales (hourly to daily) forming a 3-dimensional model application. The water flux and nutrients transport in the soil is modelled using a 3D Richards/Darcy approach for subsurface fluxes with a kinematic wave approach for surface water runoff and the evapotranspiration is based on Penman-Monteith. Biogeochemical processes are modelled by LandscapeDNDC, including soil microclimate, plant growth and biomass allocation

  13. Nitrate leaching from organic arable crop rotations is mostly determined by autumn field management

    DEFF Research Database (Denmark)

    Askegaard, M; Olesen, Jørgen E; Rasmussen, Ilse Ankjær;

    2011-01-01

    in the manured treatments the application rate was lower than crop demand. The results identify management of crop and soil during autumn as the main determinant of N leaching. Nitrate leaching was lowest for a catch crop soil cover during autumn and winter (avg. 20 kg N ha−1), a soil cover of weeds......Two main challenges facing organic arable farming are the supply of nitrogen (N) to the crop and the control of perennial weeds. Nitrate leaching from different organic arable crop rotations was investigated over three consecutive four-year crop rotations in a field experiment at three locations...... in Denmark (12 years in total). The experimental treatments were: (i) crop rotation, (ii) catch crop and (iii) animal manure. Nitrate leaching was estimated from measured soil nitrate concentration in ceramic suction cells and modelled drainage. There were significant effects on annual N leaching of location...

  14. International bioenergymarkets - the effects of biofuelpolicies on agriculture and arable area; Kansainvaelinen bioenergiakauppa. Biopolttoainetavoitteiden vaikutukset maatalouteen ja viljelyalan kaeyttoeoen

    Energy Technology Data Exchange (ETDEWEB)

    Rintamaeki, H.; Aro-Heinilae, E.

    2012-11-01

    is based on corn and the oil seed affects the prices of foods and weakens access of especially the world's poorest to the food market. Biofuels production has increased so direct as indirect changes into the use of the land. Direct changes refer to the introduction of the new land to the biofuels production. The indirect changes in the use of the land can be the result from biofuels production displacing services or commodities (food, feed, fiber products) on land currently in production. It is supposed the growth of the arable land in the different biofuel scenarios being 1-4 per cent at a global level compared with a situation without the production of biofuels. Growth pressure of arable land remain moderate, however effects to food prices with firs generation biofuels are high, which dilutes food security. This comes crucial when taken into account pressure that comes from population growth, as well as the fact that effects allocates the most towards the most poor which use prominent share of their income for staple foodstuff purchase. Development of second generation biofuels, which production is based on byproduct and wastes or biomass that is cultivated in marginal lands, is essential to meet political biofuel targets in sustainable manner. (orig.)

  15. Impacts of projected climate change on productivity and nitrogen leaching of crop rotations in arable and pig farming systems in Denmark

    DEFF Research Database (Denmark)

    Doltra, Jordi; Lægdsmand, Mette; Olesen, Jørgen E

    2014-01-01

    The effects of projected changes in climate and atmospheric CO2 concentration on productivity and nitrogen (N) leaching of characteristic arable and pig farming rotations in Denmark were investigated with the FASSET simulation model. The LARS weather generator was used to provide climatic data...... in Denmark, differing in soil and climate, and representative of the selected production systems. The CO2 effects were modelled using projected CO2 concentrations for the A1B emission scenario. Crop rotations were irrigated (sandy soil) and unirrigated (sandy loam soil), and all included systems...... rather than single crops for impact assessments. Potato and sugar beet in arable farming and grain maize in pig farming contributed most to the productivity increase in the future scenarios. The highest productivity was obtained in the arable system on the sandy loam soil, with an increase of 20...

  16. 典型农耕区棕壤水稳性团聚体及其有机碳特征%Characterization of Water Stable Aggregates and Organic Carbon in Typical Brown Arable Soil

    Institute of Scientific and Technical Information of China (English)

    任雅阁; 成杭新; 徐殿斗; 刘应汉; 刘飞; 欧阳宏; 刘志明; 马玲玲

    2013-01-01

    This paper was aimed at the distribution and composition of water stable aggregates together with organic carbons in brown soil in Shandong peninsula. The results showed that; The size distribution of water stable aggregates was as irregular "W" with two lower "shoulders". The microaggregates (< 250 μm) accounted for 51. 74% in arable soil and 51. 61% in uncultivated soil, respectively. The dispersion degree of soil particles was increased due to the cultivation disturbance and the smaller aggregates resisted the water erosion. The distribution of soil organic carbon(SOC) in soil predominately was constrained by the allocation of aggregates, which was increased with the decreasing of particle sizes. The average content of SOC in macroaggregates was 5. 98 g/kg in arable soil and 3. 48 g/kg in uncultivated soil, respectively. The content was 8. 05 g/kg for arable soil and 9. 11 g/kg for uncultivated soil in microaggregates, accounting for 55. 36% and 68. 58% of the total organic carbon content in soil, respectively. It was notable that the content of SOC in silt-clay microaggregates(<20 μm) was the highest(10. 97 g/kg and 11. 63 g/kg in arable and uncultivated soil, respectively), which could be regarded as the indicator for potential of SOC sequestration of brown soil in study areas. Fourier transform infrared spectroscopy (FTIR) resolve showed that organic carbon in microaggregates predominately consisted of stable aromatic and carbohydrate carbon.%对山东半岛棕壤区耕地和荒地土壤水稳性团聚体及其有机碳进行解析.结果表明:各级土壤团聚体质量比总体呈“两头低中间高”的不规则“W”形分布,耕地和荒地土壤微团聚体(<250μm)平均含量分别为51.74%和51.61%,耕种的扰动增加了土壤颗粒分散度,水流对大团聚体的破坏作用更大.有机碳分布受团聚体分配的制约,其含量随团聚体粒径减小而增加.耕地和荒地有机碳在大团聚体中平均含量分别为5

  17. Effect of Afforestation on Soil Properties and Mycorrhizal Formation

    Institute of Scientific and Technical Information of China (English)

    P. KAHLE; C. BAUM; B. BOELCKE

    2005-01-01

    A study was conducted on Cambisols in Northern Germany to analyze the effect of fast growing trees (Salix and Populus spp.) used in agroforestry on soil chemical and physical properties and also on endo- and ectomycorrhizal colonization measure the topsoil inventories at the very beginning and after six (GUL), seven (VIP) and ten (ROS) years of afforestation with fast growing trees. The effect on soil organic carbon, plant available nutrients, reaction, bulk density, porosity and water conditions was analyzed. Arable soils without tree coppice were used as controls. Additionally, the endoand ectomycorrhizal colonization of two Salix and two Populus clones were investigated at one site (GUL) in 2002. The amounts of organic carbon in the topsoil increased significantly (P<0.01) presumably induced by leaf and root litter and also by the lack of tillage. The soil bulk density significantly decreased and the porosity of the soil increased significantly (both P<0.01). The proportion of medium pores in the soil also rose significantly (P<0.05 and 0.01). Generally,afforestation of arable soils improved soil water retention. Ectomycorrhizas dominated the mycorrhizal formation of the Salix and Populus clones, with the accumulation of organic matter in the topsoil suspected of supporting the ectomycorrhizal formation. Thus, agroforestry with Salix and Populus spp. conspicuously affected chemical and additionally physical properties of the top layer of Cambisols within a period of six years.

  18. Crop residue management in arable cropping systems under a temperate climate. Part 2: Soil physical properties and crop production. A review

    Directory of Open Access Journals (Sweden)

    Hiel, MP.

    2016-01-01

    Full Text Available Introduction. Residues of previous crops provide a valuable amount of organic matter that can be used either to restore soil fertility or for external use. A better understanding of the impact of crop residue management on the soil-water-plant system is needed in order to manage agricultural land sustainably. This review focuses on soil physical aspects related to crop residue management, and specifically on the link between soil structure and hydraulic properties and its impact on crop production. Literature. Conservation practices, including crop residue retention and non-conventional tillage, can enhance soil health by improving aggregate stability. In this case, water infiltration is facilitated, resulting in an increase in plant water availability. Conservation practices, however, do not systematically lead to higher water availability for the plant. The influence of crop residue management on crop production is still unclear; in some cases, crop production is enhanced by residue retention, but in others crop residues can reduce crop yield. Conclusions. In this review we discuss the diverse and contrasting effects of crop residue management on soil physical properties and crop production under a temperate climate. The review highlights the importance of environmental factors such as soil type and local climatic conditions, highlighting the need to perform field studies on crop residue management and relate them to specific pedo-climatic contexts.

  19. Responses of bacterial communities in arable soils in a rice-wheat cropping system to different fertilizer regimes and sampling times.

    Science.gov (United States)

    Zhao, Jun; Ni, Tian; Li, Yong; Xiong, Wu; Ran, Wei; Shen, Biao; Shen, Qirong; Zhang, Ruifu

    2014-01-01

    Soil physicochemical properties, soil microbial biomass and bacterial community structures in a rice-wheat cropping system subjected to different fertilizer regimes were investigated in two seasons (June and October). All fertilizer regimes increased the soil microbial biomass carbon and nitrogen. Both fertilizer regime and time had a significant effect on soil physicochemical properties and bacterial community structure. The combined application of inorganic fertilizer and manure organic-inorganic fertilizer significantly enhanced the bacterial diversity in both seasons. The bacterial communities across all samples were dominated by Proteobacteria, Acidobacteria and Chloroflexi at the phylum level. Permutational multivariate analysis confirmed that both fertilizer treatment and season were significant factors in the variation of the composition of the bacterial community. Hierarchical cluster analysis based on Bray-Curtis distances further revealed that bacterial communities were separated primarily by season. The effect of fertilizer treatment is significant (P = 0.005) and accounts for 7.43% of the total variation in bacterial community. Soil nutrients (e.g., available K, total N, total P and organic matter) rather than pH showed significant correlation with the majority of abundant taxa. In conclusion, both fertilizer treatment and seasonal changes affect soil properties, microbial biomass and bacterial community structure. The application of NPK plus manure organic-inorganic fertilizer may be a sound fertilizer practice for sustainable food production.

  20. Responses of bacterial communities in arable soils in a rice-wheat cropping system to different fertilizer regimes and sampling times.

    Directory of Open Access Journals (Sweden)

    Jun Zhao

    Full Text Available Soil physicochemical properties, soil microbial biomass and bacterial community structures in a rice-wheat cropping system subjected to different fertilizer regimes were investigated in two seasons (June and October. All fertilizer regimes increased the soil microbial biomass carbon and nitrogen. Both fertilizer regime and time had a significant effect on soil physicochemical properties and bacterial community structure. The combined application of inorganic fertilizer and manure organic-inorganic fertilizer significantly enhanced the bacterial diversity in both seasons. The bacterial communities across all samples were dominated by Proteobacteria, Acidobacteria and Chloroflexi at the phylum level. Permutational multivariate analysis confirmed that both fertilizer treatment and season were significant factors in the variation of the composition of the bacterial community. Hierarchical cluster analysis based on Bray-Curtis distances further revealed that bacterial communities were separated primarily by season. The effect of fertilizer treatment is significant (P = 0.005 and accounts for 7.43% of the total variation in bacterial community. Soil nutrients (e.g., available K, total N, total P and organic matter rather than pH showed significant correlation with the majority of abundant taxa. In conclusion, both fertilizer treatment and seasonal changes affect soil properties, microbial biomass and bacterial community structure. The application of NPK plus manure organic-inorganic fertilizer may be a sound fertilizer practice for sustainable food production.

  1. Prediction of the immediate effect of traffic on field soil qualities.

    NARCIS (Netherlands)

    Lerink, P.

    1994-01-01

    Field traffic by heavy machinery and transport vehicles is an integral part of modem arable crop production systems. The greater part of the field area is trafficked once or several times per year during the successive field operations. The traffic induced effect on the soil physical condition is of

  2. Effects of DCD addition to slurry on nitrate leaching in sandy soils

    NARCIS (Netherlands)

    Corré, W.J.; Zwart, K.B.

    1995-01-01

    The effects of the addition of the nitrification inhibitor dicyandiamide (DCD) to cattle slurry, applied in autumn to an arable sandy soil, were investigated in a three-year field experiment in the Netherlands. Treatments included application of slurry with DCD in November and December, application

  3. Ecological impacts of arable intensification in Europe

    NARCIS (Netherlands)

    Stoate, C.; Boatman, N.D.; Borralho, R.J.; Rio Carvalho, C.; Snoo, de G.R.; Eden, P.

    2001-01-01

    Although arable landscapes have a long history, environmental problems have accelerated in recent decades. The effects of these changes are usually externalised, being greater for society as a whole than for the farms on which they operate, and incentives to correct them are therefore largely lackin

  4. Effects of band-steaming on microbial activity and abundance in organic farming soil

    DEFF Research Database (Denmark)

    Elsgaard, Lars; Jørgensen, Martin Heide; Elmholt, Susanne

    2010-01-01

    Band-steaming of arable soil at 80-90 degrees C kill off weed seeds prior to crop establishment which allows an extensive intra-row weed control. Here we evaluated the side-effects of in situ band-steaming on soil respiration, enzyme activities, and numbers of culturable bacteria and fungi...... insignificant or slightly stimulatory (P activity were significantly (P soil steaming...... and therefore possible long-term effects. However, band-steaming affects only a minor volume of the plough layer (soil. In conclusion, the side-effects on soil microbiology may not disqualify band-steaming as an option in organic...

  5. Archaeal abundance across a pH gradient in an arable soil and its relationship to bacterial and fungal growth rates.

    Science.gov (United States)

    Bengtson, Per; Sterngren, Anna E; Rousk, Johannes

    2012-08-01

    Soil pH is one of the most influential factors for the composition of bacterial and fungal communities, but the influence of soil pH on the distribution and composition of soil archaeal communities has yet to be systematically addressed. The primary aim of this study was to determine how total archaeal abundance (quantitative PCR [qPCR]-based estimates of 16S rRNA gene copy numbers) is related to soil pH across a pH gradient (pH 4.0 to 8.3). Secondarily, we wanted to assess how archaeal abundance related to bacterial and fungal growth rates across the same pH gradient. We identified two distinct and opposite effects of pH on the archaeal abundance. In the lowest pH range (pH 4.0 to 4.7), the abundance of archaea did not seem to correspond to pH. Above this pH range, there was a sharp, almost 4-fold decrease in archaeal abundance, reaching a minimum at pH 5.1 to 5.2. The low abundance of archaeal 16S rRNA gene copy numbers at this pH range then sharply increased almost 150-fold with pH, resulting in an increase in the ratio between archaeal and bacterial copy numbers from a minimum of 0.002 to more than 0.07 at pH 8. The nonuniform archaeal response to pH could reflect variation in the archaeal community composition along the gradient, with some archaea adapted to acidic conditions and others to neutral to slightly alkaline conditions. This suggestion is reinforced by observations of contrasting outcomes of the (competitive) interactions between archaea, bacteria, and fungi toward the lower and higher ends of the examined pH gradient.

  6. About the value of species diversity in arable weeds for weed management

    Directory of Open Access Journals (Sweden)

    Gerowitt, Bärbel

    2016-02-01

    Full Text Available Arable weeds accompany arable land use – we define them based on their affiliation to ar able systems. They are adapted to such a degree that most of them cannot exist without arable land use. Weeds are part of the total biodiversity on arable fields, as primary producers they are basic for important functions within the ecosystem. This paper elaborates the relevance of species diversity in arable weeds for their management. Arable systems can be regarded for the number of different methods for preventive and direct weed control which are realized. Historical arable land use is roughly divided into three periods, which differ concerning the diversity of weed management and the occurring diversity in weed species. Obviously divers weed management in arable systems and diversity in weed species depend on each other, this is illustrated with a simple abstract picture. Arable systems, which are characterised by simpleness, favor the domination of few species which ensure an effective use of the resources within the ecosystem. One consequence under continuous pressure of an overused tool in weed management is that the genetic diversity within a dominating weed population is exploited to ensure this resource use. Current herbicides represent this tool – the results are herbicide resistant biotypes within the weed populations. Species diversity in arable weeds as a rationale within arable production can assist to prevent this development.

  7. Direct and Indirect Short-term Effects of Biochar on Physical Characteristics of an Arable Sandy Loam

    DEFF Research Database (Denmark)

    Sun, Zhencai; Moldrup, Per; Elsgaard, Lars

    2013-01-01

    .8), whereas gas transport parameters (air permeability, k(a), and gas diffusivity, D-p/D-o, where D-p is the gas diffusion coefficient in soil and D-o is the gas diffusion coefficient in free air) were measured between pF 2.0 and 3.0. Water retention under dry conditions and measured specific surface area...... were not significantly greater in the biochar-amended soil than the reference soil probably because of the relatively low biochar application rate. Yet, the biochar-amended soil showed a significant decrease in soil bulk density and an accompanying increase in total porosity. Water retention and air......-filled porosity (epsilon) were both markedly greater in the biochar-amended soil than in the reference soil between pF 1.0 and 3.0. Soil macroporosity (equivalent to >0.1 mm pore diameter) and the ratio of macroporosity to total porosity were also significantly greater in the biochar-amended soil. As a result...

  8. Arable land increase in northern China: facts and findings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on investigations between 1986 and 1996 in the four provinces of northern China, major problems on land reclamation were discovered. The increase of arable land was mainly low quality fields from barren land and was susceptible to disertification and water-induced soil erosion. In the meantime, large area of grassland and forestland was lost or degraded, and original fertile arable land was occupied for residential and industrial use. As a result the environment deteriorated. This change was mainly caused by economic development, population growth, inferior natural conditions, and irrational management strategies. Finally some positive measures were suggested to stop this negative cycle.

  9. Changes in the agrochemical properties of major arable soils in the south of the Far East of Russia under the impact of their long-term agricultural use

    Science.gov (United States)

    Burdukovskii, M. L.; Golov, V. I.; Kovshik, I. G.

    2016-10-01

    Agrochemical properties of meadow-brown (Gleyic Cambisols (Clayic, Aric)) and meadow-chernozemic (Luvic Gleyic Chernic Phaeozems (Loamic, Aric, Pachic)) soils under the impact of long-term application of mineral and organic fertilizers were studied. The investigations were performed at the agrochemical experimental stations of the Primorskii region and Amur oblast founded in 1941 and 1962, respectively. It was shown that the long-term crop cultivation without fertilizers or with great rates of mineral fertilizers and lime resulted in the soil dehumification, a rise in the soil acidity, and a decrease of the content of exchangeable bases. These processes were slowed down by the application of organic fertilizers. Agrochemical parameters of meadow-chernozemic and floodplain meadow (Fluvic Phaeozems (Loamic, Aric, Oxyaquic)) soils of Amur oblast (Russia) and the Heilongjiang border province (China) were compared.

  10. Effects of season and urea treatment on infection of stumps of Picea abies by Heterobasidion annosum in stands on former arable land

    Energy Technology Data Exchange (ETDEWEB)

    Brandtberg, P.O. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research; Johansson, Martin [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology; Seeger, P. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Statistics

    1996-09-01

    Between 1986 and 1990, a series of thinnings were made in previously unthinned first rotation stands on former arable land located in the southern half of Sweden. The aim was to evaluate the effects of season and urea treatment on the frequency of infection of stumps of Norway spruce (Picea abies (L.) Karst.) by the root-rot fungus Heterobasidion annosum (Fr.) Bref. Untreated stumps, resulting from 60 thinnings (22-100 stumps each, altogether ca 3000 stumps) made at different times of year, were investigated 3-24 months after cutting to determine whether they were infected with H. annosum. On average only 2% of the stumps from thinnings made in November-February were infected, whereas the incidence of infection among stumps thinned in June-July was 34%. Two methods of treating stumps with urea to prevent stump infection by H. annosum after thinning were evaluated in terms of effectiveness. The freshly cut stumps were treated with a 20% urea solution, transformed to a gel by adding 0.2% carboxymethyl cellulose, or with a 30% urea solution. On average, the reduction in infection rate obtained was 62% with the first method and 85% with the latter. In a separate study involving a concentration series of urea, there was a considerable drop in protection efficiency, from 89% to 58%, when the concentration was decreased from 30% to 15%. 38 refs, 3 figs, 1 tab

  11. Simulating soil N2O emissions and heterotrophic CO2 respiration in arable systems using FASSET and MoBiLE-DNDC

    DEFF Research Database (Denmark)

    Chirinda, Ngonidzashe; Kracher, Daniela; Lægdsmand, Mette;

    2011-01-01

    winter wheat grown in three different organic and one inorganic fertilizer-based cropping system using two different models, i.e., MoBiLE-DNDC and FASSET. The two models were generally capable of simulating most seasonal trends of measured soil heterotrophic CO2 respiration and N2O emissions. Annual soil......Modelling of soil emissions of nitrous oxide (N2O) and carbon dioxide (CO2) is complicated by complex interactions between processes and factors influencing their production, consumption and transport. In this study N2O emissions and heterotrophic CO2 respiration were simulated from soils under...... heterotrophic CO2 respiration was underestimated by both models in all systems (about 10–30% by FASSET and 10–40% by MoBiLE-DNDC). Both models overestimated annual N2O emissions in all systems (about 10–580% by FASSET and 20–50% by MoBiLE-DNDC). In addition, both models had some problems in simulating soil...

  12. 利用AAS研究农田土壤Cu,Zn和Cd含量及收支平衡%Study on Contents and Budgets of Cu,Zn and Cd in an Arable Soil Using AAS

    Institute of Scientific and Technical Information of China (English)

    赵颖; 姜春明; 马强; 周桦; 徐永刚; 宇万太

    2015-01-01

    Based on a long-term experiment in Shenyang Experimental Station ,the effect of manure application on the contents and budgets of Cu ,Zn and Cd in the arable soil was studied .The experiment included four treatments :no mature addition (CK) ,mature addition 10 t・ha-1 year-1 (M1) ,25 t・ha-1 year-1 (M2) ,and 50 t・ha-1 year-1 (M3) .The result showed that Cu ,Zn and Cd in soil were accumulated with manure application and prolongation of experiment ,and the accumulative magni-tude increased with increasing of manure application .The average annual growth rates of the heavy metals in the four treatments (CK ,M1 ,M2 ,M3) were 2.83% ,6.56% ,7.54% ,8.96% ;0.03% ,3.44% ,4.53% ,6.64% and 1.51% ,8.01% , 10.27% ,16.08% for Cu ,Zn and Cd ,respectively .After six years of the experiment ,the content of Cd in the M3 treatment was quite close to the threshold of Chinese Soil Quality Standard Grade III (1 mg・kg -1 ,GB15618-1995) .After 12 years of the experiment ,the contents of Cu in the mature-amended treatments fell in the Chinese Soil Quality Standard Grade III ,which should be paid more attention .Although the heavy metals in soil were gradually accumulated ,the Cu ,Zn and Cd levels in crop grain were still below the National Food Contamination Standards (GB2762-2005 ;GB13106-91 ;GB15199-94) ,indicating the contents of heavy metals in crop produced from contaminated soil might not exceed the corresponding standards .The con-tents of Cu ,Zn and Cd in the straw were much greater than those in the grain .The removal of heavy metal by crop was in the order of M3>M2>M1> CK .The average amounts of Cu ,Zn and Cd annually removed from the soil in the four treatments (CK ,M1 ,M2 and M3) were 35.68 ,47.80 ,63.65 ,69.64 ;249.14 ,375.22 ,375.16 ,444.44 ,and 0.83 ,1.39 ,1.64 ,1.66 g・ha-1 ,respectively .The contents of heavy metals in organic manure varied in different years :the contents of Cu and Zn in-creased year by year ,while Cd presented a decreasing trend .The average

  13. Research on pH Buffer Capacity and Acidification Rate of Arable Brown Soil%耕地棕壤酸碱缓冲性能及酸化速率研究

    Institute of Scientific and Technical Information of China (English)

    沈月; 依艳丽; 张大庚; 粟杰; 依妍; 徐龙超

    2012-01-01

    Significant acidification has taken place in the arable brown soil of Liaoning province since the second soil general survey.The general mean of pH were declined from 6.42 to 5.73.Arable brown soil(0-20 cm) of the four typical areas in Liaoning province(Changtu,Shenyang,Wafangdian and Qingyuan) were used to study the pH buffer capacity,acidification rate and the influencing factors.The results showed that pH buffer capacity in the four areas were from 29.66 to 39.87 mmol/kg·pH unit.The pH buffer capacity of the north and middle area in Liaoning province were higher than the south and east area.The acidification of south area was the fastest with the value of 2.69 H+ kmol/(hm2·a),and the slowest happened in the east with the value of 1.44 H+ kmol/(hm2·a).The initial pH,cation exchange capacity,soil mechanical composition and organic matter were all the factors that affect the changes of soil pH buffer capacity.The texture in the north and middle area were silt loam soil,cation exchange capacity,base saturation and clay content were higher than that in the other two areas(south and east).Therefore,they had the higher pH buffer capacities.Fertilization and the other human factors that contribute to buffer capacity and acidification rate need to be further studied.%辽宁省耕地棕壤自第二次土壤普查以来酸化趋势明显,pH整体平均值从第二次普查时期的6.42降至5.73。对辽宁省4个典型地区(昌图、沈阳、瓦房店、清原)的耕地棕壤耕层(0-20cm)缓冲性能、酸化速率及其影响因素进行研究,结果表明:各地区酸碱缓冲容量变幅为29.66~39.87mmol/kg.pH unit,其中辽宁北部和中部地区酸碱缓冲容量明显高于辽南和辽东地区。酸化速率以辽南地区下降速率最快,其值为2.69H+kmol/(hm2.a),而速率最慢的地区为辽东,其酸化速率为1.44H+kmol/(hm2.a)。土壤初始pH、阳离子交换量、颗粒组成及有机质含量均

  14. Study on Soil Magnetic Effect

    Institute of Scientific and Technical Information of China (English)

    YIYAN-LI; LIUXIAO-YI

    1995-01-01

    A study on the effect of applied magnetic field was performed with six types of soils collected from northeastern China.Magnetic field was found to cause changes of soil physico-chemical properties and soil enzyme activities.An appropriate applied magnetic field could cut down soil zeta-potential,soil specific surface,soil water potential and soil swelling capacity;raise the charge density on soil colloids and the activities of invertase,hydrogen peroxidase and amylase in the soils;enhance soil aggregation and improve soil structural status and soil water-releasing capability.

  15. Use of rare earth oxide tracers to determine source areas for sediment eroded from arable hillslopes

    Science.gov (United States)

    Deasy, C.; Quinton, J. N.

    2009-04-01

    Soil erosion from arable hillslopes has both on-site and off-site effects. On-site, erosion and redistribution of sediment can lead to the loss of productive field area and a reduction in organic matter and nutrient content in topsoil. Off-site, the transport and deposition of eroded sediment in downstream waters is associated with turbidity, sedimentation and reduced water quality, as sediments are associated with the transport of nutrients, particularly phosphorus (P) and nitrogen (N), heavy metals and pesticides. Arable land is a major source for these sediments, with studies in the UK estimating the cultivated fields may be responsible for up to 80% of particulate P in rivers. Previous studies at Loddington in Leicestershire, UK have demonstrated that most of the P and much of the N eroded from hillslope is in particulate form, transported in association with sediment suspended in runoff. Results also suggest that tramlines are the principal pathway for erosion from arable fields containing combinable crops. As tramlines are regularly spaced over the whole field, they potentially act as conduits for runoff, sediment and sediment-associated nutrients to be lost from the hillslope. However, it is not yet clear where the source areas are for sediment eroded via this pathway. To understand the movement of sediment on arable hillslopes, a hillslope-scale tracer experiment was undertaken in one year at the same site. The aims of this study were (1) to develop an application method for rare earth oxide tracers suitable for using on a hillslope scale to assess sediment movement over a number of storm events, (2) to determine the erosion rates of different contributing hillslope areas, (3) to determine the relative contributions of sediment eroded from each of these areas in order to assess the importance of different hillslope source areas for soil erosion. Different rare earth oxide tracers were applied in solution using a knapsack sprayer to four areas of the

  16. Distinct germination response of endangered and common arable weeds to reduced water potential.

    Science.gov (United States)

    Rühl, A T; Eckstein, R L; Otte, A; Donath, T W

    2016-01-01

    Arable weeds are one of the most endangered species groups in Europe. Modern agriculture and intensive land-use management are the main causes of their dramatic decline. However, besides the changes in land use, climate change may further challenge the adaptability of arable weeds. Therefore, we investigated the response pattern of arable weeds to different water potential and temperature regimes during the phase of germination. We expected that endangered arable weeds would be more sensitive to differences in water availability and temperature than common arable weeds. To this end, we set up a climate chamber experiment where we exposed seeds of five familial pairs of common and endangered arable weed species to different temperatures (5/15, 10/20 °C) and water potentials (0.0 to -1.2 MPa). The results revealed a significant relationship between the reaction of arable weed species to water availability and their Red List status. The effects of reduced water availability on total germination, mean germination time and synchrony were significantly stronger in endangered than in common arable weeds. Therefore, global climate change may present a further threat to the survival of endangered arable weed species.

  17. Arable weed flora in the Western Siberian grain belt

    Directory of Open Access Journals (Sweden)

    Kämpf, Immo

    2016-02-01

    Full Text Available Between Ekaterinburg and Nowosibirsk, in the Western Siberian grain belt, spring wheat is grown on fertile Chernozem soils. Field and farm sizes are large but the land-use intensity per area is low compared to Central Europe. Fertilizers and pesticides are applied only in low to moderate quantities and yields range between 10 and 20 dt ha-1. We studied the arable weed flora in the northern forest steppe zone of Tyumen region using a randomized sampling design. Surprisingly, the species richness was only moderate, on average 9.8 ± 3.8 species per 100 m². Compared to weed communities of Bashkiria (Southern Ural and less intensively used arable land of Central Europe these numbers are rather low. Moreover, most of the recorded species were cosmopolitans or widely distributed throughout the temperate zone. We suggest that the land use intensity was high enough to reduce the density of a number of weed species in a way that they were not registered by our random sampling design. The limited conservational value of the weed vegetation of large grain fields in Tyumen leads to the conclusion that if intensification of land use is unavoidable, it should be directed to arable land and not to ex-arable land or ancient grassland, which is of higher conservation value.

  18. Fracciones de carbono orgánico en la capa arable: efecto de los sistemas de cultivo y fertilización nitrogenada Organic carbon fractions in the arable layer: cropping systems and nitrogen fertilization effects

    Directory of Open Access Journals (Sweden)

    Maximiliano J Eiza

    2005-07-01

    Full Text Available Nuestro objetivo fue evaluar el efecto de siete sistemas de cultivo (SC en un experimento de larga duración: pastura permanente (PP, agricultura permanente bajo siembra directa (SD (SD100 y labranza convencional (LC (LC100, rotación agricultura pastura (50%-50% del tiempo bajo SD (SD50 y LC (LC50, rotación agricultura pastura (75%-25% del tiempo bajo SD (SD75 y LC (LC75 y dos dosis de fertilización nitrogenada: 0 y 120 kg N ha-1, sobre el carbono orgánico total (COT y particulado (COP, para 0-20 cm en 1994 y para 0-5, 5-20 y 0-20 cm de profundidad en 2003. En 1994, los mayores COP y COT se asociaron a manejos con períodos agrícolas previos cortos. En 2003, se encontraron diferencias entre SC en COT en la capa de 0-5 cm de profundidad, siendo PP, LC50 y SD50 los tratamientos con mayor COT. El COP fue más alto bajo PP, LC50 y SD50 a 0-5 y 0-20 cm de profundidad. A 0-5 cm COP bajo SD fue significativamente mayor que bajo LC. A 5-20 cm de profundidad, las diferencias en COP no fueron claras entre SC aunque, tendió a disminuir con los años bajo agricultura. La fertilización determinó mayor COP a 5-20 y 0-20 cm de profundidad. Las diferencias en la variación entre 1994 y 2003 entre SC fueron significativas para COP y COT. Por otro lado, la variación relativa de COP fue más alta que la de las otras variables. Se concluye que las rotaciones cortas de agricultura-pastura, la SD y la fertilización nitrogenada mejoran el COP y el COT. Para las condiciones de este experimento, COP ha sido un indicador más sensible que COT y sería capaz de detectar los efectos de las prácticas de manejo.In the southeastern Buenos Aires Province (Argentina unsuitable combination of crop rotation and tillage systems (cropping systems, SC has reduced soil organic matter content. Our aim was to evaluate the effect of seven SC in a long term experiment (since 1976 started in 1994: permanent pasture (PP, permanent cropping under no tillage (SD (SD100 and

  19. Effect of application method, manure characteristics, weather and field conditions on ammonia volatilization from manure applied to arable land

    NARCIS (Netherlands)

    Huijsmans, J.F.M.; Hol, J.M.G.; Vermeulen, G.D.

    2003-01-01

    To predict ammonia (NH3) volatilization from field-applied manure, factors affecting volatilization following manure application need to be known. A database of field measurements in the Netherlands was analysed to identify these factors and to quantify their effects on the volatilization of NH3 fro

  20. Sorption of linear alkylbenzene sulfonate to soil components and effects on microbial iron reduction.

    Science.gov (United States)

    Kristiansen, Inge Broberg; de Jonge, Hubert; Nørnberg, Per; Mather-Christensen, Ole; Elsgaard, Lars

    2003-06-01

    When sewage sludge is applied to arable land, linear alkylbenzene sulfonate (LAS) is released into the environment. In soils, LAS has been shown to impede microbial processes, such as bacterial iron reduction. The aim of the present study was to quantify LAS adsorption and desorption to agricultural soils and iron oxides and relate this to the inhibition of microbial iron reduction. Two agricultural soils were used, namely, Askov (coarse sandy loam soil) and Lundgaard (coarse sandy soil). In both soils, LAS inhibited microbial iron reduction even at low LAS concentrations with 10% effect concentrations of 6 to 7 and 26 to 32 mg LAS/kg dry-weight soil for Lundgaard and Askov soil, respectively. The sorption isotherms showed that sorption of LAS to iron oxides was 10 to 100 times stronger than sorption to the agricultural soils. Also, it appeared that at low LAS concentrations (< 10 mg/kg dry-wt soil), Lundgaard soil adsorbed approximately 10 times more LAS than Askov soil. Thus, the inhibitory effect of LAS on microbial iron reduction was highest in the Lundgaard soil, which exhibited both the strongest sorption and the lowest desorption of the two soils. A possible hypothesis to explain this correlation was that LAS toxicity toward bacterial iron reduction was, at least partly, caused by LAS adsorbed to iron oxides, which could interfere with transfer of electrons between the bacteria and their respiratory electron acceptor.

  1. Comprehensive Evaluation of Unsafe State of Arable Land Resources:A Case Study of Chengdu City

    Institute of Scientific and Technical Information of China (English)

    Li; DENG; Jin; WEI

    2013-01-01

    We establish the unsafe state indicator system reflecting the unsafe state of arable land within the scope of the city. Using analytic hierarchy process and entropy method,we determine the weight of indicator; using linear weighted method,we conduct comprehensive evaluation of unsafe operation of arable land resource system in Chengdu City during the period 1999-2010. Through the unsafe state analysis,we draw the following conclusion: the share of arable land area in total land area,effective irrigation area,the area of low-yielding field,application rate of chemical fertilizer per unit area of arable land,and application rate of pesticide per unit area of arable land,are the key factors for easing the unsafe state in the short term. Finally we put forth the following recommendations: strengthening profound understanding of the seriousness of unsafe state of arable land; strengthening the basic arable land protection; continuing to tap the quality enhancement potential of arable land; consistently implementing the guideline and policy of " Combination of Use and Maintenance" .

  2. Flash Flooding and 'Muddy Floods' on Arable Land

    Science.gov (United States)

    Boardman, J.

    2012-04-01

    Flash flooding is often associated with upland, grazed catchments. It does, however, occur in lowland arable-dominated areas. In southern England, notable examples have occurred at Rottingdean (Brighton) in 1987, at Faringdon (Oxfordshire) in 1993 and at Breaky Bottom vineyard (near Brighton) in 1987 and 2000. All resulted in damage to nearby property. Runoff was largely from recently cultivated ground. The characteristics of such floods are: Rapid runoff from bare soil surfaces. Saturated excess overland flow is likely in the early parts of storms but high intensity rainfall on loamy soils results in crusting and Hortonian overland flow; High rates of erosion; Sediment transport to downvalley sites causing property damage ('muddy flooding'). Muddy floods are known from several areas of Europe e.g. Belgium, northern France, South Limburg (Netherlands) and Slovakia (Boardman et al 2006). In other areas they occur but have gone unreported or are classified under different terms. The necessary conditions for occurrence are areas of arable land which is bare at times of the year when there is a risk of storms. For muddy floods to cause damage (and hence be reported), vulnerable property must lie downstream from such areas of arable land. In some areas the incidence of muddy floods relates to autumn and early winter rainfall and winter cereal crops (e.g. southern England). In continental Europe, flooding is more common in summer and is associated with convectional storms and land uses including sugar beet, maize and potatoes. Predictions of increased numbers of high-intensity storms with future climate change, suggest that arable areas will continue to generate both flash floods and muddy floods.

  3. Soil friability - Concept, Assessment and Effects of Soil Properties and Management

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl

    Soil friability is a key soil physical property yielding valuable information on the ease of productin a favorable seed- and root beds during tillage operations. Therefore, soil friability is acrucial soil property in relation to the ability of soil to support plant growth and to minimzethe energy...... in the light of the present renewed focus on global food security together with a focus on fossil fuel consumption and greenhouse gas emissions in crop production. Certainly, the demand for well-functioning, arable soils is rising to meet the global challenges....

  4. Managing Bioenergy Production on Arable Field Margins for Multiple Ecosystem Services: Challenges and Opportunities

    Science.gov (United States)

    Ferrarini, Andrea; Serra, Paolo; Amaducci, Stefano; Trevisan, Marco; Puglisi, Edoardo

    2013-04-01

    Growing crops for bioenergy is increasingly viewed as conflicting with food production. However, energy use continues to rise and food production requires fuel inputs, which have increased with intensification. The debate should shift from "food or fuel" to the more challenging target: how the increasing demand for food and energy can be met in the future, particularly when water and land availability will be limited. As for food crops, also for bioenergy crops it is questioned whether it is preferable to manage cultivation to enhance ecosystem services ("land sharing" strategy) or to grow crops with lower ecosystem services but higher yield, thereby requiring less land to meet bioenergy demand ("land sparing" strategy). Energy crop production systems differ greatly in the supply of ecosystem services. The use of perennial biomass (e.g. Switchgrass, Mischantus, Giant reed) for energy production is considered a promising way to reduce net carbon emissions and mitigate climate change. In addition, regulating and supporting ecosystem services could be provided when specific management of bioenergy crops is implemented. The idea of HEDGE-BIOMASS* project is to convert the arable field margins to bioenergy crop production fostering a win-win strategy at landscape level. Main objective of the project is to improve land management to generate environmental benefits and increase farmer income. The various options available in literature for an improved field boundary management are presented. The positive/unknown/negative effects of growing perennial bioenergy crops on field margins will be discussed relatively to the following soil-related ecosystem services: (I) biodiversity conservation and enhancement, (II) soil nutrient cycling, (III) climate regulation (reduction of GHG emissions and soil carbon sequestration/stabilization, (IV) water regulation (filtering and buffering), (V) erosion regulation, (VI) pollination and pest regulation. From the analysis of available

  5. Dedicated biomass crops can enhance biodiversity in the arable landscape.

    Science.gov (United States)

    Haughton, Alison J; Bohan, David A; Clark, Suzanne J; Mallott, Mark D; Mallott, Victoria; Sage, Rufus; Karp, Angela

    2016-11-01

    Suggestions that novel, non-food, dedicated biomass crops used to produce bioenergy may provide opportunities to diversify and reinstate biodiversity in intensively managed farmland have not yet been fully tested at the landscape scale. Using two of the largest, currently available landscape-scale biodiversity data sets from arable and biomass bioenergy crops, we take a taxonomic and functional trait approach to quantify and contrast the consequences for biodiversity indicators of adopting dedicated biomass crops on land previously cultivated under annual, rotational arable cropping. The abundance and community compositions of biodiversity indicators in fields of break and cereal crops changed when planted with the dedicated biomass crops, miscanthus and short rotation coppiced (SRC) willow. Weed biomass was consistently greater in the two dedicated biomass crops than in cereals, and invertebrate abundance was similarly consistently higher than in break crops. Using canonical variates analysis, we identified distinct plant and invertebrate taxa and trait-based communities in miscanthus and SRC willows, whereas break and cereal crops tended to form a single, composite community. Seedbanks were shown to reflect the longer term effects of crop management. Our study suggests that miscanthus and SRC willows, and the management associated with perennial cropping, would support significant amounts of biodiversity when compared with annual arable crops. We recommend the strategic planting of these perennial, dedicated biomass crops in arable farmland to increase landscape heterogeneity and enhance ecosystem function, and simultaneously work towards striking a balance between energy and food security.

  6. Effect of acid rain on mercury leaching from forest yellow soil in Jinyun Mountain%酸雨对缙云山林地黄壤汞溶出的影响

    Institute of Scientific and Technical Information of China (English)

    李静; 魏世强; 杨学春

    2004-01-01

    Forest yellow soil and arable yellow soil in Jinyun Mountain were collected to study the effect of simulated acid rain(adjusted to pH 2.0, 3.0, 4.0 and 5.0) on the Hg leaching from soils by the methods of static extraction and dynamic leaching. The results showed that in forest yellow soils, surface accumulation of Hg occurred, and the accumulated Hg was easier to be leached out than that in arable yellow soil by acid rain. The amount of leached Hg was the largest at pH 4.0. To abate the risk of Hg pollution in water bodies by the Hg leaching from this forest soil, the Mountain should be closed, and timber-felling should be forbidden.

  7. Effect of Clay Content and Soil-water Potential On Mobilization and Leaching of Colloids In Unsaturated Macroporous Soil

    Science.gov (United States)

    Kjaergaard, C.; de Jonge, L. W.; Moldrup, P.

    The transport of strongly sorbed environmental contaminants may be enhanced due to sorption to mobile soil colloids. The most common source of mobile colloids in soil is the in-situ release of water-dispersible colloids (WDC), however experimental investigations of colloid mobilization in unsaturated macroporous soil are scarce. An understanding of the arrangement of colloids in aggregates, and the influence of clay on the development of the soil fabric and pore-size distributions is essential for the in- terpretation of colloid mobilization in soils. This emphasizes the important role of clay content, when evaluating the susceptibility of soils to release colloids and associated contaminants. This study was conducted to determine the effect of clay content and initial soil- water potential on colloid mobilization and leaching. Intact soil cores were sampled from an arable field at six locations along a naturally occurring texture gradient. Soil dispersibility was investigated using capillary saturation and drainage of field-moist packed aggregates. The amount of WDC in the soil was measured for each com- bination of clay content and initial soil-water potential (-2.5, -98 and -15530 hPa). Mobilization and leaching of colloids was investigated from unsaturated intact soil cores. The soils were irrigated at low intensity (1 mm/h), and effluent sampling was conducted at 5 cm tension. The results showed that colloid dispersion was significantly affected by both clay con- tent and initial soil-water potential. With a soil-water potential of -15530 hPa the col- loid release was generally low and no variation occurred between the soils. With in- creasing soil-water potential there was an increase in the amount of WDC for all soils. The increase in WDC was negatively correlated with clay content. The leaching of colloids from intact soil cores also decreased with increasing clay content at an ini- tial soil-water potential of -98 and -2.5 hPa, and no difference between

  8. Medium-term effect of perennial energy crops on soil organic carbon storage

    Directory of Open Access Journals (Sweden)

    Enrico Ceotto

    2011-11-01

    Full Text Available The scope of this study was to evaluate the effect of perennial energy crops on soil organic carbon (SOC storage. A field experiment was undertaken in 2002 at Anzola dell’Emilia in the lower Po Valley, Northern Italy. Five perennial energy crops were established on a land area which had been previously cultivated with arable crops for at least 20 years. The compared crops are: the herbaceous perennials giant reed and miscanthus, and the woody species poplar, willow and black locust, managed as short rotation coppice (SRC. SOC was measured in 2009, seven years after the start of the experiment, on an upper soil layer of 0.0-0.2 m and a lower soil layer of 0.2-0.4 m. The study aimed to compare the SOC storage of energy crops with alternative land use. Therefore, two adjacent areas were sampled in the same soil layers: i arable land in steady state, cultivated with rainfed annual crops; ii natural meadow established at the start of the experiment. The conversion of arable land into perennial energy crops resulted in SOC storage, in the upper soil layer (0.0-0.2 m ranging from 1150 to 1950 kg C ha-1 year-1 during the 7-year period. No significant differences were detected in SOC among crop species. We found no relationship between the harvested dry matter and the SOC storage. The conversion of arable land into perennial energy crops provides a substantial SOC sequestration benefit even when the hidden C cost of N industrial fertilizers is taken into account. While the SOC increased, the total N content in the soil remained fairly constant. This is probably due to the low rate of nitrogen applied to the perennial crops. However, our data are preliminary and the number of years in which the SOC continues to increase needs to be quantified, especially for the herbaceous species giant reed and miscanthus, with a supposedly long duration of the useful cropping cycle of 20 years or longer.

  9. An econometric analysis of changes in arable land utilization using multinomial logit model in Pinggu district, Beijing, China.

    Science.gov (United States)

    Xu, Yueqing; McNamara, Paul; Wu, Yanfang; Dong, Yue

    2013-10-15

    Arable land in China has been decreasing as a result of rapid population growth and economic development as well as urban expansion, especially in developed regions around cities where quality farmland quickly disappears. This paper analyzed changes in arable land utilization during 1993-2008 in the Pinggu district, Beijing, China, developed a multinomial logit (MNL) model to determine spatial driving factors influencing arable land-use change, and simulated arable land transition probabilities. Land-use maps, as well as social-economic and geographical data were used in the study. The results indicated that arable land decreased significantly between 1993 and 2008. Lost arable land shifted into orchard, forestland, settlement, and transportation land. Significant differences existed for arable land transitions among different landform areas. Slope, elevation, population density, urbanization rate, distance to settlements, and distance to roadways were strong drivers influencing arable land transition to other uses. The MNL model was proved effective for predicting transition probabilities in land use from arable land to other land-use types, thus can be used for scenario analysis to develop land-use policies and land-management measures in this metropolitan area.

  10. 我国土地利用动态监测的耕地保护效果评价%Arable Land Conservation Effects of Land Use Dynamic Monitoring in China

    Institute of Scientific and Technical Information of China (English)

    金雨泽; 徐智颖; 钟太洋; 黄贤金

    2016-01-01

    为了对耕地保护技术层面措施进行定性定量研究,测度土地利用动态监测在省级层面的耕地保护效果,以1999—2008年省级面板数据为基础,借助STATA软件分别通过聚类稳健标准差下固定效应模型、随机效应模型和混合OLS模型进行估计,选择最优拟合结果。 F检验,B-P检验,Hausman检验显示固定效应模型拟合结果最优,以该模型对土地利用动态监测的耕地保护效果进行测度。结果表明:土地利用动态监测的实行对减少耕地面积下降有显著作用;土地利用动态监测比率每提高1%,能减少耕地流失188.05 hm2;从土地利用动态监测耕地保护效率来说4个直辖市要高于其他省份。%This study aimed to evaluate the arable land conservation effects of land use dynamic monitoring , which was regarded as a technological approach , on provincial level quantitatively and qualitatively .Based on the panel data collected from 1999 to 2008, this article applied fixed-effects model, random-effect model and pooled OLS model to estimate the question .After testing the results , the fix-effect model was finally chosed to explain the question .On that basis , this paper estimated the effect of dynamic monitoring of land use in arable land conserva -tion and the results are as follows:The implementation of dynamic monitoring technology of land use does contribute to the decline in land loss and every 1%increase in the dynamic monitoring rate of land use will bring a 188.05 hm2 decline in land loss .As for arable land conservation efficiency of dynamic monitoring of land use , those of the four centrally administered municipalities in China shows a higher rate than that of other provinces and municipali -ties.

  11. [Effect of long-term fertilization on microbial community functional diversity in black soil].

    Science.gov (United States)

    Liu, Jing-xin; Chi, Feng-qin; Xu, Xiu-hong; Kuang, En-jun; Zhang, Jiu-ming; Su, Qing-rui; Zhou, Bao-ku

    2015-10-01

    In order to study the effects of long-term different fertilization on microbial community functional diversity in arable black. soil, we examined microbial metabolic activities in two soil la- yers (0-20 cm, 20-40 cm) under four treatments (CK, NPK, M, MNPK) from a 35-year continuous fertilization field at the Ministry of Agriculture Key Field Observation Station of Harbin Black Soil Ecology Environment using Biolog-ECO method. The results showed that: in the 0-20 cm soil layer, combined application of organic and inorganic fertilizer(MNPK) increased the rate of soil microbial carbon source utilization and community metabolism richness, diversity and dominance; In the 20-40 cm layer, these indices of the MNPK treatment was lower than that of the NPK treat- ment; while NPK treatment decreased soil microbial community metabolism evenness in both layers. Six groups of carbon sources used by soil microbes of all the treatments were different between the two soil layers, and the difference was significant among all treatments in each soil layer (P functional diversity in both tillage soil layer and down soil layers, and chemical fertilization alone had a larger influence on the microbial community functional diversity in the 20-40 cm layer.

  12. Root and soil carbon distribution at shoulderslope and footslope positions of temperate toposequences cropped to winter wheat

    DEFF Research Database (Denmark)

    Chirinda, Ngoni; Roncossek, Svenja Doreen; Heckrath, Goswin Johann;

    2014-01-01

    Crop root residues are an important source of soil organic carbon (SOC) in arable systems. However, the spatial distribution of root biomass in arable systems remains largely unknown. In this study, we determined the spatial distribution of macro-root and shoot biomass of winter wheat at shoulder......Crop root residues are an important source of soil organic carbon (SOC) in arable systems. However, the spatial distribution of root biomass in arable systems remains largely unknown. In this study, we determined the spatial distribution of macro-root and shoot biomass of winter wheat...... to simulate or predict C dynamics and crop productivity should consider topography-controlled variations in root C input and SOC redistribution as well as their effects on soil properties, root growth and crop productivity....

  13. Cadmium mobility and accumulation in soils of the European Communities

    NARCIS (Netherlands)

    Fraters B; van Beurden AUCJ

    1993-01-01

    In this overview of the effects of cadmium pollution on agricultural soils in the European Community, both the cadmium loads on agricultural land and the soil sensitivity to cadmium accumulation have been estimated. Cadmium loads have been estimated separately for arable land and grassland. The ef

  14. Biofuel intercropping effects on soil carbon and microbial activity.

    Science.gov (United States)

    Strickland, Michael S; Leggett, Zakiya H; Sucre, Eric B; Bradford, Mark A

    2015-01-01

    Biofuels will help meet rising demands for energy and, ideally, limit climate change associated with carbon losses from the biosphere to atmosphere. Biofuel management must therefore maximize energy production and maintain ecosystem carbon stocks. Increasingly, there is interest in intercropping biofuels with other crops, partly because biofuel production on arable land might reduce availability and increase the price of food. One intercropping approach involves growing biofuel grasses in forest plantations. Grasses differ from trees in both their organic inputs to soils and microbial associations. These differences are associated with losses of soil carbon when grasses become abundant in forests. We investigated how intercropping switchgrass (Panicum virgalum), a major candidate for cellulosic biomass production, in loblolly pine (Pinus taeda) plantations affects soil carbon, nitrogen, and microbial dynamics. Our design involved four treatments: two pine management regimes where harvest residues (i.e., biomass) were left in place or removed, and two switchgrass regimes where the grass was grown with pine under the same two biomass scenarios (left or removed). Soil variables were measured in four 1-ha replicate plots in the first and second year following switchgrass planting. Under switchgrass intercropping, pools of mineralizable and particulate organic matter carbon were 42% and 33% lower, respectively. These declines translated into a 21% decrease in total soil carbon in the upper 15 cm of the soil profile, during early stand development. The switchgrass effect, however, was isolated to the interbed region where switchgrass is planted. In these regions, switchgrass-induced reductions in soil carbon pools with 29%, 43%, and 24% declines in mineralizable, particulate, and total soil carbon, respectively. Our results support the idea that grass inputs to forests can prime the activity of soil organic carbon degrading microbes, leading to net reductions in stocks

  15. Change We Can Fight Over: The Relationship between Arable Land Supply and Substate Conflict

    Science.gov (United States)

    2010-01-01

    experienced a period of arable land growth, followed by a sudden plateau (or cliff) in that trajectory . One could imagine a study structured quite similarly...Conflict. Respect: Sudanese Journal for Human Rights, Culture and Issues of Cultural Diversity 1, 1-25. Theisen, Ole Magnus . 2008. Blood and Soil

  16. Species richness and weed abundance in the vegetation of arable field boundaries.

    NARCIS (Netherlands)

    Kleijn, D.

    1997-01-01

    In the modem arable landscape, the vegetation of perennial field boundaries have important ecological functions such as providing a habitat for farmland wildlife, providing overwintering sites for predatory insects, providing movement corridors, reducing soil erosion and acting as an agrochemical bu

  17. Temporal variations in microbial biomass C and cellulolytic enzyme activity in arable soils: effects of organic matter input

    DEFF Research Database (Denmark)

    Debosz, K.; Rasmussen, Peter Have; Pedersen, A. R.

    1999-01-01

    -OM). The cultivation systems differed in whether their source of fertiliser was mainly mineral or organic, in whether a winter cover crop was grown, and whether straw was mulched or removed. Sampling occurred at approximately monthly intervals, over a period of two years. Distinct temporal variations in microbial...

  18. The Effect of Land Use Change on Transformation of Relief and Modification of Soils in Undulating Loess Area of East Poland

    Directory of Open Access Journals (Sweden)

    Jerzy Rejman

    2014-01-01

    Full Text Available The change of primary forest areas into arable land involves the transformation of relief and modification of soils. In this study, we hypothesized that relatively flat loess area was largely transformed after the change of land use due to erosion. The modifications in soil pedons and distribution of soil properties were studied after 185 years of arable land use. Structure of pedons and solum depth were measured in 128 and soil texture and soil organic carbon in 39 points. Results showed that soils of noneroded and eroded profiles occupied 14 and 50%, respectively, and depositional soils 36% of the area. As a consequence, the clay, silt, and SOC concentration varied greatly in the plowed layer and subsoil. The reconstructed profiles of eroded soils and depositional soils without the accumulation were used to develop the map of past relief. The average inclination of slopes decreased from 4.3 to 2.2°, and slopes >5° vanished in the present topography. Total erosion was 23.8 Mg ha−1 year−1. From that amount, 88% was deposited within the study area, and 12% was removed outside. The study confirmed the hypothesis of the significant effect of the land use change on relief and soils in loess areas.

  19. Impact of cultivation year, nitrogen fertilization rate and irrigation water quality on soil salinity and soil nitrogen in saline-sodic paddy fields in Northeast China

    Science.gov (United States)

    Saline-sodic soils are a valuable potential arable land resource, and are widely distributed in the western Songnen Plain of Northeast China. Reclaiming and planting rice is an effective and feasible approach for improving saline-sodic soil and increasing food production. Assessment of the effective...

  20. Quantitative Study on the Relationship between Arable Land and Its Influencing Factors in Southern Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    Bin; GUO; Lin; PEI

    2015-01-01

    With the Southern Loess Plateau as the object of study,we select the nonbiological factors( physical factors),biological factors and human factors that affect the landscape of arable land to build indicator system. Using GIS,we perform the visualization expression and hierarchical storage of influencing factors to build 1 km × 1 km integrated vector and raster database of arable land landscape pattern and its influencing factors. Using spatial regression analysis,we determine the quantitative relationship between arable land landscape and its influencing factors. The results show that the arable land in the Southern Loess Plateau is mainly distributed in the regions with high temperature,great average annual precipitation,high altitude,high soil N content,small slope,GDP per unit area of land,low ≥10℃ accumulated temperature,and short distance away from the rivers and roads. The study provides a scientific basis for clarifying the relationship between arable land landscape and its influencing factors.

  1. Proton accumulation accelerated by heavy chemical nitrogen fertilization and its long-term impact on acidifying rate in a typical arable soil in the Huang-Huai-Hai Plain

    Institute of Scientific and Technical Information of China (English)

    HUANG Ping; ZHANG Jia-bao; XIN Xiu-li; ZHU An-ning; ZHANG Cong-zhi; MA Dong-hao; ZHU Qiang-gen; YANG Shan; WU Sheng-jun

    2015-01-01

    Cropland productivity has been signiifcantly impacted by soil acidiifcation resulted from nitrogen (N) fertilization, especialy as a result of excess ammoniacal N input. With decades’ intensive agricultural cultivation and heavy chemical N input in the Huang-Huai-Hai Plain, the impact extent of induced proton input on soil pH in the long term was not yet clear. In this study, acidiifcation rates of different soil layers in the soil proifle (0–120 cm) were calculated by pH buffer capacity (pHBC) and net input of protons due to chemical N incorporation. Topsoil (0–20 cm) pH changes of a long-term fertilization ifeld (from 1989) were determined to validate the predicted values. The results showed that the acid and alkali buffer capacities varied signiifcantly in the soil proifle, averaged 692 and 39.8 mmolc kg–1 pH–1, respectively. A signiifcant (P<0.05) correlation was found between pHBC and the content of calcium carbonate. Based on the commonly used application rate of urea (500 kg N ha–1 yr–1), the induced proton input in this region was predicted to be 16.1 kmol ha–1 yr–1, and nitriifcation and plant uptake of nitrate were the most important mechanisms for proton producing and consuming, respectively. The acidiifcation rate of topsoil (0–20 cm) was estimated to be 0.01 unit pH yr–1 at the assumed N fertilization level. From 1989 to 2009, topsoil pH (0–20 cm) of the long-term fertilization ifeld decreased from 8.65 to 8.50 for the PK (phosphorus, 150 kg P2O5 ha–1 yr–1;potassium, 300 kg K2O ha–1 yr–1; without N fertilization), and 8.30 for NPK (nitrogen, 300 kg N ha–1 yr–1; phosphorus, 150 kg P2O5 ha–1 yr–1; potassium, 300 kg K2O ha–1 yr–1), respectively. Therefore, the apparent soil acidiifcation rate induced by N fertilization equaled to 0.01 unit pH yr–1, which can be a reference to the estimated result, considering the effect of atmospheric N deposition, crop biomass, ifeld management and plant uptake of other

  2. Effects of digestate on soil chemical and microbiological properties: A comparative study with compost and vermicompost.

    Science.gov (United States)

    Gómez-Brandón, María; Juárez, Marina Fernández-Delgado; Zangerle, Matthias; Insam, Heribert

    2016-01-25

    Anaerobic digestion has become increasingly popular as an alternative for recycling wastes from different origins. Consequently, biogas residues, most of them with unknown chemical and biological composition, accrue in large quantities and their application into soil has become a widespread agricultural practise. The aim of this study was to evaluate the effects of digestate application on the chemical and microbiological properties of an arable soil in comparison with untreated manure, compost and vermicompost. Once in the soil matrix either the addition of compost or digestate led to an increased nitrification rate, relative to unamended and manure-treated soil, after 15 and 60 days of incubation. Faecal coliform and E. coli colony forming units (CFUs) were not detected in any of the amended soils after 60 days. The highest number of Clostridium perfringens CFUs was recorded in manure-amended soil at the beginning of the experiment and after 15 days; whilst after 60 days the lowest CFU number was registered in digestate-treated soil. Denaturing gradient gel electrophoresis patterns also showed that besides the treatment the date of sampling could have contributed to modifications in the soil ammonia-oxidising bacteria community, thereby indicating that the soil itself may influence the community diversity more strongly than the treatments.

  3. Changes in the Bacterial Community Structure of Remediated Anthracene-Contaminated Soils.

    Science.gov (United States)

    Delgado-Balbuena, Laura; Bello-López, Juan M; Navarro-Noya, Yendi E; Rodríguez-Valentín, Analine; Luna-Guido, Marco L; Dendooven, Luc

    2016-01-01

    Mixing soil or adding earthworms (Eisenia fetida (Savigny, 1826)) accelerated the removal of anthracene, a polycyclic aromatic hydrocarbon, from a pasture and an arable soil, while a non-ionic surfactant (Surfynol® 485) inhibited the removal of the contaminant compared to the untreated soil. It was unclear if the treatments affected the soil bacterial community and consequently the removal of anthracene. Therefore, the bacterial community structure was monitored by means of 454 pyrosequencing of the 16S rRNA gene in the pasture and arable soil mixed weekly, amended with Surfynol® 485, E. fetida or organic material that served as food for the earthworms for 56 days. In both soils, the removal of anthracene was in the order: mixing soil weekly (100%) > earthworms applied (92%) > organic material applied (77%) > untreated soil (57%) > surfactant applied (34%) after 56 days. There was no clear link between removal of anthracene from soil and changes in the bacterial community structure. On the one hand, application of earthworms removed most of the contaminant from the arable soil and had a strong effect on the bacterial community structure, i.e. a decrease in the relative abundance of the Acidobacteria, Chloroflexi and Gemmatimonadetes, and an increase in that of the Proteobacteria compared to the unamended soil. Mixing the soil weekly removed all anthracene from the arable soil, but had little or no effect on the bacterial community structure. On the other hand, application of the surfactant inhibited the removal of anthracene from the arable soil compared to the untreated soil, but had a strong effect on the bacterial community structure, i.e. a decrease in the relative abundance of Cytophagia (Bacteroidetes), Chloroflexi, Gemmatimonadetes and Planctomycetes and an increase in that of the Flavobacteria (Bacteroidetes) and Proteobacteria. Additionally, the removal of anthracene was similar in the different treatments of both the arable and pasture soil, but the

  4. An interdisciplinary approach towards improved understanding of soil deformation during compaction

    DEFF Research Database (Denmark)

    Keller, T.; Lamandé, Mathieu; Peth, S.;

    2013-01-01

    highlight the important role of technological advances in non-destructive measurement methods at pore (X-ray tomography) and soil profile (seismic) scales that not only offer new insights into soil architecture and enable visualization of soil deformation, but are becoming instrumental in the development...... and deformation processes in arable soils remains limited. Yet such knowledge is essential for better predictions of effects of soil management practices such as agricultural field traffic on soil functioning. Concepts and theory used in agricultural soil mechanics (soil compaction and soil tillage) are often...... mechanical processes, theoretical frameworks often differ and reflect disciplinary focus. We review concepts from different but complementary fields concerned with porous media mechanics and highlight opportunities for synergistic advances in understanding deformation and compaction of arable soils. We...

  5. Anthropogenic effects on soil micromycetes

    Directory of Open Access Journals (Sweden)

    Đukić Dragutin A.

    2007-01-01

    Full Text Available This paper is a synthesis of long-term investigations based on the effect of different authropogenic pollutants (mineral and organic fertilizers, heavy metals, contaminated irrigation water, nitrification inhibitor and detergents on the dynamics of soil fungi number. The investigations were performed at the Microbiology Department and trial fields of the Faculty of Agronomy in Čačak on smonitza and alluvium soils in field and under greenhouse conditions. Maize, wheat, barley and red clover were used as test plants in these studies. The quantitative composition of the fungi in the soils investigated was determined by the Čapek selective agar dilution method. The study results show that the number of soil fungi was dependent on the type and rate of agrochemicals used, on the growing season, and the soil zone the samples were taken from for the analysis. Lower nitrogen fertiliser rates (80 and 120 kg x ha-1 and organic fertilizers stimulated the development of soil fungi, unlike the rate of 150 kg x ha-1. Heavy metals, mercury and cadmium in particular, as well as high rates of the N-serve nitrification inhibitor, inhibited the development of this group of soil microorganisms. Generally, the adverse effect of contaminated irrigation water on the soil fungi was recorded in both soil types, and particularly in the smonitza under red clover. Low detergent (Meril concentrations did not have any significant effect on this group of microorganisms. In this respect, it can be concluded that the soil fungi number dynamics can be used in monitoring soils polluted by different toxinogenic substances.

  6. ANTHROPOGENIC EFFECTS ON SOIL MICROMYCETES

    Directory of Open Access Journals (Sweden)

    Dragutin A. Đukić

    2007-09-01

    Full Text Available This paper is a synthesis of long-term investigations based on the effect of different (mineral and organic fertilisers, heavy metals, contaminated irrigation water, nitrification inhibitor and detergents on the dynamics of soil fungi number. The investigations were performed at the Microbiology Department and trial fields of the Faculty of Agronomy in Cacak on smonitza and alluvium soils in field and greenhouse conditions. Maize, wheat, barley and red clover were used as test plants in these studies. The quantitative composition of the fungi in the soils investigated was determined by the Czapek selective agar dilution method. The study results show that the number of soil fungi was dependent on the type and rate of agrochemicals used, on the growing season and the soil zone the samples were taken from for the analysis. Lower nitrogen fertiliser rates (80 and 120 kg?ha-1 and organic fertilisers stimulated the development of soil fungi, unlike the rate of 150 kg?ha- 1. Heavy metals, mercury and cadmium in particular, as well as high rates of the N-serve nitrification inhibitor inhibited the development of this group of soil microorganisms. Generally, the adverse effect of contaminated irrigation water on the soil fungi was recorded in both soil types, and particularly in the smonitza under red clover. Low detergent (Meril concentrations did not have any significant effect on this group of microorganisms. In this respect, it can be concluded that the soil fungi number dynamics can be used in monitoring soils polluted by different toxinogenic substances.

  7. Bioavailability of {sup 137}Cs - geographical variability in Swedish forest- and arable soil. Construction of a database using GIS; Biotillgaenglighet av {sup 137}Cs - geografisk variation i svensk skogs- och aakermark. Uppbyggnad av databas med hjaelp av GIS

    Energy Technology Data Exchange (ETDEWEB)

    Heikkilae, Taina; Lindmark, Malin

    2000-12-01

    Soil acts as a sink for long-lived radionuclides such as {sup 137}Cs . The bioavailability and the plant root uptake of {sup 137}Cs are therefore influenced by chemical and physical characteristics of the soil. The aim of this study is to gather information about Swedish soil conditions, focusing on parameters known to influence the bioavailability of {sup 137}Cs and to indicate areas which may have a higher probability of containing persistent bioavailable {sup 137}Cs. This project was carried out in two parts. First, an information database on soil properties in Swedish forest and agricultural landscapes was constructed using GIS (Geographic Information System). Next, Swedish agricultural and forest soils were characterised according to low, intermediate and high estimated bioavailability of {sup 137}Cs. Agricultural soils were ranked according to clay and organic matter content; forest soils according to podzol, cambisol and peat. The physical and chemical properties of agricultural soils are quite different from forest soils. In contrast to forest soils, agricultural soils are characterised by reduced quantities of organic matter and a higher proportion of clay. Several investigations have indicated. a faster decline in {sup 137}Cs levels in agricultural soils when compared to forest soils. Due to these differences, these soil types are dealt with separately in this report.

  8. Biotic and abiotic properties mediating plant diversity effects on soil microbial communities in an experimental grassland.

    Science.gov (United States)

    Lange, Markus; Habekost, Maike; Eisenhauer, Nico; Roscher, Christiane; Bessler, Holger; Engels, Christof; Oelmann, Yvonne; Scheu, Stefan; Wilcke, Wolfgang; Schulze, Ernst-Detlef; Gleixner, Gerd

    2014-01-01

    Plant diversity drives changes in the soil microbial community which may result in alterations in ecosystem functions. However, the governing factors between the composition of soil microbial communities and plant diversity are not well understood. We investigated the impact of plant diversity (plant species richness and functional group richness) and plant functional group identity on soil microbial biomass and soil microbial community structure in experimental grassland ecosystems. Total microbial biomass and community structure were determined by phospholipid fatty acid (PLFA) analysis. The diversity gradient covered 1, 2, 4, 8, 16 and 60 plant species and 1, 2, 3 and 4 plant functional groups (grasses, legumes, small herbs and tall herbs). In May 2007, soil samples were taken from experimental plots and from nearby fields and meadows. Beside soil texture, plant species richness was the main driver of soil microbial biomass. Structural equation modeling revealed that the positive plant diversity effect was mainly mediated by higher leaf area index resulting in higher soil moisture in the top soil layer. The fungal-to-bacterial biomass ratio was positively affected by plant functional group richness and negatively by the presence of legumes. Bacteria were more closely related to abiotic differences caused by plant diversity, while fungi were more affected by plant-derived organic matter inputs. We found diverse plant communities promoted faster transition of soil microbial communities typical for arable land towards grassland communities. Although some mechanisms underlying the plant diversity effect on soil microorganisms could be identified, future studies have to determine plant traits shaping soil microbial community structure. We suspect differences in root traits among different plant communities, such as root turnover rates and chemical composition of root exudates, to structure soil microbial communities.

  9. Biotic and abiotic properties mediating plant diversity effects on soil microbial communities in an experimental grassland.

    Directory of Open Access Journals (Sweden)

    Markus Lange

    Full Text Available Plant diversity drives changes in the soil microbial community which may result in alterations in ecosystem functions. However, the governing factors between the composition of soil microbial communities and plant diversity are not well understood. We investigated the impact of plant diversity (plant species richness and functional group richness and plant functional group identity on soil microbial biomass and soil microbial community structure in experimental grassland ecosystems. Total microbial biomass and community structure were determined by phospholipid fatty acid (PLFA analysis. The diversity gradient covered 1, 2, 4, 8, 16 and 60 plant species and 1, 2, 3 and 4 plant functional groups (grasses, legumes, small herbs and tall herbs. In May 2007, soil samples were taken from experimental plots and from nearby fields and meadows. Beside soil texture, plant species richness was the main driver of soil microbial biomass. Structural equation modeling revealed that the positive plant diversity effect was mainly mediated by higher leaf area index resulting in higher soil moisture in the top soil layer. The fungal-to-bacterial biomass ratio was positively affected by plant functional group richness and negatively by the presence of legumes. Bacteria were more closely related to abiotic differences caused by plant diversity, while fungi were more affected by plant-derived organic matter inputs. We found diverse plant communities promoted faster transition of soil microbial communities typical for arable land towards grassland communities. Although some mechanisms underlying the plant diversity effect on soil microorganisms could be identified, future studies have to determine plant traits shaping soil microbial community structure. We suspect differences in root traits among different plant communities, such as root turnover rates and chemical composition of root exudates, to structure soil microbial communities.

  10. Anthrosols in Iron Age Shetland: Implications for Arable and Economic Activity

    DEFF Research Database (Denmark)

    2008-01-01

    The soils surrounding three Iron Age settlements on South Mainland, Shetland, were sampled and compared for indicators of soil amendment. Two of the sites (Old Scatness and Jarlshof) were on lower-lying, better-drained, sheltered land; the third (Clevigarth) was in an acid, exposed environment...... at a higher elevation. The hypothesis, based on previous regional assessments, soil thicknesses, and excavations at Old Scatness, was that the lowland sites would have heavily fertilized soils and that the thin upland soil would show little if any amendment. Our findings indicate that the Middle Iron Age...... soils at Old Scatness had extremely high phosphorus levels, while the soil at Jarlshof had lower levels of enhancement. At Clevigarth, where charcoal from the buried soil was 14C dated to the Neolithic and Bronze Age, there was no evidence of arable activity or soil amendment associated with the Iron...

  11. Effects of green manure storage and incorporation methods on nitrogen release and N2O emissions after soil application

    DEFF Research Database (Denmark)

    Carter, Mette Sustmann; Sørensen, Peter; Petersen, Søren O.;

    2014-01-01

    More efficient use of green manure-derived nitrogen (N) may improve crop yields and reduce environmental impacts in stockless organic arable farming. In this 3-month incubation study, we tested a new strategy where green manure leys are harvested and preserved until the following spring either...... as compost mixed with straw or as silage of harvested ley biomass. Grass-clover compost or silage was soil-incorporated by either simulated ploughing (green manure placed at 15 cm depth) or harrowing (green manure mixed into the upper 5-cm soil horizon) in order to assess treatment effects on net release...... release was observed for the composted grass-clover and straw mixture. In fact, soil incorporation of compost by harrowing caused temporal immobilization of soil mineral N. Silage incorporated by ploughing gave rise to largest N2O effluxes with silage-induced emissions corresponding to 0.3 % of applied...

  12. Changes in the Structure of a Nigerian Soil under Different Land Management Practices

    Directory of Open Access Journals (Sweden)

    Joshua Olalekan Ogunwole

    2015-06-01

    Full Text Available Quantification of soil physical quality (SPQ and pore size distribution (PSD can assist understanding of how changes in land management practices influence dynamics of soil structure, and this understanding could greatly improve the predictability of soil physical behavior and crop yield. The objectives of this study were to measure the SPQ index under two different land management practices (the continuous arable cropping system and natural bush fallow system, and contrast the effects of these practices on the structure of PSD using soil water retention data. Soil water retention curves obtained from a pressure chamber were fitted to van Genuchten’s equation, setting m (= 1-1/n. Although values for soil bulk density were high, soils under the continuous arable cropping system had good SPQ, and maintained the capacity to support root development. However, soils under the natural bush fallow system had a worse structure than the continuous arable system, with restrictions in available water capacity. These two management systems had different PSDs. Results showed the inferiority of the natural bush fallow system with no traffic restriction (which is the common practice in relation to the continuous arable cropping system in regard to physical quality and structure.

  13. Effects of crop rotation and soil tillage on weeds in organic farming

    Directory of Open Access Journals (Sweden)

    Schulz, Franz

    2014-02-01

    Full Text Available An organic long-term field experiment with two factors has been carried out since 1998 at the experimental station Gladbacherhof, University of Giessen. Effects of 3 different farm types (with lifestock raising, stockless farming with rotational set-aside, stockless farming only cash crops combined with 4 tillage treatments (mouldboard plough, two-layer-plough, reduced tillage depth and tillage without plough on plants, soil and environment have been investigated. This article presents results on the coverage rate of arable wild plants (weed coverage, the range of weed species, the abundance of C. arvense (L. Scop. (Canada thistle and the weed phytomass during harvest time of the main crops dependent on farm type and soil tillage. It can be concluded that, compared to conventional economic weed thresholds, the weed coverage was generally relatively low and only limited ranges of species were found. Wild arable plants probably did not have any impact on yields of the cultivated plants due to intensive mechanical regulatory measures. In stockless organic farming without alfalfa-grass in the crop rotation Cirsium arvense (L. Scop. (Canada thistle might become a problem whereas this perennial root-weed does not seem to raise a long term problem in a soil tillage system without ploughing. In all treatments the abundance of weeds like Galium aparine L. (catchweed bedstraw and Stellaria media L. (chickweed was high. However, none of the farm types or soil tillage systems succeeded in providing evidence of promoting rare species or encouraging biodiversity. In order to achieve this special support measures should be implemented.

  14. Effects of long-term use of different farming systems on some physical, chemical and microbiological parameters of soil quality

    Science.gov (United States)

    Gajda, Anna M.; Czyż, Ewa A.; Dexter, Anthony R.

    2016-04-01

    The aim of this study was to compare the effects of different farming systems (organic, integrated, conventional and monoculture) on some soil properties as: bulk density, contents of readily-dispersible clay, organic matter and particulate organic matter, and enzymatic activity measured in terms of the intensity of fluorescein diacetate hydrolysis. Soil under permanent grass was used as a control. The study was conducted on the 20 years lasting field experiment. Samples of Haplic Luvisol soil were collected twice a year on fields under winter wheat from the layers of 0-5, 5-10, 15-20, and 30-35 cm. Within arable soils the soil under organic farming contained the greatest amount of organic matter, which influenced strongly the readily-dispersible clay content, especially in the layer of 5-20 cm. The readily-dispersible clay content in soil under organic farming was 3 times lower, as compared to the conventional and monoculture farming. The highest contents of particulate organic matter 6.2 and 3.5 mg g-1 air dry soil, on average were measured in the 0-5 cm layer of control soil and soil under organic farming, respectively. Also, soil under organic farming and control soil from the depth of 0-5 cm showed 2-2.5 times greater activity of microorganisms in fluorescein diacetate hydrolysis than soil under conventional and monoculture farming. Increase of concentration of organic matter in soil under organic farming decreased soil bulk density. Statistical analysis showed significant correlations between studied parameters of soil quality and confirmed their effectiveness as indicators of disturbances in soil environment.

  15. Effects of biochar on organic matter dynamics in unamended soils and soils amended with municipal solid waste compost and sewage sludge

    Science.gov (United States)

    Plaza, César; Giannetta, Beatrice; Fernández, José M.; López-de-Sá, Esther G.; Gascó, Gabriel; Méndez, Ana; Zaccone, Claudio

    2015-04-01

    Biochar is a loosely-defined C-rich solid byproduct obtained from biomass pyrolysis, which is intended for use as a soil amendment. A full understanding of the agronomic and environmental potential of biochar, especially its potential as a C sequestration strategy, requires a full understanding of its effects on native soil organic matter, as well as of its interactions with other organic amendments applied to soil. Here we determined the organic C distribution in an arable soil amended with biochar at rates of 0 and 20 t ha-1 in a factorial combination with two types of organic amendment (viz. municipal solid waste compost and sewage sludge) in a field experiment under Mediterranean conditions. The analysis of variance revealed that biochar and organic amendment factors increased significantly total organic C and mineral-associated organic C contents, and had little effect on intra-macroaggregate and intra-microaggregate organic C pools. Free soil organic C content was significantly affected by biochar application, but not by the organic amendments. Especially noteworthy were the interaction effects found between the biochar and organic amendment factors for mineral-associated organic C contents, which suggested a promoting action of biochar on C stabilization in organically-amended soils.

  16. Effect of different soil washing solutions on bioavailability of residual arsenic in soils and soil properties.

    Science.gov (United States)

    Im, Jinwoo; Yang, Kyung; Jho, Eun Hea; Nam, Kyoungphile

    2015-11-01

    The effect of soil washing used for arsenic (As)-contaminated soil remediation on soil properties and bioavailability of residual As in soil is receiving increasing attention due to increasing interest in conserving soil qualities after remediation. This study investigates the effect of different washing solutions on bioavailability of residual As in soils and soil properties after soil washing. Regardless of washing solutions, the sequential extraction revealed that the residual As concentrations and the amount of readily labile As in soils were reduced after soil washing. However, the bioassay tests showed that the washed soils exhibited ecotoxicological effects - lower seed germination, shoot growth, and enzyme activities - and this could largely be attributed to the acidic pH and/or excessive nutrient contents of the washed soils depending on washing solutions. Overall, this study showed that treated soils having lower levels of contaminants could still exhibit toxic effects due to changes in soil properties, which highly depended on washing solutions. This study also emphasizes that data on the As concentrations, the soil properties, and the ecotoxicological effects are necessary to properly manage the washed soils for reuses. The results of this study can, thus, be utilized to select proper post-treatment techniques for the washed soils.

  17. Coupling a high resolution soil erosion model with an agro-ecosystem model of SOC dynamics. An approach to assess the potential environmental effect of the new Common Agricultural Policy on soil degradation

    Science.gov (United States)

    Borrelli, Pasqualle; Paustian, Keith; Panagos, Panos; Jones, Arwyn; Schütt, Brigitta; Lugato, Emanuele

    2016-04-01

    At the European Union level, the main mechanisms to promote a more sustainable and environmentally friendly agriculture was introduced by the Common Agricultural Policy (CAP) reform in 2003, through the Cross-compliance. According to this new regulation, the farmer support payments were regulated with respect to environmental, animal welfare and food safety standards. This brought to the Good Agricultural and Environmental Conditions (GAEC), firstly established by Council Regulation No. 1782/2003 and subsequently Council Regulation (EC) No 73/2009. The prevention of soil erosion and maintenance of soil organic matter were two of GAEC requirements, which each Member State was obliged to address through national standards such as: i) minimal soil cover maintenance (GAEC 4); ii) minimum land management reflecting site specific conditions to limit soil loss (GAEC 5) and iii) maintenance of soil organic matter level through appropriate practices including ban on burning arable stubbles (GAEC 6). Although Member States are required to verify whether the farmers are compliant with the regulations (Cross-compliance), the environmental effect of Good Agricultural and Environmental Conditions (GAEC) applications on erosion and carbon budgets are still little known and studied. To investigate the potential impacts of the GAEC, we coupled a high resolution erosion model based on Revised Universal Soil Loss Equation (RUSLE) with the CENTURY biogeochemical model (Land Use Policy, 50, 408-421; 2016). The Italian arable land was selected as a study area, since it is well-known to be highly sensitive to soil erosion. Multi scenario modelling approach was undertaken, i.e., i) a baseline scenario without scenario excluding GAEC (pre 2003 period); ii) a present scenario including the current GAEC standards (post 2003 period), and iii) a technical potential scenario assuming that the GAEC standards were applied to the entire Italian arable land. The results show a 10.8% decrease, from

  18. Estimation of soil-to-plant transfer factors of radiocesium in 99 wild plant species grown in arable lands 1 year after the Fukushima 1 Nuclear Power Plant accident.

    Science.gov (United States)

    Yamashita, Jun; Enomoto, Takashi; Yamada, Masao; Ono, Toshiro; Hanafusa, Tadashi; Nagamatsu, Tomohiro; Sonoda, Shoji; Yamamoto, Yoko

    2014-01-01

    One year after the deposition of radionuclides from the Fukushima 1 Nuclear Power Plant (A formal name is Fukushima Daiichi Nuclear Power Station) in March 2011, radiocesium (¹³⁴Cs, ¹³⁷Cs) concentrations ([Cs]) were comprehensively investigated in the wild plants of 99 species most of which were annual or summer green perennial herbs and started to grow from April 2012 at the heavily contaminated fields of paddy (three study sites) and upland (one study site) in Fukushima Prefecture. The survey was conducted three times (April, July and October) in the year. In each site, soils (soil cores of 5-cm depth) and plants (aerial shoots) were collected for determination of [Cs] on a dry weight basis, and then the transfer factor (TF) of radiocesium from soil to plant ([Cs]plant/[Cs]soil) was estimated in each species. The [Cs] values of both soils and plants largely varied. However, some species exhibited relatively high TF values (more than 0.4) (e.g., Athyrium yokoscense, Dryopteris tokyoensis, and Cyperus brevifolius), while others exhibited almost negligible values (less than 0.01) (e.g., Salix miyabeana, Humulus scandens, and Elymus tsukushiensis). In addition, judging from the 11 species grown in both paddy and upland fields, TF values were generally higher in the paddy fields. The estimation of phytoextraction efficiency of soil radiocesium by weed communities in the paddy fields suggests that the weed community is not a practical candidate for phytoremediation technique.

  19. The history and assessment of effectiveness of soil erosion control measures deployed in Russia

    Directory of Open Access Journals (Sweden)

    Valentin Golosov

    2013-09-01

    Full Text Available Research activities aimed at design and application of soil conservation measures for reduction of soil losses from cultivated fields started in Russia in the last quarter of the 19th century. A network of "zonal agrofor-estry melioration experimental stations" was organized in the different landscape zones of Russia in the first half of the 20th century. The main task of the experiments was to develop effective soil conservation measures for Russian climatic,soil and land use conditions. The most widespread and large-scale introduction of coun-termeasures to cope with soil erosion by water and wind into agricultural practice supported by serious governmental investments took place during the Soviet Union period after the Second World War. After the Soviet Union collapse in 1991 ,general deterioration of the agricultural economy sector and the absence of investments resulted in cessation of organized soil conservation measures application at the nation-wide level. However, some of the long-term erosion control measures such as forest shelter belts, artificial slope terracing, water diversion dams above formerly active gully heads survived until the present. In the case study of sediment redistribution within the small cultivated catchment presented in this paper an attempt was made to evaluate average annual erosion rates on arable slopes with and without soil conservation measures for two time intervals. It has been found that application of conservation measures on cultivated slopes within the experimental part of the case study catchment has led to a decrease of average soil loss rates by at least 2. 5 2. 8 times. The figures obtained are in good agreement with previously published results of direct monitoring of snowmelt erosion rates, reporting approximately a 3 -fold decrease of average snowmelt erosion rates in the experimental sub-catchment compared to a traditionally cultivated control sub-catchment. A substantial decrease of soil

  20. Carbon footprints of crops from organic and conventional arable crop rotations – using a life cycle assessment approach

    DEFF Research Database (Denmark)

    Knudsen, Marie Trydeman; Meyer-Aurich, A; Olesen, Jørgen E

    2014-01-01

    organic arable crop rotations with different sources of N supply. Data from long-term field experiments at three different locations in Denmark were used to analyse three different organic cropping systems (‘Slurry’, ‘Biogas’ and ‘Mulching’), one conventional cropping system (‘Conventional’) and a “No...... input” system as reference systems. The ‘Slurry’ and ‘Conventional’ rotations received slurry and mineral fertilizer, respectively, whereas the ‘No input’ was unfertilized. The ‘Mulching’ and ‘Biogas’ rotations had one year of grass-clover instead of a faba bean crop. The grass-clover biomass...... was incorporated in the soil in the ‘Mulching’ rotation and removed and used for biogas production in the ‘Biogas’ rotation (and residues from biogas production were simulated to be returned to the field). A method was suggested for allocating effects of fertility building crops in life cycle assessments...

  1. SoilEffects - start characterization of the experimental soil

    DEFF Research Database (Denmark)

    Løes, Anne-Kristin; Johansen, Anders; Pommeresche, Reidun

    Summary This report describes the establishment, experimental plan and initial soil characteristics of the field experiment linked to the project “Effects of anaerobically digested manure on soil fertility - establishment of a long-term study under Norwegian conditions” (SoilEffects, 2010......-14). The aim of the SoilEffects project is to identify potential risks and benefits for soil fertility when animal manure is anaerobically digested for biogas production. The field experiment was established on Tingvoll research farm in 2011. A biogas plant was built at this farm in 2010, to digest the manure...... from a herd of about 25 organically managed dairy cows. This report describes the initial characterization of the soil biology, chemistry and physics, along with the background of the project, the selection process of the research field and the project design. Effects of the manure treatment...

  2. Spatial Prediction Method of Available Potassium Contents in Arable Soil%耕地土壤速效钾含量的空间预测方法研究

    Institute of Scientific and Technical Information of China (English)

    王彬武; 周卫军; 马苏; 刘少坤; 王金国; 于良艺

    2011-01-01

    利用插值方法进行土壤属性的空间预测是土壤学科的研究热点之一,以土壤发生学相关信息作为辅助变量的克里格空间插值方法则少有研究.该文以成土母质多样的湖南省石门县为例,基于GS十、ArcGIS和Matlab,结合成土母质信息的克里格(PMK)插值方法,对研究区土壤速效钾空间分布进行了预测.结果表明,PMK法较好地解决了因成土母质间速效钾含量差异给预测带来的误差,预测精度较反距离权重(IDW)、普通克里格(OK)法分别提高了21.68%、16.43%;PMK法制作的空间预测图中速效钾分布突变而非渐变,较IDW、OK预测结果接近研究区实际情况,进而证明在成土母质较为复杂的地区,PMK法适合对土壤速效钾含量的预测.%There has been a great concern about using interpolation to predict soil properties in the soil science. At present, little information on using Pedology information as auxiliary variables to predict soil properties is available. In this paper, A study was initiated in Shimen County,Hunan Province, which has variety of parent materials,Based on GS+, ArcGIS and Matlab,using Kriging method combined with parent material information (PMK) to predict the spatial distribution of soil available K. PMK method could reduce the deviation that caused by the differences of AK content among various soil parent materials. Comparing to Inverse Distance Weighted (IDW) .Ordinary Kriging (OK) method,predicting precision was raised 21. 68% and 16. 43% .respectively. The polygons of predicting map generated by PMK method distributes are mutational rather than gradual, which shows more closely to the actual situation of the study area. PMK method is more suitable to predict the AK in the region, where has complicated parent materials.

  3. Effectiveness of the GAEC standard of cross compliance Management of set aside on soil erosion control

    Directory of Open Access Journals (Sweden)

    Paolo Bazzoffi

    2011-08-01

    Full Text Available The GAEC standard Management of set aside is applied to arable lands subjected to set aside and kept non-cultivated throughout the year. The standard is also applied to other set aside areas eligible for direct payments. For the implementation of this Standard, the farmer must assure the presence of natural or artificial green cover on the surface throughout the year and adopt consistent agronomic practices as mowing, or other equivalent, in order to maintain the normal state of soil fertility, protect wildlife, prevent the formation of a potential inoculum of fires, especially during drought and prevent the spread of weeds. Up to the CAP Health Check the legislation on the set aside required the farmer to plough the soil by mid-May. Therefore, the natural vegetation cover could neither establish nor express its value against erosion throughout the year. Since mid 2004, cross compliance has banned ploughing of set aside surfaces. This novelty is very important in relation to the effectiveness of the standard in erosion control. In Italy there are only few studies carried out in the field that have measured the effect of set aside on soil erosion. The few existing experiments regarded the effect of set aside managed in accordance with the CAP dictates prior to the CAP Health Check. The results of case studies show very contrasting results regarding soil erosion on set aside plots managed through the annual ploughing in the period in which this rule remained in force. This finding can be explained by considering that most of soil erosion in the Mediterranean environment is determined by extreme events; so, set aside resulted ineffective in protecting the soil, when very erosive events occurred on bare soil (soil in seed bed condition after ploughing and harrowing or when the plant cover of soil was still scarce. In these conditions soil erosion rate resulted similar to that observed in the intensive cropping systems. On the contrary, for events

  4. Root Function in Nutrient Uptake and Soil Water Effect on NO3- -N and NH4+-N Migration

    Institute of Scientific and Technical Information of China (English)

    SONG Hai-xing; LI Sheng-xiu

    2006-01-01

    Root function in uptake of nutrients and the effect of soil water on the transfer and distribution of NO3--N in arable soil were studied using summer maize (Zea mays L. var. Shandan 9) as a testing crop. Results showed that root growth and water supply had a significant effect on NO3--N transfer and made NO3--N distributed evenly from bulk soil to rhizosphere soil. Under a natural condition with irrigation, the difference of NO3--N concentration at different distance points from a maize plant was smaller, while obvious difference of NO3--N concentration was observed under conditions of limited root growth space without irrigation. Whether root growth space was restricted or not, the content of soil NO3--N decreased gradually from 10 to 0 cm from the plant, being opposite to the root absorbing area in soils. When root-grown space was limited, changes of NO3--N concentration at different distances from a plant were similar to that of water content in tendency. Results showed that NO3--N could be transferred as solute to plant root systems with water uptake by plants.However, the transfer and distribution of NH4+-N were not influenced by root growth and soil water supply, being different to NO3--N.

  5. Land-cover effects on soil organic carbon stocks in a European city.

    Science.gov (United States)

    Edmondson, Jill L; Davies, Zoe G; McCormack, Sarah A; Gaston, Kevin J; Leake, Jonathan R

    2014-02-15

    Soil is the vital foundation of terrestrial ecosystems storing water, nutrients, and almost three-quarters of the organic carbon stocks of the Earth's biomes. Soil organic carbon (SOC) stocks vary with land-cover and land-use change, with significant losses occurring through disturbance and cultivation. Although urbanisation is a growing contributor to land-use change globally, the effects of urban land-cover types on SOC stocks have not been studied for densely built cities. Additionally, there is a need to resolve the direction and extent to which greenspace management such as tree planting impacts on SOC concentrations. Here, we analyse the effect of land-cover (herbaceous, shrub or tree cover), on SOC stocks in domestic gardens and non-domestic greenspaces across a typical mid-sized U.K. city (Leicester, 73 km(2), 56% greenspace), and map citywide distribution of this ecosystem service. SOC was measured in topsoil and compared to surrounding extra-urban agricultural land. Average SOC storage in the city's greenspace was 9.9 kg m(-2), to 21 cm depth. SOC concentrations under trees and shrubs in domestic gardens were greater than all other land-covers, with total median storage of 13.5 kg m(-2) to 21 cm depth, more than 3 kg m(-2) greater than any other land-cover class in domestic and non-domestic greenspace and 5 kg m(-2) greater than in arable land. Land-cover did not significantly affect SOC concentrations in non-domestic greenspace, but values beneath trees were higher than under both pasture and arable land, whereas concentrations under shrub and herbaceous land-covers were only higher than arable fields. We conclude that although differences in greenspace management affect SOC stocks, trees only marginally increase these stocks in non-domestic greenspaces, but may enhance them in domestic gardens, and greenspace topsoils hold substantial SOC stores that require protection from further expansion of artificial surfaces e.g. patios and driveways.

  6. Observation of high seasonal variation in community structure of denitrifying bacteria in arable soil receiving artificial fertilizer and cattle manure by determining T-RFLP of nir gene fragments

    DEFF Research Database (Denmark)

    Priemé, Anders; Wolsing, Martin

    2004-01-01

    Temporal and spatial variation of communities of soil denitrifying bacteria at sites receiving mineral fertilizer (60 and 120 kg N ha-1 year-1) and cattle manure (75 and 150 kg N ha-1 year-1) were explored using terminal restriction fragment length polymorphism (T-RFLP) analyses of PCR amplified...... a significant seasonal shift in the community structure of nirK-containing bacteria. Also, sites treated with mineral fertilizer or cattle manure showed different communities of nirK-containing denitrifying bacteria, since the T-RFLP patterns of soils treated with these fertilizers were significantly different...... nitrite reductase (nirK and nirS) gene fragments. The analyses were done three times during the year: in March, July and October. nirK gene fragments could be amplified in all three months, whereas nirS gene fragments could be amplified only in March. Analysis of similarities in T-RFLP patterns revealed...

  7. Correspondence of ectomycorrhizal diversity and colonisation of willows (Salix spp.) grown in short rotation coppice on arable sites and adjacent natural stands.

    Science.gov (United States)

    Hrynkiewicz, Katarzyna; Toljander, Ylva K; Baum, Christel; Fransson, Petra M A; Taylor, Andy F S; Weih, Martin

    2012-11-01

    Willows (Salix spp.) are mycorrhizal tree species sometimes cultivated as short rotation coppice (SRC) on arable sites for energy purposes; they are also among the earliest plants colonising primary successional sites in natural stands. The objective of this study was to analyse the degree of colonisation and diversity of ectomycorrhizal (EM) communities on willows grown as SRC in arable soils and their adjacent natural or naturalized stands. Arable sites usually lack ectomycorrhizal host plants before the establishment of SRC, and adjacent natural or naturalized willow stands were hypothesized to be a leading source of ectomycorrhizal inoculum for the SRC. Three test sites including SRC stands (Salix viminalis, Salix dasyclados, and Salix schwerinii) and adjacent natural or naturalized (Salix caprea, Salix fragilis, and Salix × mollissima) stands in central Sweden were investigated on EM colonisation and morphotypes, and the fungal partners of 36 of the total 49 EM fungi morphotypes were identified using molecular tools. The frequency of mycorrhizas in the natural/naturalized stands was higher (two sites) or lower (one site) than in the corresponding cultivated stands. Correspondence analysis revealed that some EM taxa (e.g. Agaricales) were mostly associated with cultivated willows, while others (e.g. Thelephorales) were mostly found in natural/naturalized stands. In conclusion, we found strong effects of sites and willow genotype on EM fungi formation, but poor correspondence between the EM fungi abundance and diversity in SRC and their adjacent natural/naturalized stands. The underlying mechanism might be selective promotion of some EM fungi species by more effective spore dispersal.

  8. Possibilities for modelling the effect of compression on mechanical and physical properties of various Dutch soil types

    NARCIS (Netherlands)

    Perdok, U.D.; Kroesbergen, B.; Hoogmoed, W.B.

    2002-01-01

    The state of compactness of the arable soil layer changes during the growing season as a result of tillage and traction. The aim of this study was to assess and predict some soil mechanical and physical properties governing machine performance and crop response. The following mechanical properties w

  9. Assessing soil carbon lability by near infrared spectroscopy and NaOCl oxidation

    DEFF Research Database (Denmark)

    Thomsen, Ingrid Kaag; Bruun, Sander; Jensen, Lars S;

    2009-01-01

    The feasibility of near infrared (NIR) spectroscopy for quantifying labile organic matter (OM) in arable soils and for predicting soil refractory OM fractions was tested on 37 soils varying in texture and soil carbon (C) content. Three sets of arable soils (0-20 cm depth) were sampled from 1) long...

  10. Tillage Effects on Soil Properties & Respiration

    Science.gov (United States)

    Rusu, Teodor; Bogdan, Ileana; Moraru, Paula; Pop, Adrian; Duda, Bogdan; Cacovean, Horea; Coste, Camelia

    2015-04-01

    Soil tillage systems can be able to influence soil compaction, water dynamics, soil temperature and soil structural condition. These processes can be expressed as changes of soil microbiological activity, soil respiration and sustainability of agriculture. Objectives of this study were: 1) to assess the effects of tillage systems (Conventional System-CS, Minimum Tillage-MT, No-Tillage-NT) on soil compaction, soil temperature, soil moisture and soil respiration and 2) to establish the relationship that exists in changing soil properties. Three treatments were installed: CS-plough + disc; MT-paraplow + rotary grape; NT-direct sowing. The study was conducted on an Argic-Stagnic Faeoziom. The MT and NT applications reduce or completely eliminate the soil mobilization, due to this, soil is compacted in the first year of application. The degree of compaction is directly related to soil type and its state of degradation. The state of soil compaction diminished over time, tending toward a specific type of soil density. Soil moisture was higher in NT and MT at the time of sowing and in the early stages of vegetation and differences diminished over time. Moisture determinations showed statistically significant differences. The MT and NT applications reduced the thermal amplitude in the first 15 cm of soil depth and increased the soil temperature by 0.5-2.20C. The determinations confirm the effect of soil tillage system on soil respiration; the daily average was lower at NT (315-1914 mmoli m-2s-1) and followed by MT (318-2395 mmoli m-2s-1) and is higher in the CS (321-2480 mmol m-2s-1). Comparing with CS, all the two conservation tillage measures decreased soil respiration, with the best effects of no-tillage. An exceeding amount of CO2 produced in the soil and released into the atmosphere, resulting from aerobic processes of mineralization of organic matter (excessive loosening) is considered to be not only a way of increasing the CO2 in the atmosphere, but also a loss of

  11. Perennial crop phase effects on soil fertility

    Science.gov (United States)

    There is a need to develop agricultural management systems that enhance soil fertility and reduce reliance on external inputs. Perennial phases in crop rotations are effective at restoring soil fertility, though little information exists in the northern Great Plains regarding soil-based outcomes re...

  12. Surfactant effects on soil aggregate tensile strength

    Science.gov (United States)

    Little is known regarding a soil aggregate's tensile strength response to surfactants that may be applied to alleviate soil water repellency. Two laboratory investigations were performed to determine surfactant effects on the tensile strength of 1) Ap horizons of nine wettable, agricultural soils co...

  13. Effect of long-term compost and inorganic fertilizer application on background N2O and fertilizer-induced N2O emissions from an intensively cultivated soil.

    Science.gov (United States)

    Ding, Weixin; Luo, Jiafa; Li, Jie; Yu, Hongyan; Fan, Jianling; Liu, Deyan

    2013-11-01

    The influence of inorganic fertilizer and compost on background nitrous oxide (N2O) and fertilizer-induced N2O emissions were examined over a maize-wheat rotation year from June 2008 to May 2009 in a fluvo-aquic soil in Henan Province of China where a field experiment had been established in 1989 to evaluate the long-term effects of manure and fertilizer on soil organic status. The study involved five treatments: compost (OM), fertilizer NPK (nitrogen-phosphorus-potassium, NPK), half compost N plus half fertilizer N (HOM), fertilizer NK (NK), and control without any fertilizer (CK). The natural logarithms of the background N2O fluxes were significantly (Pcompost alone and inorganic fertilizer not only significantly (Pcompost application, then partially increasing N supply to crops instead of adding inorganic N fertilizer, may be an effective measure to mitigate N2O emissions from arable soils in the North China plain.

  14. Effects of different management practices on fungal biodiversity in agricultural soils

    Science.gov (United States)

    Borriello, R.; Lumini, E.; Bonfante, P.; Bianciotto, V.

    2009-04-01

    Symbiotic associations between arbuscular mycorrhizal fungi (AMF) and plant roots are widespread in natural environments and provide a range of benefits to the host plant. These include improved nutrition, enhanced resistance to soil-borne pests, diseases, and drought, as well as tolerance to heavy metals. In addition, the presence of a well developed AMF hyphal network improve the soil structure. As obligate mutualistic symbionts these fungi colonize the roots of many agricultural crops and it is often claimed that agricultural practices (use of fertilizers and biocides, tillage, dominance of monocultures and the growing of non-mycorrhizal crops) are detrimental to AMF. As a result, agro ecosystems impoverished in AMF may not get the fully expected range of benefits from these fungi. Using molecular markers on DNA extracted directly from soil and roots we studied the effects of different management practices (tillage and nitrogen fertilization) on the AMF populations colonizing an experimental agro ecosystem in Central Italy. Fungi in roots and soil were identified by cloning and sequencing a region of ~550bp of the 18S rDNA and ~600bp of the 28S rDNA. In symbiosis with the maize roots we detected only members of Glomeraceae group A that showed decrement in number under nitrogen fertilization. Instead in soil were mainly present members of two AMF groups, respectively Gigasporaceae and Glomeraceae group A. In addition only the low input management practices preserve also members of Diversisporaceae and Glomeraceae group B. From our study we can conclude that agricultural practices can directly or indirectly influence AMF biodiversity. The result of this study highlight the importance and significant effects of the long term nitrogen fertilization and tillage practices on specific groups of fungi playing a key role in arable soils. The research was founded by Biodiversity Project (IPP-CNR) and by SOILSINK (FISR-MIUR)

  15. Layout method for monitoring sample point of arable land quality level based on combination of factors%基于因素组合的耕地质量等级监测样点布控方法

    Institute of Scientific and Technical Information of China (English)

    余述琼; 张蚌蚌; 相慧; 孔祥斌

    2014-01-01

    科学确定耕地质量等级监测样点布控方法,形成中国耕地质量动态监测布控体系,是掌握耕地质量动态、支撑国家粮食安全的重要技术依据。该文基于标准样地设置,以滇黔高原山地区为例,提出以耕地质量等别为控制,熟制—土壤类型—海拔—土地利用系数—土地经济系数因素组合确定监测样点的方法,即因素组合法;其步骤为:根据因素组合类型初步确定监测点数量;依据面积比例修正各等别监测点数量;基于GIS确定和选取监测点空间位置和来源,形成监测样点;构建模型对监测点代表性进行检验。结果表明,滇黔高原山地区确定144个监测样点,其中7个来源于国家级标准样地,44个来源于省级标准样地,93个来源于耕地分等单元图斑;采用因素组合法形成滇黔高原山地区监测样点,能够实现国家尺度上二级区内对耕地质量变化的动态监测,监测样点满足统计学要求和面积代表性。基于因素组合的耕地质量监测样点布控方法,可以为建立覆盖全国的耕地质量监测体系提供借鉴,为中国耕地数量、质量并重的宏观管理提供技术支撑。%With the stability of arable land’s quantity, monitoring land quality has become a high priority research for understanding the effects of the dynamic change of arable land on food security in China, as well as the layout method on monitoring arable land quality change. However, there are integrated factors such as climate, terrain, soil, access to irrigation, rural road, trade-off between input and output, which affect arable land quality change over time and space. We propose a new monitoring framework titled factors’ combination, which includes such factors affecting arable land quality as natural conditions (e.g., climate, soil, geomorphology), the utilization of level (e.g., farmland infrastructure, land management, land use

  16. Less or More Intensive Crop Arable Systems of Alentejo Region of Portugal: what is the sustainable option?

    Directory of Open Access Journals (Sweden)

    Carlos Marques

    2015-03-01

    Full Text Available Competitiveness of traditional arable crop system of Alentejo region of Portugal has been questioned for long. Discussion and research on the sustainability of the system has evolved on two contrasted alternative options for production technologies to traditional system. On the one hand reduced and no tillage systems aim to more extensive technical operations reducing costs and maintaining production, or even to increase it in the long run as soil fertility improves. On the other hand, input intensification using irrigation, as a complement in the last stage of crop cycle or always when needed, aimed to increase system production levels. To evaluate competitiveness and sustainability of arable crop system we evaluated traditional rotation technology and alternative no tillage and irrigation systems and analyze their farm economic results as well as their energy efficiency and environmental impacts. The analysis of the impact of no tillage and irrigation on arable land production system showed that both alternatives contributed to cost savings and profit earnings, energy savings and reduced GHG emissions, increasing physical and economic factor efficiency. Research and technological development of both options are worthwhile to promote competitiveness and sustainability of arable crop production systems of the Alentejo region in Portugal.

  17. Fire effects on soils: the human dimension.

    Science.gov (United States)

    Santín, Cristina; Doerr, Stefan H

    2016-06-05

    Soils are among the most valuable non-renewable resources on the Earth. They support natural vegetation and human agro-ecosystems, represent the largest terrestrial organic carbon stock, and act as stores and filters for water. Mankind has impacted on soils from its early days in many different ways, with burning being the first human perturbation at landscape scales. Fire has long been used as a tool to fertilize soils and control plant growth, but it can also substantially change vegetation, enhance soil erosion and even cause desertification of previously productive areas. Indeed fire is now regarded by some as the seventh soil-forming factor. Here we explore the effects of fire on soils as influenced by human interference. Human-induced fires have shaped our landscape for thousands of years and they are currently the most common fires in many parts of the world. We first give an overview of fire effect on soils and then focus specifically on (i) how traditional land-use practices involving fire, such as slash-and-burn or vegetation clearing, have affected and still are affecting soils; (ii) the effects of more modern uses of fire, such as fuel reduction or ecological burns, on soils; and (iii) the ongoing and potential future effects on soils of the complex interactions between human-induced land cover changes, climate warming and fire dynamics.This article is part of the themed issue 'The interaction of fire and mankind'.

  18. Microbial effect on soil hydraulic properties

    Science.gov (United States)

    Furman, Alex; Rosenzweig, Ravid; Volk, Elazar; Rosenkranz, Hella; Iden, Sascha; Durner, Wolfgang

    2014-05-01

    Although largely ignored, the soil contains large amount of biofilms (attached microbes) that can affect many processes. While biochemical processes are studied, biophysical processes receive only little attention. Biofilms may occupy some of the pore space, and by that affect the soil hydraulic properties. This effect on unsaturated soils, however, was not intensively studied. In this research we directly measure the hydraulic properties, namely the soil's unsaturated hydraulic conductivity function and retention curve, for soils containing real biofilm. To do that we inoculate soil with biofilm-forming bacteria and incubate it with sufficient amounts of nutrient until biofilm is formed. The hydraulic properties of the incubated soil are then measured using several techniques, including multi-step outflow and evaporation method. The longer measurements (evaporation method) are conducted under refrigeration conditions to minimize microbial activity during the experiment. The results show a clear effect of the biofilm, where the biofilm-affected soil (sandy loam in our case) behaves like a much finer soil. This qualitatively makes sense as the biofilm generates an effective pore size distribution that is characterized by smaller pores. However, the effect is much more complex and needs to be studied carefully considering (for example) dual porosity models. We compare our preliminary results with other experiments, including flow-through column experiments and experiments with biofilm analogues. Clearly a better understanding of the way microbial activity alters the hydraulic properties may help designing more efficient bioremediation, irrigation, and other soil-related processes.

  19. Effect of the slope and initial moisture content on soil loss, aggregate and particle size distribution

    Science.gov (United States)

    Szabó, Judit Alexandra; Jakab, Gergely; Szabó, Boglárka

    2015-04-01

    Soil structure degradation has effect through the soil water balance and nutrient supply on the agricultural potential of an area. The soil erosion process comprises two phases: detachment and transport by water. To study the transport phase nozzle type laboratory-scale rainfall simulator was used with constant 80 mmhr-1 intensity on an arable haplic Cambisol. Measuring the aggregate and particle size distribution of the soil loss gives a good approach the erosion process. The primary objective of this study was to examine the sediment concentration, and detect the quality and quantity change of the soil loss during a single precipitation under six treatment combinations (recently tilled and crusty soil surface on two different slope steepness, inland inundation and drought soil conditions). Soil loss were collected continually, and separated per aggregate size fractions with sieves in three rounds during a rain to measure the weights. The particle size distribution was measured with Horiba LA-950 particle size analyzer. In general the ratio of the macro aggregates decreases and the ratio of the micro aggregates and clay fraction increases in the sediment with time during the precipitation due to the raindrop impact. Sediment concentration depends on the slope steepness, as from steeper slopes the runoff can transport bigger amount of sediment, but from the tilled surface bigger aggregates were washing down. Micro aggregate fraction is one of the indicators of good soil structure. The degradation of micro aggregates occurs in steeper slopes and the most erosive time period depends on the micromorphology of the surface. And while the aggregate size distribution of the soil loss of the treatments shows high variety of distribution and differs from the original soil, the particle size distribution of each aggregate size fraction shows similar trends except the 50-250 µm fraction where the fine sand fraction is dominating instead of the loam. This anomaly may be

  20. Uses of glyphosate in German arable farming – aspects of weed management and arable practice

    Directory of Open Access Journals (Sweden)

    Wiese, Armin

    2016-02-01

    Full Text Available Data on glyphosate use, personal attitudes and farm characteristics were collected in a Germany-wide inventory from 2026 farms. About 1700 farms could be analyzed in detail. Categories of glyphosate users were split into: non-users, low proportion users and high proportion users. The latter apply glyphosate on > 20% of their arable land are characterized by a high amount of non-inversion tillage, low labor effort and aboveaverage farm size. Perennial weeds play a less important role for glyphosate use than managing weed populations that are regarded as less susceptible to regular herbicides. Non-users and users of glyphosate differ in their attitude towards the benefits of glyphosate and the amount of glyphosate use in agriculture.

  1. Aging effects on molybdate lability in soils.

    Science.gov (United States)

    Kirby, Jason K; McLaughlin, Michael J; Ma, Yibing; Ajiboye, Babasola

    2012-10-01

    Aging reactions in soils can influence the lability and hence bioavailability of added metals in soils through their removal from labile pools into pools from which desorption is slow (non-labile pools). The aims of this study were to examine the effect of aging reactions on the lability of soluble molybdate (MoO(4)(2-)) added into soils with varying physical and chemical properties and develop models to predict changes in the labile pool of MoO(4)(2-) in soils with incubation time. Soils were spiked with soluble MoO(4)(2-) at quantities sufficient to inhibit barley root growth by 10% (EC(10)) or 90% (EC(90)) and incubated for up to 18 months. The labile pool of MoO(4)(2-) (E value) was observed to decrease in soils with incubation time, particularly in soils with high clay content. A strong relationship was observed between measures of MoO(4)(2-) lability in soils determined using E and L value techniques (R(2)=0.98) suggesting E values provided a good measure of the potential plant available pool of MoO(4)(2-) in soils. A regression model was developed that indicates clay content and incubation time were the most important factors affecting the labile pool of MoO(4)(2-) in soils with time after addition (R(2)=0.70-0.75). The aging model developed suggests soluble MoO(4)(2-) will be removed into non-labile pools more rapidly with time in neutral to alkaline clay soils than in acidic sandy soils. Labile MoO(4)(2-) concentrations in molybdenum (Mo) contaminated soils was found to be <10% of the total Mo concentrations in soils.

  2. Contamination of urban garden soils with copper and boron

    Energy Technology Data Exchange (ETDEWEB)

    Purves, D.

    1966-06-04

    Spectrochemical analyses of garden soils sampled in the Edinburgh and Dundee areas indicate that there is substantial contamination of urban soils with copper and boron. These soils were analyzed spectrochemically with respect to total copper and water-extractable boron content with the view of comparing the levels obtained in urban areas with levels in arable soils in rural areas. The results indicate that urban garden soils contain about four times as much copper and two to three times as much water-soluble boron as rural arable soils. The existence of such a marked disparity between the levels of two potentially toxic elements in urban and rural areas is evidence of slow poisoning of the soil environment in built-up areas and is cause for concern. While the major source of contamination of soils with copper and boron is still a matter for speculation, it is probable that the addition of soot to garden soils and the fall-out of sooty material in built-up areas where atmospheric pollution is a problem make a substantial contribution to the water-extractable boron content of urban soils. Three samples of soot from domestic chimneys, obtained from independent sources, were found on analysis to contain 640, 650 and 555 p.p.m. water-extractable boron, and it is evident that the addition to soil of even small amounts of soot with a boron content of this order would have a marked effect on its water-extractable boron content.

  3. Transformation of upper part soil profile of sod-podzolic light loamy soils under the conditions of long-term soil improvement

    Directory of Open Access Journals (Sweden)

    Nikolay S. Matyuk

    2013-01-01

    Full Text Available Arable sod-podzolic soils have the definite characteristics inherited from the virgin soils and obtained during the modern process of soil genesis under the influence of mankind activity. In arable soils hydrothermal conditions, biological turnover of nutrients change significantly that connected with their taking out with the yield and the compensation with mineral and organic fertilizers. The period of agricultural treatment of the soils indicates the total influence of the intensification factors and causes the changes in characteristics, regimes and fertility not only of arable layer, but lower layers of the upper part of soil profile (0-100 cm.

  4. EFFECTS OF SOIL FAUNA ON LITTER DECOMPOSITION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Forest litter is the physical makeup part of forest ecosystem. The rate of decomposition of forest litter is low in temperate and cool temperate zones. There is important significance to search and utilize the function of soil animals, in order to probe the material circulation and energy flow in forest ecosystem. We selected three kinds of mesh bag with different mesh size, in which, large pore mesh bag is large enough to permit the activities of all kinds of soil animals, medium mesh bag is designed to exclude the function of soil macrofauna, while small mesh bag is small enough to exclude the effects of any kind of soil animals as far as possible. The decomposition time is three years. The studying results show that: the decomposing speed of the bags with big meshes, under functions of all kinds of soil animals, faster than the bags with medium meshes, under functions of medium and small soil animals, as well as the bags with small meshes that excluding all possibility of functions of soil animals; in the process of decomposition of litter, relationship of the litter lost weight with number of soil animals is not obvious clearly; the degree of functions of soil animals to soft litter higher than hard litter; according to the analysis of diversity index, no regular changes will happen to the diversity of soil animals as the time of decomposing samples lengthen.

  5. Glyphosate applications on arable fields considerably coincide with migrating amphibians.

    Science.gov (United States)

    Berger, Gert; Graef, Frieder; Pfeffer, Holger

    2013-01-01

    Glyphosate usage is increasing worldwide and the application schemes of this herbicide are currently changing. Amphibians migrating through arable fields may be harmed by Glyphosate applied to field crops. We investigated the population-based temporal coincidence of four amphibian species with Glyphosate from 2006 to 2008. Depending on a) age- and species-specific main migration periods, b) crop species, c) Glyphosate application mode for crops, and d) the presumed DT50 value (12 days or 47 days) of Glyphosate, we calculated up to 100% coincidence with Glyphosate. The amphibians regularly co-occur with pre-sowing/pre-emerging Glyphosate applications to maize in spring and with stubble management prior to crop sowing in late summer and autumn. Siccation treatment in summer coincides only with early pond-leaving juveniles. We suggest in-depth investigations of both acute and long-term effects of Glyphosate applications on amphibian populations not only focussed on exposure during aquatic periods but also terrestrial life stages.

  6. Weed vegetation ecology of arable land in Salalah, Southern Oman.

    Science.gov (United States)

    El-Sheikh, Mohamed A

    2013-07-01

    This paper applies multivariate statistical methods to a data set of weed relevés from arable fields in two different habitat types of coastal and mountainous escarpments in Southern Oman. The objectives were to test the effect of environmental gradients, crop plants and time on weed species composition, to rank the importance of these particular factors, and to describe the patterns of species composition and diversity associated with these factors. Through the application of TWINSPAN, DCA and CCA programs on data relating to 102 species recorded in 28 plots and farms distributed in the study area, six plant communities were identified: I- Dichanthium micranthum, II- Cynodon dactylon-D. micranthum, III- Convolvulus arvensis, IV- C. dactylon-Sonchus oleraceus, V- Amaranthus viridis and VI- Suaeda aegyptiaca-Achyranthes aspera. The ordination process (CCA) provided a sequence of plant communities and species diversity that correlated with some anthropogenic factors, physiographic variables and crop types. Therefore, length of time since farm construction, disturbance levels and altitude are the most important factors related to the occurrence of the species. The perennial species correlated with the more degraded mountain areas of new farm stands, whereas most of the annuals correlated with old lowland and less disturbed farms.

  7. The Presence of Plants Alters the Effect of Soil Moisture on Soil C Decomposition in Two Different Soil Types

    Science.gov (United States)

    Dijkstra, F. A.; Cheng, W.

    2005-12-01

    While it is well known that soil moisture directly affects microbial activity and soil C decomposition, it is unclear if the presence of plants alters these effects through rhizosphere processes. We studied soil moisture effects on soil C decomposition with and without sunflower and soybean. Plants were grown in two different soil types with soil moisture contents of 45 and 85% of field capacity in a greenhouse experiment. We continuously labeled plants with depleted 13C, which allowed us to separate plant-derived CO2-C from original soil-derived CO2-C in soil respiration measurements. We observed an overall increase in soil-derived CO2-C efflux in the presence of plants (priming effect) in both soils with on average a greater priming effect in the high soil moisture treatment (60% increase in soil-derived CO2-C compared to control) than in the low soil moisture treatment (37% increase). Greater plant biomass in the high soil moisture treatment contributed to greater priming effects, but priming effects remained significantly higher after correcting for plant biomass. Possibly, root exudation of labile C may have increased more than plant biomass and may have become more effective in stimulating microbial decomposition in the higher soil moisture treatment. Our results indicate that changing soil moisture conditions can significantly alter rhizosphere effects on soil C decomposition.

  8. Effect of land use change on soil properties and functions

    Science.gov (United States)

    Tonutare, Tonu; Kõlli, Raimo; Köster, Tiina; Rannik, Kaire; Szajdak, Lech; Shanskiy, Merrit

    2014-05-01

    , and pedo-ecological conditions. LUC from natural to arable is accompanied by different regulations: (1) regular restoration of plant available nutrition elements' stocks in soil, (2) regulation (if needed) of water regime of gleyed and gley soils, (3) optimizing of soil actual acidity by liming, and (4) forming a suitable for crops seed bed instead of natural epipedon. Principal changes are occurred in fabric and agrochemical properties of topsoil and in soil functioning. The connected with LUC changes in soil functioning are: (1) increase of openness level of chemical elements cycling and nutrition elements concentration in phytomass, and (2) decrease of total phytomass, species diversity, amount of annual falling litter and content of mortmass in soil cover. These changes lead to decreasing of biological control on soil resources, flux of energy and substances to soil processes, and volume of cycling. At the same time the intensity of organic matter decomposition and outflow of nutrition elements are increased. All these changes are resulted by alteration of food chains and exhausting of nutrition elements' stocks. The changes in soil functioning (decrease or increase of productivity) depend much on soil type. The aspects of functioning, which do not changed with LUC are chemical-textural potential of soil cover and functioning character of subsoil. The sound matching of soil and plant cover is of decisive importance for sustainable functioning of ecosystem and in attaining a good environmental status of the area.

  9. Rhizosphere priming effects in two contrasting soils

    Science.gov (United States)

    Lloyd, Davidson; Kirk, Guy; Ritz, Karl

    2015-04-01

    Inputs of fresh plant-derived carbon may stimulate the turnover of existing soil organic matter by so-called priming effects. Priming may occur directly, as a result of nutrient 'mining' by existing microbial communities, or indirectly via population adjustments. However the mechanisms are poorly understood. We planted C4 Kikuyu grass (Pennisetum clandestinum) in pots with two contrasting C3 soils (clayey, fertile TB and sandy, acid SH), and followed the soil CO2 efflux and its δ13C. The extent of C deposition in the rhizosphere was altered by intermittently clipping the grass in half the pots; there were also unplanted controls. At intervals, pots were destructively sampled for root and shoot biomass. Total soil CO2 efflux was measured using a gas-tight PVC chamber fitted over bare soil, and connected to an infra-red gas analyser; the δ13C of efflux was measured in air sub-samples withdrawn by syringe. The extent of priming was inferred from the δ13C of efflux and the δ13C of the plant and soil end-members. In unclipped treatments, in both soils, increased total soil respiration and rhizosphere priming effects (RPE) were apparent compared to the unplanted controls. The TB soil had greater RPE overall. The total respiration in clipped TB soil was significantly greater than in the unplanted controls, but in the clipped SH soil it was not significantly different from the controls. Clipping affected plant C partitioning with greater allocation to shoot regrowth from about 4 weeks after planting. Total plant biomass decreased in the order TB unclipped > SH unclipped >TB clipped > SH clipped. The results are consistent with priming driven by microbial activation stimulated by rhizodeposits and by nitrogen demand from the growing plants under N limited conditions. Our data suggest that photosynthesis drives RPE and soil differences may alter the rate and intensity of RPE but not the direction.

  10. Land-use effects on flood generation – considering soil hydraulic measurements in modelling

    Directory of Open Access Journals (Sweden)

    A. Münch

    2009-08-01

    Full Text Available The investigation in the catchment of the Mulde (51°0'55" N, 13°15'54" E Saxony, Germany researches the effect of afforestation measures on the soil hydraulic properties. The concept of a "false chronosequence" was used to quantify the time-dependent dynamical character of the forest impact. Four adjacent plots were identified at a test location with comparable pedological start conditions and a set of tree stands of different age: (1 arable field (initial state; (2 6-year-old afforestation; (3 50-year-old afforestation; (4 ancient natural forest ("target" stocking. Water retention curves and unsaturated conductivities were analysed in the lab. In the field, the undisturbed infiltration capacities were measured quantitatively (hood infiltrometer and qualitatively (brilliant blue tracer. Pronounced differences between all 4 plots were detected. The afforestation causes an increased infiltration and soil water retention potential. Especially the topsoil layers showed a distinct increase in conductivity and portion of coarse/middle pores. The influence of these changes on rainfall-runoff calculations at the test location was analysed in this study.

  11. Arsenic Content in Arable Land of the Ząbkowice District

    Directory of Open Access Journals (Sweden)

    Kaszubkiewicz Jarosław

    2014-06-01

    Full Text Available The aim of this study was to determine the content of arsenic in soils used for agriculture in the Ząbkowicki district. The content of arsenic in collected soil samples ranged 1.1-569.5 mg·kg-1. The standard for arable lands of Group B has been exceeded in 24 out of 231 test points. The highest concentrations occurred in the Złoty Stok commune. This is due to the output of arsenic and gold in this area. Exceeding the standard also occurred in neighboring communes: Kamieniec Ząbkowicki and Ziębice. This is due to the blowing and washing pollutions form the source of contamination, the arsenic mines in the Złoty Stok commune.

  12. Effects of environmental factors and soil properties on topographic variations of soil respiration

    Directory of Open Access Journals (Sweden)

    K. Tamai

    2010-03-01

    Full Text Available Soil respiration rates were measured along different parts of a slope in (a an evergreen forest with common brown forest soil and (b a deciduous forest with immature soil. The effects of soil temperature, soil moisture and soil properties were estimated individually, and the magnitudes of these effects in the deciduous and evergreen forests were compared. In the evergreen forest with common brown forest soil, soil properties had the greatest effect on soil respiration rates, followed by soil moisture and soil temperature. These results may be explained by the fact that different soil properties matured within different environments. It can be argued that the low soil respiration rates in the low parts of the slope in the evergreen forest resulted from soil properties and not from wet soil conditions. In the deciduous forest, soil respiration rates were more strongly affected by soil moisture and soil temperature than by soil properties. These effects were likely due to the immaturity of the forest soil.

  13. Application of Remote Sensing and GIS Technology to the Study of Desertification of Arable Lands in North Shaanxi, China

    Institute of Scientific and Technical Information of China (English)

    Mushtak Talib Jabbar; HU Guangdao; ZHANG Zhenfei

    2004-01-01

    The policy of the Chinese government concerning the horizontal expansion of the cultivated land through the reclamation of desert soils result in a total increase of 665.985 km2 during the period 1987-1999 in North Shaanxi. This increase is less than the loss in arable land by urbanization. The accelerated rate of change in agricultural areas calls for more rapid surveys of urbanization and loss of arable land. Remote sensing has a number of advantages over ground-based methods for such surveys. The multi-scale concept of remote sensing data help us study the problem in four towns. Several maps were produced to analyze the situation of urban coverage in different times. The evaluation of the status, rate and risk of urbanization are based on an accepted average of urban increase as 2% of population growth per year.

  14. Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land

    Science.gov (United States)

    Zhou, L.; Liu, J. H.; Zhao, B. P.; Xue, A.; Hao, G. C.

    2016-08-01

    A 4-year experiment was conducted to investigate the inter-annual effects of sandy soil amendment on maize yield, soil water storage and soil enzymatic activities in sandy soil in Northeast China in 2010 to 2014. We applied the sandy soil amendment in different year, and investigated the different effects of sandy soil amendment in 2014. There were six treatments including: (1) no sandy soil amendment application (CK); (2) one year after applying sandy soil amendment (T1); (3) two years after applying sandy soil amendment(T2); (4) three years after applying sandy soil amendment(T3); (5)four years after applying sandy soil amendment(T4); (6) five years after applying sandy soil amendment (T5). T refers to treatment, and the number refers to the year after application of the sandy soil amendment. Comparing with CK, sandy soil amendments improved the soil water storage, soil urease, invertase, and catalase activity in different growth stages and soil layers, the order of soil water storage in all treatments roughly performed: T3 > T5 > T4 > T2 > T1 > CK. the order of soil urease, invertase, and catalase activity in all treatments roughly performed: T5 > T3 > T4 > T2 > T1 > CK. Soil application of sandy soil amendment significantly (p≤⃒0.05) increased the grain yield and biomass yield by 22.75%-41.42% and 29.92%-45.45% respectively, and maize yield gradually increased with the years go by in the following five years. Sandy soil amendment used in poor sandy soil had a positive effect on soil water storage, soil enzymatic activities and maize yield, after five years applied sandy soil amendment (T5) showed the best effects among all the treatments, and deserves further research.

  15. Effects of toxaphene on soil organisms.

    Science.gov (United States)

    Bezchlebová, Jitka; Cernohlávková, Jitka; Lána, Jan; Sochová, Ivana; Kobeticová, Klára; Hofman, Jakub

    2007-11-01

    The polychlorinated insecticide toxaphene belonged to the most used pesticides in the 20th century. Even recently, significant residues have been found in soils at various sites in the world. However, knowledge on toxicity to soil organisms is limited. In this study, the effects of toxaphene on soil invertebrates Folsomia candida, Eisenia fetida, Enchytraeus albidus, Enchytraeus crypticus, Caenorhabditis elegans, and microorganisms were investigated. Among the organisms tested, F. candida was the most sensitive. The 50% effect on survival and reproduction output (LC50 and EC50) was found at concentrations of 10.4 and 3.6 mg/kg, respectively. Sensitivity of other organisms was significantly lower with effective concentrations at tens or hundreds of mg/kg. Our data on soil toxicity were recalculated to soil pore-water concentrations and good accordance with available data reported for aquatic toxicity was found. Since soil concentrations at some sites are comparable to concentrations effective in our tests, toxaphene may negatively affect soil communities at these sites.

  16. Afforestation effects on soil carbon

    DEFF Research Database (Denmark)

    Bárcena, Teresa G

    Understanding carbon (C) dynamics has become increasingly important due to the major role of C in global warming. Soils store the largest amount of organic C in the biosphere; therefore, changes in this compartment can have a large impact on the C storage of an ecosystem. Land-use change is a main...... respiration. In Denmark chronosequences (i.e. space-for-time substitution) of oak and Norway spruce stands at the Vestskoven site were the tool used to explore these changes. Soil OC dynamics predicted by the chronosequence approach have often been used, however they never been validated by resampling before...... driver of changes in soil organic carbon (SOC) pools worldwide. In Europe, afforestation (i.e. the establishment of new forest on non-forested land), is a major land-use change driven by economic and environmental interests due to its role as a C sequestration tool following the ratification of the Kyoto...

  17. Field scale studies on the spatial variability of soil quality indicators in Washington State, USA

    Science.gov (United States)

    Arable lands are needed for sustainable agricultural systems to support an ever growing human population. Soil quality needs to be defined to assure the new arable land is sustainable. To evaluate soil quality a number of soil attributes will need to be measured, evaluated and integrated into a soi...

  18. Purchase of Catastrophe Insurance by Dutch Dairy and Arable Farmers

    NARCIS (Netherlands)

    Ogurtsov, V.; Asseldonk, van M.A.P.M.; Huirne, R.B.M.

    2009-01-01

    This article analyzed the impact of risk perception, risk attitude, and other farmer personal and farm characteristics on the actual purchase of catastrophe insurance by Dutch dairy and arable farmers. The specific catastrophe insurance types considered were hail–fire–storm insurance for buildings,

  19. Effect of cryogel on soil properties

    Science.gov (United States)

    Altunina, L. K.; Fufaeva, M. S.; Filatov, D. A.; Svarovskaya, L. I.; Rozhdestvenskii, E. A.; Gan-Erdene, T.

    2014-05-01

    Samples from the A1 and A1A2 horizons of sandy loamy gray forest soil containing 3.1% organic matter have been mixed with a 5% solution of polyvinyl alcohol (PVA) at a ratio of 7 : 1 under laboratory conditions. The samples were frozen at -20°C in a refrigerator; after a freezing-thawing cycle, the evaporation of water from their surface, their thermal conductivity coefficient, their elasticity modulus, and other properties were studied. It has been experimentally found that the thermal conductivity coefficient of cryostructured soil is lower than that of common soil by 25%. It has been shown that the cryostructured soil retains water for a longer time and that the water evaporation rate from its surface is significantly lower compared to the control soil. Cryogel has no negative effect on the catalase activity of soil; it changes the physical properties of soils and positively affects the population of indigenous soil microflora and the growth of the sown plants.

  20. Long-term effects of soil management on ecosystem services and soil loss estimation in olive grove top soils

    NARCIS (Netherlands)

    Parras-Alcántara, Luis; Lozano-García, Beatriz; Keesstra, Saskia; Cerdà, Artemi; Brevik, Eric C.

    2016-01-01

    Soil management has important effects on soil properties, runoff, soil losses and soil quality. Traditional olive grove (OG) management is based on reduced tree density, canopy size shaped by pruning and weed control by ploughing. In addition, over the last several decades, herbicide use has been

  1. The effects of the soil improvement by the desulfurization gypsum on the agricultural production and the Tianjin economy - the case study of China's Tianjin City

    Energy Technology Data Exchange (ETDEWEB)

    Asahi, S. [Yokkaichi University, Yokkaichi (Japan). Faculty of Environmental and Information Sciences

    2001-07-01

    This study examined the utilization of the desulfurization gypsum (by-product) as an inducement in installation the desulfurization equipment. In particular, this allocated the focus for increased yield of agricultural products by the by-product. The following conclusions can be drawn from this analysis. In the case where the soil was improved on a quarter of the arable land of the corn, the rate of the increase in 1995 was 1.85% of the total output for corn in Tianjin city. A year later, in 1996, the rate increased by 4.25% of total output for corn. Increased production by the soil improvement in the first year is equal to about 22000 persons, when increased production is evaluated at the consumption rate per farming village in China, and the repercussion effect of the increased yield of agricultural products benefits mostly the industrial sector. 6 refs., 1 fig., 2 tabs.

  2. Plant species richness and composition in the arable land of Kosovo

    Directory of Open Access Journals (Sweden)

    A. Mehmeti

    2009-03-01

    Full Text Available This study investigates today’s plant species richness and composition in cultivated and recently abandoned arable land of Kosovo. Relationships between these aspects of vegetation and both environmental features and agricultural management measures are studied at the regional and plot scale. In 2006, 432 vegetation relevés with a standard plot size of 25 m² were recorded in cultivated fields. In 2007, data collection focussed on 41 plots in arable fields that had been abandoned the year before. With respect to the environment, data analysis accounts for topography, soil base-richness and moisture, and geographic location. As to the management, crops and weed control are considered. A total number of 235 species was documented. In comparison to literature dating back to about 1980, the regional weed flora considerably changed. At the plot scale, today’s weed flora of Kosovo is fairly species-poor and species composition is rather uniform between plots. According to General Regression Model analyses, Indicator Species Analyses and Detrended Correspondence Analyses, species richness and composition mainly differ between crops and weed management, with highest mean species richness in recently abandoned and lowest in herbicide-treated maize fields.

  3. Non-invasive observation of the shallow soil profile stratification and its effect on soil water regime

    Science.gov (United States)

    Jeřábek, Jakub; Zumr, David

    2016-04-01

    Arable soils are exhibited to many stresses resulting in changes of the soil structure and properties at various scales. The most affected layer is the topsoil, which is periodically disrupted and consolidated due to tillage, rapid crop growth and changing weather conditions. The compacted layer often forms below the topsoil as a result of the pressure induced by the agriculture machinery and because of the finest particles caught on the divide between the tilled soil and untreated subsoil. The compacted layer is rather homogeneous, but there are features of different sizes, such as wheel tracks, till drainage shafts, local depressions, wormholes or cracks which redirect the water flow pathways or allow water to percolate into deeper horizon. The data acquisition targeting the spatial evaluation of the soil structure is, however, complicated. In this study, we utilize electrical resistance tomography in combination with penetration resistance tests and compare the results with complementary measured soil characteristics. Soil profile samples were taken to gain more complex information of soil physical characteristics possibly influencing the soil resistivity. We tried to relate the observed features to previous management activities at the field. Results showed, that the proposed technique can be used to compacted layer identification, but the information about its macroscopic heterogeneities is only in qualitative manner. The research was performed within the framework of a postdoctoral project granted by Czech Science Foundation No. 13-20388P and internal CTU project.

  4. Effect of soil property on evaporation from bare soils

    Science.gov (United States)

    Zhang, Chenming; Li, Ling; Lockington, David

    2015-04-01

    Quantifying the actual evaporation rate from bare soils remains a challenging task as it not only associates with the atmospheric demand and liquid water saturation on the soil surface, but also the properties of the soils (e.g., porosity, pore size distribution). A physically based analytical model was developed to describe the surface resistance varying with the liquid water saturation near the soil surface. This model considers the soil pore size distribution, hydraulic connection between the main water cluster and capillary water in the soil surface when the soil surface is wet and the thickness of the dry soil layer when the soil surface is dry. The surface resistance model was then integrated to a numerical model based on water balance, heat balance and surface energy balance equations. The integrated model was validated by simulating water and heat transport processes during six soil column drying experiments. The analysis indicates that the when soil surface is wet, the consideration of pore size distribution in the surface resistance model offers better estimation of transient evaporation among different soil types than the estimations given by empirically based surface resistance models. Under fixed atmospheric boundary condition and liquid water saturation, fine sand has greater evaporation rate than coarse sand as stronger capillary force devlivers more water from the main water cluster. When the soil surface becomes dry, the impact of soil property to evaporation becomes trivial as the thickness of the dry soil layer turns to be the key factor to determine the evaporation rate.

  5. Urban tree effects on soil organic carbon.

    Directory of Open Access Journals (Sweden)

    Jill L Edmondson

    Full Text Available Urban trees sequester carbon into biomass and provide many ecosystem service benefits aboveground leading to worldwide tree planting schemes. Since soils hold ∼75% of ecosystem organic carbon, understanding the effect of urban trees on soil organic carbon (SOC and soil properties that underpin belowground ecosystem services is vital. We use an observational study to investigate effects of three important tree genera and mixed-species woodlands on soil properties (to 1 m depth compared to adjacent urban grasslands. Aboveground biomass and belowground ecosystem service provision by urban trees are found not to be directly coupled. Indeed, SOC enhancement relative to urban grasslands is genus-specific being highest under Fraxinus excelsior and Acer spp., but similar to grasslands under Quercus robur and mixed woodland. Tree cover type does not influence soil bulk density or C∶N ratio, properties which indicate the ability of soils to provide regulating ecosystem services such as nutrient cycling and flood mitigation. The trends observed in this study suggest that genus selection is important to maximise long-term SOC storage under urban trees, but emerging threats from genus-specific pathogens must also be considered.

  6. Urban tree effects on soil organic carbon.

    Science.gov (United States)

    Edmondson, Jill L; O'Sullivan, Odhran S; Inger, Richard; Potter, Jonathan; McHugh, Nicola; Gaston, Kevin J; Leake, Jonathan R

    2014-01-01

    Urban trees sequester carbon into biomass and provide many ecosystem service benefits aboveground leading to worldwide tree planting schemes. Since soils hold ∼75% of ecosystem organic carbon, understanding the effect of urban trees on soil organic carbon (SOC) and soil properties that underpin belowground ecosystem services is vital. We use an observational study to investigate effects of three important tree genera and mixed-species woodlands on soil properties (to 1 m depth) compared to adjacent urban grasslands. Aboveground biomass and belowground ecosystem service provision by urban trees are found not to be directly coupled. Indeed, SOC enhancement relative to urban grasslands is genus-specific being highest under Fraxinus excelsior and Acer spp., but similar to grasslands under Quercus robur and mixed woodland. Tree cover type does not influence soil bulk density or C∶N ratio, properties which indicate the ability of soils to provide regulating ecosystem services such as nutrient cycling and flood mitigation. The trends observed in this study suggest that genus selection is important to maximise long-term SOC storage under urban trees, but emerging threats from genus-specific pathogens must also be considered.

  7. Soil degradation effect on biological activity in Mediterranean calcareous soils

    Science.gov (United States)

    Roca-Pérez, L.; Alcover-Sáez, S.; Mormeneo, S.; Boluda, R.

    2009-04-01

    Soil degradation processes include erosion, organic matter decline, compaction, salinization, landslides, contamination, sealing and biodiversity decline. In the Mediterranean region the climatological and lithological conditions, together with relief on the landscape and anthropological activity are responsible for increasing desertification process. It is therefore considered to be extreme importance to be able to measure soil degradation quantitatively. We studied soil characteristics, microbiological and biochemical parameters in different calcareous soil sequences from Valencia Community (Easter Spain), in an attempt to assess the suitability of the parameters measured to reflect the state of soil degradation and the possibility of using the parameters to assess microbiological decline and soil quality. For this purpose, forest, scrubland and agricultural soil in three soil sequences were sampled in different areas. Several sensors of the soil biochemistry and microbiology related with total organic carbon, microbial biomass carbon, soil respiration, microorganism number and enzyme activities were determined. The results show that, except microorganism number, these parameters are good indicators of a soil biological activity and soil quality. The best enzymatic activities to use like indicators were phosphatases, esterases, amino-peptidases. Thus, the enzymes test can be used as indicators of soil degradation when this degradation is related with organic matter losses. There was a statistically significant difference in cumulative O2 uptake and extracellular enzymes among the soils with different degree of degradation. We would like to thank Spanish government-MICINN for funding and support (MICINN, project CGL2006-09776).

  8. Effects of Biochar Amendment on Soil Properties and Soil Carbon Sequestration

    Science.gov (United States)

    Zhang, R.; Zhu, S.

    2015-12-01

    Biochar addition to soils potentially affects various soil properties and soil carbon sequestration, and these effects are dependent on biochars derived from different feedstock materials and pyrolysis processes. The objective of this study was to investigate the effects of amendment of different biochars on soil physical and biological properties as well as soil carbon sequestration. Biochars were produced with dairy manure and woodchip at temperatures of 300, 500, and 700°C, respectively. Each biochar was mixed at 5% (w/w) with a forest soil and the mixture was incubated for 180 days, during which soil physical and biological properties, and soil respiration rates were measured. Results showed that the biochar addition significantly enhanced the formation of soil macroaggregates at the early incubation time. The biochar application significantly reduced soil bulk density, increased the amount of soil organic matter, and stimulated microbial activity and soil respiration rates at the early incubation stage. Biochar applications improved water retention capacity, with stronger effects by biochars produced at higher pyrolysis temperatures. At the same suction, the soil with woodchip biochars possessed higher water content than with the dairy manure biochars. Biochar addition significantly affected the soil physical and biological properties, which resulted in different soil carbon mineralization rates and the amount of soil carbon storage.

  9. Soil carbon sequestration by three perennial legume pastures is greater in deeper soil layers than in the surface soil

    Directory of Open Access Journals (Sweden)

    X.-K. Guan

    2015-07-01

    Full Text Available Soil organic carbon (SOC plays a vital role as both a sink for and source of atmospheric carbon. Revegetation of degraded arable land in China is expected to increase soil carbon sequestration, but the role of perennial legumes on soil carbon stocks in semiarid areas has not been quantified. In this study, we assessed the effect of alfalfa (Medicago sativa L. and two locally adapted forage legumes, bush clover (Lespedeza davurica S. and milk vetch (Astragalus adsurgens Pall. on the SOC concentration and SOC stock accumulated annually over a 2 m soil profile, and to estimate the long-term potential for SOC sequestration in the soil under the three forage legumes. The results showed that the concentration of SOC of the bare soil decreased slightly over the 7 years, while 7 years of legume growth substantially increased the concentration of SOC over the 0–2.0 m soil depth measured. Over the 7 year growth period the SOC stocks increased by 24.1, 19.9 and 14.6 Mg C ha−1 under the alfalfa, bush clover and milk vetch stands, respectively, and decreased by 4.2 Mg C ha−1 under bare soil. The sequestration of SOC in the 1–2 m depth of soil accounted for 79, 68 and 74 % of SOC sequestered through the upper 2 m of soil under alfalfa, bush clover and milk vetch, respectively. Conversion of arable land to perennial legume pasture resulted in a significant increase in SOC, particularly at soil depths below 1 m.

  10. Uses of glyphosate in German arable farming – operational aspects

    Directory of Open Access Journals (Sweden)

    Wiese, Armin

    2016-02-01

    Full Text Available Glyphosate is the most frequently used herbicide active ingredient in Germany. Studies regarding its usage in non-GMO arable farming are still rare even though it plays an important role in several agronomic situations. Therefore, we conducted a comprehensive survey, which was carried out among conventional German farms in Winter 2014/2015. Based on the results of this survey we analyzed via cluster analysis how types of farms differ in terms of glyphosate usage. An illustration of seven clusters allows deep insights into arable farm structures. The farm types can be distinguished regarding their tillage system and similar to this differentiation also concerning their intensity of glyphosate application. Furthermore, it becomes obvious that farm clusters with a higher level of glyphosate usage are characterized by a lower number of labourers per hectare, more arable land and/or enhanced cover cropping. Moreover, groups of farmers who rely more on glyphosate are more likely to state that they need glyphosate for herbicide resistance management. Farmers’ assessments of the economic importance of glyphosate usage vary depending on the type of farm. By means of the farm clusters, the most important situations of glyphosate usage can be further analyzed economically and scenarios for impact assessments can be made.

  11. Patterns of bryophyte diversity in arable fields of Lithuania

    Directory of Open Access Journals (Sweden)

    Danguolė Andriušaitytė

    2013-03-01

    Full Text Available The paper presents research data on bryophyte diversity in arable land throughout the territory of Lithuania. The bryoflora was analyzed regarding systematic structure and morphological forms, life-history strategies, mode of reproduction and frequency of species. Bryophyte diversity in arable fields of Lithuania was compared with that of Slovakia and the British Isles, which are positioned in different geographical regions of Europe. A total of 97 species of bryophytes of 25 families and 48 genera were ascertained. Dominance of acrocarpous mosses and thalloid liverworts, high representation of Pottiaceae, Bryaceae, Mielichhoferiaceae and Ricciaceae families as well as Bryum, Dicranella, Pohlia and Riccia genera, wide distribution of annual shuttles and ephemeral colonists, high reproduction effort of the species (frequent sporophytes and asexual propagules were specific features of the bryophytes of the studied habitats as a result of adaptations to regular disturbances. The distribution of species into six frequency groups seemed to be uneven. The most abundant group of species with the lowest frequency (1–3 records covered 53.6% of all species. The group contained about 90% of all many-year potential life span species recorded in the habitat. Species with short life span were distributed quite evenly throughout frequency groups. No regionally-specific species were ascertained in the studied habitat. Most of arable-land-specific species recorded in Lithuania is distributed throughout different regions of Europe.

  12. The Effect of Gasification Biochar on Soil Carbon Sequestration, Soil Quality and Crop Growth

    DEFF Research Database (Denmark)

    Hansen, Veronika

    have been raised about the potential negative impacts of incorporating bioenergy residuals (biochar) in soil and increasing the removal of crop residues such as straw, possibly reducing important soil functions and services for maintaining soil quality. Therefore, a combination of incubation studies...... negative impact on soil biota. However, the effects of biochar on soil quality and plant growth differed according to the biochar properties and the soil type used. Furthermore, the positive impact on some soil structural properties observed after straw incorporation was not achieved with biochar amendment...... and pot and field experiments was used to study the effect of straw and wood biochar on carbon sequestration, soil quality and crop growth. Overall, the biochar amendment improved soil chemical and physical properties and plant growth and showed a potential for soil carbon sequestration without having any...

  13. [Characteristics of nutrient loss by runoff in sloping arable land of yellow-brown under different rainfall intensities].

    Science.gov (United States)

    Chen, Ling; Liu, De-Fu; Song, Lin-Xu; Cui, Yu-Jie; Zhang, Gei

    2013-06-01

    In order to investigate the loss characteristics of N and P through surface flow and interflow under different rainfall intensities, a field experiment was conducted on the sloping arable land covered by typical yellow-brown soils inXiangxi River watershed by artificial rainfall. The results showed that the discharge of surface flow, total runoff and sediment increased with the increase of rain intensity, while the interflow was negatively correlated with rain intensity under the same total rainfall. TN, DN and DP were all flushed at the very beginning in surface flow underdifferent rainfall intensities; TP fluctuated and kept consistent in surface flow without obvious downtrend. While TN, DN and DP in interflow kept relatively stable in the whole runoff process, TP was high at the early stage, then rapidly decreased with time and kept steady finally. P was directly influenced by rainfall intensity, its concentration in the runoff increased with the increase of the rainfall intensity, the average concentration of N and P both exceeded the threshold of eutrophication of freshwater. The higher the amount of P loss was, the higher the rain intensity. The change of N loss was the opposite. The contribution rate of TN loss carried by surface flow increased from 36.5% to 57.6% with the increase of rainfall intensity, but surface flow was the primary form of P loss which contributed above 90.0%. Thus, it is crucial to control interflow in order to reduce N loss. In addition, measures should be taken to effectively manage soil erosion to mitigate P loss. The proportion of dissolved nitrogen in surface flow elevated with the decrease of rainfall intensity, but in interflow, dissolved form was predominant. P was exported mainly in the form of particulate under different rainfall intensities and runoff conditions.

  14. Effect of Different Vegetation Types on the Rhizosphere Soil Microbial Community Structure in the Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chao; LIU Guo-bin; XUE Sha; and XIAO Lie

    2013-01-01

    The Loess Plateau in China is one of the most eroded areas in the world. Accordingly, vegetation restoration has been implemented in this area over the past two decades to remedy the soil degradation problem. Understanding the microbial community structure is essential for the sustainability of ecosystems and for the reclamation of degraded arable land. This study aimed to determine the effect of different vegetation types on microbial processes and community structure in rhizosphere soils in the Loess Plateau. The six vegetation types were as follows:two natural grassland (Artemisia capillaries and Heteropappus altaicus), two artificial grassland (Astragalus adsurgens and Panicum virgatum), and two artificial shrubland (Caragana korshinskii and Hippophae rhamnoides) species. The microbial community structure and functional diversity were examined by analyzing the phospholipid fatty acids (PLFAs) and community-level physiological profiles. The results showed that rhizosphere soil sampled from the H. altaicus and A. capillaries plots had the highest values of microbial biomass C, average well color development of carbon resources, Gram-negative (G-) bacterial PLFA, bacterial PLFA, total PLFA, Shannon richness, and Shannon evenness, as well as the lowest metabolic quotient. Soil sampled from the H. rhamnoides plots had the highest metabolic quotient and Gram-positive (G+) bacterial PLFA, and soil sampled from the A. adsurgens and A. capillaries plots had the highest fungal PLFA and fungal:bacterial PLFA ratio. Correlation analysis indicated a signiifcant positive relationship among the microbial biomass C, G- bacterial PLFA, bacterial PLFA, and total PLFA. In conclusion, plant species under arid climatic conditions signiifcantly affected the microbial community structure in rhizosphere soil. Among the studied plants, natural grassland species generated the most favorable microbial conditions.

  15. [Priming Effects of Soil Moisture on Soil Respiration Under Different Tillage Practices].

    Science.gov (United States)

    Zhang, Yan; Liang, Ai-zhen; Zhang, Xiao-ping; Chen, Sheng-long; Sun, Bing-jie; Liu, Si-yi

    2016-03-15

    In the early stage of an incubation experiment, soil respiration has a sensitive response to different levels of soil moisture. To investigate the effects of soil moisture on soil respiration under different tillage practices, we designed an incubation trial using air-dried soil samples collected from tillage experiment station established on black soils in 2001. The tillage experiment consisted of no-tillage (NT), ridge tillage (RT), and conventional tillage (CT). According to field capacity (water-holding capacity, WHC), we set nine moisture levels including 30%, 60%, 90%, 120%, 150%, 180%, 210%, 240%, 270% WHC. During the 22-day short-term incubation, soil CO₂ emission was measured. In the early stage of incubation, the priming effects occurred under all tillage practices. There were positive correlations between soil respiration and soil moisture. In addition to drought and flood conditions, soil CO₂ fluxes followed the order of NT > RT > CT. We fitted the relationship between soil moisture and soil CO₂ fluxes under different tillage practices. In the range of 30%-270% WHC, soil CO₂ fluxes and soil moisture fitted a quadratic regression equation under NT, and linear regression equations under RT and CT. Under the conditions of 30%-210% WHC of both NT and RT, soil CO₂ fluxes and soil moisture were well fitted by the logarithmic equation with fitting coefficient R² = 0.966 and 0.956, respectively.

  16. Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type

    DEFF Research Database (Denmark)

    Gomes, Helena I.; Dias-Ferreira, Celia; Ottosen, Lisbeth M.

    2015-01-01

    Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero...... nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used...

  17. Effects of physical soil crusts on infiltration and splash erosion in three typical Chinese soils

    Institute of Scientific and Technical Information of China (English)

    Chong-feng BU; Shu-fang WU; Kai-bao YANG

    2014-01-01

    Physical soil crusts likely have significant effects on infiltration and soil erosion, however, little is known on whether the effects of the crusts change during a rainfall event. Further, there is a lack of discussions on the differences among the crusting effects of different soil types. The objectives of this study are as follows: (i) to study the effects of soil crusts on infiltration, runoff, and splash erosion using three typical soils in China, (ii) to distinguish the different effects on hydrology and erosion of the three soils and discuss the primary reasons for these differences, and (iii) to understand the variations in real soil shear strength of the three soils during rainfall events and mathematically model the effects of the crusts on soil erosion. This study showed that the soil crusts delayed the onset of infiltration by 5 to 15 min and reduced the total amount of infiltration by 42.9 to 53.4%during rainfall events. For a purple soil and a loess soil, the initial crust increased the runoff by 2.8%and 3.4%, respectively, and reduced the splash erosion by 3.1% and 8.9%, respectively. For a black soil, the soil crust increased the runoff by 42.9%and unexpectedly increased the splash erosion by 95.2%. In general, the effects of crusts on the purple and loess soils were similar and negligible, but the effects were significant for the black soil. The soil shear strength decreased dynamically and gradually during the rainfall events, and the values of crusted soils were higher than those of incrusted soils, especially during the early stage of the rainfall. Mathematical models were developed to describe the effects of soil crusts on the splash erosion for the three soils as follows:purple soil, 0.384Fc =0.002t− ; black soil, 3.060Fc =−0.022t+ ; and loess soil, Fc =0.233 ln t−1.239 . Combined with the equation 1)Rc=Fc⋅(Ruc− , the splash erosion of the crusted soil can be predicted over time.

  18. Spatial assessment of soil nitrogen availability and varying effects of related main soil factors on soil available nitrogen.

    Science.gov (United States)

    Qu, Mingkai; Li, Weidong; Zhang, Chuanrong; Huang, Biao; Zhao, Yongcun

    2016-11-09

    To effectively understand the availability of soil nitrogen and assist in soil nitrogen control at the regional scale, it is essential to understand the accurate spatial distribution patterns of the three soil nitrogen parameters [i.e., total nitrogen (TN), available nitrogen (AN) and nitrogen availability ratio (NAR)] and explore the spatially varying influences of major impact factors on soil AN. Land use affects the spatial distributions of soil TN, AN and NAR (i.e., AN/TN). To explore the effects of different land use types and improve mapping accuracy, residual kriging with land use information and ordinary kriging (without land use information) were compared based on the sample data of soil TN and AN in Hanchuan county, China. A local regression technique, geographically weighted regression (GWR), was adopted to explore the varying relationships between soil AN and its major impact factors in soil (i.e., soil TN and soil pH), due to the advantages of GWR over the traditional ordinary least squares regression (OLS) model. The results showed that (1) land use types as auxiliary information obviously improved the prediction accuracies of the three soil nitrogen parameters; (2) GWR performed much better than OLS in terms of fitting accuracy; and (3) GWR effectively revealed the spatially varying influences of the impact factors on soil AN, which were ignored by OLS. Based on the results, suggestions for soil nitrogen control measures in different subareas were proposed.

  19. [Effect of Biochar Application on Soil Aggregates Distribution and Moisture Retention in Orchard Soil].

    Science.gov (United States)

    An, Yan; Ji, Qiang; Zhao, Shi-xiang; Wang, Xu-dong

    2016-01-15

    Applying biochar to soil has been considered to be one of the important practices in improving soil properties and increasing carbon sequestration. In order to investigate the effects of biochar application on soil aggregates distribution and its organic matter content and soil moisture constant in different size aggregates, various particle-size fractions of soil aggregates were obtained with the dry-screening method. The results showed that, compared to the treatment without biochar (CK), the application of biochar reduced the mass content of 5-8 mm and soil aggregates at 0-10 cm soil horizon, while increased the content of 1-2 mm and 2-5 mm soil aggregates at this horizon, and the content of 1-2 mm aggregates significantly increased along with the rates of biochar application. The mean diameter of soil aggregates was reduced by biochar application at 0-10 cm soil horizon. However, the effect of biochar application on the mean diameter of soil aggregates at 10-20 cm soil horizon was not significant. Compared to CK, biochar application significantly increased soil organic carbon content in aggregates, especially in 1-2 mm aggregates which was increased by > 70% compared to CK. Both the water holding capacity and soil porosity were significantly increased by biochar application. Furthermore, the neutral biochar was more effective than alkaline biochar in increasing soil moisture.

  20. The Influence of Biomass Ash on the Migration of Heavy Metals in the Flooded Soil Profile - Model Experiment

    Directory of Open Access Journals (Sweden)

    Ciesielczuk Tomasz

    2014-12-01

    also washed out from flood sediments by precipitation when the flood recedes. This paper presents the results of research on the effects of fertilization with ash from incineration or pyrolysis of biomass on the migration process of heavy metals (Zn, Cu, Cr, Ni, Pb, Cd, Mn in the arable layer of soil. It has been shown that the metals in the flood sediment migrate actively in the soil profile what leads to the enrichment of the soils, also in the case of the soil fertilization with biomass ash.

  1. Effects of lignin on nitrification in soil

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The effects of two lignins isolated from black liquor from pulping process on nitrification in soils after addition of urea, (NH4)2SO4 and (NH4)2HPO4 were investigated by incubation at 20 or 30℃ for 7 or 14d. The effects of lignin on nitrous oxide emissions from soil were also determined. Results showed that both lignins were more effective for inhibiting nitrification of NH4+-N as (NH4)2SO4 or (NH4)2HPO4 as compared to urea-N. The effectiveness of lignin on nitrification was markedly affected by different soil type and temperature. Nitrous oxide emissions from soil declined when lignin was used. Urea plus 20 and 50 g/kg lignin reduced N2O emissions by about 83% and 96%, respectively, while (NH4)2HPO4 plus 20 and 50 g/kg lignin respectively reduced emissions by 83% and 93%. Because of its low cost and nonhazardous characteristics, lignin has potential value as a fertilizer amendment to improve N fertilizer efficiency.

  2. Conservation agriculture effects on soil pore characteristics

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Abdollahi, Lotfollah

    Conservation tillage in combination with crop rotation, residue management and cover crops are key components of conservation agriculture. A positive long-term effect of applying all components of conservation agriculture on soil structural quality is expected. However, there is a lack...

  3. EFFECT OF ELECTRIC FERTILIZER ON SOIL PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    WANG Ya-qin; WANG Ji-hong

    2004-01-01

    Electric fertilizer, I. E. Exerting electric field on plants during growing season instead of chemical fertilizer, is a kind of physical fertilizer, and the third kind of fertilizer with developmental prospect after inorganic fertilizer and organic fertilizer. For the purpose of studying the changes of physical and chemical properties of soil after exerting electric field, five treatments with different applications of chemical fertilizer were arranged on the black soil in Yushu City of Jilin Province by randomized block method, and electric field was exerted on plants every ten days during the growing season. Through sample analysis the paper arrives at following conclusions: 1) Exerting electric field can make soil's granular structure increase, bulk density decrease, moisture capacity increase,thus improving the perviousness of soil. 2) Exerting electric field can make microorganism's number increase and activity strengthen, thus activating nutrient and increasing organic matter content. 3) Exerting electric field with 0.1A medium has the best effect. So the chemical fertilizer can be saved. Therefore, we can say that the application of electric fertilizer is favorable for decreasing chemical poison, improving soil, relaxing the contradiction between the supply and demand of chemical fertilizer, and decreasing production cost of agriculture and forestry.

  4. Effects of Rice Straw and Its Biochar Addition on Soil Labile Carbon and Soil Organic Carbon

    Institute of Scientific and Technical Information of China (English)

    YIN Yun-feng; HE Xin-hua; GAO Ren; MA Hong-liang; YANG Yu-sheng

    2014-01-01

    Whether the biochar amendment could affect soil organic matter (SOM) turnover and hence soil carbon (C) stock remains poorly understood. Effects of the addition of 13C-labelled rice straw or its pyrolysed biochar at 250 or 350°C to a sugarcane soil (Ferrosol) on soil labile C (dissolved organic C, DOC;microbial biomass C, MBC;and mineralizable C, MC) and soil organic C (SOC) were investigated after 112 d of laboratory incubation at 25°C. Four treatments were examined as (1) the control soil without amendment (Soil);(2) soil plus 13C-labelled rice straw (Soil+Straw);(3) soil plus 250°C biochar (Soil+B250) and (4) soil plus 350°C biochar (Soil+B350). Compared to un-pyrolysed straw, biochars generally had an increased aryl C, carboxyl C, C and nitrogen concentrations, a decreased O-alkyl C and C:N ratio, but similar alkyl C and d13C (1 742-1 877‰). Among treatments, signiifcant higher DOC, MBC and MC derived from the new C (straw or biochar) ranked as Soil+Straw>Soil+B250>Soil+B350, whilst signiifcant higher SOC from the new C as Soil+B250>Soil+Straw≈Soil+B350. Compared to Soil, DOC and MBC derived from the native soil were decreased under straw or biochar addition, whilst MC from the native soil was increased under straw addition but decreased under biochar addition. Meanwhile, native SOC was similar among the treatments, irrespective of the straw or biochar addition. Compared to Soil, signiifcant higher total DOC and total MBC were under Soil+Straw, but not under Soil+B250 and Soil+B350, whilst signiifcant higher total MC and total SOC were under straw or biochar addition, except for MC under Soil+B350. Our results demonstrated that the application of biochar to soil may be an appropriate management practice for increasing soil C storage.

  5. Root development during soil genesis: effects of root-root interactions, mycorrhizae, and substrate

    Science.gov (United States)

    Salinas, A.; Zaharescu, D. G.

    2015-12-01

    A major driver of soil formation is the colonization and transformation of rock by plants and associated microbiota. In turn, substrate chemical composition can also influence the capacity for plant colonization and development. In order to better define these relationships, a mesocosm study was set up to analyze the effect mycorrhizal fungi, plant density and rock have on root development, and to determine the effect of root morphology on weathering and soil formation. We hypothesized that plant-plant and plant-fungi interactions have a stronger influence on root architecture and rock weathering than the substrate composition alone. Buffalo grass (Bouteloua dactyloides) was grown in a controlled environment in columns filled with either granular granite, schist, rhyolite or basalt. Each substrate was given two different treatments, including grass-microbes and grass-microbes-mycorrhizae and incubated for 120, 240, and 480 days. Columns were then extracted and analyzed for root morphology, fine fraction, and pore water major element content. Preliminary results showed that plants produced more biomass in rhyolite, followed by schist, basalt, and granite, indicating that substrate composition is an important driver of root development. In support of our hypothesis, mycorrhizae was a strong driver of root development by stimulating length growth, biomass production, and branching. However, average root length and branching also appeared to decrease in response to high plant density, though this trend was only present among roots with mycorrhizal fungi. Interestingly, fine fraction production was negatively correlated with average root thickness and volume. There is also slight evidence indicating that fine fraction production is more related to substrate composition than root morphology, though this data needs to be further analyzed. Our hope is that the results of this study can one day be applied to agricultural research in order to promote the production of crops

  6. Effects of soil compaction on the relationships between nematodes, grass production and soil physical properties

    NARCIS (Netherlands)

    Bouwman, L.A.; Arts, W.B.M.

    2000-01-01

    As farm machinery has become heavier, concern has grown about its direct effects on soil physical conditions and its indirect effects on crop yields and soil biota. To study the relationships between these parameters, non-grazed temporary grassland plots on a loamy sand soil were subjected to full-w

  7. Effects of soil temperature and moisture on carbon and nitrogen mineralisation in coniferous forests

    Energy Technology Data Exchange (ETDEWEB)

    Seyferth, U.

    1998-12-31

    Three laboratory studies were performed to assess the effects of soil temperature and moisture on CO{sub 2} evolution rate, net N mineralisation and nitrification rate in nitrifying and non-nitrifying humus materials from southern Sweden. In two of the experiments, the samples were incubated at alternating -4/+5 deg C and constant -4, +0.5, +5, +15 and +25 deg C for up to 300 days. The water contents were 15, 30, 60 and 100 % of the water-holding capacity (WHC). In the third study, mineralisation processes were measured at 11 different moisture levels at 15 deg C. Mineralisation rates were highest at 25 deg C and 60 % WHC. A quadratic function (the Ratkowsky function) was fitted in order to quantify temperature responses of C and N mineralisation. Q{sub 10} values were 2-4 between 5 and 25 deg C and increased with decreasing temperatures. Mineralisation rates were linear in the logarithm of the water potential for a wide range of moisture levels. Water saturation and subsequent oxygen deficiency led to decreased rates. Because of denitrification, no net N mineralisation could be detected in the nitrifying humus at 100 % WHC. Temperatures down to 0.5 deg C did not hamper nitrification. The amount of mineralised nitrogen in the samples incubated at alternating -4 and +5 deg C was similar to that in the jars stored at constant 5 deg C. Temperature and moisture effects seemed to operate independently, at least at mesic conditions. The ratio of mineralised C to mineralised N tended to be higher than expected from the C:N ratio in the soil substrate at high temperatures, whereas this ratio was much lower than the soil C:N ratio at low temperatures. Our interpretation is that different organism groups can play different roles at high and low temperatures, but also that the net microbial growth yield efficiency is lower at low than at high temperatures. We assume that a log-linear response of C and N mineralisation to water potential is broadly applicable for humus

  8. Investigation of biochar effects as a non-structural BMP on soil erosional properties using a rainfall simulator

    DEFF Research Database (Denmark)

    Khademalrasoul, Ataalah; Kuhn, Nikolaus J; Hu, Yaxian;

    runoff events. We hypothesized that erodibility is reduced in biochar-amended soils and tested this in controlled rainfall-runoff simulations. The specific objectives of our study were (1) to compare runoff and sediment generation between a biochar and an unamended control treatment on an arable sandy......, and plots had been harrowed and ploughed twice to a depth of 25 cm prior to sampling. In the laboratory soil samples from (0-20 cm) were analyzed for aggregate stability and soil organic carbon (SOC) content. Soil erosional properties were measured during 3.5 hour rainfall simulations using a round flume...... setup. Artificial rain was applied with a FullJet nozzle at a rate of 30 mm h-1. Biochar-amended soils showed significantly lower runoff and erosion rates compared to unamended soils, and correspondingly runoff coefficients in biochar-treated soils were lower than in control soils. Less SOC was eroded...

  9. The effect of intrinsic soil properties on soil quality assessments

    Directory of Open Access Journals (Sweden)

    Alessandro Samuel-Rosa

    2013-10-01

    Full Text Available The assessment of soil quality is based on indicators and indices derived from soil properties. However, intrinsic soil properties may interfere with other soil properties that vary under different land uses and are used to calculate the indices. The aim of this study was to assess the extent to which intrinsic soil properties (clay and iron oxide contents explain variable soil properties (sum of bases, potential acidity, organic carbon, total porosity, and bulk density under different land uses (native forest, no-tillage and conventional agriculture on small family farms in Southern Brazil. The results showed that the five properties evaluated can be included in soil quality assessments and are not influenced by the clay and iron oxide contents. It was concluded that for little weathered 1:1 and 2:1 phyllosilicate rich-soils, if the difference between the maximum and the minimum clay content under the different land uses is less than about 200 g kg-1 and the iron oxide content less than about 15 g kg-1, the physico-chemical soil properties in the surface layer are determined mostly by the land use.

  10. Impact of a pesticide cocktail (fenhexamid, folpel, deltamethrin) on the abundance of Glomeromycota in two agricultural soils.

    Science.gov (United States)

    Rivera-Becerril, Facundo; van Tuinen, Diederik; Chatagnier, Odile; Rouard, Nadine; Béguet, Jérémie; Kuszala, Catherine; Soulas, Guy; Gianinazzi-Pearson, Vivienne; Martin-Laurent, Fabrice

    2017-01-15

    Pesticide contamination of the environment can result from agricultural practices. Persistence of pesticide residues is a threat to the soil biota including plant roots and beneficial microorganisms, which support an important number of soil ecosystem services. Arbuscular mycorrhizal fungi (AMF) are key symbiotic microorganisms contributing to plant nutrition. In the present study, we assessed whether AMF could indicate eventual side effects of pesticides when directly applied to field soils. We evaluated the ecotoxicological impact of a cocktail of three commonly used agricultural pesticides (fenhexamid, folpel, deltamethrin) on the abundance and composition of the AMF community in vineyard (Montagne de Saint-Emilion) and arable (Martincourt) soils subjected to different agricultural practices. The dissipation of applied pesticides was monitored by multiresidual analyses to determine the scenario of exposure of the AMF community. Diversity analysis before application of the pesticide cocktail showed that the AMF communities of vineyard soils, subjected to mechanical weeding or grass cover, and of the arable soil subjected to intensive agriculture, were dominated by Glomerales. Ribotypes specific to each soil and to each agricultural practice in the same soil were found, with the highest abundance and diversity of AMF being observed in the vineyard soil with a grass-cover. The abundance of the global AMF community (Glomeromycota) and of three taxa of AMF (Funneliformis mosseae, Claroideoglomus etunicatum/C. claroideum) was evaluated after pesticide application. The abundance of Glomeromycota decreased in both soils after pesticide application while the abundance of Claroideoglomus and F. mosseae decreased only in the arable soil. These results show that higher doses of pesticide exposure did not affect the global abundance, but altered the composition, of the AMF community. Resilience of the AMF community composition was observed only in the vineyard soil, where F

  11. Soil compaction and structural morphology under tractor wheelings

    Science.gov (United States)

    Shanahan, Peter; Quinton, John; Binley, Andrew; Silgram, Martyn

    2010-05-01

    Compaction of cultivated soils is a major problem for agriculture in terms of yield decline and sustainable soil resource management. Tramline wheelings exacerbate runoff and increase erosion from arable land. The UK Department for Environment, Food and Rural Affairs (Defra) LINK Project - a joint venture between agri-business, land managers and research groups - is currently evaluating a number of methods for alleviating compaction in tractor wheelings across a range of soil types in England. Using innovative applications of agri-geophysics (e.g. ground penetrating radar, electrical resistivity, acoustics and x-ray tomography), this current project aims to determine relationships between properties derived from geophysical methods (e.g. soil moisture, porosity), soil compaction and structural morphology. Such relationships are important for a clearer understanding of hydrological and biogeochemical processes in compacted soils, to address land management practices and develop cost-effective mitigation measures. Our poster will present some early results of this study.

  12. How historical copper contamination affects soil structure and mobilization and transport of colloids

    DEFF Research Database (Denmark)

    Paradelo, Marcos; Møldrup, Per; Holmstrup, Martin;

    between 0.01 to 0.43 pore volumes, with longer times for the most contaminated point, likely related with its higher soil density and lower air permeability. The copper pollution affected colloid and tracer transport in the soil columns. The release of colloids especially in the most contaminated points......Copper is accumulated in soils due to human activities such as mining industry, agriculture practises, or waste deposals. High concentrations of copper can affect plants and soil organisms, and subsequently the soil structure and its inner space architecture. In this work we investigated the effect...... of copper concentration on the movement of an inert tracer, tritium, and the mobilization and transport of colloid particles in undisturbed soil cores (10 cm diameter and 8 cm height). The cores were sampled along a copper gradient of 21 to 3837 mg Cu kg-1 soil on an abandoned arable soil polluted by copper...

  13. A specialist-generalist classification of the arable flora and its response to changes in agricultural practices

    Directory of Open Access Journals (Sweden)

    Fried Guillaume

    2010-09-01

    Full Text Available Abstract Background Theory in ecology points out the potential link between the degree of specialisation of organisms and their responses to disturbances and suggests that this could be a key element for understanding the assembly of communities. We evaluated this question for the arable weed flora as this group has scarcely been the focus of ecological studies so far and because weeds are restricted to habitats characterised by very high degrees of disturbance. As such, weeds offer a case study to ask how specialization relates to abundance and distribution of species in relation to the varying disturbance regimes occurring in arable crops. Results We used data derived from an extensive national monitoring network of approximately 700 arable fields scattered across France to quantify the degree of specialisation of 152 weed species using six different ecological methods. We then explored the impact of the level of disturbance occurring in arable fields by comparing the degree of specialisation of weed communities in contrasting field situations. The classification of species as specialist or generalist was consistent between different ecological indices. When applied on a large-scale data set across France, this classification highlighted that monoculture harbour significantly more specialists than crop rotations, suggesting that crop rotation increases abundance of generalist species rather than sets of species that are each specialised to the individual crop types grown in the rotation. Applied to a diachronic dataset, the classification also shows that the proportion of specialist weed species has significantly decreased in cultivated fields over the last 30 years which suggests a biotic homogenization of agricultural landscapes. Conclusions This study shows that the concept of generalist/specialist species is particularly relevant to understand the effect of anthropogenic disturbances on the evolution of plant community composition and that

  14. Effects of myclobutanil on soil microbial biomass, respiration, and soil nitrogen transformations.

    Science.gov (United States)

    Ju, Chao; Xu, Jun; Wu, Xiaohu; Dong, Fengshou; Liu, Xingang; Zheng, Yongquan

    2016-01-01

    A 3-month-long experiment was conducted to ascertain the effects of different concentrations of myclobutanil (0.4 mg kg(-1) soil [T1]; 1.2 mg kg(-1) soil [T3]; and 4 mg kg(-1) soil [T10]) on soil microbial biomass, respiration, and soil nitrogen transformations using two typical agricultural soils (Henan fluvo-aquic soil and Shanxi cinnamon soil). Soil was sampled after 7, 15, 30, 60, and 90 days of incubation to determine myclobutanil concentration and microbial parameters: soil basal respiration (RB), microbial biomass carbon (MBC) and nitrogen (MBN), NO(-)3-N and NH(+)4-N concentrations, and gene abundance of total bacteria, N2-fixing bacteria, fungi, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB). The half-lives of the different doses of myclobutanil varied from 20.3 to 69.3 d in the Henan soil and from 99 to 138.6 d in the Shanxi soil. In the Henan soil, the three treatments caused different degrees of short-term inhibition of RB and MBC, NH(+)4-N, and gene abundance of total bacteria, fungi, N2-fixing bacteria, AOA, and AOB, with the exception of a brief increase in NO(-)3-N content during the T10 treatment. The MBN (immobilized nitrogen) was not affected. In the Shanxi soil, MBC, the populations of total bacteria, fungi, and N2-fixing bacteria, and NH(+)4-N concentration were not significantly affected by myclobutanil. The RB and MBN were decreased transitorily in the T10 treatment. The NO(-)3-N concentrations and the abundance of both AOA and AOB were erratically stimulated by myclobutanil. Regardless of whether stimulation or suppression occurred, the effects of myclobutanil on the two soil types were short term. In summary, myclobutanil had no long-term negative effects on the soil microbial biomass, respiration, and soil nitrogen transformations in the two types of soil, even at 10-fold the recommended dosage.

  15. Long-term effects of soil management on ecosystem services and soil loss estimation in olive grove top soils.

    Science.gov (United States)

    Parras-Alcántara, Luis; Lozano-García, Beatriz; Keesstra, Saskia; Cerdà, Artemi; Brevik, Eric C

    2016-11-15

    Soil management has important effects on soil properties, runoff, soil losses and soil quality. Traditional olive grove (OG) management is based on reduced tree density, canopy size shaped by pruning and weed control by ploughing. In addition, over the last several decades, herbicide use has been introduced into conventional OG management. These management strategies cause the soil surface to be almost bare and subsequently high erosion rates take place. To avoid these high erosion rates several soil management strategies can be applied. In this study, three strategies were assessed in OG with conventional tillage in three plots of 1ha each. Soil properties were measured and soil erosion rates were estimated by means of the RUSLE model. One plot was managed with no amendments (control), and the other two were treated with olive leaves mulch and oil mill pomace applied yearly from 2003 until 2013. The control plot experienced the greatest soil loss while the use of olive leaves as mulch and olive mill pomace as an amendment resulted in a soil loss reduction of 89.4% and 65.4% respectively (assuming a 5% slope). In addition, the chemical and physical soil properties were improved with the amendments. This combined effect will created a higher quality soil over the long term that it is more resilient to erosion and can provide better ecosystem services, as its functions are improved.

  16. Thresholds and interactive effects of soil moisture on the temperature response of soil respiration

    DEFF Research Database (Denmark)

    Lellei-Kovács, Eszter; Kovács-Láng, Edit; Botta-Dukát, Zoltán;

    2011-01-01

    Ecosystem carbon exchange is poorly understood in low-productivity, semiarid habitats. Here we studied the controls of soil temperature and moisture on soil respiration in climate change field experiment in a sandy forest-steppe. Soil CO2 efflux was measured monthly from April to November in 2003......–2008 on plots receiving either rain exclusion or nocturnal warming, or serving as ambient control. Based on this dataset, we developed and compared empirical models of temperature and moisture effects on soil respiration. Results suggest that in this semiarid ecosystem the main controlling factor for soil CO2...... efflux is soil temperature, while soil moisture has less, although significant effect on soil respiration. Clear thresholds for moisture effects on temperature sensitivity were identified at 0.6, 4.0 and 7.0vol% by almost each model, which relate well to other known limits for biological activity...

  17. Soil type-depending effect of paddy management: composition and distribution of soil organic matter

    Science.gov (United States)

    Urbanski, Livia; Kölbl, Angelika; Lehndorff, Eva; Houtermans, Miriam; Schad, Peter; Zhang, Gang-Lin; Rahayu Utami, Sri; Kögel-Knabner, Ingrid

    2016-04-01

    Paddy soil management is assumed to promote soil organic matter accumulation and specifically lignin caused by the resistance of the aromatic lignin structure against biodegradation under anaerobic conditions during inundation of paddy fields. The present study investigates the effect of paddy soil management on soil organic matter composition compared to agricultural soils which are not used for rice production (non-paddy soils). A variety of major soil types, were chosen in Indonesia (Java), including Alisol, Andosol and Vertisol sites (humid tropical climate of Java, Indonesia) and in China Alisol sites (humid subtropical climate, Nanjing). This soils are typically used for rice cultivation and represent a large range of soil properties to be expected in Asian paddy fields. All topsoils were analysed for their soil organic matter composition by solid-state 13C nuclear magnetic resonance spectroscopy and lignin-derived phenols by CuO oxidation method. The soil organic matter composition, revealed by solid-state 13C nuclear magnetic resonance, was similar for the above named different parent soil types (non-paddy soils) and was also not affected by the specific paddy soil management. The contribution of lignin-related carbon groups to total SOM was similar in the investigated paddy and non-paddy soils. A significant proportion of the total aromatic carbon in some paddy and non-paddy soils was attributed to the application of charcoal as a common management practise. The extraction of lignin-derived phenols revealed low VSC (vanillyl, syringyl, cinnamyl) values for all investigated soils, being typical for agricultural soils. An inherent accumulation of lignin-derived phenols due to paddy management was not found. Lignin-derived phenols seem to be soil type-dependent, shown by different VSC concentrations between the parent soil types. The specific paddy management only affects the lignin-derived phenols in Andosol-derived paddy soils which are characterized by

  18. Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type

    DEFF Research Database (Denmark)

    Gomes, Helena I.; Dias-Ferreira, Celia; Ottosen, Lisbeth M.;

    2015-01-01

    Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero...... nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used...... as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two...

  19. The effects of the physical and chemical properties of soils on the spectral reflectance of soils

    Science.gov (United States)

    Montgomery, O. L.; Baumgardner, M. F.

    1974-01-01

    The effects of organic matter, free iron oxides, texture, moisture content, and cation exchange capacity on the spectral reflectance of soils were investigated along with techniques for differentiating soil orders by computer analysis of multispectral data. By collecting soil samples of benchmark soils from the different climatic regions within the United States and using the extended wavelength field spectroradiometer to obtain reflectance values and curves for each sample, average curves were constructed for each soil order. Results indicate that multispectral analysis may be a valuable tool for delineating and quantifying differences between soils.

  20. Soil suppressiveness and functional diversity of soil microflora in organic farming systems

    NARCIS (Netherlands)

    Postma, J.; Schilder, M.T.; Speksnijder, A.G.C.L.

    2008-01-01

    Arable fields of 10 organic farms from different locations within the Netherlands were sampled in four subsequent years. The soil samples were analysed for disease suppressiveness against Rhizoctonia solani, Streptomyces scabies and Verticillium dahliae. Furthermore, a variety of microbial character

  1. Factors Influencing the Conversion of Arable Land to Urban Use and Policy Implications in Beijing, China

    Directory of Open Access Journals (Sweden)

    Daquan Huang

    2014-12-01

    Full Text Available Rapid urban land expansion and the resulting arable land loss have put food security in China at risk. This paper investigates the characteristics and mechanism of arable land conversion in Beijing using a logistic model based on land-use data for 2001 and 2010. The results suggest that (1 arable land conversion tends to occur near built-up areas, city centers and major roads; (2 arable land that lies closer to irrigation canals and country roads is less likely to be converted to urban use; (3 arable land that is bigger in size and has a more regular shape has a lower probability of conversion to urban use; and (4 the Prime Farmland Protection policy and related land-use plan have played a positive role in preserving arable land, demonstrated by the probability for arable land conversion inside a prime farmland boundary is 63.9 percent less than for land outside the boundary. Based on these findings and on sustainable-development principles, we suggest that, rather than an exclusive focus on controlling the quantity of arable land, the location and characteristics of the arable land should be a primary consideration when designing urban policies and plans.

  2. Effects of slurry from sulfadiazine- (SDZ) and difloxacin- (DIF) medicated pigs on the structural diversity of microorganisms in bulk and rhizosphere soil

    NARCIS (Netherlands)

    Reichel, R.; Rosendahl, I.; Peeters, E.T.H.M.; Focks, A.; Groeneweg, K.J.I.; Bierl, R.

    2013-01-01

    Conventional farming still consumes considerable amounts of antibiotics such as sulfadiazine (SDZ) or difloxacin (DIF) to protect livestock from infectious diseases. Consequently, slurries from medicated animals are applied to arable soils. Antibiotics, co-applied with pig slurry, are increasingly r

  3. Soil factors exhibit greater influence than bacterial inoculation on alfalfa growth and nitrogen fixation.

    Science.gov (United States)

    Neumann, Ute; Kosier, Bob; Jahnke, Joachim; Priefer, Ursula B; Al-Halbouni, Djamila

    2011-09-01

    In order to study the effects of soil factors and bacterial inoculation on alfalfa (Medicago sativa), plants were inoculated with Ensifer meliloti L33 and Azospirillum brasilense Sp7 in pot experiments using two different soils separately as well as in a mixture. One soil was contaminated with chemical waste products; the other was an arable soil. Soil factors, including the availability of macro- and micronutrients as well as carbon and nitrogen contents, were found to exhibit a much greater influence on the growth of alfalfa than any of the inoculations. In contaminated soil, the shoot and root growth of alfalfa was decreased and nodules were diminished and ineffective. Bacterial inoculations did not significantly improve this hostile growth environment. However, in a mixture (44% arable, 22% contaminated soil, 34% vermiculite), growth conditions for alfalfa were improved so that shoot dry weight and nodule numbers increased up to 100- and 20-fold, respectively, compared with the contaminated soil. For the strain L33, its persistence in the rhizosphere was correlated to the presence of its host plant, but its dynamics were influenced by competition with indigenous rhizobia. The strain Sp7, once provided with a suitable soil, was not dependent on the plant's rhizosphere, but it enhanced the performance of L33 and native rhizobia.

  4. Effect of Irrigation Water Quality on Soil Hydraulic Conductivity

    Institute of Scientific and Technical Information of China (English)

    XIAOZHEN-HUA; B.PRENDERGAST; 等

    1992-01-01

    The effect of irrigation water quality on unsaturated hydraulic conductivity (HC) of undisturbed soil in field was studied.Results show that within the operating soil suction range (0-1.6 KPa) of disc permeameters,the higher the electric conductivity (EC) of irrigation water,the higher the soil HC became.The soil HC doubled when EC increased from 0.1 to 6.0ds m-1.High sodium-adsorption ratio(SAR) of irrigation water would have an unfavorable effect on soil HC.Soil HC decreased with the increasing of SAR,especially in the case of higher soil suction.An interaction existed between the effects of EC and SAR of irrigation water on soil HC.The HC of unsaturated soil dependent upon the macropores in surface soil decreased by one order of magnitude with 1 KPa increase of soil suction.In the study on the effect of very low soluble salt concentration (EC=0.1 ds m-1 of irrigation water on soil HC,soil HC was found to be lowered by 30% as a consequence of blocking up of some continuous pores by the dispersed and migrated clay particles.Nonlinear successive regression analysis and significance test show that the effects of EC and SAR of irrigation water on soil HC reached the extremely significant level.

  5. Mobility and degradation of trinitrotoluene/metabolites in soil columns: effect of soil organic carbon content.

    Science.gov (United States)

    Singh, Neera; Hennecke, Dieter; Hoerner, Jennifer; Koerdel, Werner; Schaeffer, Andreas

    2008-06-01

    There has been increasing interest in enhancing natural attenuation of munitions-contaminated soils. Present study reports the effect of increasing soil organic matter content on fate and mobility of trinitrotoluene (TNT) and metabolites in soil columns. This study was performed using 30-cm-long columns containing a top 5 cm of contaminated soil as a source layer and an uncontaminated soil (25 cm) adjusted to 0.5, 1.0, 1.5 and 3.0% organic carbon (OC) content using compost. Contaminated soil layer was fortified with uniformly ring-labeled (14)C-trinitrotoluene (TNT) or 2,4-dinitrotoluene (DNT); in total there were 8 treatments. Columns were leached with synthetic rain water under unsaturated flow conditions in downside up direction. There was significant increase in the retention of both (14)C-TNT and (14)C-DNT in soils with increasing soil OC content and in 3.0% soil OC content column degradation of TNT and metabolites from contaminated soil was significantly increased and resulted in greater soil-bound residues. Formation of monoamino-dinitrotoluene (ADNTs), diamino-mononitrotoluene (DANTs) and monoamino-mononitrotoluene (ANTs) metabolites was greatly enhanced with increase in OC content of soils. Study suggests that increasing OC content of contaminated soil to 3.0% significantly enhanced the reduction of nitroaromatics to more polar amine metabolites and the formation of soil-bound residues.

  6. Effects of plant species identity, diversity and soil fertility on biodegradation of phenanthrene in soil.

    Science.gov (United States)

    Oyelami, Ayodeji O; Okere, Uchechukwu V; Orwin, Kate H; De Deyn, Gerlinde B; Jones, Kevin C; Semple, Kirk T

    2013-02-01

    The work presented in this paper investigated the effects of plant species composition, species diversity and soil fertility on biodegradation of (14)C-phenanthrene in soil. The two soils used were of contrasting fertility, taken from long term unfertilised and fertilised grassland, showing differences in total nitrogen content (%N). Plant communities consisted of six different plant species: two grasses, two forbs, and two legume species, and ranged in species richness from 1 to 6. The degradation of (14)C-phenanthrene was evaluated by measuring indigenous catabolic activity following the addition of the contaminant to soil using respirometry. Soil fertility was a driving factor in all aspects of (14)C-phenanthrene degradation; lag phase, maximum rates and total extents of (14)C-phenanthrene mineralisation were higher in improved soils compared to unimproved soils. Plant identity had a significant effect on the lag phase and extents of mineralisation. Soil fertility was the major influence also on abundance of microbial communities.

  7. Effects of plant species identity, diversity and soil fertility on biodegradation of phenanthrene in soil

    NARCIS (Netherlands)

    Oyelami, A.O.; Okere, U.V.; Orwin, K.; Deyn, de G.B.; Jones, K.C.; Semple, K.T.

    2013-01-01

    The work presented in this paper investigated the effects of plant species composition, species diversity and soil fertility on biodegradation of 14C-phenanthrene in soil. The two soils used were of contrasting fertility, taken from long term unfertilised and fertilised grassland, showing difference

  8. Effects of electrokinetic treatment of a heavy metal contaminated soil on soil enzyme activities

    Energy Technology Data Exchange (ETDEWEB)

    Cang Long [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Zhou Dongmei, E-mail: dmzhou@issas.ac.cn [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Wang Quanying; Wu Danya [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China)

    2009-12-30

    There is a growing concern on the potential application of a direct current (DC) electric field to soil for removing contaminants, but little is known about its impact on soil enzyme activities. This study investigated the change of enzyme activities of a heavy metal contaminated soil before and after electrokinetic (EK) treatments at lab-scale and the mechanisms of EK treatment to affect soil enzyme activities were explored. After treatments with 1-3 V cm{sup -1} of voltage gradient for 420 h, soil pH, electrical conductivity (EC), soil organic carbon, dissolved organic carbon (DOC), soil heavy metal concentration and enzyme activities were analyzed. The results showed that the average removal efficiencies of soil copper were about 65% and 83% without and with pH control of catholyte, respectively, and all the removal efficiencies of cadmium were above 90%. The soil invertase and catalase activities increased and the highest invertase activity was as 170 times as the initial one. The activities of soil urease and acidic phosphatase were lower than the initial ones. Bivariate correlation analyses indicated that the soil invertase and acidic phosphatase activities were significantly correlated with soil pH, EC, and DOC at P < 0.05, but the soil urease activities had no correlation with the soil properties. On the other hand, the effects of DC electric current on solution invertase and catalase enzyme protein activities indicated that it had negative effect on solution catalase activity and little effect on solution invertase activity. From the change of invertase and catalase activities in soil and solution, the conclusion can be drawn that the dominant effect mechanism is the change of soil properties by EK treatments.

  9. The Balanced Scorecard as a Management Tool for Arable Farming

    Directory of Open Access Journals (Sweden)

    Margit Paustian

    2015-07-01

    Full Text Available Management requirements for crop farming are high and will rise in the future. Arable farms are challenged by volatile markets, growing administrative burdens, increasing operating costs and growing competition for land. Management skills have become much more important for farmers in recent years and this trend will continue in the future. There are numerous instruments like accounting software or crop field cards integrated in daily management practice, but there is a deficiency of a fully integrated management system to give an overview of all areas of the farming business. This gap can be closed by the management tool Balanced Scorecard (BSC that provides an overview of all production and management activities on a farm. Therefore, with the aim to transfer the BSC concept to crop farming, German farmers and agricultural advisors were surveyed to get insights into the success factors and key performance indicators in the four BSC perspectives they consider most relevant for the operational success of arable farms. By the use of a cluster analysis, three different farm types were identified according to their visions and strategies. For the three farm types the key performance indicators that the respondents considered most relevant for farm performance were figured out. Implementation of the BSC to crop farming can result in a big benefit for management practice. The BSC focuses vision and long-term strategy with the main goal to ensure consistency of the farm and increase farm performance.

  10. Effects of poultry manure on soil biochemical properties in phthalic acid esters contaminated soil.

    Science.gov (United States)

    Gao, Jun; Qin, Xiaojian; Ren, Xuqin; Zhou, Haifeng

    2015-12-01

    This study aimed to evaluate the effects of poultry manure (PM) on soil biological properties in DBP- and DEHP-contaminated soils. An indoor incubation experiment was conducted. Soil microbial biomass C (Cmic), soil enzymatic activities, and microbial phospholipid fatty acid (PLFA) concentrations were measured during incubation period. The results indicated that except alkaline phosphatase activity, DBP and DEHP had negative effects on Cmic, dehydrogenase, urease, protease activities, and contents of total PLFA. However, 5 % PM treatment alleviated the negative effects of PAEs on the above biochemical parameters. In DBP-contaminated soil, 5 % PM amendment even resulted in dehydroenase activity and Cmic content increasing by 17.8 and 11.8 % on the day 15 of incubation, respectively. During the incubation periods, the total PLFA contents decreased maximumly by 17.2 and 11.6 % in DBP- and DEHP-contaminated soils without PM amendments, respectively. Compared with those in uncontaminated soil, the total PLFA contents increased slightly and the value of bacPLFA/fugalPLFA increased significantly in PAE-contaminated soils with 5 % PM amendment. Nevertheless, in both contaminated soils, the effects of 5 % PM amendment on the biochemical parameters were not observed with 10 % PM amendment. In 10 % PM-amended soils, DBP and DEHP had little effect on Cmic, soil enzymatic activities, and microbial community composition. At the end of incubation, the effects of PAEs on these parameters disappeared, irrespective of PM amendment. The application of PM ameliorated the negative effect of PAEs on soil biological environment. However, further work is needed to study the effect of PM on soil microbial gene expression in order to explain the change mechanisms of soil biological properties.

  11. Assessing Tillage Effects on Soil Hydraulic Properties via Inverse Parameter Estimation using Tension Infiltrometry

    Science.gov (United States)

    Schwen, Andreas; Bodner, Gernot; Loiskandl, Willibald

    2010-05-01

    Hydraulic properties are key factors controlling water and solute movement in soils. While several recent studies have focused on the assessment of the spatial variability of hydraulic properties, the temporal dynamics are commonly not taken into account, primarily because its measurement is costly and time-consuming. However, there is extensive empirical evidence that these properties are subject to temporal changes, particularly in the near-saturated range where soil structure strongly influences water flow. One main source of temporal variability is soil tillage. It can improve macroporosity by loosening the soil and thereby changing the pore-size distribution. Since these modifications are quite unstable over time, the pore space partially collapses after tillage. This effect should be largest for conventional tillage (CT), where the soil is ploughed after harvest every year. Assessing the effect of different tillage treatments on the temporal variability of hydraulic properties requires adequate measurement techniques. Tension infiltrometry has become a popular and convenient method providing not only the hydraulic conductivity function but also the soil rentention properties. The inverse estimation of parameters from infiltration measurements remains challenging, despite some progress since the first approach of Šimůnek et al. (1998). Measured data like the cumulative infiltration, the initial and final volumetric water content, as well as independently measured retention data from soil core analysis with laboratory methods, have to be considered to find an optimum solution describing the soil's pore space. In the present study we analysed tension infiltration measurements obtained several times between August 2008 and December 2009 on an arable field in the Moravian Basin, Lower Austria. The tillage treatments were conventional tillage including ploughing (CT), reduced tillage with chisel only (RT), and no-tillage treatment using a direct seeding

  12. Effects of rhamnolipid biosurfactants on removal of phenanthrene from soil

    NARCIS (Netherlands)

    Noordman, Wouter H.; Ji, Wei; Brusseau, Mark L.; Janssen, Dick B.

    1998-01-01

    Solubilizing agents may enhance remediation of-soils contaminated with hydrophobic organic contaminants by diminishing sorption of the contaminants or increasing desorption rates. The effectiveness of rhamnolipid biosurfactants to enhance the removal of sorbed contaminants from soil was determined u

  13. Soil and plant factors driving the community of soil-borne microorganisms across chronosequences of secondary succession of chalk grasslands with a neutral pH.

    Science.gov (United States)

    Kuramae, Eiko; Gamper, Hannes; van Veen, Johannes; Kowalchuk, George

    2011-08-01

    Although soil pH has been shown to be an important factor driving microbial communities, relatively little is known about the other potentially important factors that shape soil-borne microbial community structure. This study examined plant and microbial communities across a series of neutral pH fields (pH=7.0-7.5) representing a chronosequence of secondary succession after former arable fields were taken out of production. These fields ranged from 17 to >66 years since the time of abandonment, and an adjacent arable field was included as a reference. Hierarchical clustering analysis, nonmetric multidimensional scaling and analysis of similarity of 52 different plant species showed that the plant community composition was significantly different in the different chronosequences, and that plant species richness and diversity increased with time since abandonment. The microbial community structure, as analyzed by phylogenetic microarrays (PhyloChips), was significantly different in arable field and the early succession stage, but no distinct microbial communities were observed for the intermediate and the late succession stages. The most determinant factors in shaping the soil-borne microbial communities were phosphorous and NH(4)(+). Plant community composition and diversity did not have a significant effect on the belowground microbial community structure or diversity.

  14. Spatiotemporal Pattern and Driving Forces of Arable Land-Use Intensity in China: Toward Sustainable Land Management Using Emergy Analysis

    Directory of Open Access Journals (Sweden)

    Hualin Xie

    2014-05-01

    Full Text Available The level of arable land-use intensity has important impacts on food security and rural sustainable development. Using the emergy method, we investigate the spatial disparities and driving forces of arable land-use intensity in China from 1999 to 2008 at the national, regional and provincial levels. The empirical results show that chemical fertilizer was the largest component of agricultural inputs and that agricultural diesel oil recorded the highest growth rate. The degree of heterogeneities in arable land-use intensity in China showed a decreasing trend, which resulted mainly from the differences among the eastern, northeastern, central and western regions. The regional disparities in labor, pesticides and plastic sheeting decreased from 1999 to 2008. The per capita annual net incomes of household operations and the agricultural policies had a significant positive correlation with total inputs, fertilizer inputs, pesticide inputs and agricultural plastic sheeting. In addition, the nonagricultural population had a greater impact on agricultural plastic sheeting. Finally, we suggest that there is an urgent need to focus on the effects of chemical fertilizer and pesticide inputs on the ecological environment. Agricultural support policies should be introduced for the poor agricultural production provinces.

  15. The effects of high metal concentrations in soil-compost mixtures on soil enzymes.

    Science.gov (United States)

    Warman, P R; Munroe, M D

    2010-10-01

    The study was undertaken to determine the impact of high-metal composts on the activities of four soil enzymes. High concentrations of metal salts (Cr, Cu, Ni or a Co-Mo-Pb combination) were added to feedstocks during the thermophilic stage of composting. These four metal-enriched composts and an unamended control compost were then mixed with soil collected from long-term agriculture plots under organic management or conventional management. The compost-soil mixtures were prepared at two rates (1:1 or 1:3 compost:soil, v/v) and incubated at 20 degrees C for three weeks. These 20 combinations plus the five composts and the two soils were added to pots and incubated for three weeks. Following incubation, soil enzyme activities (acid phosphatase, arysulfatase, dehydrogenase, phosphodiesterase) were measured using traditional assay procedures. Compared to the control, none of the high-metal composts inhibited soil enzyme activity. Notably, the Cu compost treatment produced significantly higher activity of all four enzymes in the soil compared to the control. Previous soil management influenced the activity of three enzymes, arysulfatase and dehydrogenase had greater activity in the organic soil while phosphatase activity was greater in the conventional soil. Increasing the proportion of compost in the pot had a positive effect on phosphodiesterase activity only. In conclusion, the high-metal compost treatments either enhanced or caused no adverse effects on soil enzyme activity.

  16. Effects of Lanthanum on Hydrolytic Enzyme Activities in Red Soil

    Institute of Scientific and Technical Information of China (English)

    褚海燕; 朱建国; 谢祖彬; 李振高; 曹志洪; 曾青; 林先贵

    2002-01-01

    The effects of La on some hydrolytic enzyme activities in red soil were studied in incubation and pot culture experiments. In the incubation experiment, La slightly stimulates the activities of urease and acidic phosphatase in soil and strongly stimulates sucrase activity in soil. In the pot culture experiment, La stimulates the activities of urease, acidic phosphatase and sucrase to different degrees. The stimulative effects of rare earth elements (REE) on hydrolytic enzyme activities in soil may result in increasing yield of crops.

  17. Effect of Different Vegetation Systems on Soil Erosion and Soil Nutrients in Red Soil Region of Southeastern China

    Institute of Scientific and Technical Information of China (English)

    TIAN GUANGMING; WANG FEIER; CHEN YINGXU; HE YUNFENG; FU QINGLIN; S.KUMAR; LIN QI

    2003-01-01

    The effect of different vegetation systems including bamboo plantation (BP), forest ecosystem (CF),citrus orchard (Ctr) and farmland (FL) on erosion and nutrients of red soil were investigated in hilly region of southeastern China to find effective control measures for soil erosion. The results showed that all the vegetation systems could significantly reduce soil erosion and nutrient losses compared to bare land (Br).The ability of different vegetation systems to conserve soil and water was in the order of Ctr > BP > CF > FL > Br. Vegetation could also improve soil fertility. The soil organic matter, total N and total P contents were much higher in all the vegetation systems than in bare land, especially for the top soils. Vegetation systems improved soil physical properties remarkably. Compared to the bare land, soil organic matter, TP,TK and available K, especially soil microbial biomass C, N and P, increased under all the vegetation covers.However, they were still much lower than expected, thus these biological measurements are still needed to be carried out continuously.

  18. Recent changes of arable weeds flora and management as a basis for future adaptations

    Directory of Open Access Journals (Sweden)

    Breitsameter, Laura

    2014-02-01

    Full Text Available In the course of the past decennia, numerous shifts of the arable weeds flora have been observed as a result of climate change and of changes of land use and agricultural management practice. These shifts necessitate appropriate adaptations of weed management. The present study depicts alterations of the arable weeds flora of Lower Saxony based on data from two different sources, and describes recent changes of arable weeds management. We firstly conducted a questionnaire-based survey among plant protection consultants and experts of agronomy and plant protection in industry and the federal agriculture authorities. This survey was aimed at identifying which weed taxa have gained or lost relevance for management, and which tendencies with regard to their relevance is expected according to expert knowledge. In addition, the experts were asked for information on possible adaptations and challenges of weed management expected for the future. Secondly, we used protocols of plant protection trails published by the Lower Saxony chamber of agriculture in order to determine alterations of the weed management practice since the 1980s. The screened data gave a clear indication of an increase of the relevance during the past 30 years for a number of weed taxa, in particular for several millet taxa, Geranium species, Alopecurus myosuroides and Chenopodium album. In the evaluation of changes of the relevance of individual weed taxa, the impact of climate change cannot be segregated from effects of altered agricultural practices, which are in turn themselves influenced by climate change. Records of the agricultural practice have pointed out shifts in herbicide application dates which parallel altered sowing dates, e. g., an increase in the frequency of herbicide application in autumn rather than in spring for winter wheat. The recent shifts of weed flora and management practices can serve as a basis for the development of management adaptations for the future

  19. Land use and land management effects on soil organic carbon stock in Mediterranean agricultural areas (Southern Spain)

    Science.gov (United States)

    Parras-Alcántara, Luis; Lozano-García, Beatriz

    2014-05-01

    INTRODUCTION Soils play a key role in the carbon geochemical cycle. Agriculture contributes to carbon sequestration through photosynthesis and the incorporation of carbon into carbohydrates. Soil management is one of the best tools for climate change mitigation. Small increases or decreases in soil carbon content due to changes in land use or management practices, may result in a significant net exchange of carbon between the soil carbon pool and the atmosphere. In the last decades arable crops (AC) have been transformed into olive grove cultivations (OG) or vineyards (V) in Mediterranean areas. A field study was conducted to determine long-term effects of land use change (LUC) (AC by OG and V) on soil organic carbon (SOC), total nitrogen (TN), C:N ratio and their stratification in Calcic-Chromic Luvisols (LVcc/cr) in Mediterranean conditions. MATERIAL AND METHODS An unirrigated farm in Montilla-Moriles (Córdoba, Spain) cultivated under conventional tillage (animal power with lightweight reversible plows and non-mineral fertilization or pesticides) was selected for study in 1965. In 1966, the farm was divided into three plots with three different uses (AC, OG and V). The preliminary analyses were realized in 1965 for AC (AC1), and the second analyses were realized in 2011 for AC (AC2 - winter crop rotation with annual wheat and barley, receiving mineral fertilization or pesticides), OG (annual passes with disk harrow and cultivator in the spring, followed by a tine harrow in the summer receiving mineral fertilization and weed control with residual herbicides), and V (with three or five chisel passes a year from early spring to early autumn with mineral fertilization or pesticides.). In all cases (AC1, AC2, OG and V) were collected soil entire profiles. Soil properties determined were: soil particle size, bulk density, SOC, TN, C:N ratio, stocks and SRs. The statistical significance of the differences in the variables between land use practices was tested using the

  20. Partitioning of carbon sources among functional pools to investigate short-term priming effects of biochar in soil: A {sup 13}C study

    Energy Technology Data Exchange (ETDEWEB)

    Kerré, Bart [Department of Earth and Environmental Science, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium); Hernandez-Soriano, Maria C., E-mail: m.hernandezsoriano@uq.edu.au [Department of Earth and Environmental Science, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium); The University of Queensland, School of Agriculture and Food Sciences, St. Lucia, Queensland 4072 (Australia); Smolders, Erik [Department of Earth and Environmental Science, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium)

    2016-03-15

    Biochar sequesters carbon (C) in soils because of its prolonged residence time, ranging from several years to millennia. In addition, biochar can promote indirect C-sequestration by increasing crop yield while, potentially, reducing C-mineralization. This laboratory study was set up to evaluate effects of biochar on C-mineralization with due attention to source appointment by using {sup 13}C isotope signatures. An arable soil (S) (7.9 g organic C, OC kg{sup −1}) was amended (single dose of 10 g kg{sup −1} soil) with dried, grinded maize stover (leaves and stalks), either natural (R) or {sup 13}C enriched (R*), and/or biochar (B/B*) prepared from the maize stover residues (450 °C). Accordingly, seven different combinations were set up (S, SR, SB, SR*, SB*, SRB*, SR*B) to trace the source of C in CO{sub 2} (180 days), dissolved organic-C (115 days) and OC in soil aggregate fractions (90 days). The application of biochar to soil reduced the mineralization of native soil organic C but the effect on maize stover-C mineralization was not consistent. Biochar application decreased the mineralization of the non-enriched maize stover after 90 days, this being consistent with a significant reduction of dissolved organic C concentration from 45 to 18 mg L{sup −1}. However, no significant effect was observed for the enriched maize stover, presumably due to differences between the natural and enriched materials. The combined addition of biochar and enriched maize stover significantly increased (twofold) the presence of native soil organic C or maize derived C in the free microaggregate fraction relative to soil added only with stover. Although consistent effects among C sources and biochar materials remains elusive, our outcomes indicate that some biochar products can reduce mineralization and solubilization of other sources of C while promoting their physical protection in soil particles. - Highlights: • Biochar can reduce native soil organic carbon mineralization.

  1. Effects of glyphosate on soil microbial communities and its mineralization in a Mississippi soil.

    Science.gov (United States)

    Weaver, Mark A; Krutz, L Jason; Zablotowicz, Robert M; Reddy, Krishna N

    2007-04-01

    Transgenic glyphosate-resistant (GR) soybean [Glycine max (L.) Merr.] has enabled highly effective and economical weed control. The concomitant increased application of glyphosate could lead to shifts in the soil microbial community. The objective of these experiments was to evaluate the effects of glyphosate on soil microbial community structure, function and activity. Field assessments on soil microbial communities were conducted on a silt loam soil near Stoneville, MS, USA. Surface soil was collected at time of planting, before initial glyphosate application and 14 days after two post-emergence glyphosate applications. Microbial community fatty acid methyl esters (FAMEs) were analyzed from these soil samples and soybean rhizospheres. Principal component analysis of the total FAME profile revealed no differentiation between field treatments, although the relative abundance of several individual fatty acids differed significantly. There was no significant herbicide effect in bulk soil or rhizosphere soils. Collectively, these findings indicate that glyphosate caused no meaningful whole microbial community shifts in this time period, even when applied at greater than label rates. Laboratory experiments, including up to threefold label rates of glyphosate, resulted in up to a 19% reduction in soil hydrolytic activity and small, brief (glyphosate was mineralized when applied at threefold field rates, with about 9% forming bound residues. These results indicate that glyphosate has only small and transient effects on the soil microbial community, even when applied at greater than field rates.

  2. Effects of imidacloprid on soil microbial communities in different saline soils.

    Science.gov (United States)

    Zhang, Qingming; Xue, Changhui; Wang, Caixia

    2015-12-01

    The effects of imidacloprid in the soil environment are a worldwide concern. However, the impact of imidacloprid on soil microorganisms under salt stress is almost unknown. Therefore, an indoor incubation test was performed, and the denaturing gradient gel electrophoresis (DGGE) approach was used to determine the response of different saline soil bacterial and fungal community structures to the presence of imidacloprid (0.4, 2, 10 mg kg(-1)). The results showed that the soil bacterial diversity slightly declined with increasing imidacloprid concentration in soils with low salinity. In moderately saline soils, a new band in the DGGE profile suggested that imidacloprid could improve the soil bacterial diversity to some degree. An analysis of variance indicated that the measured soil bacterial diversity parameters were significantly affected by dose and incubation time. Compared with the control, the soil fungal community structure showed no obvious changes in low and moderately saline soils treated with imidacloprid. The results of these observations provide a basic understanding of the potential ecological effects of imidacloprid on different microorganisms in saline soils.

  3. Progress in Significant Soil Science Fields of China over the Last Three Decades: A Review

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qi-Guo; HE Ji-Zheng; YAN Xiao-Yuan; ZHANG Bin; ZHANG Gan-Lin; CAI Zu-Cong

    2011-01-01

    Due to continuous decreases in arable land area and continuous population increases, Chinese soil scientists face great challenges in meeting food demands, mitigating adverse environmental impacts, and sustaining or enhancing soil productivity under intensive agriculture.With the aim of promoting the application of soil science knowledge, this paper reviews the achievements of Chinese scientists in soil resource use and management, soil fertility, global change mitigation and soil biology over the last 30 years.During this period, soil resource science has provided essential support for the use and exploitation of Chinese soil resources, and has itself developed through introduction of new theories such as Soil Taxonomy and new technologies such us remote sensing.Soil fertility science has contributed to the alleviation and elimination of impeding physical and chemical factors that constrain availability of essential nutrients and water in soils, the understanding of nutrient cycling in agroecosystems, and the increase in nutrient use efficiency for sustainable crop production.Chinese soil scientists have contributed to the understanding of the cropland's role in global change, particularly to the understanding of methane and nitrous oxide emission from rice fields and the effect of elevated carbon dioxide and ozone on rice-wheat system.Soil biology research has progressed in biological N fixation, distribution of fauna in Chinese soils, and bioremediation of polluted soils.A new generation of soil scientists has arisen in the last three decades.The gaps between research and application in these soil science fields are also discussed.

  4. Greywater reuse for irrigation: effect on soil properties.

    Science.gov (United States)

    Travis, Micheal J; Wiel-Shafran, Alit; Weisbrod, Noam; Adar, Eilon; Gross, Amit

    2010-05-15

    A controlled study of the effect of greywater (GW) irrigation on soil properties was conducted. Containers of sand, loam and loess soils were planted with lettuce, and irrigated with fresh water, raw artificial GW or treated artificial GW. Greywater was treated using a recirculating vertical-flow constructed wetland. Soil samples were collected every 10 days for the 40-day duration of the study, and plant growth was measured. Soils were analysed for physicochemical and biological parameters to determine changes caused by the different treatments. It was demonstrated that raw artificial GW significantly increased the development of hydrophobicity in the sand and loam soils, as determined by water droplet penetration time. No significant changes were observed for the loess soil under all treatments. Observed hydrophobicity was correlated with increased oil and grease and surfactant concentrations in the soil. Zeta (zeta) potential of the soils was measured to determine changes in the soil particle surface properties as a result of GW irrigation. A significant change in zeta-potential (less negative) was observed in the raw artificial GW-irrigated sand, whereas no difference was observed in the loam or loess. Soils irrigated with fresh water or treated GW exhibited no increase in hydrophobicity. Fecal coliform bacteria were absent or <10 CFU g(-1) in soils irrigated with fresh water or treated GW, but at least 1 order of magnitude higher in raw artificial GW irrigated soils. Only in the last sampling event and only for the loess soil was plant growth significantly higher for fresh water irrigated vs. raw or treated GW irrigated soils. This study demonstrates that treated GW can be effectively irrigated without detrimental effects on soil or plant growth; however, raw GW may significantly change soil properties that can impact the movement of water in soil and the transport of contaminants in the vadose zone.

  5. Effect of Thickness of a Water Repellent Soil Layer on Soil Evaporation Rate

    Science.gov (United States)

    Ahn, S.; Im, S.; Doerr, S.

    2012-04-01

    A water repellent soil layer overlying wettable soil is known to affect soil evaporation. This effect can be beneficial for water conservation in areas where water is scarce. Little is known, however, about the effect of the thickness of the water repellent layer. The thickness of this layer can vary widely, and particularly after wildfire, with the soil temperature reached and the duration of the fire. This study was conducted to investigate the effect of thickness of a top layer of water repellent soil on soil evaporation rate. In order to isolate the thickness from other possible factors, fully wettable standard sand (300~600 microns) was used. Extreme water repellency (WDPT > 24 hours) was generated by 'baking' the sand mixed with oven-dried pine needles (fresh needles of Pinus densiflora) at the mass ratio of 1:13 (needle:soil) at 185°C for 18 hours. The thicknesses of water repellent layers were 1, 2, 3 and 7 cm on top of wettable soil. Fully wettable soil columns were prepared as a control. Soil columns (8 cm diameter, 10 cm height) were covered with nylon mesh. Tap water (50 ml, saturating 3 cm of a soil column) was injected with hypoderm syringes from three different directions at the bottom level. The injection holes were sealed with hot-melt adhesive immediately after injection. The rate of soil evaporation through the soil surface was measured by weight change under isothermal condition of 40°C. Five replications were made for each. A trend of negative correlation between the thickness of water repellent top layer and soil evaporation rate is discussed in this contribution.

  6. Effects of Prairie Restoration on Soil Quality Indicators

    Science.gov (United States)

    Characterization of soil ecosystem functioning based on soil quality assessments of native prairie may provide a reference for evaluating improvement in soil quality of cultivated agroecosystems converted to perennial vegetation during prairie restoration. Our objective was to determine the effect o...

  7. Effects of Tillage Practices on Soil Organic Carbon and Soil Respiration

    Science.gov (United States)

    Rusu, Teodor; Ioana Moraru, Paula; Bogdan, Ileana; Ioan Pop, Adrian

    2016-04-01

    Soil tillage system and its intensity modify by direct and indirect action soil temperature, moisture, bulk density, porosity, penetration resistance and soil structural condition. Minimum tillage and no-tillage application reduce or completely eliminate the soil mobilization, due to this, soil is compacted in the first years of application. The degree of compaction is directly related to soil type and its state of degradation. All this physicochemical changes affect soil biology and soil respiration. Soil respiration leads to CO2 emissions from soil to the atmosphere, in significant amounts for the global carbon cycle. Soil respiration is one measure of biological activity and decomposition. Soil capacity to produce CO2 varies depending on soil, season, intensity and quality of agrotechnical tillage, soil water, cultivated plant and fertilizer. Our research follows the effects of the three tillage systems: conventional system, minimum tillage and no-tillage on soil respiration and finally on soil organic carbon on rotation soybean - wheat - maize, obtained on an Argic Faeoziom from the Somes Plateau, Romania. To quantify the change in soil respiration under different tillage practices, determinations were made for each crop in four vegetative stages (spring, 5-6 leaves, bean forming, harvest). Soil monitoring system of CO2 and O2 included gradient method, made by using a new generation of sensors capable of measuring CO2 concentration in-situ and quasi-instantaneous in gaseous phase. At surface soil respiration is made by using ACE Automated Soil CO2 Exchange System. These areas were was our research presents a medium multi annual temperature of 8.20C medium of multi annual rain drowns: 613 mm. The experimental variants chosen were: i). Conventional system: reversible plough (22-25 cm) + rotary grape (8-10 cm); ii). Minimum tillage system: paraplow (18-22 cm) + rotary grape (8-10 cm); iii). No-tillage. The experimental design was a split-plot design with three

  8. Long-term effects of deep soil loosening on root distribution and soil physical parameters in compacted lignite mine soils

    Science.gov (United States)

    Badorreck, Annika; Krümmelbein, Julia; Raab, Thomas

    2015-04-01

    Soil compaction is a major problem of soils on dumped mining substrates in Lusatia, Germany. Deep ripping and cultivation of deep rooting plant species are considered to be effective ways of agricultural recultivation. Six years after experiment start, we studied the effect of initial deep soil loosening (i.e. down to 65 cm) on root systems of rye (Secale cereale) and alfalfa (Medicago sativa) and on soil physical parameters. We conducted a soil monolith sampling for each treatment (deep loosened and unloosened) and for each plant species (in three replicates, respectively) to determine root diameter, length density and dry mass as well as soil bulk density. Further soil physical analysis comprised water retention, hydraulic conductivity and texture in three depths. The results showed different reactions of the root systems of rye and alfalfa six years after deep ripping. In the loosened soil the root biomass of the rye was lower in depths of 20-40 cm and the root biomass of alfalfa was also decreased in depths of 20-50 cm together with a lower root diameter for both plant species. Moreover, total and fine root length density was higher for alfalfa and vice versa for rye. The soil physical parameters such as bulk density showed fewer differences, despite a higher bulk density in 30-40cm for the deep loosened rye plot which indicates a more pronounced plough pan.

  9. Heavy Metal Polluted Soils: Effect on Plants and Bioremediation Methods

    OpenAIRE

    Chibuike, G. U.; Obiora, S. C.

    2014-01-01

    Soils polluted with heavy metals have become common across the globe due to increase in geologic and anthropogenic activities. Plants growing on these soils show a reduction in growth, performance, and yield. Bioremediation is an effective method of treating heavy metal polluted soils. It is a widely accepted method that is mostly carried out in situ; hence it is suitable for the establishment/reestablishment of crops on treated soils. Microorganisms and plants employ different mechanisms for...

  10. Geochemistry Of Lead In Contaminated Soils: Effects Of Soil Physico-Chemical Properties

    Science.gov (United States)

    Saminathan, S.; Sarkar, D.; Datta, R.; Andra, S. P.

    2006-05-01

    Lead (Pb) is an environmental contaminant with proven human health effects. When assessing human health risks associated with Pb, one of the most common exposure pathways typically evaluated is soil ingestion by children. However, bioaccessibility of Pb primarily depends on the solubility and hence, the geochemical form of Pb, which in turn is a function of site specific soil chemistry. Certain fractions of ingested soil-Pb may not dissociate during digestion in the gastro-intestinal tract, and hence, may not be available for transport across the intestinal membrane. Therefore, this study is being currently performed to assess the geochemical forms and bioaccessibility of Pb in soils with varying physico-chemical properties. In order to elucidate the level of Pb that can be ingested and assimilated by humans, an in-vitro model that simulates the physiological conditions of the human digestive system has been developed and is being used in this study. Four different types of soils from the Immokalee (an acid sandy soil with minimal Pb retention potential), Millhopper (a sandy loam with high Fe/Al content), Pahokee (a muck soil with more than 80% soil organic matter), and Tobosa series (an alkaline soil with high clay content) were artificially contaminated with Pb as lead nitrate at the rate equivalent to 0, 400, 800, and 1200 mg/kg dry soil. Analysis of soils by a sequential extraction method at time zero (immediately after spiking) showed that Immokalee and Millhopper soils had the highest amount of Pb in exchangeable form, whereas Pahokee and Tobosa soils had higher percentages of carbonate-bound and Fe/Al-bound Pb. The results of in-vitro experiment at time zero showed that majority of Pb was dissolved in the acidic stomach environment in Immokalee, Millhopper, and Tobosa, whereas it was in the intestinal phase in Pahokee soils. Because the soil system is not in equilibrium at time zero, the effect of soil properties on Pb geochemistry is not clear as yet. The

  11. How much Nitrous Oxide is produced in cultivation of biofuels on arable land in Sweden?; Hur mycket lustgas blir det vid odling av biobraenslen paa aakermark i Sverige?

    Energy Technology Data Exchange (ETDEWEB)

    Kasimir Klemedtsson, Aasa (Univ. of Goeteborg, Dept. of Earth Sciences, Goeteborg (Sweden). Physical Geography)

    2010-03-15

    Several methods that can be used to estimate the emission of nitrous oxide from arable land are discussed, all of them with their pros and cons. 1 The base for all estimation methods is field measurements, well executed with a technique designed for the production of high quality data. Published field data of good quality were collected from areas in north Europe and America, both from grain and rape crops and unfertilised grasslands where natural background emission is assumed. The compilation shows that grasslands emit in average 0.3 +- 0.1 kg N{sub 2}O-N/ha/year. In crop systems where a high amount of nitrogen is repeatedly added to the soil, the soil N store will contribute to N{sub 2}O emission coming years. This is one reason why emission is higher for unfertilised arable land (where nitrogen have been added previous years) compared to unfertilised grassland, 1 +- 0.1 kg N{sub 2}O-N/ha/year. Fertilised arable lands have higher emission, in average around 3 kg N{sub 2}O-N/ha/year. In comparison, field measurements in Sweden have shown lower emission, 0.6 and 2 kg N{sub 2}O-N/ha/year from clay and sandy soil respectively. 2 The IPCC method is the best known, where the emission from arable land is estimated as a function of added nitrogen. In reality there is no correlation between a low N-addition and the emission of nitrous oxide since the N-addition needs to be high to have influence on the nitrous oxide emission..25 or the new factor 1% of added N has been used in many LCA's as an estimator for nitrous oxide and the uncertainty span of 0,3 and 3% is seldom used. The method underestimates the size of nitrous oxide emission in many systems and cannot estimate a true emission from individual fields. 3 Globally there is a connection between the increase in reactive nitrogen and the increase of atmospheric nitrous oxide, which is the base for a method suggested by Crutzen et al. Nitrous oxide emission has been estimated to be 3-5% of both biological nitrogen

  12. How much Nitrous Oxide is produced in cultivation of biofuels on arable land in Sweden?; Hur mycket lustgas blir det vid odling av biobraenslen paa aakermark i Sverige?

    Energy Technology Data Exchange (ETDEWEB)

    Kasimir Klemedtsson, Aasa (Univ. of Goeteborg, Dept. of Earth Sciences, Goeteborg (Sweden). Physical Geography)

    2010-03-15

    Several methods that can be used to estimate the emission of nitrous oxide from arable land are discussed, all of them with their pros and cons. 1 The base for all estimation methods is field measurements, well executed with a technique designed for the production of high quality data. Published field data of good quality were collected from areas in north Europe and America, both from grain and rape crops and unfertilised grasslands where natural background emission is assumed. The compilation shows that grasslands emit in average 0.3 +- 0.1 kg N{sub 2}O-N/ha/year. In crop systems where a high amount of nitrogen is repeatedly added to the soil, the soil N store will contribute to N{sub 2}O emission coming years. This is one reason why emission is higher for unfertilised arable land (where nitrogen have been added previous years) compared to unfertilised grassland, 1 +- 0.1 kg N{sub 2}O-N/ha/year. Fertilised arable lands have higher emission, in average around 3 kg N{sub 2}O-N/ha/year. In comparison, field measurements in Sweden have shown lower emission, 0.6 and 2 kg N{sub 2}O-N/ha/year from clay and sandy soil respectively. 2 The IPCC method is the best known, where the emission from arable land is estimated as a function of added nitrogen. In reality there is no correlation between a low N-addition and the emission of nitrous oxide since the N-addition needs to be high to have influence on the nitrous oxide emission..25 or the new factor 1% of added N has been used in many LCA's as an estimator for nitrous oxide and the uncertainty span of 0,3 and 3% is seldom used. The method underestimates the size of nitrous oxide emission in many systems and cannot estimate a true emission from individual fields. 3 Globally there is a connection between the increase in reactive nitrogen and the increase of atmospheric nitrous oxide, which is the base for a method suggested by Crutzen et al. Nitrous oxide emission has been estimated to be 3-5% of both biological nitrogen

  13. Effects of Cd and Pb pollution on soil enzymatic activities and soil microbiota

    Institute of Scientific and Technical Information of China (English)

    LIU Shuqing; YANG Zhixin; WANG Xiaomin; ZHANG Xiaogui; GAO Rutai; LIU Xia

    2007-01-01

    Based on a representative sampling method and pot experiment with different concentrations of Cd and Pd,the enzymatic activities(urease,phosphatase,catalase,invertase),population of bacteria,fungus and actinomycete in the soil,the Cd and Pd pollution status of soil samples(from the wastewater-irrigated area of Baoding suburb)were appraised.Unitary linear and nonlinear curve-fitting optimization models were applied in the research,and the relationship between Pb and Cd causing pollution and enzymatic activities of the tested soils were discussed.The research may provide a theoretical basis for protecting the environment in the region of Baiyangdian Lake,Hebei province,prevent soil pollution,and ascertain biochemical indexes,which reflect soil heavy metal pollution levels.The research results indicated that:(1)there was obvious accumulation of Pb and Cd in the wastewater-irrigated area,also the accumulation in wastewater-irrigated soil is more than that in fresh water-irrigated soil,and accumulation on surface layer was more than that in the lower layer.Pb and Cd contents in the tested soils exceeded the standards of soil background values for some major cities at home and abroad and the world soil Cd and Pb contents range.This means that the tested soil had reached a lightly polluted level;(2)there existed an obvious negative correlation between soil enzymatic activities and Pb and Cd contents in wastewaterirrigated soil,where the soil urease and catalase activities decreased obviously with the increase of Pb and Cd contents in soil.Therefore,the urease and catalase can be considered as biochemical indexes that reflect the degree of soil Pb and Cd pollution;(3)the pot experiments indicated that the influence of Cd on soil enzymatic activities was greater than that of Pb.Generally,the effect of Cd on soil phosphatase,urease,catalase is more obvious than that on invertase,while Pb has a more obvious effect on invertase than Cd;(4)pot experiments of triple cropping

  14. Residue cover effects on soil erosion and the infiltration in black soil under simulated rainfall experiments

    Science.gov (United States)

    Xin, Yan; Xie, Yun; Liu, Yuxin; Liu, Hongyuan; Ren, Xiaoyu

    2016-12-01

    Residue cover is widely used in the Northeastern China Black Soil Region for soil erosion control due to the large annual production of crop residues. Quantitative evaluations of the residue cover effects on preventing soil loss and on the cumulative infiltration amount are thus desirable. Herein, rainfall simulation experiments were conducted using simulators and soil flumes to study the effects of residue cover on soil erosion and infiltration under various rainfall events. Laboratory experiments were designed utilizing five levels of residue cover (bare, 15%, 35%, 55% and 75%), four rainfall intensities (30 mm/h, 60 mm/h, 90 mm/h and 120 mm/h), two soil moistures (dry and wet run) and a fixed slope of 7%. The results indicated that residue cover strongly affects runoff, soil loss and infiltration. Equations for predicting the soil loss ratio and infiltration ratio (the ratio of residue cover soil to bare soil) are herein proposed based on nonlinear curve regression. An empirical approach presented as the infiltration ratios multiplied Philip's equation derived from bare soil was established for estimating the cumulative infiltration amounts under various residue covers. The equation was demonstrated to be suitable for infiltration prediction for black soil by the root mean square error value and 1:1 line method. In addition, the relationship between the residue cover and biomass of corn residues was provided in order to enable accurate measurement of the residue coverage. These derived equations could be used for soil erosion and infiltration prediction under no-till and residue cover management conditions in the black soil region.

  15. Biochar has no effect on soil respiration across Chinese agricultural soils.

    Science.gov (United States)

    Liu, Xiaoyu; Zheng, Jufeng; Zhang, Dengxiao; Cheng, Kun; Zhou, Huimin; Zhang, Afeng; Li, Lianqing; Joseph, Stephen; Smith, Pete; Crowley, David; Kuzyakov, Yakov; Pan, Genxing

    2016-06-01

    Biochar addition to soil has been widely accepted as an option to enhance soil carbon sequestration by introducing recalcitrant organic matter. However, it remains unclear whether biochar will negate the net carbon accumulation by increasing carbon loss through CO2 efflux from soil (soil respiration). The objectives of this study were to address: 1) whether biochar addition increases soil respiration; and whether biochar application rate and biochar type (feedstock and pyrolyzing system) affect soil respiration. Two series of field experiments were carried out at 8 sites representing the main crop production areas in China. In experiment 1, a single type of wheat straw biochar was amended at rates of 0, 20 and 40 tha(-1) in four rice paddies and three dry croplands. In experiment 2, four types of biochar (varying in feedstock and pyrolyzing system) were amended at rates of 0 and 20 tha(-1) in a rice paddy under rice-wheat rotation. Results showed that biochar addition had no effect on CO2 efflux from soils consistently across sites, although it increased topsoil organic carbon stock by 38% on average. Meanwhile, CO2 efflux from soils amended with 40 t of biochar did not significantly higher than soils amended with 20 t of biochar. While the biochars used in Experiment 2 had different carbon pools and physico-chemical properties, they had no effect on soil CO2 efflux. The soil CO2 efflux following biochar addition could be hardly explained by the changes in soil physic-chemical properties and in soil microbial biomass. Thus, we argue that biochar will not negate the net carbon accumulation by increasing carbon loss through CO2 efflux in agricultural soils.

  16. Effects of soil moisture content and tractor wheeling intensity on traffic-induced soil compaction

    Directory of Open Access Journals (Sweden)

    Iman AHMADI

    2015-12-01

    Full Text Available Soil compaction causes deleterious effects on physical and mechanical proprieties of agricultural soils. In order to investigate the effect of soil moisture content and tractor wheeling intensity on traffic-induced soil compaction, this study was carried out on a field with clay loam soil. Soil dry bulk density and hydraulic conductivity as well as emergence percentage of corn seedlings and dry mass of the sampled mature plants were considered the dependent variables of the experiment. Independent variables consisted of soil moisture content with five levels (12, 15, 17, 19, and 21%, traffic intensity with three levels (four, two, and zero passes of tractor wheel (tractor model: John Deere 3350 from the entire area of the plot, and soil sampling depth with three levels (0-10, 10-20, and 20-30 cm. According to the results of this study, gradual increase in soil water content generally resulted in an increase in soil bulk density; moreover, increasing the tractor wheeling intensity from 0 to 4 passes increased bulk density by 13%. Furthermore, the driest soil water content had the highest and the wettest soil water content had the lowest emergence percentage of corn seedlings among the treatments; moreover, traffic intensity treatment inversely affected the emergence percentage of corn seedlings and the dry mass of mature plants. To sum up, these results indicate that, for improving water permeability and reducing dry bulk density of the examined clay loam soil, as well as better emergence of corn seedlings and ultimately increasing crop yield, it is recommended to avoid wheeling when soil moisture content is high, reduce the number of machinery wheel passes from the farm as low as possible, and restrict the wheel passes to fixed strips along the field, whenever possible.

  17. Influence of effective stress on swelling pressure of expansive soils

    Directory of Open Access Journals (Sweden)

    Baille Wiebke

    2016-01-01

    Full Text Available The volume change and shear strength behaviour of soils are controlled by the effective stress. Recent advances in unsaturated soil mechanics have shown that the effective stress as applicable to unsaturated soils is equal to the difference between the externally applied stress and the suction stress. The latter can be established based on the soil-water characteristic curve (SWCC of the soil. In the present study, the evolution of swelling pressure in compacted bentonite-sand mixtures was investigated. Comparisons were made between magnitudes of applied suction, suction stress, and swelling pressure.

  18. The destination of arable land in a marginal agricultural landscape in South Portugal: an exploration of land use change determinants

    NARCIS (Netherlands)

    Doorn, van A.M.; Bakker, M.M.

    2007-01-01

    This research attempts to investigate what drives three conversions of arable land during the period 1985¿2000 in a marginal agricultural landscape in Southern Portugal: afforestation of arable land, abandonment of arable land and regeneration of the agro-silvo-pastoral system. This was done by expl

  19. Effects of Soil and Air Drying Methods on Soil Plasticity of Different Cities of Pakistan

    Directory of Open Access Journals (Sweden)

    Aashan Ijaz

    2014-12-01

    Full Text Available Atterberg Limits were initially defined in 1911, by Albert Atterberg, a Swedish scientist. Their purposes are to classifying cohesive soils and determine engineering properties of soils. According to ASTM, all the soils tested by Atterberg limits should be oven dried, it is because drying the soils in different degree will alter their properties significantly. Some of the physical properties of soils will undergo changes that appear to be permanent. Therefore, the soil samples should be in natural or air-dried form. However, in reality, due to time constraint and other factors, many will run the tests by using soil samples that are prepared by oven drying method. They assumed that there is no difference between the results of two types of drying method. However, in reality, the properties of soil will be affected and thus give a misleading result. The objective of this study is to determine the effect of two drying methods, air-drying method and oven drying method, on the soil plasticity. Six soil samples from different cities were tested. These tests include sieve analysis, specific gravity test, hydrometer analysis, Plastic limit and liquid limit test. Conclusively, the oven drying method could not replace the air-drying method in soil preparation for both Atterberg limits tests.

  20. [Effects of nitrogen fertilization, soil moisture and soil temperature on soil respiration during summer fallow season].

    Science.gov (United States)

    Zhang, Fang; Guo, Sheng-Li; Zou, Jun-Liang; Li, Ze; Zhang, Yan-Jun

    2011-11-01

    On the loess plateau, summer fallow season is a hot rainy time with intensive soil microbe activities. To evaluate the response of soil respiration to soil moisture, temperature, and N fertilization during this period is helpful for a deep understanding about the temporal and spatial variability of soil respiration and its impact factors, then a field experiment was conducted in the Changwu State Key Agro-Ecological Experimental Station, Shaanxi, China. The experiment included five N application rates: unfertilized 0 (N0), 45 (N45), 90 (N90), 135(N135), and 180 (N180) kg x hm(-2). The results showed that at the fallow stage, soil respiration rate significantly enhanced from 1.24 to 1.91 micromol x (m2 x s)(-1) and the average of soil respiration during this period [6.20 g x (m2 x d)(-1)] was close to the growing season [6.95 g x (m2 x d)(-1)]. The bivariate model of soil respiration with soil water and soil temperature was better than the single-variable model, but not so well as the three-factor model when explaining the actual changes of soil respiration. Nitrogen fertilization alone accounted for 8% of the variation soil respiration. Unlike the single-variable model, the results could provide crucial information for further research of multiple factors on soil respiration and its simulation.

  1. Heavy Metal Polluted Soils: Effect on Plants and Bioremediation Methods

    Directory of Open Access Journals (Sweden)

    G. U. Chibuike

    2014-01-01

    Full Text Available Soils polluted with heavy metals have become common across the globe due to increase in geologic and anthropogenic activities. Plants growing on these soils show a reduction in growth, performance, and yield. Bioremediation is an effective method of treating heavy metal polluted soils. It is a widely accepted method that is mostly carried out in situ; hence it is suitable for the establishment/reestablishment of crops on treated soils. Microorganisms and plants employ different mechanisms for the bioremediation of polluted soils. Using plants for the treatment of polluted soils is a more common approach in the bioremediation of heavy metal polluted soils. Combining both microorganisms and plants is an approach to bioremediation that ensures a more efficient clean-up of heavy metal polluted soils. However, success of this approach largely depends on the species of organisms involved in the process.

  2. EFFECTS OF SOIL CRUSTING ON SOIL MOISTURE, RUNOFF AND EROSION: FIELD OBSERVATIONS

    Institute of Scientific and Technical Information of China (English)

    Tongxin ZHU

    2002-01-01

    Soil crusting may have significant impacts on infiltration, runoff generation and erosion in agricultural lands or semi-arid and arid soils. The previous investigations on soil crusting were often conducted under simulated rainfall conditions. This study aims to evaluate the effects of soil crusting on soil moisture during inter-storm periods and soil and water losses during storm periods under natural rainfalls. The study site was located in the Loess Plateau of China. Four plots with a uniform slope and size were selected. Soil crusts were kept intact on the two plots throughout the monitoring periods of 1999 and 2000,but were broken after each rain storm event on the other two plots. Soil moisture was measured on all plots with an interval of one week at three depths and total event runoff and sediment discharges were measured in each storm. It was found that no marked difference in soil moisture and runoff exists between the crusted and uncrusted plots. This is because the rapid development of new crusts on the uncrusted plots during the storm events. However, the erosion rate on the uncrusted plots was significantly higher than that on the crusted plots, which was mainly caused by the disturbance of the surface soils on the uncrusted plots. This study questions the effectiveness of a common agricultural practice in the Loess Plateau, hoeing lands after rainfall, in reducing runoff and erosion.

  3. Effects of AMF on soil enzyme activity and carbon sequestration capacity in reclaimed mine soil

    Institute of Scientific and Technical Information of China (English)

    Qian Kuimei; Wang Liping; Yin Ningning

    2012-01-01

    A series of pot experiments and field trials were carried out to evaluate the effects of arbuscular mycorrhizal fungi (AMF) on activities of soil enzymes and carbon sequestration capacity in reclaimed mine soil.A complex substrate of coal gangue,fly ash and sludge was used as reclaimed mine soil,and ryegrass was planted with AMF inoculation to construct a plant-complex substrate-microbe ecological restoration system.The changes to the soil organic carbon (SOC),activities of soil enzymes and glomalin-related soil protein (GRSP) were measured and the effects of AMF on activities of soil enzymes and carbon sequestration capacity in reclaimed mine soil were analyzed.The results show that the contents of GRSP (total glomalin (TG) and easily extractable glomalin (EEG)),SOC and activities of enzymes increased,and the increments were higher in the AMF inoculation treated plant-complex substrate-microbe ecological restoration systems than those with no AMF inoculated treatments after 12 months of ryegrass growth.TG,EEG and soil enzyme activity have a significant positive correlation,and the correlative coefficient was 0.427-0.573; SOC and TG,EEG have a significant positive correlation (p < 0.01 ),indicating that AMF plays an important role in carbon sequestration of reclaimed mine soils.

  4. Effects of Soil properties on phosphorus subsurface migration in sandy soils

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming-Kui

    2008-01-01

    The soil factors influencing the potential migration of dissolved and particulate phosphorus (P) from structurallyweak sandy subsoils were evaluated by means of soil column leaching experiments.Soil colloids were extracted from two types of soils to make the colloid-bound forms of P solution.Eight sandy soils with diverse properties were collected for packing soil columns.The effects of influent solutions varying in concentrations of colloids,P,and electrolyte,on the transport of P and quality of leachates were characterized.P migration in the soils was soil property-dependent.High soil electrical conductivity values retarded the mobility of colloids and transportability of colloid-associated P (particulate P).Soil electrical conductivity was negatively correlated with colloids and reactive particulate P (RPP) concentrations in the leachates,whereas,the total reactive P (TRP) and dissolved reactive P (DRP) concentrations in the leachates were mainly controlled by the P adsorption capacity and the P levels in the subsoil.The reactive particulate P in the leachates was positively correlated with the colloidal concentration.Increased colloidal concentration in the influent could significantly increase the colloidal concentration in the leachates.Elevated P concentration in the influent had little effect on P recovery in the leachates,but it resulted in significant increases in the absolute P concentration in the leachates.

  5. Reducing pesticide use while preserving crop productivity and profitability on arable farms.

    Science.gov (United States)

    Lechenet, Martin; Dessaint, Fabrice; Py, Guillaume; Makowski, David; Munier-Jolain, Nicolas

    2017-03-01

    Achieving sustainable crop production while feeding an increasing world population is one of the most ambitious challenges of this century(1). Meeting this challenge will necessarily imply a drastic reduction of adverse environmental effects arising from agricultural activities(2). The reduction of pesticide use is one of the critical drivers to preserve the environment and human health. Pesticide use could be reduced through the adoption of new production strategies(3-5); however, whether substantial reductions of pesticide use are possible without impacting crop productivity and profitability is debatable(6-17). Here, we demonstrated that low pesticide use rarely decreases productivity and profitability in arable farms. We analysed the potential conflicts between pesticide use and productivity or profitability with data from 946 non-organic arable commercial farms showing contrasting levels of pesticide use and covering a wide range of production situations in France. We failed to detect any conflict between low pesticide use and both high productivity and high profitability in 77% of the farms. We estimated that total pesticide use could be reduced by 42% without any negative effects on both productivity and profitability in 59% of farms from our national network. This corresponded to an average reduction of 37, 47 and 60% of herbicide, fungicide and insecticide use, respectively. The potential for reducing pesticide use appeared higher in farms with currently high pesticide use than in farms with low pesticide use. Our results demonstrate that pesticide reduction is already accessible to farmers in most production situations. This would imply profound changes in market organization and trade balance.

  6. Effect of Particle Size and Soil Compaction on Gas Transport Parameters in Variably Saturated, Sandy Soils

    DEFF Research Database (Denmark)

    Hamamoto, Shoichiro; Møldrup, Per; Kawamoto, Ken

    2009-01-01

    the water retention curve), both exhibiting similar and exponential relationships with D50. Under variably saturated conditions, higher Dp and ka in coarser sand (larger D50) were observed due to rapid gas diffusion and advection through the less tortuous large-pore networks. In addition, soil compaction......The soil gas diffusion coefficient (Dp) and air permeability (ka) and their dependency on soil air content ( ) control gas diffusion and advection in soils. This study investigated the effects of average particle size (D50) and dry bulk density ( b) on Dp and ka for six sandy soils under variably...... saturated conditions. Data showed that particle size markedly affects the effective diameter of the drained pores active in leading gas through the sample at –100 cm H2O of soil water matric potential (calculated from Dp and ka) as well as the average pore diameter at half saturation (calculated from...

  7. Soil carbon dioxide emission from intensively cultivated black soil in Northeast China. Nitrogen fertilization effect

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Kang [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Graduate University of Chinese Academy of Sciences, Beijing (China); Ding, Weixin; Cai, Zucong [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Wang, Yufeng; Zhang, Xilin; Zhou, Baoku [Heilongjiang Academy of Agricultural Sciences, Harbin (China). Inst. of Soil and Fertilizer

    2012-08-15

    Purpose: The aim of this study was to understand the effect of nitrogen fertilization on soil respiration and native soil organic carbon (SOC) decomposition and to identify the key factor affecting soil respiration in a cultivated black soil. Materials and methods: A field experiment was conducted at the Harbin State Key Agroecological Experimental Station, China. The study consisted of four treatments: unplanted and N-unfertilized soil (U0), unplanted soil treated with 225 kg N ha{sup -1} (UN), maize planted and N-unfertilized soil (P0), and planted soil fertilized with 225 kg N ha{sup -1} (PN). Soil CO{sub 2} and N{sub 2}O fluxes were measured using the static closed chamber method. Results and discussion: Cumulative CO{sub 2} emissions during the maize growing season with the U0, UN, P0, and PN treatments were 1.29, 1.04, 2.30 and 2.27 Mg C ha{sup -1}, respectively, indicating that N fertilization significantly reduced the decomposition of native SOC. However, no marked effect on soil respiration in planted soil was observed because the increase of rhizosphere respiration caused by N addition was counteracted by the reduction of native SOC decomposition. Soil CO{sub 2} fluxes were significantly affected by soil temperature but not by soil moisture. The temperature sensitivity (Q{sub 10}) of soil respiration was 2.16-2.47 for unplanted soil but increased to 3.16-3.44 in planted soil. N addition reduced the Q{sub 10} of native SOC decomposition possibly due to low labile organic C but increased the Q{sub 10} of soil respiration due to the stimulation of maize growth. The estimated annual CO{sub 2} emission in N-fertilized soil was 1.28 Mg C ha{sup -1} and was replenished by the residual stubble, roots, and exudates. In contrast, the lost C (1.53 Mg C ha{sup -1}) in N-unfertilized soil was not completely supplemented by maize residues, resulting in a reduction of SOC. Although N fertilization significantly increased N{sub 2}O emissions, the global warming potential

  8. Effects of sulfadiazine on soil bacterial communities

    DEFF Research Database (Denmark)

    Hangler, Martin

    as fertilizers on agricultural lands they represent a route for antibiotics into the soil environment where they may persist and affect levels of antibiotic resistance in soil microbial communities over time. In this work the level of tolerance to the antibiotic sulfadiazine (SDZ) was studied in a number......-threshold, of a non-contaminated soil environment at various pH of which to compare other soils. Soil samples representing a broad range of natural pH were collected from the pH gradient at the Hoosfield acid strip, part of the long-term field experiment at the Rothamstead Research Station (UK) and exposed...... and transport of SDZ at the interphase between dewatered SDZ-amended sewage sludge and soil. SDZ was not mineralized within sludge aggregates and travelled more than 10 mm into the surrounding soil. The strongest PICT response was observed in soils fertilized with organic fertilizers or inorganic NPK fertilizer...

  9. The effect of soil redistribution on soil organic carbon: an experimental study

    Directory of Open Access Journals (Sweden)

    H. Van Hemelryck

    2010-12-01

    Full Text Available Soil erosion, transport and deposition by water drastically affect the distribution of soil organic carbon (SOC within a landscape. Furthermore, soil redistribution is assumed to have a large impact on the exchange of carbon (C between the pedosphere and the atmosphere. There is, however, significant scientific disagreement concerning the relative importance of the key-mechanisms at play. One of the major uncertainties concerns the fraction of SOC that is mineralized when soil is eroded by water, from the moment when detachment takes place until the moment when the SOC becomes protected by burial. In this study, the changes in C-exchange between soil and atmosphere as affected by soil redistribution processes were experimentally quantified. During a laboratory experiment, three types of erosional events were simulated, each of which was designed to produce a different amount of eroded soil material with a different degree of aggregation. During a 98-day period, CO2-efflux was measured in-situ and under field conditions on undisturbed soils with a layer of deposited soil material. Depending on the initial conditions of the soil and the intensity of the erosion process, a significant fraction of eroded SOC was mineralized after deposition. However, results also suggest that deposition produces a dense stratified layer of sediment that caps the soil surface, leading to a decrease in SOC decomposition in deeper soil layers. As a result, the net effect of erosion on SOC can be smaller, depending on the functioning of the whole soil system. In this study, soil redistribution processes contributed an additional emission of 2 to 12% of total C contained in eroded sediment.

  10. The effect of soil redistribution on soil organic carbon: an experimental study

    Directory of Open Access Journals (Sweden)

    H. Van Hemelryck

    2009-05-01

    Full Text Available Soil erosion, transport and deposition by water drastically affect the distribution of soil organic carbon (SOC within a landscape. Furthermore, soil redistribution is assumed to have a large impact on the exchange of carbon (C between the pedosphere and the atmosphere. There is, however, significant scientific disagreement concerning the relative importance of the key-mechanisms at play. One of the major uncertainties concerns the fraction of SOC that is mineralized when soil is eroded by water, from the moment when detachment takes place until the moment when the SOC becomes protected by burial. In this study, the changes in C-exchange between soil and atmosphere as affected by soil redistribution processes were experimentally quantified. During a laboratory experiment, three types of erosional events were simulated, each of which was designed to produce a different amount of eroded soil material with a different degree of aggregation. During a 98-day period, CO2-efflux was measured in-situ and under field conditions on undisturbed soils with a layer of deposited soil material. Depending on the initial conditions of the soil and the intensity of the erosion process, a significant fraction of eroded SOC was mineralized after deposition (between 14 and 22%. However, results also suggest that deposition produces a dense stratified layer of sediment that caps the soil surface, leading to a decrease in SOC decomposition in deeper soil layers. As a result, the net effect of erosion on SOC can be smaller, depending on the functioning of the whole soil system. In this study, soil redistribution processes contributed an additional emission of 2 to 12% of total C contained in eroded sediment.

  11. Process and mechanism of arable land change in Hebei Province during the past 50 years

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Hebei Province is one of the regions with most densely population, fastest economic growth and most intensive land use in China. The contradiction of land shortage sharpened by high-speed economic development with population growth has become a serious problem, which has restricted regional sustainable development. This paper revealed the basic process, regional differences of change and the gravity center of arable land area according to the long-series statistical data of arable land during the past 50 years. On the basis of the above mentioned, the major driving forces that influence the changes of the arable land are discussed. The research results indicate that there is a trend of obvious fluctuating decrease in arable land area during the last 50 years. The changes of aruble land area undergo the process from increase to sharp decrease to gently decrease.The regional disparity of change in arable land area is very notable and the gravity center of arable land area moves to the northeast 49.22 km. Regarding the decrease in arable land, the direct driving forces include adjustments of agricultural structure and reclamation, and indirect driving forces include advance in technology, economic interest and population growth etc.

  12. Effect of Lanthanum on Major Microbial Populations in Red Soil

    Institute of Scientific and Technical Information of China (English)

    CHUHAIYAN; WANGJUNHUA; 等

    2001-01-01

    Pure culture and pot culture experiments were carried out to study the effect of lanthanum(La)on bacteria,actinomyces and fungus,and some microbial physiological groups,nitrifir,azotobacter and phos-phobacteria in a red soil taken form the Ecological Experimental Station of Red Soil,the Chinese Academy of Sciences,Jiangxi Province.LaCl3 was added into media at levels of 0,25,50,100,150,200,250 and 500 mg L-1 in the pure culture experiment ,and into soil samples in porcelain pots before rice growing at levles of 0,6,30,150,300,600 and 900 mg kg-1 dry soil in the pot culture experiment.The populations of the three soil microbes in the pure cultre experiment decreased with the addition level of La,indicating that La was toxic to the soil microbes in pure culture ,and the sensitivity of the 3 major mircrobial types to La was in a decreasing order of actinomyces>bacteria>fungus.In the pot experiment,La had slightly stimulaive effect on soil bacteria and actinomyces when applied at olw concentrations while had inhibitory effect on soil bacteria,actinomyces and fungus at high concentrations.When the concentration of La Was low,soil azotobacter was stimulated slightly while soil nitrifier was stimulated strongly and the maximum increase was up to 50%.When the concentration of La was highy,both soil aztobacter and nitrifier ware inhibited ,and the inhibition of La to the nitrifier increased with La conentration,La added at all the levels had stimulative effect on soil inorgaic and organic phosphobacteria.Among the 4 physiological groups,soil nitrifier was most sensitive to La,so,it migh be reasonble to assume that soil nitrifier was a sensitive indicator for evaluating the biological and environmental effects of rare earths.

  13. [Effect of fertilization levels on soil microorganism amount and soil enzyme activities].

    Science.gov (United States)

    Wang, Wei-Ling; Du, Jun-Bo; Xu, Fu-Li; Zhang, Xiao-Hu

    2013-11-01

    Field experiments were conducted in Shangluo pharmaceutical base in Shaanxi province to study the effect of nitrogen, phosphorus and potassium in different fertilization levels on Platycodon grandiflorum soil microorganism and activities of soil enzyme, using three-factor D-saturation optimal design with random block design. The results showed that N0P2K2, N2P2K0, N3P1K3 and N3P3K1 increased the amount of bacteria in 0-20 cm of soil compared with N0P0K0 by 144.34%, 39.25%, 37.17%, 53.58%, respectively. The amount of bacteria in 2040 cm of soil of N3P1K3 increased by 163.77%, N0P0K3 increased the amount of soil actinomycetes significantly by 192.11%, while other treatments had no significant effect. N2P0K2 and N3P1K3 increased the amounts of fungus significantly in 0-20 cm of soil compared with N0P0K0, increased by 35.27% and 92.21%, respectively. N3P0K0 increased the amounts of fungus significantly in 20-40 cm of soil by 165.35%, while other treatments had no significant effect. All treatments decrease soil catalase activity significantly in 0-20 cm of soil except for N2P0K2, and while N2P2K0 and NPK increased catalase activity significantly in 2040 cm of soil. Fertilization regime increased invertase activity significantly in 2040 cm of soil, and decreased phosphatase activity inordinately in 0-20 cm of soil, while increased phosphatase activity in 2040 cm of soil other than N1P3K3. N3P0K0, N0P0K3, N2P0K2, N2P2K0 and NPK increased soil urease activity significantly in 0-20 cm of soil compared with N0P0K0 by 18.22%, 14.87%,17.84%, 27.88%, 24.54%, respectively. Fertilization regime increased soil urease activity significantly in 2040 cm of soil other than N0P2K2.

  14. Effect of Fluctuating Temperatures on Forest Soil Nitrogen Minerealization

    Institute of Scientific and Technical Information of China (English)

    LIAOLIPING; P.INESON

    1997-01-01

    Nitrogen mineralization in forest soil wa studied in laboratory by incubating undisturbed soil cores enclosed within PVC columns at different temperatures to compare the effect of flucttuating temperature with that of constant temperaature,and to find out whether soil nitrification shows linearity over time .The results showed that there was no significant difference between soil nitrification at fluctuating temperature and that at constant temperature,and suggested that it must be careful to make the conclusion that soil nitrification has linearity over time.

  15. Reconciling pesticide reduction with economic and environmental sustainability in arable farming.

    Science.gov (United States)

    Lechenet, Martin; Bretagnolle, Vincent; Bockstaller, Christian; Boissinot, François; Petit, Marie-Sophie; Petit, Sandrine; Munier-Jolain, Nicolas M

    2014-01-01

    Reducing pesticide use is one of the high-priority targets in the quest for a sustainable agriculture. Until now, most studies dealing with pesticide use reduction have compared a limited number of experimental prototypes. Here we assessed the sustainability of 48 arable cropping systems from two major agricultural regions of France, including conventional, integrated and organic systems, with a wide range of pesticide use intensities and management (crop rotation, soil tillage, cultivars, fertilization, etc.). We assessed cropping system sustainability using a set of economic, environmental and social indicators. We failed to detect any positive correlation between pesticide use intensity and both productivity (when organic farms were excluded) and profitability. In addition, there was no relationship between pesticide use and workload. We found that crop rotation diversity was higher in cropping systems with low pesticide use, which would support the important role of crop rotation diversity in integrated and organic strategies. In comparison to conventional systems, integrated strategies showed a decrease in the use of both pesticides and nitrogen fertilizers, they consumed less energy and were frequently more energy efficient. Integrated systems therefore appeared as the best compromise in sustainability trade-offs. Our results could be used to re-design current cropping systems, by promoting diversified crop rotations and the combination of a wide range of available techniques contributing to pest management.

  16. The arable plant ecosystem as battleground for emergence of human pathogens

    Directory of Open Access Journals (Sweden)

    Leo eVan Overbeek

    2014-03-01

    Full Text Available Disease incidences related to Escherichia coli and Salmonella enterica infections by consumption of (fresh vegetables, sprouts and occasionally fruits made clear that these pathogens are not only transmitted to humans via the ‘classical’ routes of meat, eggs and dairy products, but also can be transmitted to humans via plants or products derived from plants. Nowadays, it is of major concern that these human pathogens, especially the ones belonging to the taxonomical family of Enterobacteriaceae, become adapted to environmental habitats without losing their virulence to humans. Adaptation to the plant environment would lead to longer persistence in plants, increasing their chances on transmission to humans via consumption of plant-derived food. One of the mechanisms of adaptation to the plant environment in human pathogens, proposed in this paper, is horizontal transfer of genes from different microbial communities present in the arable ecosystem, like the ones originating from soil, animal digestive track systems (manure, water and plants themselves. Genes that would confer better adaptation to the phytosphere might be genes involved in plant colonization, stress resistance and nutrient acquisition and utilization. Because human pathogenic enterics often were prone to genetic exchanges via phages and conjugative plasmids, it was postulated that these genetic elements may be hold key responsible for horizontal gene transfers between human pathogens and indigenous microbes in agroproduction systems. In analogy to zoonosis, we coin the term phytonosis for a human pathogen that is transmitted via plants and not exclusively via animals.

  17. Reconciling pesticide reduction with economic and environmental sustainability in arable farming.

    Directory of Open Access Journals (Sweden)

    Martin Lechenet

    Full Text Available Reducing pesticide use is one of the high-priority targets in the quest for a sustainable agriculture. Until now, most studies dealing with pesticide use reduction have compared a limited number of experimental prototypes. Here we assessed the sustainability of 48 arable cropping systems from two major agricultural regions of France, including conventional, integrated and organic systems, with a wide range of pesticide use intensities and management (crop rotation, soil tillage, cultivars, fertilization, etc.. We assessed cropping system sustainability using a set of economic, environmental and social indicators. We failed to detect any positive correlation between pesticide use intensity and both productivity (when organic farms were excluded and profitability. In addition, there was no relationship between pesticide use and workload. We found that crop rotation diversity was higher in cropping systems with low pesticide use, which would support the important role of crop rotation diversity in integrated and organic strategies. In comparison to conventional systems, integrated strategies showed a decrease in the use of both pesticides and nitrogen fertilizers, they consumed less energy and were frequently more energy efficient. Integrated systems therefore appeared as the best compromise in sustainability trade-offs. Our results could be used to re-design current cropping systems, by promoting diversified crop rotations and the combination of a wide range of available techniques contributing to pest management.

  18. Effects of extreme drought on agriculture soil and sustainability of different drought soil

    Directory of Open Access Journals (Sweden)

    S. M. Geng

    2014-01-01

    Full Text Available Content of microbial biomass carbon was selected as indicator for identifying effects of extreme drought on agriculture soil ecosystem. Through a series of prototype observation experiments, changing tendencies of microbial biomass carbon content and the proportion of microbial biomass carbon in soil organic carbon were identified. The optimum mass water content of soil for microbial biomass carbon was 19.5% and the demarcation point of microbial biomass carbon to drought was 14.3%, which could be used to demonstrate alters and degradation of soil ecosystem as well as the irrigation requirement of crops. We evaluated sustainability of different drought soil ecosystems after experiencing rainstorm with rehabilitation. The results suggested that soil ecosystem which was interfered by moderate drought could recover and its tolerance to drought was improved, as well as its function and activity. Soil ecosystem could barely recover from severe drought and could not adapt to severe drought stress. Soil ecosystem could not restore from extreme drought within a few days, the function and structure were damaged. We came to the conclusion that mass water content of soil should kept above 10% to avoid destroying function and structure while soil ecosystem would better be watered when mass water content was lower than 14.3% in order to maintain high productivity.

  19. Sewage sludge applied to agricultural soil: Ecotoxicological effects on representative soil organisms.

    Science.gov (United States)

    Carbonell, G; Pro, J; Gómez, N; Babín, M M; Fernández, C; Alonso, E; Tarazona, J V

    2009-05-01

    Application of sewage sludge to agricultural lands is a current practice in EU. European legislation permits its use when concentrations of metals in soil do not increase above the maximum permissible limits. In order to assess the fate and the effects on representative soil organisms of sewage sludge amendments on agricultural lands, a soil microcosm (multi-species soil system-MS3) experiment was performed. The MS3 columns were filled with spiked soil at three different doses: 30, 60 and 120tha(-1) fresh wt. Seed plants (Triticum aestivum, Vicia sativa and Brassica rapa) and earthworms (Eisenia fetida) were introduced into the systems. After a 21-d exposure period, a statistically significant increase for Cd, Cu, Zn and Hg concentrations was found for the soils treated with the highest application rate. Dose-related increase was observed for nickel concentrations in leachates. Plants and earthworm metal body burden offer much more information than metal concentrations and help to understand the potential for metal accumulation. Bioaccumulation factor (BAF(plant-soil)) presented a different behavior among species and large differences for BAF(earthworm-soil), from control or sewage-amended soil, for Cd and Hg were found. B. rapa seed germination was reduced. Statistically significant decrease in fresh biomass was observed for T. aestivum and V. sativa at the highest application rate, whereas B. rapa biomass decreased at any application rate. Enzymatic activities (dehydrogenase and phosphatase) as well as respiration rate on soil microorganisms were enlarged.

  20. Electrodialytic Remediation of Pb Contaminated Soil - Effects of Soil Properties and Pb Distribution

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Jensen, Pernille Erland

    1999-01-01

    The aim of this work was to investigate the effects of soil properties and Pb distribution on the electrodialytic remediation of Pb contaminated soil. Two naturally Pb contaminated soils were compared with respect to total Pb content, Pb distribution, pH, carbonate content, clay content and organic...... matter, and an electrodialytic remediation experiment was made on each soil.It was concluded that soil pH was the most important factor limiting the mobilisation of Pb. In one of the remediation experiments it was possible to mobilise and reduce the amount of Pb significantly, whereas in the other only...... a small amount of the initial Pb was mobilised at similar experimental conditions. A high buffering capacity of one of the soils, which was partly due to a high carbonate content, led to a bad remediation result....

  1. Effect of soil properties, heavy metals and emerging contaminants in the soil nematodes diversity.

    Science.gov (United States)

    Gutiérrez, Carmen; Fernández, Carlos; Escuer, Miguel; Campos-Herrera, Raquel; Beltrán Rodríguez, M Eulalia; Carbonell, Gregoria; Rodríguez Martín, Jose Antonio

    2016-06-01

    Among soil organisms, nematodes are seen as the most promising candidates for bioindications of soil health. We hypothesized that the soil nematode community structure would differ in three land use areas (agricultural, forest and industrial soils), be modulated by soil parameters (N, P, K, pH, SOM, CaCO3, granulometric fraction, etc.), and strongly affected by high levels of heavy metals (Cd, Pb, Zn, Cr, Ni, Cu, and Hg) and emerging contaminants (pharmaceuticals and personal care products, PPCPs). Although these pollutants did not significantly affect the total number of free-living nematodes, diversity and structure community indices vastly altered. Our data showed that whereas nematodes with r-strategy were tolerant, genera with k-strategy were negatively affected by the selected pollutants. These effects diminished in soils with high levels of heavy metals given their adaptation to the historical pollution in this area, but not to emerging pollutants like PPCPs.

  2. Soil Surface Sealing Effect on Soil Moisture at a Semiarid Hillslope: Implications for Remote Sensing Estimation

    Directory of Open Access Journals (Sweden)

    Shai Sela

    2014-08-01

    Full Text Available Robust estimation of soil moisture using microwave remote sensing depends on extensive ground sampling for calibration and validation of the data. Soil surface sealing is a frequent phenomenon in dry environments. It modulates soil moisture close to the soil surface and, thus, has the potential to affect the retrieval of soil moisture from microwave remote sensing and the validation of these data based on ground observations. We addressed this issue using a physically-based modeling approach that accounts explicitly for surface sealing at the hillslope scale. Simulated mean soil moisture at the respective layers corresponding to both the ground validation probe and the radar beam’s typical effective penetration depth were considered. A cyclic pattern was found in which, as compared to an unsealed profile, the seal layer intensifies the bias in validation during rainfall events and substantially reduces it during subsequent drying periods. The analysis of this cyclic pattern showed that, accounting for soil moisture dynamics at the soil surface, the optimal time for soil sampling following a rainfall event is a few hours in the case of an unsealed system and a few days in the case of a sealed one. Surface sealing was found to increase the temporal stability of soil moisture. In both sealed and unsealed systems, the greatest temporal stability was observed at positions with moderate slope inclination. Soil porosity was the best predictor of soil moisture temporal stability, indicating that prior knowledge regarding the soil texture distribution is crucial for the application of remote sensing validation schemes.

  3. The effect of soil on cork quality.

    Science.gov (United States)

    Pestana, Miguel N; Gomes, Alberto A

    2014-01-01

    The present work aimed to contribute for a better knowledge regarding soil features as cork quality indicators for stoppers. Cork sampling was made in eight Cork oak stands (montados de sobreiro) located in the Plio-Plistocene sedimentary formations of Península de Setúbal in southern Tagus River region. The samples used to classify the cork as stopper for wine bottles were obtained in eight cork oak stands, covering soils of different types of sandstones of the Plio-plistocene. In each stand, we randomly chose five circular plots with 30 m radius and five trees per plot with same stripping conditions determined by: dendrometric features (HD- height stipping, PBH- perimeter at breaster height), trees vegetative condition (defoliation degree); stand features (density, percentage canopy cover); site conditions (soil type and orientation). In the center of each plot a pit was open to characterize the soil profile and to classify the soil. Cork quality for stoppers was evaluated according to porosity, pores/per cm(2) and cork boards thickness. The soil was characterized according to morphological soil profile features (lithology, soil profound, and soil horizons) and chemical soil surface horizon features (organic matter, pH, macro, and micronutrients availability). Based on the variables studied and using the numerical taxonomy, we settled relationships between the cork quality and some soil features. The results indicate: (1) high correlation between the cork caliber and boron, cation exchange capacity, total nitrogen, exchange acidity, and exchangeable magnesium, potassium, calcium, and sodium in soils of theirs cork oaks; (2) the cork porosity is correlated with the number of pores/cm(2) and magnesium soil content; (3) the other soil features have a lower correlation with the caliber, porosity, and the number of pores per cm(2).

  4. Soil Drying Effects on the Carbon Isotope Composition of Soil Respiration

    Science.gov (United States)

    Phillips, C. L.; Nickerson, N.; Risk, D.; Kayler, Z. E.; Rugh, W.; Mix, A. C.; Bond, B. J.

    2008-12-01

    -steady-state effects are necessary to avoid spurious correlations between measured δ13CO2 and soil moisture. A third experiment, using closed-system soil incubations to avoid non-steady state mixing with atmospheric CO2, indicates that the isotopic composition of microbial soil respiration appears to be unchanging under a large range of soil moisture contents.

  5. Stimulatory effects of arsenic-tolerant soil fungi on plant growth promotion and soil properties.

    Science.gov (United States)

    Srivastava, Pankaj Kumar; Shenoy, Belle Damodara; Gupta, Manjul; Vaish, Aradhana; Mannan, Shivee; Singh, Nandita; Tewari, Shri Krishna; Tripathi, Rudra Deo

    2012-01-01

    Fifteen fungi were obtained from arsenic-contaminated agricultural fields in West Bengal, India and examined for their arsenic tolerance and removal ability in our previous study. Of these, the four best arsenic-remediating isolates were tested for plant growth promotion effects on rice and pea in the present study. A greenhouse-based pot experiment was conducted using soil inocula of individual fungi. The results indicated a significant (Psoil properties in inoculated soils compared to the control. A significant increase in plant growth was recorded in treated soils and varied from 16-293%. Soil chemical and enzymatic properties varied from 20-222% and 34-760%, respectively, in inoculated soil. Plants inoculated with inocula of Westerdykella and Trichoderma showed better stimulatory effects on plant growth and soil nutrient availability than Rhizopus and Lasiodiplodia. These fungi improved soil nutrient content and enhanced plant growth. These fungi may be used as bioinoculants for plant growth promotion and improved soil properties in arsenic-contaminated agricultural soils.

  6. Effect of soil coarseness on soil base cations and available micronutrients in a semi-arid sandy grassland

    Science.gov (United States)

    Lü, Linyou; Wang, Ruzhen; Liu, Heyong; Yin, Jinfei; Xiao, Jiangtao; Wang, Zhengwen; Zhao, Yan; Yu, Guoqing; Han, Xingguo; Jiang, Yong

    2016-04-01

    Soil coarseness is the main process decreasing soil organic matter and threatening the productivity of sandy grasslands. Previous studies demonstrated negative effect of soil coarseness on soil carbon storage, but less is known about how soil base cations (exchangeable Ca, Mg, K, and Na) and available micronutrients (available Fe, Mn, Cu, and Zn) response to soil coarseness. In a semi-arid grassland of Northern China, a field experiment was initiated in 2011 to mimic the effect of soil coarseness on soil base cations and available micronutrients by mixing soil with different mass proportions of sand: 0 % coarse elements (C0), 10 % (C10), 30 % (C30), 50 % (C50), and 70 % (C70). Soil coarseness significantly increased soil pH in three soil depths of 0-10, 10-20 and 20-40 cm with the highest pH values detected in C50 and C70 treatments. Soil fine particles (smaller than 0.25 mm) significantly decreased with the degree of soil coarseness. Exchangeable Ca and Mg concentrations significantly decreased with soil coarseness degree by up to 29.8 % (in C70) and 47.5 % (in C70), respectively, across three soil depths. Soil available Fe, Mn, and Cu significantly decreased with soil coarseness degree by 62.5, 45.4, and 44.4 %, respectively. As affected by soil coarseness, the increase of soil pH, decrease of soil fine particles (including clay), and decline in soil organic matter were the main driving factors for the decrease of exchangeable base cations (except K) and available micronutrients (except Zn) through soil profile. Developed under soil coarseness, the loss and redistribution of base cations and available micronutrients along soil depths might pose a threat to ecosystem productivity of this sandy grassland.

  7. Effect of different fertilizer application on the soil fertility of paddy soils in red soil region of southern China.

    Science.gov (United States)

    Dong, Wenyi; Zhang, Xinyu; Wang, Huimin; Dai, Xiaoqin; Sun, Xiaomin; Qiu, Weiwen; Yang, Fengting

    2012-01-01

    Appropriate fertilizer application is an important management practice to improve soil fertility and quality in the red soil regions of China. In the present study, we examined the effects of five fertilization treatments [these were: no fertilizer (CK), rice straw return (SR), chemical fertilizer (NPK), organic manure (OM) and green manure (GM)] on soil pH, soil organic carbon (SOC), total nitrogen (TN), C/N ratio and available nutrients (AN, AP and AK) contents in the plowed layer (0-20 cm) of paddy soil from 1998 to 2009 in Jiangxi Province, southern China. Results showed that the soil pH was the lowest with an average of 5.33 units in CK and was significantly higher in NPK (5.89 units) and OM (5.63 units) treatments (Pfertilizers have remarkably improved SOC and TN values compared with the CK, Specifically, the OM treatment resulted in the highest SOC and TN concentrations (72.5% and 51.2% higher than CK) and NPK treatment increased the SOC and TN contents by 22.0% and 17.8% compared with CK. The average amounts of C/N ratio ranged from 9.66 to 10.98 in different treatments, and reached the highest in OM treatment (Psoil fertility in this region and K fertilizer should be simultaneously applied considering the soil K contents. Considering the long-term fertilizer efficiency, our results also suggest that annual straw returning application could improve soil fertility in this trial region.

  8. The effects of soil amendments on heavy metal bioavailability in two contaminated Mediterranean soils

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.J.; Clemente, Rafael; Roig, Asuncion; Bernal, M.P

    2003-04-01

    The effects of organic amendments on metal bioavailability were not always related to their degree of humification. - Two heavy metal contaminated calcareous soils from the Mediterranean region of Spain were studied. One soil, from the province of Murcia, was characterised by very high total levels of Pb (1572 mg kg{sup -1}) and Zn (2602 mg kg{sup -1}), whilst the second, from Valencia, had elevated concentrations of Cu (72 mg kg{sup -1}) and Pb (190 mg kg{sup -1}). The effects of two contrasting organic amendments (fresh manure and mature compost) and the chelate ethylenediaminetetraacetic acid (EDTA) on soil fractionation of Cu, Fe, Mn, Pb and Zn, their uptake by plants and plant growth were determined. For Murcia soil, Brassica juncea (L.) Czern. was grown first, followed by radish (Raphanus sativus L.). For Valencia soil, Beta maritima L. was followed by radish. Bioavailability of metals was expressed in terms of concentrations extractable with 0.1 M CaCl{sub 2} or diethylenetriaminepentaacetic acid (DTPA). In the Murcia soil, heavy metal bioavailability was decreased more greatly by manure than by the highly-humified compost. EDTA (2 mmol kg{sup -1} soil) had only a limited effect on metal uptake by plants. The metal-solubilising effect of EDTA was shorter-lived in the less contaminated, more highly calcareous Valencia soil. When correlation coefficients were calculated for plant tissue and bioavailable metals, the clearest relationships were for Beta maritima and radish.

  9. Independent variations of plant and soil mixtures reveal soil feedback effects on plant community overyielding

    NARCIS (Netherlands)

    Hendriks, M.; Mommer, L.; Caluwe, de H.; Smit-Tiekstra, A.E.; Putten, van der W.H.; Kroon, de H.

    2013-01-01

    1. Recent studies have shown that the positive relationship between plant diversity and plant biomass ('overyielding') can be explained by soil pathogens depressing productivity more in low than in high diverse plant communities. However, tests of such soil effects in field studies were constrained

  10. Independent variations of plant and soil mixtures reveal soil feedback effects on plant community overyielding

    NARCIS (Netherlands)

    Hendriks, M.; Mommer, L.; De Caluwe, H.; Smit-Tiekstra, A.E.; Van der Putten, W.H.; De Kroon, H.

    2013-01-01

    * Recent studies have shown that the positive relationship between plant diversity and plant biomass (‘overyielding’) can be explained by soil pathogens depressing productivity more in low than in high diverse plant communities. However, tests of such soil effects in field studies were constrained b

  11. Soil Fauna Alter the Effects of Litter Composition on Nitrogen Cycling in a Mineral Soil

    Science.gov (United States)

    Plant chemical composition and the soil community are known to influence litter and soil organic matter decomposition. Although these two factors are likely to interact, their mechanisms and outcomes of interaction are not well understood. Studies of their interactive effects are...

  12. Effects of Bio-char on Soil Microbes in Herbicide Residual Soils

    Directory of Open Access Journals (Sweden)

    WANG Gen-lin

    2015-10-01

    Full Text Available Effects of biological carbon (bio-char on soil microbial community were studied by pot experiments simulating long residual herbicide residues in soil environment, which clarifed the improvement of biochar and its structural properties on soil microenvironment. The results showed that fungi and actinomycetes had the same effect tendency within 0~0.72 mg·kg-1 in clomazone residue which increased the role of stimulation with crop growth process prolonged, especially in high residue treatment, but strong inhibitory effect on bacteria community was occured early which returned to normal until sugar beet growth to fiftieth day. Soil fungi community decreased with bio-char adding, but had no significant difference with the control. When clomazone residue in soil was below 0.24 mg·kg-1, soil actinomycetes community was higher than control without bio-char, bacteria increased first and then reduced after adding carbon as below 0.12 mg·kg-1. Biochar was ‘deep hole’ structure containing C, O, S and other elements. The results showed that a certain concentration clomazone residue in soil would stimulate soil fungi and actinomycetes to grow. After adding the biochar, the inhibition effect of high herbicides residual on bacterial would be alleviated.

  13. Climate-change effects on soils: Accelerated weathering, soil carbon and elemental cycling

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Nikolla

    2015-04-01

    Climate change [i.e., high atmospheric carbon dioxide (CO2) concentrations (≥400 ppm); increasing air temperatures (2-4°C or greater); significant and/or abrupt changes in daily, seasonal, and inter-annual temperature; changes in the wet/dry cycles; intensive rainfall and/or heavy storms; extended periods of drought; extreme frost; heat waves and increased fire frequency] is and will significantly affect soil properties and fertility, water resources, food quantity and quality, and environmental quality. Biotic processes that consume atmospheric CO2, and create organic carbon (C) that is either reprocessed to CO2 or stored in soils are the subject of active current investigations, with great concern over the influence of climate change. In addition, abiotic C cycling and its influence on the inorganic C pool in soils is a fundamental global process in which acidic atmospheric CO2 participates in the weathering of carbonate and silicate minerals, ultimately delivering bicarbonate and Ca2+ or other cations that precipitate in the form of carbonates in soils or are transported to the rivers, lakes, and oceans. Soil responses to climate change will be complex, and there are many uncertainties and unresolved issues. The objective of the review is to initiate and further stimulate a discussion about some important and challenging aspects of climate-change effects on soils, such as accelerated weathering of soil minerals and resulting C and elemental fluxes in and out of soils, soil/geo-engineering methods used to increase C sequestration in soils, soil organic matter (SOM) protection, transformation and mineralization, and SOM temperature sensitivity. This review reports recent discoveries, identifies key research needs, and highlights opportunities offered by the climate-change effects on soils.

  14. Impacts of fractal features of soil on moisture infiltration capacity of typical stands in Jinyun mountain of Chongqing city

    Institute of Scientific and Technical Information of China (English)

    WANG Yujie; WANG Yunqi

    2007-01-01

    The soil structure was expressed with fractal dimensions of particle size distribution (PSD),aggregate size distribution (ASD),and soil pore size distribution (SPD).The effect of soil fractal features on soil infiltration velocity and process was studied.The result of the fractal feature shows that fractal dimensions of PSD are obviously greater than those of ASD and SPD,and in different soil genetic horizons,the fractal dimension of ASD has the greatest variability,and shows a downtrend on the top-to-bottom genetic horizon.According to the soil infiltration process curve,the infiltration process was divided into three phases:(1) the initial phase (0-5 rain),(2) the transition phase (5-30 min),and (3)the stable phase (30-180 min).In the initial phase of infiltration,the soil structure of soil genetic horizon A was the major influencing factor;in the transition phase of infiltration,the pore distribution of soil horizon AB and soil structure of horizon B were the major influencing factors;in the stable phase of infiltration,the soil structure of horizon C was the major influencing factor to the infiltration velocity.Soil infiltration process is influenced comprehensively by soil PSD,ASD,and SPD.In the overall soil water infiltration,the infiltration in shrub forest land was much faster than that in other land uses,and in the initial infiltration phase,arable land soil infiltration was much faster than that in forest land,and in the stable infiltration phase,the infiltration velocity in forest land was faster than that in arable land.

  15. Comparison of energetic productivity in differently renaturalized arable land

    Science.gov (United States)

    Kazlauskaite-Jadzevice, Asta; Marcinkonis, Saulius; Baksiene, Eugenija

    2014-05-01

    Soil renaturalization or ecological recovery has been studied from local to global scales. On a global scale - it's one of the ways of carbon fixation, preservation of natural diversity, locally - renaturalization processes help to solve problems of damaged (eroded and polluted) and infertile soils areas. Efficient land use can improve soil structure and therefore be attractive as a renewable energy resource that can encourage thermal energy, fuel production and installation of new technologies. Soil renaturalization is very important not only in that it helps to decrease the impact on the environment, but it can produce higher energy value of biomass at a lower cost. The aim of this study is to evaluate and compare different renaturalization methods through analyzing biomass yields and chemical composition (pine afforested, fallowing, manage grassland - Alfalfa and cropland) carried out during almost two decades (1995 - 2012). The four stationary experimental sites were set up in 1995 in Vilnius district, Lithuania. Common sandy soils prevail in the region, and the agronomic value of soil is very low. All sites were arranged in one row (the divided sides is 400 m2 each). Managed grassland and cropland areas were subdivided into fertilized and unfertilized subplots. The size of the subdivided plots was 200 m2 each. Gross productions (straw, grain, hay, pine biomass) was recalculated into total energy amount (in the calculationswere used K. Neringa and R. Siman equation) expressed in MJ and the site's productivity data compared. Gross productions total energy amount of pine afforestration was recalculated into trees volume using diameter (DBH), height and density of pines. Observed data suggest that the difference between fertilized and unfertilized plots in the cropland site was on average 1.62 times and made up an average of 20 339 MJ y-1 ha-1. The grassland site was characterized by higher productivity and a bigger difference of total energy between fertilized

  16. Effect of Biochar on Soil Physical Characteristics

    DEFF Research Database (Denmark)

    Sun, Zhencai; Møldrup, Per; Vendelboe, Anders Lindblad

    -gas diffusivity on intact 100cm3 soil samples (5 replicates in each plot). We found that biochar application significantly decreased soil bulk density, hereby creating higher porosity. At the same soil-water matric potential, all the soil-gas phase parameters (air-filled porosity, air permeability and gas...... and B plots were placed in a mixed sequence (C-B-C-B-C-B-C-B) and at the same time the eight plots formed a natural pH gradient ranging from pH 7.7 to 6.3. We determined bulk density, saturated hydraulic conductivity (K-sat), soil water retention characteristics, soil-air permeability, and soil...... due to the high micro porosity of added biochar. In conclusion, the results showed that biochar addition to soil changed key soil structural parameters at least in the short term (1 year). In perspective, the long-term variations in soil structural parameters and related changed in microbial activity...

  17. Biochar and biological carbon cycling in temperate soils

    Science.gov (United States)

    McCormack, S. A.; Vanbergen, A. J.; Bardgett, R. D.; Hopkins, D. W.; Ostle, N.

    2012-04-01

    Production of biochar, the recalcitrant residue formed by pyrolysis of plant matter, is suggested as a means of increasing storage of stable carbon (C) in the soil (1). Biochar has also been shown to act as a soil conditioner, increasing the productivity of certain crops by reducing nutrient leaching and improving soil water-holding capacity. However, the response of soil carbon pools to biochar addition is not yet well understood. Studies have shown that biochar has highly variable effects on microbial C cycling and thus on soil C storage (2,3,4). This discrepancy may be partially explained by the response of soil invertebrates, which occupy higher trophic levels and regulate microbial activity. This research aims to understand the role of soil invertebrates (i.e. Collembola and nematode worms) in biochar-mediated changes to soil C dynamics across a range of plant-soil communities. An open-air, pot-based mesocosm experiment was established in May, 2011 at the Centre for Ecology and Hydrology, Edinburgh. Three treatments were included in a fully-factorial design: biochar (presence [2 % w/w] or absence), soil type (arable sandy, arable sandy loam, grassland sandy loam), and vegetation type (Hordeum vulgare, Lolium perenne, unvegetated). Monitored parameters include: invertebrate and microbial species composition, soil C fluxes (CO2 and trace gas evolution, leachate C content, primary productivity and soil C content), and soil conditions (pH, moisture content and water-holding capacity). Preliminary results indicate that biochar-induced changes to soil invertebrate communities and processes are affected by pre-existing soil characteristics, and that soil texture in particular may be an important determinant of soil response to biochar addition. 1. Lehmann, 2007. A handful of carbon. Nature 447, 143-144. 2. Liang et al., 2010. Black carbon affects the cycling of non-black carbon in soil. Organic Geochemistry 41, 206-213. 3. Van Zwieten et al., 2010. Influence of

  18. The effect of soil on cork quality

    Directory of Open Access Journals (Sweden)

    Miguel Nugent Pestana

    2014-10-01

    Full Text Available The present work aimed to contribute for a better knowledge regarding soil features as cork quality indicators for stoppers.Cork sampling was made in eight Cork oak stands (montados de sobreiro located in different Plio-Plistocene sedimentary formations of Península de Setúbal and Carbonic shistes from paleozoic periods in Saw Grândola, both in southern Tagus River regionThe samples used to classify the cork as stopper for wine bottles were obtained in eight cork oak stands located in Península de Setúbal, south of the River Tagus, covering soils of different types of sandstones of the Plio-plistoceneIn each stand, we randomly chose five circular plots with 30 m radius. Five trees with same stripping conditions determined by the dendrometric features: HD (height stipping, PBH (perimeter at breaster height, and percentage canopy cover, trees vegetative condition (defoliation degree stand features (density, and site conditions (soil type and orientation. In the center of each plot a pit was open to characterize the soil profile and to classify the soil of each plot sampling.Cork quality for stoppers was evaluated according to porosity, pores/per cm 2 and thickness. The soil was characterized according to morphological soil profile features (lithology, soil profound and soil horizons and chemical soil surface horizon features (organic matter, pH, macro and micronutrients availability.Based on the variables studied and using the numerical taxonomy, we settled relationships between the cork quality and some soil features. The results indicate: (1 high correlation between the cork caliber and boron, caption exchange capacity, total nitrogen, exchange acidity and exchangeable magnesium, potassium, calcium and sodium in soils of theirs cork oaks; (2 the cork porosity is correlated with the number of pores/cm2 and magnesium; (3 the other soil features have a lower correlation with the caliber, porosity and the number of pores per cm2.

  19. The effect of soil on cork quality

    Science.gov (United States)

    Pestana, Miguel; Gomes, Alberto

    2014-10-01

    The present work aimed to contribute for a better knowledge regarding soil features as cork quality indicators for stoppers. Cork sampling was made in eight Cork oak stands (montados de sobreiro) located in different Plio-Plistocene sedimentary formations of Península de Setúbal and Carbonic shistes from paleozoic periods in Saw Grândola, both in southern Tagus River region The samples used to classify the cork as stopper for wine bottles were obtained in eight cork oak stands located in “Península de Setúbal”, south of the River Tagus, covering soils of different types of sandstones of the Plio-plistocene In each stand, we randomly chose five circular plots with 30 m radius. Five trees with same stripping conditions determined by the dendrometric features: HD (height stipping, PBH (perimeter at breaster height), and percentage canopy cover, trees vegetative condition (defoliation degree) stand features (density), and site conditions (soil type and orientation). In the center of each plot a pit was open to characterize the soil profile and to classify the soil of each plot sampling. Cork quality for stoppers was evaluated according to porosity, pores/per cm 2 and thickness. The soil was characterized according to morphological soil profile features (lithology, soil profound and soil horizons) and chemical soil surface horizon features (organic matter, pH, macro and micronutrients availability). Based on the variables studied and using the numerical taxonomy, we settled relationships between the cork quality and some soil features. The results indicate: (1) high correlation between the cork caliber and boron, caption exchange capacity, total nitrogen, exchange acidity and exchangeable magnesium, potassium, calcium and sodium in soils of theirs cork oaks; (2) the cork porosity is correlated with the number of pores/cm2 and magnesium; (3) the other soil features have a lower correlation with the caliber, porosity and the number of pores per cm2.

  20. Clay mineral type effect on bacterial enteropathogen survival in soil.

    Science.gov (United States)

    Brennan, Fiona P; Moynihan, Emma; Griffiths, Bryan S; Hillier, Stephen; Owen, Jason; Pendlowski, Helen; Avery, Lisa M

    2014-01-15

    Enteropathogens released into the environment can represent a serious risk to public health. Soil clay content has long been known to have an important effect on enteropathogen survival in soil, generally enhancing survival. However, clay mineral composition in soils varies, and different clay minerals have specific physiochemical properties that would be expected to impact differentially on survival. This work investigated the effect of clay materials, with a predominance of a particular mineral type (montmorillonite, kaolinite, or illite), on the survival in soil microcosms over 96 days of Listeria monocytogenes, Salmonella Dublin, and Escherichia coli O157. Clay mineral addition was found to alter a number of physicochemical parameters in soil, including cation exchange capacity and surface area, and this was specific to the mineral type. Clay mineral addition enhanced enteropathogen survival in soil. The type of clay mineral was found to differentially affect enteropathogen survival and the effect was enteropathogen-specific.

  1. Biochar effects on soils: overview and knowledge gaps

    Science.gov (United States)

    Verheijen, F. G. A.; Jeffery, S.; Bastos, A. C.; van der Velde, M.

    2012-04-01

    One of the cornerstones of the sustainable biochar concept is to improve, or at least to not deteriorate, soil quality and functioning. The idea of global sustainable biochar systems, with biochar applied to global cropland and grassland soils, has highlighted limitations in: i) current scientific understanding of biochar interactions with soil components, ii) the capacity to assess ecosystem services provided by soils, and iii) the uncertainty in spatio-temporal representation of both (i) and (ii). Pyrolysis conditions and feedstock characteristics largely control the physico-chemical properties of the resulting biochar, which in turn determine the suitability for a given application. Soils are highly heterogeneous systems at a range of scales. Combinations of land use, soil management and changing climatic conditions further enhance this heterogeneity. While this leads to difficulties in identifying the underlying mechanisms behind reported effects in the scientific literature, it also provides an opportunity for 'critical matching' of biochar properties that are best suited to a particular site (depending on soil type, hydrology, climate, land use, soil contaminants, etc.). Biochar's relatively long mean residence times in soils (100s of years) make it a potential instrument for sequestering carbon (if done sustainably). However, that same long mean residence time sets biochar apart from conventional soil amendments (such as manures and other organic fertilizers) that are considered as transient in the soil (1-10s of years). The functional life time of biochar in soils essentially moves biochar from a soil management tool to a geo-engineering technique. One of the consequences is that desired ecosystem services that are provided by soils, have to be projected for the same time period. This presentation aims to discuss critical knowledge gaps in biochar-soil-ecosystem interactions against a background of ecosystem services.

  2. Reclamation and Management of Saline and Alkali Soils

    DEFF Research Database (Denmark)

    Singh, Anoop; Katiyar, D.; Agrawal, S.B.

    2014-01-01

    Soil is the most precious natural resource and thus requires proper management. Estimates show that the world as a whole is losing at least 3.0 ha of arable land every minute due to salinization or sodification. In India about 7.0 M ha land is affected by salinity and alkalinity. The problem...... to combat with the problem. The present review is an attempt to emphasize the problem of salinity and alkalinity of soils, its effect on plants and application of physical, chemical and biological methods of soil reclamation along with management issues...... of saline and alkali soils is old but its magnitude and intensity have been increasing because of poor land and water management practices. The proper land management by way of its reclamation involves physical, chemical and biological means, which are site specific and their integration is highly desirable...

  3. [Effects of soil compositions on sorption and desorption behavior of tetrachloroethylene in soil].

    Science.gov (United States)

    Hu, Lin; Qiu, Zhao-Fu; He, Long; Dou, Ying; Lü, Shu-Guang; Sui, Qian; Lin, Kuang-Fei

    2013-12-01

    Sorption and desorption play an important role in the transport and the fate of tetrachloroethylene (PCE) in soil. In order to examine influences of different soil compositions on PCE sorption-desorption, equilibrium batch experiments were carried out using four sorbents (natural soil with 2.23% total organic carbon (TOC), H2O2-treated soil, 375 degrees C-treated soil and 600 degrees C-treated soil) with different initial PCE liquid concentrations (c0). The effects of main parameters (TOC, soft carbon, hard carbon, minerals, c0) on PCE sorption-desorption were investigated. At 16 degrees C, when c0 was increased from 5 to 80 mg x L(-1), the results showed that sorption and desorption isotherms of PCE on four sorbents can be best described by the Freundlich model (r2 > 0.96). The sorption contribution rate of SOM was higher than 60% in natural soil, and hard carbon was the main influencing factor,while the desorption contribution rate of SOM was close to that of minerals in natural soil, and soft carbon accounted for more than 80% in the total desorption contribution rate of SOM. In addition, the higher the c0, the higher the sorption contribution rate of PCE in hard carbon and desorption contribution rate of PCE in soft carbon and minerals were. Moreover, desorption of PCE from four sorbents exhibited hysteresis, and hard carbon played a remarkable role in the hysteresis of natural soil.

  4. Effects of soil management in vineyard on soil physical and chemical characteristics

    Directory of Open Access Journals (Sweden)

    Linares Rubén

    2014-01-01

    Full Text Available Cover crops in Mediterranean vineyards are scarcely used due to water competition between the cover crop and the grapevine; however, bare soil management through tillage or herbicides tends to have negative effects on the soil over time (organic matter decrease, soil structure and soil fertility degradation, compaction, etc. The objective of this study was to understand how soil management affects soil fertility, compaction and infiltration over time. To this end, two bare soil techniques were compared, tillage (TT and total herbicide (HT with two cover crops; annual cereal (CT and annual grass (AGT, established for 8 years. CT treatment showed the highest organic matter content, having the biggest amount of biomass incorporated into the soil. The annual adventitious vegetation in TT treatment (568 kg dry matter ha-1 that was incorporated into the soil, kept the organic matter content higher than HT levels and close to AGT level, in spite of the greater aboveground annual biomass production of this treatment (3632 kg dry matter ha-1 whereas only its roots were incorporated into the soil. TT presented the highest bulk density under the tractor track lines and a greatest resistance to penetration (at 0.2 m depth. AGT presented bulk density values (upper 0.4 m lower than TT and penetration resistance in CT lower (at 0.20 m depth than TT too. The HT decreased water infiltration due to a superficial crust generated for this treatment. These results indicate that the use of annual grass cover can be a good choice of soil management in Mediterranean climate due to soil quality improvement, with low competition and simple management.

  5. Economic assessment of alternatives for glyphosate application in arable farming

    Directory of Open Access Journals (Sweden)

    Kehlenbeck, Hella

    2016-02-01

    Full Text Available Application and sales of herbicides with glyphosate have strongly increased in Germany during the past 10 years. This has raised a number of questions and discussions concerning glyphosate use. Therefore, this paper identifies and evaluates alternatives with an efficacy almost equivalent to glyphosate for different treatmentareas in terms of economic consequences for farms in comparison to glyphosate use by way of example. With the help of exemplary crop rotations uses in arable farming for winter wheat, winter oilseed rape, winter barley, maize and summer barley were analyzed. Within a “worst case scenario” a complete abandonment of glyphosate applications was assumed. Different tillage systems (plough, no-plough were considered. The only alternatives with an efficacy almost equivalent to glyphosate were mechanical measures. For the analyzed treatment-areas (desiccation, pre-sowing, stubble no approved and efficient chemical alternative could be identified. The economic advantages and disadvantages of substituting glyphosate by mechanical alternatives were strongly depending on the treatment-area, the efficacy concerning yield expectations (in comparison to glyphosate use, the tillage system, the necessity of grain drying as well as further operational factors such as the availability of sufficient field work days and mechanical equipment.

  6. Effects of heat-activated persulfate oxidation on soil microorganisms

    DEFF Research Database (Denmark)

    Tsitonaki, Aikaterini; Smets, Barth F.; Bjerg, Poul Løgstrup

    2008-01-01

    /L). The results emphasize the necessity of using multiple toxicity assays and indigenous cultures in order to realistically assess the potential effects of in situ chemical oxidation on soil microorganisms. A comparison to other studies suggests that the effects of activated persulfate on soil microorganisms...

  7. Ecological effects of atmospheric nitrogen deposition on soil enzyme activity

    Institute of Scientific and Technical Information of China (English)

    WANG Cong-yan; Lv Yan-na; LIU Xue-yan Liu; WANG Lei

    2013-01-01

    The continuing increase in human activities is causing global changes such as increased deposition of atmospheric nitrogen.There is considerable interest in understanding the effects of increasing atmospheric nitrogen deposition on soil enzyme activities,specifically in terms of global nitrogen cycling and its potential future contribution to global climate change.This paper summarizes the ecological effects of atmospheric nitrogen deposition on soil enzyme activities,including size-effects,stage-effects,site-effects,and the effects of different levels and forms of atmospheric nitrogen deposition.We discuss needs for further research on the relationship between atmospheric nitrogen deposition and soil enzymes.

  8. Effects of pumice mining on soil quality

    Science.gov (United States)

    Cruz-Ruíz, A.; Cruz-Ruíz, E.; Vaca, R.; Del Aguila, P.; Lugo, J.

    2016-01-01

    Mexico is the world's fourth most important maize producer; hence, there is a need to maintain soil quality for sustainable production in the upcoming years. Pumice mining is a superficial operation that modifies large areas in central Mexico. The main aim was to assess the present state of agricultural soils differing in elapsed time since pumice mining (0-15 years) in a representative area of the Calimaya region in the State of Mexico. The study sites in 0, 1, 4, 10, and 15 year old reclaimed soils were compared with an adjacent undisturbed site. Our results indicate that gravimetric moisture content, water hold capacity, bulk density, available phosphorus, total nitrogen, soil organic carbon, microbial biomass carbon and phosphatase and urease activity were greatly impacted by disturbance. A general trend of recovery towards the undisturbed condition with reclamation age was found after disturbance, the recovery of soil total N being faster than soil organic C. The soil quality indicators were selected using principal component analysis (PCA), correlations and multiple linear regressions. The first three components gathered explain 76.4 % of the total variability. The obtained results revealed that the most appropriate indicators to diagnose the quality of the soils were urease, available phosphorus and bulk density and minor total nitrogen. According to linear score analysis and the additive index, the soils showed a recuperation starting from 4 years of pumice extraction.

  9. Belowground environmental effects of transgenic crops: a soil microbial perspective.

    Science.gov (United States)

    Turrini, Alessandra; Sbrana, Cristiana; Giovannetti, Manuela

    2015-04-01

    Experimental studies investigated the effects of transgenic crops on the structure, function and diversity of soil and rhizosphere microbial communities playing key roles in belowground environments. Here we review available data on direct, indirect and pleiotropic effects of engineered plants on soil microbiota, considering both the technology and the genetic construct utilized. Plants modified to express phytopathogen/phytoparasite resistance, or traits beneficial to food industries and consumers, differentially affected soil microorganisms depending on transformation events, experimental conditions and taxa analyzed. Future studies should address the development of harmonized methodologies by taking into account the complex interactions governing soil life.

  10. Effect of Magnetic Field on Enzyme Activities in Main Soils of Northeast China

    Institute of Scientific and Technical Information of China (English)

    LIUXIAOYI; YIYANLI; 等

    1996-01-01

    Soil enzyme activities as affected by applied magnetic field were studied with three main soils (brown soil,black soil and albic soil) collected from Northeast China,Appropriate intensities of magnetic field could obviously enhance the activities of hydrogen peroxidases,invertases,amylases and phosphatases in the three soils,although the effect varied with types and water regimes of the soils.Increasing times of magnetic treatment could multiple its good effect on the activities of hydrogen peroxidases in soils.

  11. Fire effects on soil aggregate stability: a review and synthesis

    Science.gov (United States)

    Mataix-Solera, J.; Cerdà, A.; Arcenegui, V.; Jordán, A.; Zavala, L. M.

    2012-04-01

    Fire can affect soil properties depending on a number of factors including fire severity and soil type. Aggregate stability (AS) refers to soil structure resilience in response to external mechanical forces. Many authors consider soil aggregation to be a parameter reflecting soil health, as it depends on chemical, physical and biological factors. The response of AS to forest fires is complex, since it depends on how fire has affected other related properties such as organic matter content, soil microbiology, water repellency and soil mineralogy. Opinions differ concerning the effect of fire on AS. Some authors have observed a decrease in AS in soils affected by intense wildfire or severe laboratory heating. However, others have reported increases. We provide an up to date review of the research on this topic and an analysis of the causes for the different effects observed. The implications for soil system functioning and for the hydrology of the affected areas are also discussed. Generally, low severity fires do not produce notable changes in AS, although in some cases an increase has been observed and attributed to increased water repellency. In contrast, high severity fires can induce important changes in this property, but with different effects depending on the type of soil affected. The patterns observed can vary from a disaggregation as a consequence of the organic matter destruction, to a strong aggregation if a recrystallization of some minerals such as Fe and Al oxyhydroxides occurs when they are present in sufficient quantities in the soil, after exposure to high temperatures. Because of the complexity of the different possible effects and reasons for the potential changes in the fire-affected soil aggregates, the inclusion of other parameters in the studies is necessary to understand the results. The suggested parameters to include in the examination of AS are: soil organic matter, microbial biomass, water repellency, texture, aggregate size distribution

  12. Effects of Multiple Soil Conditioners on a Mine Site Acid Sulfate Soil for Vetiver Growth

    Institute of Scientific and Technical Information of China (English)

    LIN Chu-Xia; LONG Xin-Xian; XU Song-Jun; CHU Cheng-Xing; MAI Shao-Zhi; JIANG Dian

    2004-01-01

    A pot experiment was conducted to investigate the effects of various soil treatments on the growth of vetiver grass ( Vetiveria zizanioides (L.) Nash) with the objective of formulating appropriate soil media for use in sulfide-bearing mined areas. An acidic mine site acid sulfate soil (pH 2.8) was treated with different soil conditioner formula including hydrated lime, red mud (bauxite residues), zeolitic rock powder, biosolids and a compound fertilizer. Soils treated with red mud and hydrated lime corrected soil acidity and reduced or eliminated metal toxicity enabling the establishment of vetiver grass.Although over-liming affected growth, some seedlings of vetiver survived the initial strong alkaline conditions. Addition of appropriate amounts of zeolitic rock powder also enhanced growth, but over-application caused detrimental effects. In this experiment, soil medium with the best growth performance of vetiver was 50 g of red mud, 10 g of lime, 30 g of zeolitic rock powder and 30 g of biosolids with 2000 g of mine soils (100% survival rate with the greatest biomass and number of new shoots), but adding a chemical fertilizer to this media adversely impacted plant growth. In addition, a high application rate of biosolids resulted in poorer growth of vetiver, compared to a moderate application rate.

  13. Potential effects of vinasse as a soil amendment to control runoff and soil loss

    Science.gov (United States)

    Hazbavi, Z.; Sadeghi, S. H. R.

    2016-02-01

    Application of organic materials are well known as environmental practices in soil restoration, preserving soil organic matter and recovering degraded soils of arid and semiarid lands. Therefore, the present research focused on evaluating the effectiveness of vinasse, a byproduct mainly of the sugar-ethanol industry, on soil conservation under simulated rainfall. Vinasse can be recycled as a soil amendment due to its organic matter content. Accordingly, the laboratory experiments were conducted by using 0.25 m2 experimental plots at 20 % slope and rainfall intensity of 72 mm h-1 with 0.5 h duration. The effect of vinasse was investigated on runoff and soil loss control. Experiments were set up as a control (with no amendment) and three treated plots with doses of 0.5, 1, and 1.5 L m-2 of vinasse subjected to simulated rainfall. Laboratory results indicated that vinasse at different levels could not significantly (P > 0.05) decrease the runoff amount and soil loss rate in the study plots compared to untreated plots. The average amounts of minimum runoff volume and soil loss were about 3985 mL and 46 g for the study plot at a 1 L m-2 level of vinasse application.

  14. Soil Insect Diversity and Abundance Following Different Fertilizer Treatments on the Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    LIN Ying-hua; LU Ping; YANG Xue-yun; ZHANG Fu-dao

    2013-01-01

    The presence of abundant and diverse communities of macro-arthropods is considered an indicator of sustainability in agroecosystems. This study was designed to investigate the effects of different fertilizer treatments on abundance and diversity of insects of arable loess soil on the Loess Plateau of China. These regimes included a control with no fertilizer addition or manure, treatments with application of mineral fertilizers (N, NK, NP, PK, NPK), treatments with NPK in combination with organic materials such as wheat straw or maize stalk, treatments with two rates of organic manure application;and different crop rotations (Rot.1:winter wheat summer maize;Rot.2:winter wheat summer maize soybean intercropping;and Rot.3:winter wheat or rapeseed summer maize soybean intercropping). Soil macro-arthropods were collected from the plough layer (0-20 cm) and sorted by hand after each harvest in June and October 2001 and 2002. A total of 3 132 individuals were collected, from 7 orders and 55 families, dominated by Formicidae (61.72%) and Staphylinidae (14.24%). The results showed that individuals and groups were significantly influenced by sampling dates, while groups were significantly influenced by the fertilization treatments. Soil insect biodiversity, as determined by the Shannon index, was significantly influenced by fertilization and sampling dates. The abundance of soil insects was positively and significantly correlated with soil moisture content in October 2002. Nitrogen, phosphorus and potassium fertilizers and incorporation of organic materials were favorable factors for abundance and diversity in arable loess soil.

  15. Spatial Heterogeneity of Leaf Area Index (LAI) and Its Temporal Course on Arable Land: Combining Field Measurements, Remote Sensing and Simulation in a Comprehensive Data Analysis Approach (CDAA).

    Science.gov (United States)

    Reichenau, Tim G; Korres, Wolfgang; Montzka, Carsten; Fiener, Peter; Wilken, Florian; Stadler, Anja; Waldhoff, Guido; Schneider, Karl

    2016-01-01

    The ratio of leaf area to ground area (leaf area index, LAI) is an important state variable in ecosystem studies since it influences fluxes of matter and energy between the land surface and the atmosphere. As a basis for generating temporally continuous and spatially distributed datasets of LAI, the current study contributes an analysis of its spatial variability and spatial structure. Soil-vegetation-atmosphere fluxes of water, carbon and energy are nonlinearly related to LAI. Therefore, its spatial heterogeneity, i.e., the combination of spatial variability and structure, has an effect on simulations of these fluxes. To assess LAI spatial heterogeneity, we apply a Comprehensive Data Analysis Approach that combines data from remote sensing (5 m resolution) and simulation (150 m resolution) with field measurements and a detailed land use map. Test area is the arable land in the fertile loess plain of the Rur catchment on the Germany-Belgium-Netherlands border. LAI from remote sensing and simulation compares well with field measurements. Based on the simulation results, we describe characteristic crop-specific temporal patterns of LAI spatial variability. By means of these patterns, we explain the complex multimodal frequency distributions of LAI in the remote sensing data. In the test area, variability between agricultural fields is higher than within fields. Therefore, spatial resolutions less than the 5 m of the remote sensing scenes are sufficient to infer LAI spatial variability. Frequency distributions from the simulation agree better with the multimodal distributions from remote sensing than normal distributions do. The spatial structure of LAI in the test area is dominated by a short distance referring to field sizes. Longer distances that refer to soil and weather can only be derived from remote sensing data. Therefore, simulations alone are not sufficient to characterize LAI spatial structure. It can be concluded that a comprehensive picture of LAI spatial

  16. Importance of Soil Quality in Environment Protection

    Directory of Open Access Journals (Sweden)

    Márta Birkás

    2007-03-01

    Full Text Available Soil quality can be characterised by the harmony between it’s physical and biological state and the fertility. From the practical crop production viewpoint, some important contrasting factors of soil quality are: (1 soil looseness – compaction; (2 aggregation – clod and dust formation; friable structure – smeared or cracked structure; (3 organic material: conservation – decrease; (4 soil moisture: conservation – loss; water transmission – water-logging; (5 at least soil condition as a result of the long term effect of land use moderates or strengthens climatic harm. In our long-term research project practical soil quality factors were examined in arable field and experimental conditions. We state that prevention of the soil quality deterioration can be done by the developing and maintaining harmony between land use and environment. Elements of the soil quality conditions such as looseness, aggregation, workability, organic matter, water transport are examined and the improving methods are suggested. Tillage and production factors which can be adopted to alleviate the harmful climatic impacts are also summarised.

  17. Rimsulfuron in soil: Effects on microbiological properties under varying soil conditions

    OpenAIRE

    Ljiljana Radivojević; Ljiljana Šantrić; Jelena Gajić Umiljendić,

    2011-01-01

    The effects of rimsulfuron a sulfonylurea herbicide on the growth and activity of soil microorganisms under laboratory conditions was investigated in two soils. The application rates were: 0.2, 2.0 and 20.0 mg a.i kg-1 soil. The lowest concentration tested was the label rate (0.2 mg a.i kg-1), and the other two were ten and hundred times higher. No adverse effects on microbiological processes were observed for the label rate. Decrease in microbial biomass c...

  18. On arable land changes in Shandong Province and their driving forces

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The decrease of total cultivated area and the lower per capitaavailable arable land resource are now serious problems in Shandong Province, a major agricultural province in China. These problems will become more serious along with the further development of economy. In this paper,based on the statistical information at provincial and county levels, the changes of arable land in Shandong Province and their driving forces during the last 50 years are analyzed. The general changing trends of arable land and per capita available arable land are reducing, and the trends of decrease will continue when the economy is developing. The result of GIS spatial analysis shows that the change of the arable land use in Shandong Province has a regional difference. Eight variables having influences on cultivated land change are analyzed by principal component analysis. The results show that the dynamic development of economy, pressure of social system and progress of scientific techniques in agriculture are the main causes for cultivated land reduction. The principal factors which can be considered as driving forces for arable land change include per capita net living space, total population and per ha grain yield. By using regressive equation, along with analysis on population growth and economic development, cultivated areas in Shandong Province in 2005 and 2010 are predicted respectively. The predicted cultivated areas in Shandong will be 6435.47 thousand hain 2005 and 6336.23 thousand ha in 2010 respectively.

  19. Comparative Analysis on Eco-Efficiency of Arable Land Ecological Footprint in Hubei

    Institute of Scientific and Technical Information of China (English)

    CHENG Bihai; WANG Qing; LIU Jianxing

    2006-01-01

    This paper uses the ecological footprint model to make comparison of the eco-efficiency of arable land ecological footprint in different years in Hubei Province, and makes comparison of that in Hubei and some countries. The results indicate that, since 1965, the eco-efficiency of arable land ecological footprint in Hubei has been improved year by year. However, the efficiency of arable land ecological footprint, compared with some other areas in the world, is much lower. In 1965, average eco-efficiency of world arable land ecological footprint is 3 421 US dollar/hm2 while that of Hubei Province is 134 US dollar/hm2, about 1/26 of the world's average level. The eco-efficiency of arable land ecological footprint for 2003 in Hubei Province, however, has become about 1/9 of the world's average level for the same year. Finally the author puts forward the ways to raise the eco-efficiency of arable land ecological footprint.

  20. Effects of pumice mining on soil quality

    Science.gov (United States)

    Cruz-Ruíz, A.; Cruz-Ruíz, E.; Vaca, R.; Del Aguila, P.; Lugo, J.

    2015-04-01

    México is the worl's fourth most important maize producer; hence, there is a need to maintain soil quality for a sustainable production in the upcoming years. Pumice mining, a superficial operation, modifies large areas in Central Mexico. The main aim was to assess the present state of agricultural soils differing in elapsed-time since pumice mining (0-15 years), in a representative area of the Calimaya region in the State of Mexico. The study sites in 0, 1, 4, 10 and 15 year-old reclaimed soils were compared with adjacent undisturbed site. Our results indicate that soil organic carbon, total nitrogen, microbial biomass carbon and microbial quotients were greatly impacted by disturbance. A general trend of recovery towards the undisturbed condition with reclamation age was found after disturbance. Recovery of soil total nitrogen was faster than soil organic carbon. Principal components analysis was applied. The first three components together explain 71.72 % of the total variability. First factor reveals strong associations between total nitrogen, microbial biomass carbon and pH. The second factor reveals high loading of urease and catalase. The obtained results revealed that the most appropriate indicators to diagnose the quality of the soils were: total nitrogen, microbial biomass carbon and soil organic carbon.

  1. Effects of pumice mining on soil quality

    Directory of Open Access Journals (Sweden)

    A. Cruz-Ruíz

    2015-04-01

    Full Text Available México is the worl's fourth most important maize producer; hence, there is a need to maintain soil quality for a sustainable production in the upcoming years. Pumice mining, a superficial operation, modifies large areas in Central Mexico. The main aim was to assess the present state of agricultural soils differing in elapsed-time since pumice mining (0–15 years, in a representative area of the Calimaya region in the State of Mexico. The study sites in 0, 1, 4, 10 and 15 year-old reclaimed soils were compared with adjacent undisturbed site. Our results indicate that soil organic carbon, total nitrogen, microbial biomass carbon and microbial quotients were greatly impacted by disturbance. A general trend of recovery towards the undisturbed condition with reclamation age was found after disturbance. Recovery of soil total nitrogen was faster than soil organic carbon. Principal components analysis was applied. The first three components together explain 71.72 % of the total variability. First factor reveals strong associations between total nitrogen, microbial biomass carbon and pH. The second factor reveals high loading of urease and catalase. The obtained results revealed that the most appropriate indicators to diagnose the quality of the soils were: total nitrogen, microbial biomass carbon and soil organic carbon.

  2. Nitrous oxide and nitrate concentration in under-drainage from arable fields subject to diffuse pollution mitigation measures

    Science.gov (United States)

    Hama-Aziz, Zanist; Hiscock, Kevin; Adams, Christopher; Reid, Brian

    2016-04-01

    Atmospheric nitrous oxide concentrations are increasing by 0.3% annually and a major source of this greenhouse gas is agriculture. Indirect emissions of nitrous oxide (e.g. from groundwater and surface water) account for about quarter of total nitrous oxide emissions. However, these indirect emissions are subject to uncertainty, mainly due to the range in reported emission factors. It's hypothesised in this study that cover cropping and implementing reduced (direct drill) cultivation in intensive arable systems will reduce dissolved nitrate concentration and subsequently indirect nitrous oxide emissions. To test the hypothesis, seven fields with a total area of 102 ha in the Wensum catchment in eastern England have been chosen for experimentation together with two fields (41 ha) under conventional cultivation (deep inversion ploughing) for comparison. Water samples from field under-drainage have been collected for nitrate and nitrous oxide measurement on a weekly basis from April 2013 for two years from both cultivation areas. A purge and trap preparation line connected to a Shimadzu GC-8A gas chromatograph fitted with an electron capture detector was used for dissolved nitrous oxide analysis. Results revealed that with an oilseed radish cover crop present, the mean concentration of nitrate, which is the predominant form of N, was significantly depleted from 13.9 mg N L-1 to 2.5 mg N L-1. However, slightly higher mean nitrous oxide concentrations under the cover crop of 2.61 μg N L-1 compared to bare fields of 2.23 μg N L-1 were observed. Different inversion intensity of soil tended to have no effect on nitrous oxide and nitrate concentrations. The predominant production mechanism for nitrous oxide was nitrification process and the significant reduction of nitrate was due to plant uptake rather than denitrification. It is concluded that although cover cropping might cause a slight increase of indirect nitrous oxide emission, it can be a highly effective

  3. 河北省耕地占用与GDP增长的脱钩分析%Decoupling Analysis between Arable Land Occupation and GDP Growth in Hebei Province

    Institute of Scientific and Technical Information of China (English)

    杨克; 陈百明; 宋伟

    2009-01-01

    a weak decoupling, which could be indicative of increases in pressure from arable land occupied by construction. As a whole, elasticity values of the decoupling between arable land occupied by construction and non-agricultural GDP exhibited an "M"-shaped curve. This means arable land protection has already shown a marked positive effect. With a further development of economy in the near future, the status of decoupling will possibly show a trend to become re-coupling. The pressure from arable land occupied by construction will be likely to increase. So the management for arable land occupied by construction should be strengthened. Necessary policies and measures, such as economical and intensive utilization of arable land resources should be taken.%在经济发展过程中,大量优质耕地被占用已成为严重制约我国可持续发展的重大挑战.本文基于脱钩理论,运用经济合作与发展组织(OECD)提出的脱钩指数计算模型和Tapio等划分的脱钩状态,构建脱钩模型,计算脱钩弹性,建立脱钩程度坐标图,并以河北省为例分析各阶段脱钩状态及其原因,以期指导经济发展过程中的耕地保护问题.研究表明:1990年~1999年脱钩弹性值变化平缓,由强脱钩向复钩状态变化,建设占用耕地压力增大;2000年~2005年脱钩弹性值变化剧烈,由强脱钩向复钩状态变化,建设占用耕地压力较前一阶段急剧减小后增大;2006年~2007年脱钩弹性减小,呈现弱脱钩状态,建设占用耕地压力减小.总体来看,建设占用耕地与非农GDP产值的关系曲线呈现"M"型变化,耕地保护政策、措施实施效果明显.随着经济发展,在未来一段时期建设占有耕地与非农GDP产值关系有向复钩状态发展的趋势,建设占用耕地压力将增大,为此应加大建设占用耕地管理力度,采用节约集约利用土地的政策和措施.

  4. Long-Term Effect of Different Carbon Management Strategies on Water Flow and Related Processes for Three Loamy Soils

    DEFF Research Database (Denmark)

    Vendelboe, Anders Lindblad; Schjønning, Per; de Jonge, Lis Wollesen;

    2013-01-01

    The decline in organic matter of arable land, induced and accelerated by modern agriculture, has been identified as a threat to sustained soil quality. In this article, we studied strategies to counter this decrease by building up soil organic carbon (SOC) levels in the soils using several...... on preferential flow and loss of colloids during heavy irrigation events. The field sites were all under long-term management and therefore represent up to 30 years of pairwise different management strategies. One field in each field pair was managed with a more C-repleting strategy (HighC) than the other (Low......C). Only small differences in SOC contents were identified, and none of the management strategies had succeeded in building up SOC pools large enough to saturate the soil with C. Only at one field site was the content of water-dispersible colloids lower in the HighC than the LowC treatment. Preferential...

  5. Earthworm assemblages in an ecotone between forest and arable field and their relations with soil properties Comunidades de minhocas em um ecótono entre floresta e campo arável e suas relações com as propriedades do solo

    Directory of Open Access Journals (Sweden)

    Josef Zeithaml

    2009-08-01

    Full Text Available The objective of this work was to assess the effects of a forest-field ecotone on earthworm assemblages. Five sites (blocks differing in the type of crop rotation used in the field were studied in Central Bohemia, Czech Republic. In each block, sampling was carried out in seven parallel rows perpendicular to a transect from a forest (oak or oak-pine to the centre of a field, both in spring and autumn 2001-2003. Individual rows were located in the forest (5 m from the edge, in the forest edge, and in the field (at 5, 10, 25, 50 and 100 m distances from the forest edge. The density and biomass of earthworms were lowest in the forest, increased markedly in the forest edge, decreased again at 5 or 10 m distance from the forest edge and then continuously increased along the distance to the field boundary. The highest number of species was found in the forest edge and in the field boundary. Individual species differed in their distribution along the transect. Both density and biomass of earthworms were correlated with distance from forest edge, soil organic matter content, soil porosity, and water infiltration rate.O objetivo deste trabalho foi avaliar os efeitos de um ecótono entre floresta e campo arável sobre comunidades de minhocas. Cinco locais (blocos com diferentes tipos de rotação de culturas utilizados no campo foram estudados na Boêmia Central, República Tcheca. Em cada bloco, amostragens foram feitas em sete linhas paralelas perpendiculares a um transecto de floresta (carvalho ou carvalho e pinheiro, em direção ao centro de um campo, na primavera e no outono de 2001-2003. Linhas individuais foram marcadas na floresta (a 5 m da borda, na borda da floresta e no campo (a 5, 10, 25, 50 e 100 m da borda da floresta. A densidade e biomassa das minhocas foi menor na floresta, aumentou marcadamente na borda da floresta, decaiu novamente a 5 ou 10 m de distância da borda da floresta e aumentou continuamente com a distância até o limite do

  6. Effect of discrete fibre reinforcement on soil tensile strength

    Institute of Scientific and Technical Information of China (English)

    Jian Li; Chaosheng Tang; Deying Wang; Xiangjun Pei; Bin Shi

    2014-01-01

    The tensile behaviour of soil plays a significantly important role in various engineering applications. Compacted soils used in geotechnical constructions such as dams and clayey liners in waste containment facilities can suffer from cracking due to tensile failure. In order to increase soil tensile strength, discrete fibre reinforcement technique was proposed. An innovative tensile apparatus was developed to deter-mine the tensile strength characteristics of fibre reinforced soil. The effects of fibre content, dry density and water content on the tensile strength were studied. The results indicate that the developed test apparatus was applicable in determining tensile strength of soils. Fibre inclusion can significantly in-crease soil tensile strength and soil tensile failure ductility. The tensile strength basically increases with increasing fibre content. As the fibre content increases from 0%to 0.2%, the tensile strength increases by 65.7%. The tensile strength of fibre reinforced soil increases with increasing dry density and decreases with decreasing water content. For instance, the tensile strength at a dry density of 1.7 Mg/m3 is 2.8 times higher than that at 1.4 Mg/m3. It decreases by 30% as the water content increases from 14.5% to 20.5%. Furthermore, it is observed that the tensile strength of fibre reinforced soil is dominated by fibre pull-out resistance, depending on the interfacial mechanical interaction between fibre surface and soil matrix.

  7. Effect of soil texture on phytoremediation of arsenic-contaminated soils

    Science.gov (United States)

    Pallud, C. E.; Matzen, S. L.; Olson, A.

    2015-12-01

    Soil arsenic (As) contamination is a global problem, resulting in part from anthropogenic activities, including the use of arsenical pesticides and treated wood, mining, and irrigated agriculture. Phytoextraction using the hyperaccumulating fern Pteris vittata is a promising new technology to remediate soils with shallow arsenic contamination with minimal site disturbance. However, many challenges still lie ahead for a global application of phytoremediation. For example, remediation times using P. vittata are on the order of decades. In addition, most research on As phytoextraction with P. vittata has examined As removal from sandy soils, where As is more available, with little research focusing on As removal from clayey soils, where As is less available. The objective of this study is to determine the effects of soil texture and soil fertilization on As extraction by P. vittata, to optimize remediation efficiency and decrease remediation time under complex field conditions. A field study was established 2.5 years ago in an abandoned railroad grade contaminated with As (average 85.5 mg kg-1) with texture varying from sandy loam to silty clay loam. Organic N, inorganic N, organic P, inorganic P, and compost were applied to separate sub-plots; control ferns were grown in untreated soil. In a parallel greenhouse experiment, ferns were grown in sandy loam soil extracted from the field (180 mg As kg-1), with similar treatments as those used at the field site, plus a high phosphate treatment and treatments with arbuscular mycorrhizal fungi. In the field study, fern mortality was 24% higher in clayey soil than in sandy soil due to waterlogging, while As was primarily associated with sandy soil. Results from the sandy loam soil indicate that soil treatments did not significantly increase As phytoextraction, which was lower in phosphate-treated ferns than in control ferns, both in the field and greenhouse study. Under greenhouse conditions, ferns treated with organic N were

  8. Effect of biosolid waste compost on soil respiration in salt-affected soils

    Science.gov (United States)

    Raya, Silvia; Gómez, Ignacio; García, Fuensanta; Navarro, José; Jordán, Manuel Miguel; Belén Almendro, María; Martín Soriano, José

    2013-04-01

    respiration, compost, electrical conductivity, salinization, Bac-Trac References: Abdelbasset Lakhdar, Mokded Rabhi, Tahar Ghnaya, Francesco Montemurro, Naceur Jedidi , Chedly Abdelly. Effectiveness of compost use in salt-affected soil. Journal of Hazardous Materials 171 (2009) pp 29-37. M. Tejada, C. Garcia, J.L. Gonzalez , M.T. Hernandez . Use of organic amendment as a strategy for saline soil remediation:Influence on the physical, chemical and biological properties of soil. Soil Biology & Biochemistry 38 (2006) pp 1413-1421. I. Gomez; J.M. Disla Soriano; J. Navarro-Pedreño; F. García-Orenes; M.B. Almendro-Candel; M.M. Jordan. Quantification of soil respiration in different saline soil of Alicante (Spain). EGU General Assembly (2012). Viena. Ed. Geophysycal Research Abstracts. Vol 14 EGU2012-2399,(2012). (Acknowledgements: This work was supported by the Spanish MICINN. Project Ref.: CGL2009-11194)

  9. Effects of Soil Oxygen Conditions and Soil pH on Remediation of DDT-contaminated Soil by Laccase from White Rot Fungi

    OpenAIRE

    Yuechun Zhao; Xiaoyun Yi

    2010-01-01

    High residues of DDT in agricultural soils are of concern because they present serious threats to food security and human health. This article focuses on remediation of DDT-contaminated soil using laccase under different soil oxygen and soil pH conditions. The laboratory experiment results showed significant effects of soil oxygen conditions and soil pH on remediation of DDT-contaminated soil by laccase at the end of a 25-d incubation period. This study found the positive correlation between ...

  10. Stability analysis of slopes of expansive soils considering rainfall effect

    Institute of Scientific and Technical Information of China (English)

    ZHU Fang-cai

    2007-01-01

    Typical failure types of slopes of expansive soils are divided to two kinds: slip in surface layer and slip in shallow layer. Based on total strength law of expansive soils, the relationship between its water content and shear strength inculding cohesion and friction angle, was studied in detail. Acoording to change of water content and depth effect during rainfall, distribution of shear strength in slopes of expansive soils was analyzed. Finally,with a slope of expansive soils in Nanning city of Guangxi Autonomous Region of China as a case, safety factor and slip surface was studied.

  11. Effect of heavy metals on soil fungi

    Science.gov (United States)

    Sosak-Świderska, Bożena

    2010-05-01

    Fungi constitute a high proportion of the microbial biomass in soil.Being widespread in soil their large surface-to-volume ratio and high metabolic activity, fungi can contribute significantly to heavy metal dynamics in soil. At neutral pH heavy metals in soils tend to be immobilized to precipitation and/or absorption to cation exchange sites of clay minerals. In the acidic soils, metals are more mobile and enter food webs easier. Microbial production of acids and chelating agents can mobilize to toxic metals. Mobilization is often by uptake and intracellular accumulation of the heavy metlas, and in this way, the bioavailability of metals towards other organisms can be more reduced. Fungi were isolated from soils from Upper Silesia in Poland and belonged to widespread genera: Aspergillus, Cladosporium, Penicillium and Trichoderma. Fungi from different taxonomic groups differ greatly in their tolerance to heavy metals. This could be related to their wall structure and chemistry as well as biochemical and physiological characteristics of fungi. Localization of metals in fungal cells was studied using electron microscopy analysis. Metal biosorption in the cell wall can be complex as melanin granules. Fungal vacuoles have an important role in the regulation of the cytosolic concentration of metal ions, and may contribute to heavy metal tolerance.In polluted soils with heavy metals, fungal species composition can be changed and their physiological activity can be changed, too.

  12. Formation of Soil Water Repellency by Laboratory Burning and Its Effect on Soil Evaporation

    Science.gov (United States)

    Ahn, Sujung; Im, Sangjun

    2010-05-01

    Fire-induced soil water repellency can vary with burning conditions, and may lead to significant changes in soil hydraulic properties. However, isolation of the effects of soil water repellency from other factors is difficult, particularly under field conditions. This study was conducted to (i) investigate the effects of burning using different plant leaf materials and (ii) of different burning conditions on the formation of soil water repellency, and (iii) isolate the effects of the resulting soil water repellency on soil evaporation from other factors. Burning treatments were performed on the surface of homogeneous fully wettable sand soil contained in a steel frame (60 x 60 cm; 40 cm depth). As controls a sample without a heat treatment, and a heated sample without fuel, were also used. Ignition and heat treatments were carried out with a gas torch. For comparing the effects of different burning conditions, fuel types included oven-dried pine needles (fresh needles of Pinus densiflora), pine needle litter (litter on a coniferous forest floor, P. densiflora + P. rigida), and broad-leaf litter (Quercus mongolica + Q. aliena + Prunus serrulata var. spontanea + other species); fuel loads were 200 g, 300 g, and 500 g; and heating duration was 40 s, 90 s and 180 s. The heating duration was adjusted to control the temperature, based on previous experiments. The temperature was measured continuously at 3-second intervals and logged with two thermometers. After burning, undisturbed soil columns were sampled for subsequent experiments. Water Drop Penetration Time (WDPT) test was performed at every 1 mm depth of the soil columns to measure the severity of soil water repellency and its vertical extent. Soil water repellency was detected following all treatments. As the duration of heating increased, the thickness of the water repellent layer increased, whilst the severity of soil water repellency decreased. As regards fuel amount, the most severe soil water repellency was

  13. Effect of pineapple cropping on soil chemical and physical changes in Tha-yang soil series, Petchaburi province

    Directory of Open Access Journals (Sweden)

    Isuwan, A.

    2007-03-01

    Full Text Available The experiment was conducted to investigate the effect of pineapple cropping on chemical and physical property changes of Tha-yang soil series, located on Tumbon Nong-ya-plong, Amphor Nong-yaplong,Petchaburi province. The experimental treatments were the different pineapple cropping soil ages arranged in a completely randomized design, consisting of undisturbed soil (year 0 and pineapple croppingsoil ages of 1, 4 and 8 years with 4 replications each. Soil samples were separated according to the soil level, namely Top-soil (0-15 cm. and Sub-soil (15-30 cm. for chemical and physical evaluation. The results showedthat soil chemical properties such as pH, OM, CEC, exchangeable Ca and Mg were decreased significantly (in both Top- and Sub-soil level, whereas available P and S were increased significantly in the 4-year soilsamples when compared with undisturbed soil. However, soil physical properties were not significantly different among cropping age treatments, except for clay particle in Top-soil which increased in the 4-year soil samples when compared with the 1-year soil samples and undisturbed soil. The results revealed thatpineapple cropping notably reduced soil fertility. As a result, soil resource management and plant nutrient management strategies must be carefully planned and implemented for sustainable pineapple production.

  14. Soil conditions and land use intensification effects on soil microbial communities across a range of European field sites

    NARCIS (Netherlands)

    Thomson, Bruce C.; Tisserant, Emilie; Plassart, Pierre; Uroz, Stéphane; Griffiths, Rob I.; Hannula, S. Emilia; Buée, Marc; Mougel, Christophe; Ranjard, Lionel; Van Veen, Johannes A.; Martin, Francis; Bailey, Mark J.; Lemanceau, Philippe

    2015-01-01

    Abstract Intensive land use practices necessary for providing food and raw materials are known to have a deleterious effect on soil. However, the effects such practices have on soil microbes are less well understood. To investigate the effects of land use intensification on soil microbial communitie

  15. Effects of Biochar and Lime on Soil Physicochemical Properties and Tobacco Seedling Growth in Red Soil

    Directory of Open Access Journals (Sweden)

    ZHU Pan

    2015-12-01

    Full Text Available Red soil, mainly found in the southern China, is developed in a warm, moist climate. The main property of the soils is strong acidity, aluminum toxicity, and low available nutrients. In this study, different effects of biochar and lime on soil physicochemical properties and tobacco growth were determined in red soil, so as to provide a scientific foundation for soil improvement tobacco field. A pot experiment was designed and conducted at four biochar levels(0, 0.5%, 1%, 2% and normal lime level (0.3% to study effects of two different soil amendments on red soil pH, exchangeable aluminum(Exc-Al and exchangeable manganese(Exc-Mn, available nutrients and organic carbon (SOC. Meanwhile, agronomic traits, biomass and leaves elements of tobacco were also tested. Results showed that the agronomic characters and biomass of tobacco seedling had changed effectively after biochar or lime was added. Under 0.5%, 1% biochar treatment, the content of nitrogen(N, phosphorus(P, potassium(K, calcium(Ca and magnesium(Mg in tobacco leaves substantially raised. However, when 2% biochar was applied, leaves N content declined by 9.3%. Compared with the control, leaves N, P and Ca content increased observably in the lime treatment. However, its K and Mg content decreased by 9.0% and 13.3% respectively. Alkaline nitrogen(SAN, available phosphorus (SAP, available potassium (SAK, and exchangeable calcium (Exc-Ca and exchangeable magnesium (Exc-Mg were improved obviously in soil applied with biochar. Only the content of Exc-Ca was significantly increased in lime treatment. In addition, it was beneficial to improve soil pH and reduce soil Exc-Al when biochar or lime had been used. Thus, both biochar and lime are propitious to increase soil pH value, lessen soil Exc-Al content, and improve the growth of tobacco seedling. Furthermore, biochar application also can raise the content of available nutrient and SOC in red soil.

  16. Effects of short-chain chlorinated paraffins on soil organisms.

    Science.gov (United States)

    Bezchlebová, Jitka; Cernohlávková, Jitka; Kobeticová, Klára; Lána, Jan; Sochová, Ivana; Hofman, Jakub

    2007-06-01

    Despite the fact that chlorinated paraffins have been produced in relatively large amounts, and high concentrations have been found in sewage sludge applied to soils, there is little information on their concentrations in soils and the effect on soil organisms. The aim of this study was to investigate the toxicity of chlorinated paraffins in soils. The effects of short-chain chlorinated paraffins (64% chlorine content) on invertebrates (Eisenia fetida, Folsomia candida, Enchytraeus albidus, Enchytraeus crypticus, Caenorhabditis elegans) and substrate-induced respiration of indigenous microorganisms were studied. Differences were found in the sensitivity of the tested organisms to short-chain chlorinated paraffins. F. candida was identified as the most sensitive organism with LC(50) and EC(50) values of 5733 and 1230 mg/kg, respectively. Toxicity results were compared with available studies and the predicted no effect concentration (PNEC) of 5.28 mg/kg was estimated for the soil environment, based on our data.

  17. Overview of different aspects of climate change effects on soils.

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Nikolla

    2014-08-01

    Climate change [i.e., high atmospheric carbon dioxide (CO2) concentrations (≥400 ppm); increasing air temperatures (2-4°C or greater); significant and/or abrupt changes in daily, seasonal, and inter-annual temperature; changes in the wet/dry cycles; intensive rainfall and/or heavy storms; extended periods of drought; extreme frost; heat waves and increased fire frequency] is and will significantly affect soil properties and fertility, water resources, food quantity and quality, and environmental quality. Biotic processes that consume atmospheric CO2 and create organic carbon (C) that is either reprocessed to CO2 or stored in soils, are the subject of active current investigations with great concern over the influence of climate change. In addition, abiotic C cycling and its influence on the inorganic C pool in soils is a fundamental global process in which acidic atmospheric CO2 participates in the weathering of carbonate and silicate minerals, ultimately delivering bicarbonate and Ca2+ or other cations that precipitate in the form of carbonates in soils or are transported to the rivers, lakes, and oceans. Soil responses to climate change will be complex, and there are many uncertainties and unresolved issues. The objective of the review is to initiate and further stimulate a discussion about some important and challenging aspects of climate-change effects on soils, such as accelerated weathering of soil minerals and resulting C and elemental fluxes in and out of soils, soil/geo-engineering methods used to increase C sequestration in soils, soil organic matter (SOM) protection, transformation and mineralization, and SOM temperature sensitivity. This review reports recent discoveries and identifies key research needs required to understand the effects of climate change on soils.

  18. Overview of different aspects of climate change effects on soils

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Nikolla P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-08-01

    Climate change [i.e., high atmospheric carbon dioxide (CO2) concentrations (≥400 ppm); increasing air temperatures (2-4°C or greater); significant and/or abrupt changes in daily, seasonal, and inter-annual temperature; changes in the wet/dry cycles; intensive rainfall and/or heavy storms; extended periods of drought; extreme frost; heat waves and increased fire frequency] is and will significantly affect soil properties and fertility, water resources, food quantity and quality, and environmental quality. Biotic processes that consume atmospheric CO2 and create organic carbon (C) that is either reprocessed to CO2 or stored in soils, are the subject of active current investigations with great concern over the influence of climate change. In addition, abiotic C cycling and its influence on the inorganic C pool in soils is a fundamental global process in which acidic atmospheric CO2 participates in the weathering of carbonate and silicate minerals, ultimately delivering bicarbonate and Ca2+ or other cations that precipitate in the form of carbonates in soils or are transported to the rivers, lakes, and oceans. Soil responses to climate change will be complex, and there are many uncertainties and unresolved issues. The objective of the review is to initiate and further stimulate a discussion about some important and challenging aspects of climate-change effects on soils, such as accelerated weathering of soil minerals and resulting C and elemental fluxes in and out of soils, soil/geo-engineering methods used to increase C sequestration in soils, soil organic matter (SOM) protection, transformation and mineralization, and SOM temperature sensitivity. This review reports recent discoveries and identifies key research needs required to understand the effects of climate change on soils.

  19. Soil Mineralogy and Substrate Quality Effects on Microbial Priming

    Science.gov (United States)

    Finley, B. K.; Rasmussen, C.; Dijkstra, P.; Schwartz, E.; Mau, R. L.; Liu, X. J. A.; Hungate, B. A.

    2014-12-01

    Soil carbon (C) cycling can slow or accelerate in response to new C inputs from fresh organic matter. This change in native C mineralization, known as the "microbial priming effect," is difficult to predict because the underlying mechanisms of priming are still poorly understood. We hypothesized that soil mineral assemblage, specifically short-range-order (SRO) minerals, influences microbial responses to different quality C substrate inputs. To test this, we added 350 μg C g-1soil weekly of an artificial root exudates mixture primarily comprised of glucose, sucrose, lactate and fructose (a simple C source) or ground ponderosa pine litter (a complex C source) for six weeks to three soil types from similar ecosystems derived from different parent material. The soils, from andesite, basalt, and granite parent materials, had decreasing abundance in SRO minerals, respectively. We found that the simple C substrate induced 63 ±16.3% greater positive priming than the complex C across all soil types. The quantity of soil SRO materials was negatively correlated with soil respiration, but positively correlated with priming. The lowest SRO soil amended with litter primed the least (14 ± 11 μgCO2-C g-1), while the largest priming effect occurring in the highest SRO soil amended with simple substrate (246 ± 18 μgCO2-C g-1). Our results indicate that higher SRO mineral content could accelerate microorganisms' capacity to mineralize native soil organic carbon and respond more strongly to labile C inputs. However, while all treatments exhibited positive priming, the amount of C added over the six-week incubation was greater than total CO2 respired. This suggests that despite a relative stimulation of native C mineralization, these soils act as C sinks rather than sources in response to fresh organic matter inputs.

  20. Effect of soil contamination with azadirachtin on dehydrogenase and catalase activity of soil

    Directory of Open Access Journals (Sweden)

    Rıdvan Kızılkaya

    2012-07-01

    Full Text Available nsecticides are used in modern agriculture in large quantities to control pests and increase crop yield. Their use, however, has resulted in the disruption of ecosystems because of the effects on non-target soil microorganisms, some environmental problems, and decreasing soil fertility. These negative effects of synthetic pesticides on the environment have led to the search for alternative means of pest control. One such alternative is use of natural plant products such as azadirachtin that have pesticidal activity. The aim of this experiment was to study the effect of soil contamination by azadirachtin (C35H44O16 on dehydrogenase (DHA and catalase activity (CA of soil under field conditions in Perm, Russia. The tests were conducted on loamy soil (pHH2O 6.7, ECH2O 0.213 dSm-1, organic carbon 0.99%, to which the following quantities of azadirachtin were added: 0, 15, 30 and 60 mL da-1 of soil. Experimental design was randomized plot design with three replications. The DHA and CA analyses were performed 7, 14 and 21 days after the field experiment was established. The results of field experiment showed that azadirachtin had a positive influence on the DHA and CA at different soil sampling times. The increased doses of azadirachtin applied resulted in the higher level of DHA and CA in soil. The soil DHA and CA showed the highest activity on the 21th day after 60 mL azadirachtin da-1 application doses.

  1. Effects of olive mill wastes added to olive grove soils on erosion and soil properties

    Science.gov (United States)

    Lozano-García, Beatriz; Parras-Alcántara, Luis

    2014-05-01

    INTRODUCTION The increasing degradation of olive groves by effect of organic matter losses derived from intensive agricultural practices has promoted the use (by olive farmers) of olive mill wastes (olive leaves and alperujo) which contain large amounts of organic matter and are free of heavy metals and pathogenic microorganisms. In this work we compared the effects of these oil mill wastes on the decrease of soil erosion, also, we undertook the assessment of the organic carbon and nitrogen contents of soil, their distribution across the profile, the accumulation and Stratification ratios (SRs) of soil organic carbon (SOC) and total nitrogen (TN), and the C:N ratio, in Cambisols in Mediterranean olive groves treated with olive leaves and alperujo. MATERIALS AND METHODS The study area was a typical olive grove in southern Spain under conventional tillage (CT). Three plots were established. The first one was the control plot; the second one was treated with olive leaves (CTol) and the third one, with alperujo (CTa). 9 samples per plot were collected to examine the response of the soil 3 years after application of the wastes. Soil properties determined were: soil particle size, pH, bulk density, the available water capacity, SOC, TN and C:N ratio. SOC and N stock, expressed for a specific depth in Mg ha-1. Stratification ratios (SRs) (that can be used as an indicator of dynamic soil quality) for SOC and TN at three different depths were calculated. The erosion study was based on simulations of rain; that have been carried out in order to highlight differences in the phenomena of runoff and soil losses in the three plots considered. The effect of different treatments on soil properties was analyzed using a ANOVA, followed by an Anderson-Darling test. RESULTS Supplying the soil with the wastes significantly improved physical and chemical properties in the studied soils with respect to the control. C and N stocks increased, the SOC stock was 75.4 Mg ha-1 in CT, 91.5 Mg

  2. Herbicide impact on the growth and reproduction of characteristic and rare arable weeds of winter cereal fields.

    Science.gov (United States)

    Rotchés-Ribalta, Roser; Boutin, Céline; Blanco-Moreno, José M; Carpenter, David; Sans, F Xavier

    2015-07-01

    The decline of arable species characteristic of winter cereal fields has often been attributed to different factors related to agricultural intensification but most importantly to herbicide use. Herbicide phytotoxicity is most frequently assessed using short-term endpoints, primarily aboveground biomass. However, short-term sensitivity is usually not sufficient to detect actual effects because plants may or may not recover over time following sublethal herbicide exposures. Therefore, it is important to assess the long-term effects of herbicide applications. Annual species rely on renewable seed production to ensure their persistence; hence, assessment of herbicide sensitivity is more accurately estimated through effects on reproduction. Here we aim to assess the phytotoxicity of two commonly used herbicides: tribenuron and 2,4-D on eight plant species belonging to four families, each with one rare and one more common species. Specifically we examined the pattern of sensitivity using short-term and long-term endpoints (total aboveground biomass, total seed biomass and number of seeds) of these species; we determined the levels of and time to recovery in terms of stem length and fruit number, and assessed whether their rarity relates to their sensitivity to herbicide application. Our results suggest that although differences in herbicide sensitivity are not a direct cause of rarity for all species, it may be an important driver of declining arable plants.

  3. Crop diversity effects on soil health

    Science.gov (United States)

    Concurrent demands for abundant, healthy food, thriving rural economies, and an unpolluted physical environment represents a significant agricultural challenge in the 21st century. Trends in human population growth and changing weather patterns will make this challenge exceedingly difficult. Soil ...

  4. [Inhibitory effect of DMPP on soil nitrification as affected by soil moisture content, pH and organic matter].

    Science.gov (United States)

    Xue, Yan; Wu, Zhi-Jie; Zhang, Li-Li; Gong, Ping; Dong, Xin-Xin; Nie, Yan-Xia

    2012-10-01

    A laboratory incubation test with meadow brown soil was conducted to study the inhibitory effect of 3,4-dimethylpyrazole phosphate (DMPP) on soil nitrification as affected by soil moisture content (40%, 60% and 80% of the maximum field capacity), pH (4, 7 and 10), and organic matter (retained and removal). With the decrease of soil moisture content, the degradation of DMPP in soil tended to slow down, and the oxidation of soil NH4+ was more inhibited. At pH 10, more DMPP was remained in soil, and had the greatest inhibitory effect; at pH 7 and pH 4, the DMPP was lesser remained, with a smaller inhibitory effect. The removal of organic matter prolonged the remaining time of DMPP in soil, and decreased the apparent soil nitrification rate significantly.

  5. Effects of temperature and soil components on emissions from pyrolysis of pyrene-contaminated soil.

    Science.gov (United States)

    Risoul, Véronique; Richter, Henning; Lafleur, Arthur L; Plummer, Elaine F; Gilot, Patrick; Howard, Jack B; Peters, William A

    2005-11-11

    Effects of temperature and soil on yields and identities of light gases (H2, CH4, C2H2, C2H4, C2H6, CO, and CO2) and polycyclic aromatic hydrocarbons (PAH) from thermal treatment of a pyrene-contaminated (5 wt%) soil in the absence of oxygen were determined for a U.S. EPA synthetic soil matrix prepared to proxy U.S. Superfund soils. Shallow piles (140-170 mg) of contaminated soil particles and as controls, neat (non-contaminated) soil (140-160 mg), neat pyrene (10-15 mg), neat sand (230 mg), and pyrene-contaminated sand (160 mg), were heated in a ceramic boat inside a 1.65 cm i.d. pyrex tube at temperatures from 500 to 1100 degrees C under an axial flow of helium. Volatile products spent 0.2-0.4s at temperature before cooling. Light gases, PAH and a dichloromethane extract of the residue in the ceramic boat, were analyzed by gas chromatography or high pressure liquid chromatography (HPLC). Over 99% pyrene removal was observed when heating for a few tens of seconds in all investigated cases, i.e., at 500, 650, 750, 1000, and 1100 degrees C for soil, and 750 and 1000 degrees C for sand. However, each of these experiments gave significant yields (0.2-16 wt% of the initial pyrene) of other PAH, e.g., cyclopenta[cd]pyrene (CPP), which mutates bacterial cells and human cells in vitro. Heating pyrene-polluted soil gave pyrene conversions and yields of acetylene, CPP, and other PAH exceeding those predicted from similar, but separate heating of neat soil and neat pyrene. Up to 750 degrees C, recovered pyrene, other PAH, and light gases accounted for all or most of the initial pyrene whereas at 1000 and 1100 degrees C conversion to soot was significant. A kinetic analysis disentangled effects of soil-pyrene interactions and vapor phase pyrolysis of pyrene. Increase of residence time was found to be the main reason for the enhanced conversion of pyrene in the case of the presence of a solid soil or sand matrix. Light gas species released due to the thermal treatment, such as

  6. Effects of Nitrogen Fertilizer,Soil Moisture and Temperature on Methane Oxidation in Paddy Soil

    Institute of Scientific and Technical Information of China (English)

    YANXIAOYUAN; CAIZUCONG

    1996-01-01

    Effects of nitrogen fertilizer,soil mosture and temperature and temperature on methane oxidation in paddy soil were investigated under laboratory conditions.Addition of 0.05 g N kg-1 soil as NH4Cl strongly inhibited methane oxidation and addition of the same rate of KCl also inhibited the oxidation but with more slight effect,suggesting that the inhibitory effect was partly caused by increase in osmotic potential in microorganism cell,Not only NH4+ but also NO3- greatly affected methane oxidation.Urea did not affect methane oxidation in paddy soil in the first two days of incubation,but strong inhibitory effect was observed afterwards.Methane was oxidized in the treated soil with an optimum moisture of 280 g kg-1 ,and air-drying inhibited methane oxidation entirely.The optimum temperature of methane oxidation was about 30℃ in paddy soil.while no methane oxidation was observed at 5℃or 50℃。

  7. [Effects of Green Manure Intercropping and Straw Mulching on Winter Rape Rhizosphere Soil Organic Carbon and Soil Respiration].

    Science.gov (United States)

    Zhou, Quan; Wang, Long-chang; Xiong, Ying; Zhang, Sai; Du, Juan; Zhao, Lin-lu

    2016-03-15

    Under the background of global warming, the farmland soil respiration has become the main way of agricultural carbon emissions. And green manure has great potential to curb greenhouse gas emissions and achieve energy conservation and emissions reduction. However, in purple soil region of Southwest, China, soil respiration under green manure remains unclear, especially in the winter and intercropping. Through the green manure ( Chinese milk vetch) intercropping with rape, therefore, we compared the effects of rape rhizosphere under straw mulching. The soil organic carbon and soil respiration were examined. The results showed, compared with straw mulching, root separation was the major influencing factors of soil organic carbon on rape rhizosphere. Soil organic carbon was significantly decreased by root interaction. In addition, straw mulching promoted while green manure intercropping inhibited the soil respiration. Soil respiration presented the general characteristics of fall-rise-fall due to the strong influence of rape growth period. Therefore, it showed a cubic curve relationship with soil temperature.

  8. Effects of organic and inorganic amendments on soil erodibility

    Directory of Open Access Journals (Sweden)

    Nutullah Özdemir

    2015-10-01

    Full Text Available The objective of the present investigation is to find out the effect of incorporating of various organic and inorganic matter sources such as lime (L, zeolit (Z, polyacrylamide (PAM and biosolid (BS on the instability index. A bulk surface (0–20 cm depth soil sample was taken from Samsun, in northern part of Turkey. Some soil properties were determined as follows; fine in texture, modarete in organic matter content, low in pH and free of alkaline problem. The soil samples were treated with the inorganic and organic materials at four different levels including the control treatments in a randomized factorial block design. The soil samples were incubated for ten weeks. After the incubation period, corn was grown in all pots. The results can be summarized as organic and inorganic matter treatments increased structure stability and decreased soil erodibility. Effectiveness of the treatments varied depending on the types and levels of organic and inorganic materials.

  9. Temperature Effect on Boron Adsorption—Desorption Kinetics in Soils

    Institute of Scientific and Technical Information of China (English)

    ZHUDUANWEI; SHILEI; 等

    1999-01-01

    The effect of temperature on the properties of boron adsorption-desorption in brown-red soil,yellowbrown soil and calcareous alluvial soil of Hubei Province was investigated with the mobile displacement technique.The experimental data of B adsorption-desorption amounts and reaction time at 25 and 40℃ were fitted by the zero-order,first-order and parabolic diffusion kinetic equations.The adsorption process was in conformity with the parabolic diffusion law at both the temperatures,and the values of rate constant of the parabolic diffusion equation in B adsorption were 0.138,0.124 and 0.105 mg kg-1 min-1/2 at 25℃,and 0.147,0.146and 0.135mg kg-1 min1/2 at 40℃ for the brown-red soil,yellow-brown soil,and calcareous alluvial soil,respectively,The relationship between amount of B desorption and reaction time could be well described by the first-order kinetic equation,and the corresponding values of rate constant were 0.0422,0.0563 and 0.0384min-1 at 25℃,and 0.0408,0.0423 and 0.0401min-1 at 40℃ for the brown-red soil,the yellow-brown soil and the calcareous alluvial soil,respectively.Therefore,the desorption process of B might be related to the amount of B adsorbed in soil,The higher th temperature,the lower the amount of B adsorption of the same soil in the same reaction time,The values of the apparent activation energy of B adsorption in the three soils calculated with the rate constants of parabolic diffusion equation were 3.27,8.44 and 12.99 kJ mol-1,respectively,based on the experimental data of B adsorption amounts and reaction time at and 40℃.

  10. Earthworms and priming of soil organic matter - The impact of food sources, food preferences and fauna - microbiota interactions

    Science.gov (United States)

    Potthoff, Martin; Wichern, Florian; Dyckmans, Jens; Joergensen, Rainer Georg

    2016-04-01

    Earthworms deeply interact with the processes of soil organic matter turnover in soil. Stabilization of carbon by soil aggregation and in the humus fraction of SOM are well known processes related to earthworm activity and burrowing. However, recent research on priming effects showed inconsistent effects for the impact of earthworm activity. Endogeic earthworms can induce apparent as well as true positive priming effects. The main finding is almost always that earthworm increase the CO2 production from soil. The sources of this carbon release can vary and seem to depend on a complex interaction of quantity and quality of available carbon sources including added substrates like straw or other compounds, food preferences and feeding behavior of earthworms, and soil properties. Referring to recent studies on earthworm effects on soil carbon storage and release (mainly Eck et al. 2015 Priming effects of Aporrectodea caliginosa on young rhizodeposits and old soil organic matter following wheat straw addition, European Journal of Soil Biology 70:38-45; Zareitalabad et al. 2010 Decomposition of 15N-labelled maize leaves in soil affected by endogeic geophagous Aporrectodea caliginosa, Soil Biology and Biochemistry 42(2):276-282; and Potthoff et al. 2001 Short-term effects of earthworm activity and straw amendment on the microbial C and N turnover in a remoistened arable soil after summer drought, Soil Biology and Biochemistry 33(4):583-591) we summaries the knowledge on earthworms and priming and come up with a conceptual approach and further research needs.

  11. Effects of Accelerated Soil Erosion on Soil Nutrient Loss After Deforestation on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHENG Fen-Li

    2005-01-01

    Soil erosion and nutrient losses on newly-deforested lands in the Ziwuling Region on the Loess Plateau of China were monitored to quantitatively evaluate the effects of accelerated soil erosion, caused by deforestation, on organic matter,nitrogen and phosphorus losses. Eight natural runoff plots were established on the loessial hill slopes representing different erosion patterns of dominant erosion processes including sheet, rill and shallow gully (similar to ephemeral gully). Sediment samples were collected after each erosive rainfall event. Results showed that soil nutrients losses increased with an increase of erosion intensity. Linear relations between the losses of organic matter, total N, NH4-N, and available P and erosion intensity were found. Nutrient content per unit amount of eroded sediment decreased from the sheet to the shallow gully erosion zones, whereas total nutrient loss increased. Compared with topsoil, nutrients in eroded sediment were enriched,especially available P and NH4-N. The intensity of soil nutrient losses was also closely related to soil erosion intensity and pattern with the most severe soil erosion and nutrient loss occurring in the shallow gully channels on loessial hill slopes.These research findings will help to improve the understanding of the relation between accelerated erosion process after deforestation and soil quality degradation and to design better eco-environmental rehabilitation schemes for the Loess Plateau.

  12. Effect of elevated CO2 on chlorpyriphos degradation and soil microbial activities in tropical rice soil.

    Science.gov (United States)

    Adak, Totan; Munda, Sushmita; Kumar, Upendra; Berliner, J; Pokhare, Somnath S; Jambhulkar, N N; Jena, M

    2016-02-01

    Impact of elevated CO2 on chlorpyriphos degradation, microbial biomass carbon, and enzymatic activities in rice soil was investigated. Rice (variety Naveen, Indica type) was grown under four conditions, namely, chambered control, elevated CO2 (550 ppm), elevated CO2 (700 ppm) in open-top chambers and open field. Chlorpyriphos was sprayed at 500 g a.i. ha(-1) at maximum tillering stage. Chlorpyriphos degraded rapidly from rice soils, and 88.4% of initially applied chlorpyriphos was lost from the rice soil maintained under elevated CO2 (700 ppm) by day 5 of spray, whereas the loss was 80.7% from open field rice soil. Half-life values of chlorpyriphos under different conditions ranged from 2.4 to 1.7 days with minimum half-life recorded with two elevated CO2 treatments. Increased CO2 concentration led to increase in temperature (1.2 to 1.8 °C) that played a critical role in chlorpyriphos persistence. Microbial biomass carbon and soil enzymatic activities specifically, dehydrogenase, fluorescien diacetate hydrolase, urease, acid phosphatase, and alkaline phosphatase responded positively to elevated CO2 concentrations. Generally, the enzyme activities were highly correlated with each other. Irrespective of the level of CO2, short-term negative influence of chlorpyriphos was observed on soil enzymes till day 7 of spray. Knowledge obtained from this study highlights that the elevated CO2 may negatively influence persistence of pesticide but will have positive effects on soil enzyme activities.

  13. Effect of Lanthanum on Major Microbial Populationsin Red Soil

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Pure culture and pot culture experiments were carried out to study theeffect of lanthanum (La) on bacteria, actinomyces and fungus, and somemicrobial physiological groups, nitrifier, azotobacter andphosphobacteria, in a red soil taken form the Ecological ExperimentalStation of Red Soil, the Chinese Academy of Sciences, Jiangxi Province.LaCl{3 was added into media at levels of 0, 25, 50, 100, 150,200, 250 and 500 mg L-1 in the pure culture experiment, and intosoil samples in porcelain pots before rice growing at levels of 0, 6,30, 150, 300, 600 and 900 mg kg-1 dry soil in the pot cultureexperiment. Thepopulations of the three soil microbes in the pure culture experimentdecreased with the addition level of La, indicating that La was toxicto the soil microbes in pure culture, and the sensitivity of the 3major microbial types to La was in a decreasing order ofactinomyces > bacteria > fungus. In the pot experiment, Lahad slightly stimulative effect on soil bacteria and actinomyces whenapplied at low concentrations while had inhibitory effect on soilbacteria, actinomyces and fungus at high concentrations. When theconcentration of La was low, soil azotobacter was stimulated slightlywhile soil nitrifier was stimulated strongly and the maximum increasewas up to 50%. When the concentration of La was high, both soilazotobacter and nitrifier were inhibited, and the inhibition of La tothe nitrifier increased with La concentration. La added at all thelevels had stimulative effect on soil inorganic and organicphosphobacteria. Among the 4 physiological groups, soil nitrifier wasmost sensitive to La, so, it might be reasonable to assume that soilnitrifier was a sensitive indicator for evaluating the biological andenvironmental effects of rare earths.

  14. [Effects of different fertilizer application on soil active organic carbon].

    Science.gov (United States)

    Zhang, Rui; Zhang, Gui-Long; Ji, Yan-Yan; Li, Gang; Chang, Hong; Yang, Dian-Lin

    2013-01-01

    The variation characteristics of the content and components of soil active organic carbon under different fertilizer application were investigated in samples of calcareous fluvo-aquic soil from a field experiment growing winter wheat and summer maize in rotation in the North China Plain. The results showed that RF (recommended fertilization), CF (conventional fertilization) and NPK (mineral fertilizer alone) significantly increased the content of soil dissolved organic carbon and easily oxidized organic carbon by 24.92-38.63 mg x kg(-1) and 0.94-0.58 mg x kg(-1) respectively compared to CK (unfertilized control). The soil dissolved organic carbon content under OM (organic manure) increased greater than those under NPK and single fertilization, soil easily oxidized organic carbon content under OM and NPK increased greater than that under single chemical fertilization. OM and NPK showed no significant role in promoting the soil microbial biomass carbon, but combined application of OM and NPK significantly increased the soil microbial biomass carbon content by 36.06% and 20.69%, respectively. Soil easily oxidized organic carbon, dissolved organic carbon and microbial biomass carbon accounted for 8.41% - 14.83%, 0.47% - 0.70% and 0.89% - 1.20% of the total organic carbon (TOC), respectively. According to the results, the fertilizer application significantly increased the proportion of soil dissolved organic carbon and easily oxidized organic carbon, but there was no significant difference in the increasing extent of dissolved organic carbon. The RF and CF increased the proportion of soil easily oxidized organic carbon greater than OM or NPK, and significantly increased the proportion of microbial biomass carbon. OM or RF had no significant effect on the proportion of microbial biomass carbon. Therefore, in the field experiment, appropriate application of organic manure and chemical fertilizers played an important role for the increase of soil active organic carbon

  15. Variability in the Water Footprint of Arable Crop Production across European Regions

    Directory of Open Access Journals (Sweden)

    Anne Gobin

    2017-02-01

    Full Text Available Crop growth and yield are affected by water use during the season: the green water footprint (WF accounts for rain water, the blue WF for irrigation and the grey WF for diluting agri-chemicals. We calibrated crop yield for FAO’s water balance model “Aquacrop” at field level. We collected weather, soil and crop inputs for 45 locations for the period 1992–2012. Calibrated model runs were conducted for wheat, barley, grain maize, oilseed rape, potato and sugar beet. The WF of cereals could be up to 20 times larger than the WF of tuber and root crops; the largest share was attributed to the green WF. The green and blue WF compared favourably with global benchmark values (R2 = 0.64–0.80; d = 0.91–0.95. The variability in the WF of arable crops across different regions in Europe is mainly due to variability in crop yield ( c v ¯ = 45% and to a lesser extent to variability in crop water use ( c v ¯ = 21%. The WF variability between countries ( c v ¯ = 14% is lower than the variability between seasons ( c v ¯ = 22% and between crops ( c v ¯ = 46%. Though modelled yields increased up to 50% under sprinkler irrigation, the water footprint still increased between 1% and 25%. Confronted with drainage and runoff, the grey WF tended to overestimate the contribution of nitrogen to the surface and groundwater. The results showed that the water footprint provides a measurable indicator that may support European water governance.

  16. Short rotation coppice improve the phosphorus (P) supply of arable land through translocation of P from subsoil to topsoil

    Science.gov (United States)

    Doering, K.; Kaupenjohann, M.

    2011-12-01

    Even if the agricultural use of P will not increase during the next decades, the stock of phosphorous (P) in global mineral deposits is predicted to last for only less than 50 to 100 years. This will cause a much more severe problem than the shortage of fossil energy because P as an element essential to all life is not substitutable through any other material. Thus, efforts have to be made to close the P-cycle and it will in the near future be no more justifiable to disperse P or dump it at places where it cannot be recovered from. Additionally, new resources of P have to be explored to cover increasing P demand and to compensate for inevitable losses. Subsoil, which is hardly explored by arable crops may contain such P reserves. Deep rooting perennial plants like trees have access to these P resources and may be used to introduce subsoil P into the agricultural P cycle. Using literature data we followed the question to what extent the introduction of short rotation coppice of energy - Populus, Salix and Robinia into the agricultural crop rotation could support the P supply to annual food crops. Leaf litter of Populs, Salix and Robinia will transfer 3 to 13, 5 to 12 and 5 to 12 kg P and ha-1 a-1 to the soil surface, respectively. The large variation is mainly explained by site conditions (soil and climate). Assuming that 30 % of the nutrient requirement of the trees is assimilated from the subsoil, 1 to 5 kg of P ha-1 a-1 may be translocated to the topsoil. The knowledge about root content of P of the three tree species is very scarce. Based on information about other broadleaf trees, we consider that root litter may transfer amounts of P to the topsoil similar to leaf litter. Thus, in total the annual translocation of subsoil-P to the topsoil may range between 2 to 10 kg ha-1 in short rotation plantations. These amounts are far below the annual P removal from soils through food crops which may range from 20 to 40 kg P ha-1 a-1. Therefore subsoil P cannot replace P

  17. Temporal and soil management effects on soil infiltration and water content in a hillslope vineyard

    Science.gov (United States)

    Biddoccu, Marcella; Ferraris, Stefano; Cavallo, Eugenio

    2015-04-01

    The maintenance of bare soil in the vineyard's inter-rows with tillage, as well as other mechanized operations which increase the vehicle traffic, expose the soil to degradation, favoring overland flow and further threats as compaction, reduction of soil water holding capacity and water infiltration. Water infiltration is strongly controlled by field-saturated hydraulic conductivity, which depends primarily on soil texture and structure, and it is characterized by high spatial and temporal variability. Beyond the currently adopted soil management, some major causes in variability of infiltration rates are the history of cultivation and the structure of the first centimeters of the vineyard's soil. A study was carried out in two experimental vineyard plots included in the 'Tenuta Cannona Experimental Vine and Wine Centre of Regione Piemonte', located in NW Italy. The study was addressed to evaluate the temporal variations of the field-saturated hydraulic conductivity, in relation to the soil management adopted in the inter-rows of a hillslope vineyard. The investigation was carried out in a vineyard comparing the adoption of two different soil managements in the inter-rows: 1) conventional tillage and 2) controlled grass cover. Several series of double-ring of infiltration tests were carried out during a 2-years period of observation, using the simplified falling head technique (SFH). In order to take into account the effect of tractor traffic, the tests were done both inside the the track, the portion of soil affected by the transit of tractor wheels or tracks, and outside the track. Before the execution of each test, bulk density and initial soil water content close to the investigated area were determined. Relations among infiltration behavior and these parameters were analyzed. Field-saturated hydraulic conductivity (Kfs) at different sampling dates showed high variability, especially in the vineyard with cultivated soil. Indeed, highest infiltration rates were

  18. Influence of Robinia pseudoacacia short rotation coppice on soil physical properties

    Science.gov (United States)

    Xavier, Morvan; Isabelle, Bertrand; Gwenaelle, Gibaud

    2015-04-01

    Human activities can lead to the degradation of soil physical properties. For instance, machinery traffic across the land can induce the development of compacted areas at the wheel tracks. It leads to a decrease in porosity which results in a decrease of the hydraulic conductivity, and therefore, prevents water infiltration and promotes surface runoff. Land use, soil management and soil cover also have a significant influence on soil physical properties (Kodesova et al., 2011). In the arable land, surface runoff and soil erosion are enhanced by the absence of soil cover for part of the year and by the decrease of aggregate stability due to a decline of soil organic matter. In that context, few studies focused on the effects of a Robinia pseudoacacia short rotation coppice (SRC) on soil physical properties. Therefore, this study aims to determine the effect of the conversion of a grassland in a SRC on soil physical properties. These properties have also been compared to those of arable land and natural forest. For that, in several plots of the experimental farm of Grignon (30 km west of Paris, France), different measurements were performed: i) soil water retention on a pressure plate apparatus for 7 water potential between 0 and 1500 kPa, ii) bulk density using the method for gravelly and rocky soil recommended by the USDA, iii) aggregate stability using the method described in Le Bissonnais (1996), and iv) soil hydraulic conductivity using a Guelph permeameter. All these measurements were performed on the same soil type and on different land uses: arable land (AL), grassland (GL), natural forest (NF) and short rotation coppice (SRC) of Robinia pseudoacacia planted 5 years ago. Soil water retention measurements are still under progress and will be presented in congress. Bulk density measurements of the AL, GL and SRC are not significantly different. They ranged from 1.32 to 1.42. Only the NF measurements are significantly lower than the other (0.97). Aggregate

  19. Fate and transport of selected estrogen compounds in Hawaii soils: Effect of soil type and macropores

    Science.gov (United States)

    D'Alessio, Matteo; Vasudevan, Dharni; Lichwa, Joseph; Mohanty, Sanjay K.; Ray, Chittaranjan

    2014-10-01

    The fate and transport of estrogen compounds in the environment is of increasing concern due to their potential impact on freshwater organisms, ecosystems and human health. The behavior of these compounds in batch experiments suggests low mobility, while field studies indicate the persistence of estrogen compounds in the soil with the possibility of migration to surface water as well as groundwater. To better understand the movement of these chemicals through soils, we examined their transport in three different Hawaiian soils and two aqueous matrices. The three different soils used were an Oxisol, a Mollisol and a cinder, characterized by different mineralogical properties and collected at depths of 60-90 cm and 210-240 cm. Two liquid matrices were used; deionized (DI) water containing calcium chloride (CaCl2), and recycled water collected from a wastewater treatment facility. The experiments were conducted in packed and structured columns. Non-equilibrium conditions were observed during the study, especially in the structured soil. This is believed to be primarily related to the presence of macropores in the soil. The presence of macropores resulted in reduced contact time between soil and estrogens, which facilitated their transport. We found that the organic carbon content and mineralogical composition of the soils had a profound effect on the transport of the estrogens. The mobility of estrone (E1) and 17β-estradiol (E2) was greater in cinder than in the other soils. In column experiments with recycled water, earlier breakthrough peaks and longer tails of estrogens were produced compared to those observed using DI water. The use of recycled water for agricultural purposes and the siting of septic tanks and cesspools should be critically reviewed in light of these findings, especially in areas where groundwater is the primary source of potable water, such as Hawaii.

  20. Fate and transport of selected estrogen compounds in Hawaii soils: effect of soil type and macropores.

    Science.gov (United States)

    D'Alessio, Matteo; Vasudevan, Dharni; Lichwa, Joseph; Mohanty, Sanjay K; Ray, Chittaranjan

    2014-10-01

    The fate and transport of estrogen compounds in the environment is of increasing concern due to their potential impact on freshwater organisms, ecosystems and human health. The behavior of these compounds in batch experiments suggests low mobility, while field studies indicate the persistence of estrogen compounds in the soil with the possibility of migration to surface water as well as groundwater. To better understand the movement of these chemicals through soils, we examined their transport in three different Hawaiian soils and two aqueous matrices. The three different soils used were an Oxisol, a Mollisol and a cinder, characterized by different mineralogical properties and collected at depths of 60-90 cm and 210-240 cm. Two liquid matrices were used; deionized (DI) water containing calcium chloride (CaCl2), and recycled water collected from a wastewater treatment facility. The experiments were conducted in packed and structured columns. Non-equilibrium conditions were observed during the study, especially in the structured soil. This is believed to be primarily related to the presence of macropores in the soil. The presence of macropores resulted in reduced contact time between soil and estrogens, which facilitated their transport. We found that the organic carbon content and mineralogical composition of the soils had a profound effect on the transport of the estrogens. The mobility of estrone (E1) and 17β-estradiol (E2) was greater in cinder than in the other soils. In column experiments with recycled water, earlier breakthrough peaks and longer tails of estrogens were produced compared to those observed using DI water. The use of recycled water for agricultural purposes and the siting of septic tanks and cesspools should be critically reviewed in light of these findings, especially in areas where groundwater is the primary source of potable water, such as Hawaii.

  1. A New Mechanism of Canopy Effect in Unsaturated Freezing Soils

    Directory of Open Access Journals (Sweden)

    Teng Jidong

    2016-01-01

    Full Text Available Canopy effect refers to the phenomenon where moisture accumulates underneath an impervious cover. Field observation reveals that canopy effect can take place in relatively dry soils where the groundwater table is deep and can lead to full saturation of the soil immediately underneath the impervious cover. On the other hand, numerical analysis based on existing theories of heat and mass transfer in unsaturated soils can only reproduce a minor amount of moisture accumulation due to an impervious cover, particularly when the groundwater table is relatively deep. In attempt to explain the observed canopy effect in field, this paper proposes a new mechanism of moisture accumulation in unsaturated freezing soils: vapour transfer in such a soil is accelerated by the process of vapour-ice desublimation. A new approach for modelling moisture and heat movements is proposed, in which the phase change of evaporation, condensation and de-sublimation of vapor flow are taken into account. The computed results show that the proposed model can indeed reproduce the unusual moisture accumulation observed in relatively dry soils. The results also demonstrate that soil freezing fed by vapour transfer can result in a water content close to full saturation. Since vapour transfer is seldom considered in geotechnical design, the canopy effect deserves more attention during construction and earth works in cold and arid regions.

  2. Effects of Soil Oxygen Conditions and Soil pH on Remediation of DDT-contaminated Soil by Laccase from White Rot Fungi

    Directory of Open Access Journals (Sweden)

    Yuechun Zhao

    2010-04-01

    Full Text Available High residues of DDT in agricultural soils are of concern because they present serious threats to food security and human health. This article focuses on remediation of DDT-contaminated soil using laccase under different soil oxygen and soil pH conditions. The laboratory experiment results showed significant effects of soil oxygen conditions and soil pH on remediation of DDT-contaminated soil by laccase at the end of a 25-d incubation period. This study found the positive correlation between the concentration of oxygen in soil and the degradation of DDT by laccase. The residue of DDTs in soil under the atmosphere of oxygen decreased by 28.1% compared with the atmosphere of nitrogen at the end of the incubation with laccase. A similar pattern was observed in the remediation of DDT-contaminated soil by laccase under different flooding conditions, the higher the concentrations of oxygen in soil, the lower the residues of four DDT components and DDTs in soils. The residue of DDTs in the nonflooding soil declined by 16.7% compared to the flooded soil at the end of the incubation. The residues of DDTs in soils treated with laccase were lower in the pH range 2.5–4.5.

  3. The Dynamic Change in the Total Arable Land and its Driving Forces in Tongling City of Anhui Province

    Institute of Scientific and Technical Information of China (English)

    Yan; LI; Zhongxiang; YU

    2014-01-01

    According to Anhui Statistical Yearbook( 2003-2012) and the second national land survey data,this article analyzes the current situation of land use and the dynamic change in the total arable land in Tongling City. On the basis of this,using grey relational analysis,this article analyzes the driving forces for arable land changes in Tongling City. Studies show that population growth,the improvement of level of urbanization and the rapid development of the economy are the main driving forces for arable land changes. Based on the findings,the strategies are put forth in order to ensure the dynamic balance of total arable land.

  4. Total Factor Evaluation and Influencing Factor Analysis about Arable Land Productivity In Kaifeng City

    Institute of Scientific and Technical Information of China (English)

    Yongying HUANG; Liutao LIANG

    2016-01-01

    This paper uses DEA and Malmquist index to analyze the changes in arable land productivity in Kaifeng City during 2003- 2012.The results show that during 2003- 2011,Kaifeng’s arable land productivity was inefficient in DEA-terms,indicating that the production resources were not rationally used; in 2012,Kaifeng’s arable land productivity was efficient in DEA-terms,indicating that the ratio of input to output in 2012 was optimal; with the lapse of time,the Malmquist total factor productivity showed a trend of " increase-decrease-increase-decrease-increase",and the average technical efficiency was greater than 1,indicating that the agricultural production technology continues to advance. Using Tobit model,we analyze the factors that affect arable land productivity,and results show that the number of large and medium tractors and policy dummy variable have a significantly positive impact,while grain sown area has a significantly negative impact. Therefore,in order to improve arable land productivity in Kaifeng City,it is necessary to adhere to long-term stable agricultural support policy,improve the technological level of new agricultural modernization,increase investment in agricultural science and technology,and expand the sown area of cash crops.

  5. Effect of corylus clusters on the physicochemical properties of soil

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Soil sample plots were specified and the soil in layer A0, A1 and AB were collected in MaoershanForest Experiment Farm of Northeast Forestry University for study of the effect of corylus clusters on soil in 1999. The result shows that the pH value, contents of organic matter, total nitrogen, alkali-discomposed nitrogen and total phosphorus under the corylus clusters are higher than that under the non-corylus clusters, except the available phosphorus content. The number of soil granular aggregates or the water stable aggregates under corylus clusters is more than that under the non-corylus clusters. The corylus clusters play an important role in improving the physicochemical properties of the soil, which should be conserved and developed in the forestry production.

  6. Effects of Different Types of Sludge on Soil Microbial Properties: A Field Experiment on Degraded Mediterranean Soils

    Institute of Scientific and Technical Information of China (English)

    D.TARRAS(O)N; G.OJEDA; O.ORTIZ; J.M.ALCA(N)IZ

    2010-01-01

    T The recycling of suitable organic wastes can enhance soil fertility via effects on soil physical, chemical and biological properties. To compare the effects of digested (DS), thermally dried (TDS) and composted dewatered (CDS) sewage sludge on soil microbiological properties, an experiment was conducted at field sites for more than one year (401 d) when applied to two Mediterranean degraded soils (loam and loamy sand soils). All three types of sewage sludge had a significant effect on measured parameters. In a short time, the plots of both loamy sand and loam soils amended with TDS showed the highest microbial basal respiration (loam soil: P < 0.01; loamy sand soil: P < 0.001) and carbon mineralization coefficient (loam soil: P < 0.01; loamy sand soil: P < 0.001). Furthermore, on loamy sand soil, the plots amended with TDS showed the highest microbial metabolic quotient (qCO2) (P < 0.05). This study revealed that the addition of sludge caused transient non-equilibrium effects on almost all soil microbial properties. However, there were no differences one year later because the remaining organic carbon was stable and quite similar in all treatments. These results may have practical implications for the rehabilitation of degraded soils.

  7. Effects of land-cover change on soil loss in the Sao Gabriel do Oeste area (Pantanal, Mato Grosso do Sul, Brazil)

    Science.gov (United States)

    Disperati, Leonardo; Righini, Gaia; Salvini, Riccardo; Ciali, Alessandro; Coscini, Nicola; Fantozzi, Pier L.; Carmignani, Luigi; Fiori, Alberto P.; Paranhos Filho, Antonio C.; Bocci, Michele

    1999-12-01

    In the Sao Gabriel do Oeste area (Pantanal, Brazil), since the '60s, zootechnics and farming activities have developed and arable lands and pastures replaced shrubs and forests. The 1966 to 1996 land-cover change was investigated through Remote Sensing and GIS methodologies. The effect on soil loss was evaluated through the Universal Soil Loss Equation (USLE). By integrating supervised classification and visual interpretation techniques, geo-coded land-cover data bases were built from aerial photographs and Landsat TM images (years 1966, 1985, 1996). Multi-temporal land-cover data bases were produced through 'post-classification comparison.' The application of the USLE in the ARC/INFO$CPY Grid environment enabled to perform the multi-temporal analysis of the potential soil loss. The R, K, C and P factors of such equation were assumed from the literature. The flowdirection and flowaccumulation Grid functions and the DEM allowed calculating the L and S factors. The results show that from 1966 to 1985 large extent of forest and shrubs were deforested. After 1985, deforestation rate decreased and part of burnt areas and pastures changed to secondary forest. The land-cover transformations induced a meaningful growth of the computed average soil loss per unit area (A) from 1966 to 1985 ((Delta) A approximately equals 3.7 t(DOT)ha-1(DOT)y-1). On the contrary, the reduction of A from 1985 to 1996 ((Delta) A approximately equals 0.8 t(DOT)ha-1(DOT)y-1) suggests that more recently the human impact became steady.

  8. Updating soil CO2 emission experiments to assess climate change effects and extracellular soil respiration

    Science.gov (United States)

    Vidal Vazquez, Eva; Paz Ferreiro, Jorge

    2014-05-01

    Experimental work is an essential component in training future soil scientists. Soil CO2 emission is a key issue because of the potential impacts of this process on the greenhouse effect. The amount of organic carbon stored in soils worldwide is about 1600 gigatons (Gt) compared to 750 Gt in the atmosphere mostly in the form of CO2. Thus, if soil respiration increased slightly so that just 10% of the soil carbon pool was converted to CO2, atmospheric CO2 concentrations in the atmosphere could increase by one-fifth. General circulation model predictions indicate atmosphere warming between 2 and 5°C (IPCC 2007) and precipitation changes ranging from about -15 to +30%. Traditionally, release of CO2 was thought to occur only in an intracellular environment; however, recently CO2 emissions have been in irradiated soil, in the absence of microorganisms (Maire et al., 2013). Moreover, soil plays a role in the stabilization of respiration enzymes promoting CO2 release after microorganism death. Here, we propose to improve CO2 emission experiments commonly used in soil biology to investigate: 1) effects of climatic factors on soil CO2 emissions, and 2) rates of extracellular respiration in soils and how these rates are affected by environmental factors. Experiment designed to assess the effect of climate change can be conducted either in field conditions under different ecosystems (forest, grassland, cropland) or in a greenhouse using simple soil chambers. The interactions of climate change in CO2 emissions are investigated using climate-manipulation experiment that can be adapted to field or greenhouse conditions (e.g. Mc Daniel et al., 2013). The experimental design includes a control plot (without soil temperature and rain manipulation) a warming treatment as well as wetting and/or drying treatments. Plots are warmed to the target temperature by procedures such as infrared heaters (field) or radiant cable (greenhouse). To analyze extracellular respiration, rates of CO2

  9. Legacy effects of grassland management on soil carbon to depth.

    Science.gov (United States)

    Ward, Susan E; Smart, Simon M; Quirk, Helen; Tallowin, Jerry R B; Mortimer, Simon R; Shiel, Robert S; Wilby, Andrew; Bardgett, Richard D

    2016-08-01

    The importance of managing land to optimize carbon sequestration for climate change mitigation is widely recognized, with grasslands being identified as having the potential to sequester additional carbon. However, most soil carbon inventories only consider surface soils, and most large-scale surveys group ecosystems into broad habitats without considering management intensity. Consequently, little is known about the quantity of deep soil carbon and its sensitivity to management. From a nationwide survey of grassland soils to 1 m depth, we show that carbon in grassland soils is vulnerable to management and that these management effects can be detected to considerable depth down the soil profile, albeit at decreasing significance with depth. Carbon concentrations in soil decreased as management intensity increased, but greatest soil carbon stocks (accounting for bulk density differences), were at intermediate levels of management. Our study also highlights the considerable amounts of carbon in subsurface soil below 30 cm, which is missed by standard carbon inventories. We estimate grassland soil carbon in Great Britain to be 2097 Tg C to a depth of 1 m, with ~60% of this carbon being below 30 cm. Total stocks of soil carbon (t ha(-1) ) to 1 m depth were 10.7% greater at intermediate relative to intensive management, which equates to 10.1 t ha(-1) in surface soils (0-30 cm), and 13.7 t ha(-1) in soils from 30 to 100 cm depth. Our findings highlight the existence of substantial carbon stocks at depth in grassland soils that are sensitive to management. This is of high relevance globally, given the extent of land cover and large stocks of carbon held in temperate managed grasslands. Our findings have implications for the future management of grasslands for carbon storage and climate mitigation, and for global carbon models which do not currently account for changes in soil carbon to depth with management.

  10. pH is the primary determinant of the bacterial community structure in agricultural soils impacted by polycyclic aromatic hydrocarbon pollution

    Science.gov (United States)

    Wu, Yucheng; Zeng, Jun; Zhu, Qinghe; Zhang, Zhenfa; Lin, Xiangui

    2017-01-01

    Acidification and pollution are two major threats to agricultural ecosystems; however, microbial community responses to co-existed soil acidification and pollution remain less explored. In this study, arable soils of broad pH (4.26–8.43) and polycyclic aromatic hydrocarbon (PAH) gradients (0.18–20.68 mg kg‑1) were collected from vegetable farmlands. Bacterial community characteristics including abundance, diversity and composition were revealed by quantitative PCR and high-throughput sequencing. The bacterial 16S rRNA gene copies significantly correlated with soil carbon and nitrogen contents, suggesting the control of nutrients accessibility on bacterial abundance. The bacterial diversity was strongly related to soil pH, with higher diversity in neutral samples and lower in acidic samples. Soil pH was also identified by an ordination analysis as important factor shaping bacterial community composition. The relative abundances of some dominant phyla varied along the pH gradient, and the enrichment of a few phylotypes suggested their adaptation to low pH condition. In contrast, at the current pollution level, PAH showed marginal effects on soil bacterial community. Overall, these findings suggest pH was the primary determinant of bacterial community in these arable soils, indicative of a more substantial influence of acidification than PAH pollution on bacteria driven ecological processes.

  11. Testosterone sorption and desorption: Effects of soil particle size

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Yong, E-mail: yqi01@unomaha.edu [Civil Engineering Dept., University of Nebraska-Lincoln at Omaha Campus, Omaha, NE 68182 (United States); Zhang, Tian C. [Civil Engineering Dept., University of Nebraska-Lincoln at Omaha Campus, Omaha, NE 68182 (United States); Ren, Yongzheng [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-08-30

    Graphical abstract: - Highlights: • Smaller soil particles have higher sorption and lower desorption rates. • The sorption capacity ranks as clay > silt > sand. • Small particles like clays have less potential for desorption. • Colloids (clays) have high potential to facilitate the transport of hormones in soil–water environments. - Abstract: Soils contain a wide range of particles of different diameters with different mobility during rainfall events. Effects of soil particles on sorption and desorption behaviors of steroid hormones have not been investigated. In this study, wet sieve washing and repeated sedimentation methods were used to fractionate the soils into five ranges. The sorption and desorption properties and related mechanisms of testosterone in batch reactors filled with fractionated soil particles were evaluated. Results of sorption and desorption kinetics indicate that small soil particles have higher sorption and lower desorption rates than that of big ones. Thermodynamic results show the sorption processes are spontaneous and exothermal. The sorption capacity ranks as clay > silt > sand, depending mainly on specific surface area and surface functional groups. The urea control test shows that hydrogen bonding contributes to testosterone sorption onto clay and silt but not on sand. Desorption tests indicate sorption is 36–65% irreversible from clay to sand. Clays have highest desorption hysteresis among these five soil fractions, indicating small particles like clays have less potential for desorption. The results provide indirect evidence on the colloid (clay)-facilitated transport of hormones (micro-pollutants) in soil environments.

  12. [Effects of different type urban forest plantations on soil fertility].

    Science.gov (United States)

    Sun, Hui-zhen; Chen, Ming-yue; Cai, Chun-ju; Zhu, Ning

    2009-12-01

    Aimed to study the effects of different urban forest plantations on soil fertility, soil samples were collected from eight mono-cultured plantations (Larix gmelinii, Pinus sylvestris var. mongolica, Pinus tabulaeformis var. mukdensis, Phellodendron amurense, Juglans mandshurica, Fraxinus mandshurica, Betula platyphylla, and Quercus mongolica) and one mixed plantation (P. sylvestris var. mongolica + F. mandshurica + Picea koraiensis + P. amurense + B. platyphylla) established in Northeast Forestry University's Urban Forestry Demonstration Research Base in the 1950s, with two sites of neighboring farmland and abandoned farmland as the control. The soils in broadleaved forest plantations except Q. mongolica were near neutral, those in mixed plantation, L. gmelinii, P. sylvestris var. mongolica, and P. tabulaeformis var. mukdensis were slightly acidic, and that in Q. mongolica was acidic. The contents of soil organic matter, total N and P, available P and K, and hydrolysable N tended to decrease with soil depth. There existed significant differences in the chemical indices of the same soil layers among different plantations. The soil fertility was decreased in the order of F. mandshurica > P. amurense > mixed plantation > J. mandshurica > B. platyphylla > abandoned farmland > farmland > P. sylvestris var. mongolica > L. gmelinii > Q. mongolica > P. tabulaeformis var. mukdensis, suggesting that the soil fertility in broadleaved forest plantations except Q. mongolica and in mixed plantation increased, while that in needle-leaved forest plantations tended to decrease.

  13. Laboratory-Measured Rainfall Effects on LWIR Soil Reflectance

    Science.gov (United States)

    Howington, S. E.; Ballard, J., Jr.; Wilhelms, S.

    2012-12-01

    The long-wave infrared reflectance of soils will often have distinct spectral characteristics that depend on the soil's physical and spectral properties. Rainfall has the effect of sorting soil particles at the ground surface, thus changing its long-wave infrared reflectance. This study examines how rainfall alters the measured directional-hemispherical thermal infrared (8-14 μm) spectral reflectance by comparing disturbed soil with undisturbed soil and pre-rain with post-rain conditions. The study uses a soil with a specified sand/silt ratio and a calibrated, laboratory rainfall simulator. For an accumulated rainfall of 8 cm, the mean disturbed soil thermal infrared spectral reflectance within 8.1 - 9.2 μm waveband increases from an initial reflectance of 13 percent to a maximum reflectance of 31 percent. Sixty percent of this reflectance change occurred with only 1 cm accumulated rainfall. This study shows that, for this described disturbed sand/silt soil mixture, small accumulated rainfall amounts significantly alter the directional-hemispherical thermal infrared spectral reflectance.

  14. Effect of manure on glyphosate and trifluralin mineralization in soil.

    Science.gov (United States)

    Reimer, M; Farenhorst, A; Gaultier, J

    2005-01-01

    Manure additions to soil may alter soil chemical, physical, and biological characteristics, and thereby change pesticide fate processes in soil. This is the first study to examine the impact of liquid hog manure amendments on glyphosate and trifluralin mineralization in soil. Experiments were conducted in soil microcosms in the laboratory for a total of 332 (glyphosate) and 430 (trifluralin) days. The rate and amount of mineralization of both glyphosate and trifluralin were significantly influenced by the additions of fresh manure to soil in the laboratory and by the history of manure applications in the field. However, the maximum difference in herbicide mineralization between soils that were free of manure application and those amended with manure in the field or in the laboratory was only 6.1% and 7.3% of that initially applied, for trifluralin and glyphosate, respectively. Therefore, we conclude that liquid hog manure application to soil will have no significant effect on the mineralization of glyphosate and trifluralin under field conditions.

  15. Seasonal Effect of Geomorphological Chronosequence Features on Soil Biota Dynamics

    Institute of Scientific and Technical Information of China (English)

    S.PEN-MOURATOV; N.GENZER; N.SHUKUROV; J.PLAKHT; Y.STEINBERGER

    2010-01-01

    Numerous studies have been devoted to the physical-chemical weathering processes leading to the creation of unique soil formations having their own history that induce soil-biotic diversity.However,the extent to which unique geomorphic formations influence soil biotic seasonal variation is not clear.Our aim was to define seasonal variations of soil biota in soils of different-aged terraces of the Makhtesh Ramon anticline erosional cirque in southern Israel.The strong effect of Makhtesh Ramon(Ramon crater)erosional fluvial terrace age initiated by climatic changes during the Late Pleistocene-Early Holocene period on seasonal variations in both soil properties and the abundance and composition of soil biota were demonstrated.However,age dependence was not constant and values for observed soil properties and microbial activity were negligible between younger and older terraces for certain seasons,while free-living nematodes along with bacterial-feeding group were strongly dependent on the geomorphic features of the ages throughout the study period.

  16. RUSLE2015: Modelling soil erosion at continental scale using high resolution input layers

    Science.gov (United States)

    Panagos, Panos; Borrelli, Pasquale; Meusburger, Katrin; Poesen, Jean; Ballabio, Cristiano; Lugato, Emanuele; Montanarella, Luca; Alewell, Christine

    2016-04-01

    estimated that the policy interventions (i.e. reduced tillage, crop residues, grass margins, cover crops, stone walls and contouring) through the common agricultural policy (CAP) during last decade have reduced the rate of soil loss in the EU by an average of 9.5% overall, and by 20% for arable lands (NATURE, 526, 195). Latest developments in RUSLE2015 allow to incorporate the forthcoming intensification of rainfall (climate changes) and land use changes such as afforestation, land abandonment and arable land expansion. Recently, a module of CENTURY model was coupled with the RUSLE2015 for estimating the effect of erosion in current carbon balance in European agricultural lands.

  17. [Effect of temperature on methane production and oxidation in soils].

    Science.gov (United States)

    Ding, Weixin; Cai, Zucong

    2003-04-01

    The influence of temperature and its mechanism on methane production and oxidation in soils were reviewed in this paper. Temperature can alter the soil ability to produce methane through changing types of dominant methanogens in archaeal community. Dominant methanogen is Methanosarcinaceae at higher temperature which can utilize both H2/CO2 and acetate as the precursor to produce methane, while Methanosaetaceae at lower temperature which only use acetate as the precursor and produce far less methane than do Methanosarcinaceae. Increasing soil temperature apparently raises soil ability to produce methane, which is called temperature effectiveness and expressed as Q10 with a range from 1.5 to 28 and an average of 4.1. There is an obviously positive correlation between temperature effectiveness (Q10) on methane production and substrate content. As compared to methane production, effect of temperature on methane oxidation is lower, which may be related to the strong affinity of methanotrophs for methane.

  18. Nitrogen Deposition Effects on Soil Carbon Dynamics in Temperate Forests

    DEFF Research Database (Denmark)

    Ginzburg Ozeri, Shimon

    Soils contain the largest fraction of terrestrial carbon (C). Understanding the factors regulating the decomposition and storage of soil organic matter (SOM) is essential for predictions of the C sink strength of the terrestrial environment in the light of global change. Elevated long-term nitrogen...... (N) deposition into forest ecosystems has been increasing globally and was hypothesized to raise soil organic C (SOC) stocks by increasing forest productivity and by reducing SOM decomposition. Yet, these effects of N deposition on forest SOC stocks are uncertain and largely based on observations...... edges were used to study the effects of varying N deposition load on SOC stocks and fluxes as well as on the temperature sensitivity of SOM respiration. In a third study, the effects of 20 years of continuous experimental N addition (35 kg N ha-1 year-1) on soil C budget were investigated. Our general...

  19. Dry heat effects on survival of indigenous soil particle microflora and particle viability studies of Kennedy Space Center soil

    Science.gov (United States)

    Ruschmeyer, O. R.; Pflug, I. J.; Gove, R.; Heisserer, Y.

    1975-01-01

    Research efforts were concentrated on attempts to obtain data concerning the dry heat resistance of particle microflora in Kennedy Space Center soil samples. The in situ dry heat resistance profiles at selected temperatures for the aggregate microflora on soil particles of certain size ranges were determined. Viability profiles of older soil samples were compared with more recently stored soil samples. The effect of increased particle numbers on viability profiles after dry heat treatment was investigated. These soil particle viability data for various temperatures and times provide information on the soil microflora response to heat treatment and are useful in making selections for spacecraft sterilization cycles.

  20. Prediction of soil organic carbon concentration and soil bulk density of mineral soils for soil organic carbon stock estimation

    Science.gov (United States)

    Putku, Elsa; Astover, Alar; Ritz, Christian

    2016-04-01

    Soil monitoring networks provide a powerful base for estimating and predicting nation's soil status in many aspects. The datasets of soil monitoring are often hierarchically structured demanding sophisticated data analyzing methods. The National Soil Monitoring of Estonia was based on a hierarchical data sampling scheme as each of the monitoring site was divided into four transects with 10 sampling points on each transect. We hypothesized that the hierarchical structure in Estonian Soil Monitoring network data requires a multi-level mixed model approach to achieve good prediction accuracy of soil properties. We used this database to predict soil bulk density and soil organic carbon concentration of mineral soils in arable land using different statistical methods: median approach, linear regression and mixed model; additionally, random forests for SOC concentration. We compared the prediction results and selected the model with the best prediction accuracy to estimate soil organic carbon stock. The mixed model approach achieved the best prediction accuracy in both soil organic carbon (RMSE 0.22%) and bulk density (RMSE 0.09 g cm-3) prediction. Other considered methods under- or overestimated higher and lower values of soil parameters. Thus, using these predictions we calculated the soil organic carbon stock of mineral arable soils and applied the model to a specific case of Tartu County in Estonia. Average estimated SOC stock of Tartu County is 54.8 t C ha-1 and total topsoil SOC stock 1.8 Tg in humus horizon.

  1. Effect of different fertilizer application on the soil fertility of paddy soils in red soil region of southern China.

    Directory of Open Access Journals (Sweden)

    Wenyi Dong

    Full Text Available Appropriate fertilizer application is an important management practice to improve soil fertility and quality in the red soil regions of China. In the present study, we examined the effects of five fertilization treatments [these were: no fertilizer (CK, rice straw return (SR, chemical fertilizer (NPK, organic manure (OM and green manure (GM] on soil pH, soil organic carbon (SOC, total nitrogen (TN, C/N ratio and available nutrients (AN, AP and AK contents in the plowed layer (0-20 cm of paddy soil from 1998 to 2009 in Jiangxi Province, southern China. Results showed that the soil pH was the lowest with an average of 5.33 units in CK and was significantly higher in NPK (5.89 units and OM (5.63 units treatments (P<0.05. The application of fertilizers have remarkably improved SOC and TN values compared with the CK, Specifically, the OM treatment resulted in the highest SOC and TN concentrations (72.5% and 51.2% higher than CK and NPK treatment increased the SOC and TN contents by 22.0% and 17.8% compared with CK. The average amounts of C/N ratio ranged from 9.66 to 10.98 in different treatments, and reached the highest in OM treatment (P<0.05. During the experimental period, the average AN and AP contents were highest in OM treatment (about 1.6 and 29.6 times of that in the CK, respectively and second highest in NPK treatment (about 1.2 and 20.3 times of that in the CK. Unlike AN and AP, the highest value of AK content was observed in NPK treatments with 38.10 mg·kg(-1. Thus, these indicated that organic manure should be recommended to improve soil fertility in this region and K fertilizer should be simultaneously applied considering the soil K contents. Considering the long-term fertilizer efficiency, our results also suggest that annual straw returning application could improve soil fertility in this trial region.

  2. Effects of sodium hypochlorite and high pH buffer solution in electrokinetic soil treatment on soil chromium removal and the functional diversity of soil microbial community.

    Science.gov (United States)

    Cang, Long; Zhou, Dong-Mei; Alshawabkeh, Akram N; Chen, Hai-Feng

    2007-04-02

    Effects of sodium hypochlorite (NaClO), applied as an oxidant in catholyte, and high pH buffer solution on soil Cr removal and the functional diversity of soil microbial community during enhanced electrokinetic treatments of a chromium (Cr) contaminated red soil are evaluated. Using pH control system to maintain high alkalinity of soil together with the use of NaClO increased the electrical conductivities of soil pore liquid and electroosmotic flux compared with the control (Exp-01). The pH control and NaClO improved the removal of Cr(VI) and total Cr from the soil. The highest removal percentages of soil Cr(VI) and total Cr were 96 and 72%, respectively, in Exp-04 when the pH value of the anolyte was controlled at 10 and NaClO was added in the catholyte. The alkaline soil environment and introduction of NaClO in the soil enhanced the desorption of Cr(VI) from the soil and promoted Cr(III) oxidation to mobile Cr(VI), respectively. However, the elevated pH and introduction of NaClO in the soil, which are necessary for improving the removal efficiency of soil Cr, resulted in a significantly adverse impact on the functional diversity of soil microbial community. It suggests that to assess the negative impact of extreme conditions for enhancing the extraction efficiencies of Cr on the soil properties and function is necessary.

  3. Effects of sodium hypochlorite and high pH buffer solution in electrokinetic soil treatment on soil chromium removal and the functional diversity of soil microbial community

    Energy Technology Data Exchange (ETDEWEB)

    Cang Long [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Zhou Dongmei [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)]. E-mail: dmzhou@issas.ac.cn; Alshawabkeh, Akram N. [Department of Civil and Environmental Engineering, Northeastern University, Boston, MA (United States); Chen Haifeng [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

    2007-04-02

    Effects of sodium hypochlorite (NaClO), applied as an oxidant in catholyte, and high pH buffer solution on soil Cr removal and the functional diversity of soil microbial community during enhanced electrokinetic treatments of a chromium (Cr) contaminated red soil are evaluated. Using pH control system to maintain high alkalinity of soil together with the use of NaClO increased the electrical conductivities of soil pore liquid and electroosmotic flux compared with the control (Exp-01). The pH control and NaClO improved the removal of Cr(VI) and total Cr from the soil. The highest removal percentages of soil Cr(VI) and total Cr were 96 and 72%, respectively, in Exp-04 when the pH value of the anolyte was controlled at 10 and NaClO was added in the catholyte. The alkaline soil environment and introduction of NaClO in the soil enhanced the desorption of Cr(VI) from the soil and promoted Cr(III) oxidation to mobile Cr(VI), respectively. However, the elevated pH and introduction of NaClO in the soil, which are necessary for improving the removal efficiency of soil Cr, resulted in a significantly adverse impact on the functional diversity of soil microbial community. It suggests that to assess the negative impact of extreme conditions for enhancing the extraction efficiencies of Cr on the soil properties and function is necessary.

  4. The effect of soil properties on the toxicity of silver to the soil nitrification process.

    Science.gov (United States)

    Langdon, Kate A; McLaughlin, Mike J; Kirby, Jason K; Merrington, Graham

    2014-05-01

    Silver (Ag) is being increasingly used in a range of consumer products, predominantly as an antimicrobial agent, leading to a higher likelihood of its release into the environment. The present study investigated the toxicity of Ag to the nitrification process in European and Australian soils in both leached and unleached conditions. Overall, leaching of soils was found to have a minimal effect on the final toxicity data, with an average leaching factor of approximately 1. Across the soils, the toxicity was found to vary by several orders of magnitude, with concentrations of Ag causing a 50% reduction in nitrification relative to the controls (EC50) ranging from 0.43 mg Ag/kg to >640 mg Ag/kg. Interestingly, the dose-response relationships in most of the soils showed significant stimulation in nitrification at low Ag concentrations (i.e., hormesis), which in some cases produced responses up to double that observed in the controls. Soil pH and organic carbon were the properties found to have the greatest influence on the variations in toxicity thresholds across the soils, and significant relationships were developed that accounted for approximately 90% of the variability in the data. The toxicity relationships developed from the present study will assist in future assessment of potential Ag risks and enable the site-specific prediction of Ag toxicity.

  5. Degree of saturation effect on the grout-soil interface shear strength of soil nailing

    Directory of Open Access Journals (Sweden)

    Wang Qiong

    2016-01-01

    Full Text Available In the grouted soil nailing system, the bonding strength of cement grout-soil interface offers the required resistance to maintain the stability of whole structure. In practice, soil nailing applications are often placed at unsaturated conditions, such as soil slopes, shallow foundations, retaining walls and pavement structures. In these cases, the water content in the soil nail zone may increase or decrease due to rain water or dry weather, and even cannot become saturated during their design service life. In this study, the effect of water content (degree of saturation on the shear strength of interface between cement grout and sand are experimentally investigated by means of direct shear test. Meanwhile the water retention curve was determined and interface microstructure was observed. Experimental results show that the shear strength of interface changes non-monotonously with degree of saturation when the interface was prepared, due to the non-monotonousness of the cohesiveness between soil particles. The less the cohesiveness between sand particles, the more grout was observed been penetrated into the voids, and thus the larger the interface shear stress.

  6. EFFECT OF SOIL SOLARIZATION ON THERMAL REGIME OF PLASTIC GREENHOUSE SOIL

    Directory of Open Access Journals (Sweden)

    Nereu Augusto Streck

    1994-01-01

    Full Text Available SUMMARY Temperature modification in soil of plastic greenhouse caused by solarization was measured during the summer in the Subtropical Central Region of the Rio Grande do Sul State, Brazil. The experiment was carried out in a 10m x 25m greenhouse covered with low density transparent polyethylene (PE. Four 6m x 4m plots were mulched with 100µm thickness PE sheets, from December 12, 1992 to March 7, 1993. Four other plots (same size without the cover were used as control (bare soil. Results indicated that solarization incrased the maximum soil temperature. The average was 11.9, 10.8, 9.8, and 8.6°C over uncovered control soil at 2, 5, 10, and 20cm depth, respectively. The soil temperature reached values of up to 54.4°C at 2cm and 50.2°C at 5cm depth. Temperatures exceeding 45°C and 50°C in solarized soil have also occurred in several days. "Edge effect" in mulched plots was also detected.

  7. Effect of pH and soil structure on transport of sulfonamide antibiotics in agricultural soils.

    Science.gov (United States)

    Park, Jong Yol; Huwe, Bernd

    2016-06-01

    We investigated the effect of solution pH and soil structure on transport of sulfonamide antibiotics (sulfamethoxazole, sulfadimethoxine and sulfamethazine) in combination with batch sorption tests and column experiments. Sorption isotherms properly conformed to Freundlich model, and sorption potential of the antibiotics is as follows; sulfadimethoxine > sulfamethoxazole > sulfamethazine. Decreasing pH values led to increased sorption potential of the antibiotics on soil material in pH range of 4.0-8.0. This likely resulted from abundance of neutral and positive-charged sulfonamides species at low pH, which electrostatically bind to sorption sites on soil surface. Due to destruction of macropore channels, lower hydraulic conductivities of mobile zone were estimated in the disturbed soil columns than in the undisturbed soil columns, and eventually led to lower mobility of the antibiotics in disturbed column. The results suggest that knowledge of soil structure and solution condition is required to predict fate and distribution of sulfonamide antibiotics in environmental matrix.

  8. Effects of heavy metal pollution on soil microbial biomass

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    This paper reviews the effects of heavy metals on microbial biomass in metal-polluted soils. Laboratory and field investigations where metals were applied ass inorganic or organic salts demonstrated a significant decline in the size of s oil microbial biomass. In most of the cases, negative effects were evident at metal concentrations below the European Community's (EC) current permissible metal levels in the soil. Application of metal-enriched sludges and composts caused significant inhibition of microbial biomass at surprisingly modest concentrations of metals in the soil that were indeed smaller than those likely to decrease the growth of sensitive crop species. On the whole, relative toxicity of metals decreased in the order of Cd>Cu>Zn>Pb, but a few exceptions to this trend also existed. A significant decline in the biomass carbon to organic carbon ratio(Cmin/Corg) in metal-polluted soils indicated that this parameter can serve as a good indicator of the toxicity of metals on soil microflora. The knowledge regarding the response of soil biota to metal interactions and the factors affecting metal toxicity to soil microorganisms is still very limited and warrants further study.

  9. Atrazine degradation and enzyme activities in an agricultural soil under two tillage systems.

    Science.gov (United States)

    Mahía, Jorge; Martín, Angela; Carballas, Tarsy; Díaz-Raviña, Montserrat

    2007-05-25

    The content of atrazine and its metabolites (hydroxyatrazine, deethylatrazine and deisopropylatrazine) as well as the activities of two soil enzymes (urease and beta-glucosidase) were evaluated in an acid agricultural soil, located in a temperate humid zone (Galicia, NW Spain), with an annual ryegrass-maize rotation under conventional tillage (CT) and no tillage (NT). Samples were collected during two consecutive years from the arable layer at two depths (0-5 cm and 5-20 cm) and different times after atrazine application. Hydroxyatrazine and deisopropylatrazine were the main metabolites resulting from atrazine degradation in the acid soil studied, the highest levels being detected in the surface layer of the NT treatment. A residual effect of atrazine was observed since hydroxyatrazine was detected in the arable layer (0-5 cm, 5-20 cm) even one year after the herbicide application. Soil enzyme activities in the upper 5 cm layer under NT were consistently higher than those in the same layer under CT. Urease and beta-glucosidase activities decreased with depth in the profile under NT but they did not show any differences between the two depths for the plots under CT. For both tillage systems enzyme activities also reflected temporal changes during the maize cultivation; however, no consistent effect of the herbicide application was observed.

  10. Fate and effects of veterinary antibiotics in soil.

    Science.gov (United States)

    Jechalke, Sven; Heuer, Holger; Siemens, Jan; Amelung, Wulf; Smalla, Kornelia

    2014-09-01

    Large amounts of veterinary antibiotics are applied worldwide to farm animals and reach agricultural fields by manure fertilization, where they might lead to an increased abundance and transferability of antibiotic-resistance determinants. In this review we discuss recent advances, limitations, and research needs in determining the fate of veterinary antibiotics and resistant bacteria applied with manure to soil, and their effects on the structure and function of soil microbial communities in bulk soils and the rhizosphere. The increased abundance and mobilization of antibiotic-resistance genes (ARGs) might contribute to the emergence of multi-resistant human pathogens that increasingly threaten the successful antibiotic treatment of bacterial infections.

  11. Tillage effects on topsoil structural quality assessed using X-ray CT, soil cores and visual soil evaluation

    DEFF Research Database (Denmark)

    Garbout, Amin; Munkholm, Lars Juhl; Hansen, Søren Baarsgaard

    2013-01-01

    Soil structure plays a key role in the ability of soil to fulfil essential functions and services in relation to, e.g., root growth, gas and water transport and organic matter turnover. The objective of this paper was: (1) To quantify tillage effects on soil structural quality in the entire topsoil...

  12. Soil ecology and agricultural technology; An integrated approach towards improved soil management for sustainable farming

    Science.gov (United States)

    Pulleman, Mirjam; Pérès, Guénola; Crittenden, Stephen; Heddadj, Djilali; Sukkel, Wijnand

    2014-05-01

    Intensive arable food production systems are in need of smart solutions that combine ecological knowledge and farm technology to maximize yields while protecting natural resources. The huge diversity of soil organisms and their interactions is of crucial importance for soil functions and ecosystem services, such as organic matter incorporation and break down, nutrient mineralization, soil structure formation, water regulation and disease and pest control. Soil management decisions that take into account the soil biodiversity and associated functions are thus essential to (i) maintain soil productivity in the long term, (ii) reduce the dependency on external inputs and non-renewables such as fossil fuels, and (iii) make agroecosystems more resilient against biotic and abiotic stresses. Organic farming systems and reduced tillage systems are two approaches that aim to increase soil biodiversity and general soil quality, through improved management of organic matter but differ in their emphasis on the use of chemical inputs for crop protection or soil disturbance, respectively. In North-western Europe experience with and knowledge of reduced tillage systems is still scarce, both in conventional and organic farming. Our study targeted both conventional and organic farming and aimed at 1) documenting reduced tillage practices within different agroecological contexts in NW Europe; 2) evaluating the effects of reduced tillage systems on soil biodiversity and soil ecosystem services; 3) increase understanding of agroecological factors that determine trade-offs between different ecosystem services. Earthworm species and nematode taxa were selected as indicator organisms to be studied for their known response to soil management and effects on soil functions. Additionally, soil organic matter, physical soil parameters and processes, and crop yields have been measured across multiple sites. Data have been collected over several cropping seasons in long term field experiments

  13. Space Weathering in the Fine Size Fractions of Lunar Soils: Soil Maturity Effects

    Science.gov (United States)

    Keller, L. P.; Wentworth, S. J.; McKay, D. S.; Taylor, L. A.; Pieters, C.; Morris, R. V.

    1999-01-01

    The effects of space weathering on the optical properties of lunar materials have been well documented. These effects include a reddened continuum slope, lowered albedo, and attenuated absorption features in reflectance spectra of lunar soils as compared to finely comminuted rocks from the same Apollo sites. However, the regolith processes that cause these effects are not well known, nor is the petrographic setting of the products of these processes fully understood. A Lunar Soil Characterization Consortium has been formed with the purpose of systematically integrating chemical and mineralogical data with the optical properties of lunar soils. Understanding space-weathering effects is critical in order to fully integrate the lunar sample collection with remotely-sensed data from recent robotic missions (e.g., Lunar Prospector, Clementine, and Galileo) We have shown that depositional processes (condensation of impact-derived vapors, sputter deposits, accreted impact material, e.g., splash glass, spherules, etc.) are a major factor in the modification of the optical surfaces of lunar regolith materials. In mature soils, it is the size and distribution of the nanophase metal in the soil grains that has the major effect on optical properties. In this report, we compare and contrast the space-weathering effects in an immature and a mature soil with similar elemental compositions. For this study, we analyzed effects). The nanophase Fe in these rims probably accounts for a significant fraction of the increase in Is/FeO measured in these size fractions. In addition to the rims, the majority of particles also show abundant accreted material in the form of glass splashes and spherules that also contain nanophase Fe. In stark contrast, the surfaces of the mineral grains in the 71061 sample are relatively prisitine, as only about 14% of the mineral grains in the sample exhibited amorphous rims. Furthermore, the mineral particles are more angular and show greater surface

  14. Global Change Effects on Plant-Soil Interactions

    DEFF Research Database (Denmark)

    Dam, Marie

    Global change is expected to increasingly affect composition and functioning of soil communities. In terrestrial ecosystems, the plant-soil interactions will be of particular importance for the ecosystem response, including feed-back responses that may further increase climate change. The aim...... are able to determine effects of global change on the plant-soil system. By extraction and microscopy of nematode communities, we are able to characterize the trophic structure of a significant part of the rhizosphere community. The work compiled for this dissertation is based on field experiments...... effects. Furthermore, the plant functional type (shrub or grass) is more strongly determining the rhizosphere community structure than any global change factor. Frequent burning of prairie vegetation changes the soil community to an extent that alters the decomposition rate. Together, these results...

  15. Soil biota community structure and abundance under agricultural intensification and extensification.

    Science.gov (United States)

    Postma-Blaauw, Maria B; de Goede, Ron G M; Bloem, Jaap; Faber, Jack H; Brussaard, Lijbert

    2010-02-01

    Understanding the impacts of agricultural intensification and extensification on soil biota communities is useful in order to preserve and restore biological diversity in agricultural soils and enhance the role of soil biota in agroecosystem functioning. Over four consecutive years, we investigated the effects of agricultural intensification and extensification (including conversion of grassland to arable land and vice versa, increased and decreased levels of mineral fertilization, and monoculture compared to crop rotation) on major soil biota group abundances and functional diversity. We integrated and compared effects across taxonomic levels to identify sensitive species groups. Conversion of grassland to arable land negatively affected both abundances and functional diversity of soil biota. Further intensification of the cropping system by increased fertilization and reduced crop diversity exerted smaller and differential effects on different soil biota groups. Agricultural intensification affected abundances of taxonomic groups with larger body size (earthworms, enchytraeids, microarthropods, and nematodes) more negatively than smaller-sized taxonomic groups (protozoans, bacteria, and fungi). Also functional group diversity and composition were more negatively affected in larger-sized soil biota (earthworms, predatory mites) than in smaller-sized soil biota (nematodes). Furthermore, larger soil biota appeared to be primarily affected by short-term consequences of conversion (disturbance, loss of habitat), whereas smaller soil biota were predominantly affected by long-term consequences (probably loss of organic matter). Reestablishment of grassland resulted in increased abundances of soil biota groups, but since not all groups increased in the same measure, the community structure was not completely restored. We concluded that larger-sized soil biota are more sensitive to agricultural intensification than smaller-sized soil biota. Furthermore, since larger

  16. Effect of pineapple cropping on soil chemical and physical changes in Tha-yang soil series, Petchaburi province

    OpenAIRE

    Isuwan, A.

    2007-01-01

    The experiment was conducted to investigate the effect of pineapple cropping on chemical and physical property changes of Tha-yang soil series, located on Tumbon Nong-ya-plong, Amphor Nong-yaplong,Petchaburi province. The experimental treatments were the different pineapple cropping soil ages arranged in a completely randomized design, consisting of undisturbed soil (year 0) and pineapple croppingsoil ages of 1, 4 and 8 years with 4 replications each. Soil samples were separated according to ...

  17. Effects of cadium, zinc and lead on soil enzyme activities

    Institute of Scientific and Technical Information of China (English)

    YANG Zhi-xin; LIU Shu-qing; ZHENG Da-wei; FENG Sheng-dong

    2006-01-01

    Heavy metal (HM) is a major hazard to the soil-plant system. This study investigated the combined effects of cadium (Cd),zinc (Zn) and lead (Pb) on activities of four enzymes in soil, including calatase, urease, invertase and alkalin phosphatase. HM content in tops of canola and four enzymes activities in soil were analyzed at two months after the metal additions to the soil. Pb was not significantly inhibitory than the other heavy metals for the four enzyme activities and was shown to have a protective role on calatase activity in the combined presence of Cd, Zn and Pb; whereas Cd significantly inhibited the four enzyme activities, and Zn only inhibited urease and calatase activities. The inhibiting effect of Cd and Zn on urease and calatase activities can be intensified significantly by the additions of Zn and Cd. There was a negative synergistic inhibitory effect of Cd and Zn on the two enzymes in the presence of Cd, Zn and Pb. The urease activity was inhibited more by the HM combinations than by the metals alone and reduced approximately 20%-40% of urease activity. The intertase and alkaline phosphatase activities significantly decreased only with the increase of Cd concentration in the soil. It was shown that urease was much more sensitive to HM than the other enzymes. There was a obvious negative correlation between the ionic impulsion of HM in soil, the ionic impulsion of HM in canola plants tops and urease activity. It is concluded that the soil urease activity may be a sensitive tool for assessing additive toxic combination effect on soil biochemical parameters.

  18. Effects of soil acidification and liming on the phytoavailability of cadmium in paddy soils of central subtropical China.

    Science.gov (United States)

    Zhu, Hanhua; Chen, Cheng; Xu, Chao; Zhu, Qihong; Huang, Daoyou

    2016-12-01

    Intensive and paired soil and rice grain survey and multiple-field liming experiments were conducted to assess soil acidification in the past 30 years, quantify the relationships of Cd phytoavailability with soil acidity, and determine efficacies of liming on soil acidity and Cd phytoavailability in paddy soils of central subtropical China at a regional scale. Soil pH, total and extractable Cd (Cdtot and Cdext), rice grain Cd were determined, and all measured data were analyzed separately in groups of 0.1 pH units intervals. Paddy soil pH averagely declined at 0.031 unit yr(-1) between 1980s and 2014 (P soil pH 4.0 and 5.5 and around -1.31 between pH 6.9 and 7.3, whereas linearly decreased by a factor of 0.76 with pH 5.5-6.9, and by a factor of 1.38 with pH 7.3-8.2 (P soil pH were observed for soil Cdext to Cdtot ratio. However, the former exhibited a lag effect to soil acidification in the acidic soils and a leading effect in alkaline soils. Liming increased soil pH by 0.50 units, and decreased rice grain Cd by 35.3% and log Cd transfer ratio by a factor of 0.76 (P soil acidification occurred and accelerated in the past 30 years, and piecewise-linearly increased Cd phytoavailability of paddy soils in central subtropical China. Mitigating soil acidification, i.e. liming, should be preferentially implemented to minimize Cd phytoavailability.

  19. Long-term effects of soil management practices on selected indicators of chemical soil quality

    Directory of Open Access Journals (Sweden)

    Alicja Pecio

    2016-06-01

    Full Text Available The study was conducted in scope of Catch-C project “Compatibility of agricultural management practices and types of farming in the EU to enhance climate change mitigation and soil health” (7FP, realized in 2012–2014 by the consortium of partners from 10 European countries (http://www.catch-c.eu. This work reports the effects of soil management practices – under different soil and climatic conditions – on the selected soil chemical quality indicators, based on the analysis of data extracted from literature on long term experiments (LTEs in Europe, as well as from LTEs held by the Catch-C consortium partners. The dataset related to soil chemical quality indicators consisted of 1044 records and referred to 59 long-term trials. The following indicators of chemical soil quality were analyzed: pH, N total content, N total stock, C:N ratio, N mineral content, P and K availability. They are the most frequently used indicators in the European literature on long-term experiments collected in the Catch-C project database. Soil organic carbon, however, the most important indicator was not presented here, due to it was covered by a separate study on indicators for climate change mitigation. The indicators were analyzed using their response ratio (RR to a management practice. For a given treatment (management practice, this ratio was calculated as the quotient between the indicator value obtained in the treatment, and the indicator value in the reference treatment. The examples were: rotation (with cereals, with legume crops, with tuber or root crops, with grassland vs. adequate monoculture, catch/cover crops vs. no catch/cover crops, no-tillage and no-inversion tillage vs. conventional tillage, mineral fertilization vs. no fertilization, organic fertilization (compost, farmyard manure, slurry vs. mineral fertilization at the same available nitrogen input, crop residue incorporation vs. removal. All tested practices influenced soil chemical quality

  20. [Effects of colistin sulfate residue on soil microbial community structure].

    Science.gov (United States)

    Ma, Yi; Peng, Jin-Ju; Chen, Jin-Jun; Fan, Ting-Li; Sun, Yong-Xue

    2014-06-01

    By using fumigation extraction and phospholipid fatty acid (PLFA) methods, the change of characteristics of soil microbial community structure caused by residue of colistin sulfate (CS) was studied. The results showed that the CS (w(cs) > or = 5 mg x kg(-1)) had a significant effect on the microbial biomass carbon (MBC) and it was dose-dependent where MBC decreased with the increase of CS concentration in soil. The MBC in soil decreased by 52. 1% when the CS concentration reached 50 mg x kg(-1). The total PLFA of soil in each CS treatment was significantly decreased during the sampling period compared with the control group and showed a dose-dependent relationship. The soil microbial community structure and diversity in the low CS group (w(cs) = 0.5 mg x kg(-1)) were not significantly different from the control group on 7th and 49th day. However, they were significantly different on 21st and 35th day especially in the high CS group (w(cs) = 50 mg x kg(-1)). It was concluded that CS could change the structure of soil microorganisms and varied with time which might be caused by the chemical conversion and degradation of CS in soil.

  1. Changes in soil toxicity by phosphate-aided soil washing: effect of soil characteristics, chemical forms of arsenic, and cations in washing solutions.

    Science.gov (United States)

    Jho, Eun Hea; Im, Jinwoo; Yang, Kyung; Kim, Young-Jin; Nam, Kyoungphile

    2015-01-01

    This study was set to investigate the changes in the toxicity of arsenic (As)-contaminated soils after washing with phosphate solutions. The soil samples collected from two locations (A: rice paddy and B: forest land) of a former smelter site were contaminated with a similar level of As. Soil washing (0.5 M phosphate solution for 2 h) removed 24.5% As, on average, in soil from both locations. Regardless of soil washing, Location A soil toxicities, determined using Microtox, were greater than that of Location B and this could be largely attributed to different soil particle size distribution. With soils from both locations, the changes in As chemical forms resulted in either similar or greater toxicities after washing. This emphasizes the importance of considering ecotoxicological aspects, which are likely to differ depending on soil particle size distribution and changes in As chemical forms, in addition to the total concentration based remedial goals, in producing ecotoxicologically-sound soils for reuse. In addition, calcium phosphate used as the washing solution seemed to contribute more on the toxic effects of the washed soils than potassium phosphate and ammonium phosphate. Therefore, it would be more appropriate to use potassium or ammonium phosphate than calcium phosphate for phosphate-aided soil washing of the As-contaminated soils.

  2. The effect of heterogeneity and surface roughness on soil hydrophobicity

    Science.gov (United States)

    Hallin, I.; Bryant, R.; Doerr, S. H.; Douglas, P.

    2010-05-01

    Soil water repellency, or hydrophobicity, can develop under both natural and anthropogenic conditions. Forest fires, vegetation decomposition, microbial activity and oil spills can all promote hydrophobic behaviour in surrounding soils. Hydrophobicity can stabilize soil organic matter pools and decrease evapotranspiration, but there are many negative impacts of hydrophobicity as well: increased erosion of topsoil, an increasingly scarce resource; increased runoff, which can lead to flooding; and decreased infiltration, which directly affects plant health. The degree of hydrophobicity expressed by soil can vary greatly within a small area, depending partly on the type and severity of the disturbance as well as on temporal factors such as water content and microbial activity. To date, many laboratory investigations into soil hydrophobicity have focused on smooth particle surfaces. As a result, our understanding of how hydrophobicity develops on rough surfaces of macro, micro and nano-particulates is limited; we are unable to predict with certainty how these soil particles will behave on contact with water. Surface chemistry is the main consideration when predicting hydrophobic behaviour of smooth solids, but for particles with rough surfaces, hydrophobicity is believed to develop as a combination of surface chemistry and topography. Topography may reflect both the arrangement (aggregation) of soil particles and the distribution of materials adsorbed on particulate surfaces. Patch-wise or complete coverage of rough soil particles by hydrophobic material may result in solid/water contact angles ≥150° , at which point the soil may be classified as super-hydrophobic. Here we present a critical review of the research to date on the effects of heterogeneity and surface roughness on soil hydrophobicity in which we discuss recent advances, current trends, and future research areas. References: Callies, M., Y. Chen, F. Marty, A. Pépin and D. Quéré. 2005. Microfabricated

  3. Effect of land-use changes and site variables on surface soil organic carbon pool at Mediterranean Region

    Science.gov (United States)

    Abu-hashim, Mohamed; Elsayed, Mohamed; Belal, Abd-ElAziz

    2016-02-01

    Soil organic carbon pool (SOCP) is affected by several factors particularly soil type, climate, topography, crop management, and anthropogenic factors. The study was carried out to clarify relationships between SOCP under different soil types and land-use changes in the Mediterranean region. Data of 26 pedons were investigated in Tanta catchment, middle Nile Delta, Egypt (30°45 N, 30°55 E), that the collected soil samples covered different soil types and land-uses. There were significant differences of SOCP among soils: loam and clay loams were rather similar. Clay soils were the most extensive and have mean SOCP of 4.08 ± 1.41 kg C m-2. The highest SOCP of 7.07 kg C m-2 was in clay loam soil associated with bare soil, while the lowest of 2.57 kg C m-2 in sandy clay loam soil associated with bare soil. Losing cropland showed highest increase from 1990 to 2015 with increasing urban encroachment by 15.3%. The overall average results of SOCP in cropland area showed 53.85 Mg C ha-1 under different soils. Losing the arable lands to urbanization resulted in a decrease of 285.421 Gg C of SOCP. With the decrease in SOCP sequestrated within the soil surface, carbon dioxide would be emitted to the atmosphere. The emitted CO2 resulted from losing the cropland equal to 1047.5 Gg CO2. Land-use changes have marked impact on surface SOCP and C sequestration.

  4. Modeling Air Permeability in Variably Saturated Soil from Two Natural Clay Gradients

    DEFF Research Database (Denmark)

    Chamindu, Deepagoda T K K; Arthur, Emmanuel; Møldrup, Per

    2013-01-01

    Understanding soil–gas phase properties and processes is important for finding solutions to critical environmental problems such as greenhouse gas emissions and transport of gaseous-phase contaminants in soils. Soil–air permeability, ka (μm2), is the key parameter governing advective gas movement...... in soil and is controlled by soil physical characteristics representing soil texture and structure. Models predicting ka as a function of air-filled porosity (ɛ) often use a reference-point measurement, for example, ka,1000 at ɛ1000 (where the measurement is done at a suction of –1000 cm H2O). Using ka...... measurements from two Danish arable fields, each located on natural clay gradients, this study presents a pore tortuosity–disconnectivity analysis to characterize the soil–gas phase. The main objective of this study is to investigate the effect of soil–moisture condition, clay content, and other potential...

  5. Effects of phosphate on the adsorption of glyphosate on three different types of Chinese soils

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-jun; ZHOU Dong-mei; SUN Rui-juan

    2005-01-01

    Glyphosate (GPS) is a non-selective, post-mergence herbicide that is widely used throughout the world. Due to the similar molecular structures of glyphosate and phosphate, adsorption of glyphosate on soil is easily affected by coexisting phosphate, especially when phosphate is applied at a significant rate in farmland. This paper studied the effects of phosphate on the adsorption of glyphosate on three different types of Chinese soils including two variable charge soils and one permanent charge soil. The results indicated that Freundlich equations used to simulate glyphosate adsorption isotherms gave high correlation coefficients(0.990-0.998) with K values of 2751, 2451 and 166 for the zhuanhong soil(ZH soil, Laterite), red soil(RS, Udic Ferrisol) and Wushan paddy soil(WS soil, Anthrosol),respectively. The more the soil iron and aluminum oxides and clay contained, the more glyphosate adsorbed. The presence of phosphate significantly decreased the adsorption of glyphosate to the soils by competing with glyphosate for adsorption sites of soils. Meanwhile, the effects of phosphate on adsorption of glyphosate on the two variable charge soils were more significant than that on the permanent charge soil. When phosphate and glyphosate were added in the soils in different orders, the adsorption quantities of glyphosate on the soils were different, which followed GPS-soil>GPS-P-soil = GPS-soil-P > P-soil-GPS, meaning a complex interaction occurred among glyphosate,phosphate and the soils.

  6. Visualization and quantification of archaeal and bacterial metabolically active cells in soil using fluorescence in situ hybridization method

    Science.gov (United States)

    Semenov, Mikhail; Manucharova, Natalia; Stepanov, Alexey

    2015-04-01

    cells due to plowing was detected only within 40 cm soil layer, and this effect disappeared in lower horizons. The abundance of Archaea was higher in the upper horizons of arable soil as compared to virgin. Conversely, the abundance of Bacteria in the upper layers of arable Kastanozem decreased versus virgin soil. A relationship between soil organic carbon and the amount of soil metabolically active Bacteria and Archaea cells revealed that distribution of both Bacteria and Archaea throughout the soil profile was governed mostly by the organic matter content. Thus, the organic matter was a main factor of declining the Bacteria:Archaea ratio with the soil depth (from 7.1 to 4.2 for virgin soil and from 5 to 3.9 for arable soil). As a result, Archaea out-compete Bacteria under conditions of reduced energy supply. Thus, the FISH method combines classical microscopic and modern phylogenetic microbiological approaches and can be considered as an effective tool for ecological, diagnostic and environmental research in microbiology.

  7. Effect of Electrolytes on Surface Charge Characteristics of Red Soils

    Institute of Scientific and Technical Information of China (English)

    SHAOZONG-CHEN; HEQUN; 等

    1992-01-01

    The zero point of charge (ZPC) and the remaining charge σp at ZPC are two important parameters characterizing surface charge of red soils.Fourteen red soil samples of different soil type and parent material were treated with dithionite-citrate-dicarbonate (DCB) and Na2CO3 respectively.ZPC and σp of the samples in three indifferent electrolytes (NaCl,Na2SO4,and NaH2PO4) were determined.Kaolinite was used as reference.The results showed that ZPC of red soils was affected by the composition of parent materials and clay minerals and in significantly positive correlation with the content of total iron oxide (Fet),free iron oxide (Fed),amorphous iron oxide (Feo),aluminum oxide (Alo) and clay,but it was negatively correlated with the content of total silica (Sit).The σp of red soils was also markedly influenced by mineral components.Organic components were also contributing factor to the value of σp.The surface charges of red soils were evidently affected by the constitution of the electrolytes.Specific adsorption of anions in the electrolytes tended to make the ZPC of red soils shift to a higher pH value and to increase positive surface charges of the soils,thus leading to change of the σp value and decrease of the remaining net negative charges,even to the soils becoming net positive charge carriers.The effect of phosphate anion was greater than that of sulfate ion.

  8. Influence of reduced tillage on earthworm and microbial communities under organic arable farming

    NARCIS (Netherlands)

    Kuntz, M.; Berner, A.; Gattinger, A.; Scholberg, J.M.S.; Mäder, P.; Pfiffner, L.

    2013-01-01

    Although reduced tillage is an agricultural practice reported to decrease soil erosion and external inputs while enhancing soil fertility, it has still rarely been adopted by European organic farmers. The objective of this study was to assess the long-term interactive effects of tillage (conventiona

  9. Contrasting effects of repeated summer drought on soil carbon efflux in hydric and mesic heathland soils

    NARCIS (Netherlands)

    Sowerby, A.; Emmett, B.A.; Tietema, A.; Beier, C.

    2008-01-01

    Current predictions of climate change include altered rainfall patterns throughout Europe, continental USA and areas such as the Amazon. The effect of this on soil carbon efflux remains unclear although several modelling studies have highlighted the potential importance of drought for carbon storage

  10. Oilseed Radish (Raphanus Sativus) Effects on Soil Structure and Soil Water Relations

    Science.gov (United States)

    Oilseed radish (Raphanus sativus spp. oleifera) reduces nematode populations. Fall-incorporated radish biomass may also improve soil physical and hydraulic properties to increase the yield and quality of subsequently grown sugarbeet (Beta vulgaris L.). This field study determined radish effects on...

  11. The effect of environmental conditions and soil physicochemistry on phosphate stabilisation of Pb in shooting range soils.

    Science.gov (United States)

    Sanderson, Peter; Naidu, Ravi; Bolan, Nanthi

    2016-04-01

    The stabilisation of Pb in the soil by phosphate is influenced by environmental conditions and physicochemical properties of the soils to which it is applied. Stabilisation of Pb by phosphate was examined in four soils under different environmental conditions. The effect of soil moisture and temperature on stabilisation of Pb by phosphate was examined by measurement of water extractable and bioaccessible Pb, sequential fractionation and X-ray absorption spectroscopy. The addition of humic acid, ammonium nitrate and chloride was also examined for inhibition or improvement of Pb stability with phosphate treatment. The effect of moisture level varied between soils. In soil MB and DA a soil moisture level of 50% water holding capacity was sufficient to maximise stabilisation of Pb, but in soil TV and PE reduction in bioaccessible Pb was inhibited at this moisture level. Providing moisture at twice the soil water holding capacity did not enhance the effect of phosphate on Pb stabilisation. The difference of Pb stability as a result of incubating phosphate treated soils at 18 °C and 37 °C was relatively small. However wet-dry cycles decreased the effectiveness of phosphate treatment. The reduction in bioaccessible Pb obtained was between 20 and 40% with the most optimal treatment conditions. The reduction in water extractable Pb by phosphate was substantial regardless of incubation conditions and the effect of different temperature and soil moisture regimes was not significant. Selective sequential extraction showed phosphate treatment converted Pb in fraction 1 (exchangeable, acid and water soluble) to fraction 2 (reducible). There were small difference in fraction 4 (residual) Pb and fraction 1 as a result of treatment conditions. X-ray absorption spectroscopy of stabilised PE soil revealed small differences in Pb speciation under varying soil moisture and temperature treatments. The addition of humic acid and chloride produced the greatest effect on Pb speciation in

  12. The Effect on Soil Erosion of Different Tillage Applications

    Science.gov (United States)

    Gür, Kazım

    2016-04-01

    The Effects on Soil Erosion of Different Tillage Applications Kazım Gür1, Kazim Çarman2 and Wim M.Cornelis3 1Bahri Daǧdaş International Agricultural Research Instıtute, 42020 Konya, Turkey 2Faculty of Agriculture, Department of Agricultural Machinery, University of Selçuk, 42031 Konya, Turkey 3Department of Soil Management, Faculty of Bioscience Engineering, Ghent University, 653 Coupure Links, 9000 Gent, Belgium Traditional soil cultivation systems, with excessive and inappropriate soil tillage, will generally lead to soil degradation and loss of soil by wind erosion. Continuous reduced tillage and no-till maintaining soil cover with plant residues called Conservation Agriculture that is considered as effective in reducing erosion. There exist a wide variety of practices using different tools that comply with reduced tillage principles. However, few studies have compared the effect of several of such tools in reducing wind erosion and related soil and surface properties. We therefore measured sediment transport rates over bare soil surfaces (but with under stubbles of wheat, Triticum aestivum L.) subjected to three tillage practices using two pulling type machines and one type of power takeoff movable machines and generated with a portable field wind tunnel. At 10 ms-1, sediment transport rates varied from 107 to 573 gm-1h-1, and from 176 to 768 gm-1h-1 at 13 ms-1. The lowest transport rates were observed for N(no-tillage) and the highest for Rr(L-type rototiller). After tillage, surface roughness, mean weighted diameter, wind erodible fraction, mechanical stability and soil water content were measured as well and varied from 5.0 to 15.9%, 6.9 to 13.8 mm, 14.3 to 29.7%, 79.5 to 93.4% and 8.6 to 15.1%, respectively, with again N is being the most successful practice. In terms of conservation soil tillage technique, it can be said that the applications compared with each other; direct sowing machine is more appropriate and cause to the less erosion.

  13. Sustainability of soil fertility and the use of lignocellulosic crop harvest residues for the production of biofuels: a literature review.

    Science.gov (United States)

    Reijnders, L

    2013-01-01

    Use of lignocellulosic crop harvest residues for liquid or gaseous biofuel production may impact soil quality, long-term soil fertility and the major determinants of the latter, stocks of soil organic carbon and nutrients. When soil organic carbon stocks of mineral cropland soils are to be maintained, there is scope for the removal of lignocellulosic harvest residues in several systems with much reduced tillage or no tillage. The scope for such removal might be increased when suitably treated residues from the conversion of harvest residues into biofuel are returned to cropland soils. For mineral cropland soils under conventional tillage, the scope for the production of liquid biofuels from harvest residues is likely to be less than in the case of no-till systems. When fertility of cropland soils is to be sustainable, nutrients present in suitably treated biofuel production residues have to be returned to these soils. Apparently, the actual return of carbon and nutrients present in residues of biofuel production from crop harvest residues to arable soils currently predominantly concerns the application of digestates of anaerobic digestion. The effects thereof on soil fertility and quality need further clarification. Further clarification about the effects on soil fertility and quality of chars and of co-products of lignocellulosic ethanol production is also needed.

  14. Tillage System and Cover Crop Effects on Soil Quality

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Munkholm, Lars Juhl

    2014-01-01

    Information about the quantitative effect of conservation tillage combined with a cover crop on soil structure is still limited. This study examined the effect of these management practices on soil pore characteristics of a sandy loam soil in a long-term field trial. The tillage treatments (main...... plots) included direct drilling (D), harrowing to a depth of 8 to 10 cm (H), and moldboard plowing (MP). The cover crop treatments were subplot with cover crop (+CC) and without cover crop (−CC). Minimally disturbed soil cores were taken from the 4- to 8-, 12- to 16-, and 18- to 27-cm depth intervals...... in the spring of 2012 before cultivation. Soil water retention and air permeability were measured for matric potentials ranging from −1 to −30 kPa. Gas diffusivity was measured at −10 kPa. Computed tomography (CT) scanning was also used to characterize soil pore characteristics. At the 4- to 8- and 18- to 27-cm...

  15. What is the effect of soil use on ant communities?

    Science.gov (United States)

    Schmidt, Fernando A; Diehl, Elena

    2008-01-01

    Studies on ant communities in agroecosystems have contributed to the knowledge of the effect of agricultural activities on biological communities. The aim of this study is to explain the effect of soil use on ant communities. We tested the hypothesis that there was a decrease in ant species richness and a change in the species composition at habitats with more intense soil use. We collected ants using sardine baits, subterranean traps and direct sampling at four habitats with different soil use (secundary forest, Acacia forestry, initial stage of succession and mixed crops). The ant species richness did not decrease with intensity of soil use. In successional habitat the species numbers collected using sardine baits and subterranean traps were significantly different. Species composition of communities had a pronounced variation, with the epigaeic and hypogaeic ant faunas of the habitat with high intense soil use (mixed crops) had low similarity with ant communities of the three other habitats. The predator species were restricted to habitats with low intensity of soil use. Then, species composition could better reflect the functional changes on ant communities than species richness. Our data can help to choose the component of ant community that better reflect the response of biodiversity to agricultural impacts.

  16. Treated wastewater irrigation effects on soil hydraulic conductivity and aggregate stability of loamy soils in Israel

    Directory of Open Access Journals (Sweden)

    Schacht Karsten

    2015-03-01

    Full Text Available The use of treated wastewater (TWW for agricultural irrigation becomes increasingly important in water stressed regions like the Middle East for substituting fresh water (FW resources. Due to elevated salt concentrations and organic compounds in TWW this practice has potential adverse effects on soil quality, such as the reduction of hydraulic conductivity (HC and soil aggregate stability (SAS. To assess the impact of TWW irrigation in comparison to FW irrigation on HC, in-situ infiltration measurements using mini disk infiltrometer were deployed in four different long-term experimental orchard test sites in Israel. Topsoil samples (0-10 cm were collected for analyzing SAS and determination of selected soil chemical and physical characteristics.

  17. Thermal properties of soils: effect of biochar application

    Science.gov (United States)

    Usowicz, Boguslaw; Lukowski, Mateusz; Lipiec, Jerzy

    2014-05-01

    Thermal properties (thermal conductivity, heat capacity and thermal diffusivity) have a significant effect on the soil surface energy partitioning and resulting in the temperature distribution. Thermal properties of soil depend on water content, bulk density and organic matter content. An important source of organic matter is biochar. Biochar as a material is defined as: "charcoal for application as a soil conditioner". Biochar is generally associated with co-produced end products of pyrolysis. Many different materials are used as biomass feedstock for biochar, including wood, crop residues and manures. Additional predictions were done for terra preta soil (also known as "Amazonian dark earth"), high in charcoal content, due to adding a mixture of charcoal, bone, and manure for thousands of years i.e. approximately 10-1,000 times longer than residence times of most soil organic matter. The effect of biochar obtained from the wood biomass and other organic amendments (peat, compost) on soil thermal properties is presented in this paper. The results were compared with wetland soils of different organic matter content. The measurements of the thermal properties at various water contents were performed after incubation, under laboratory conditions using KD2Pro, Decagon Devices. The measured data were compared with predictions made using Usowicz statistical-physical model (Usowicz et al., 2006) for biochar, mineral soil and soil with addition of biochar at various water contents and bulk densities. The model operates statistically by probability of occurrence of contacts between particular fractional compounds. It combines physical properties, specific to particular compounds, into one apparent conductance specific to the mixture. The results revealed that addition of the biochar and other organic amendments into the soil caused considerable reduction of the thermal conductivity and diffusivity. The mineral soil showed the highest thermal conductivity and diffusivity

  18. [Effects of phytase transgenic corn planting on soil nematode community].

    Science.gov (United States)

    Zhao, Zong-Chao; Su, Ying; Mou, Wen-Ya; Liu, Man-Qiang; Chen, Xiao-Yun; Chen, Fa-Jun

    2014-04-01

    A healthy soil ecosystem is essential for nutrient cycling and energy conversion, and the impact of exogenous genes from genetically modified crops had aroused wide concerns. Phytase transgenic corn (i. e., the inbred line BVLA430101) was issued a bio-safety certificate on 27 September 2009 in China, which could improve the efficiency of feed utilization, reduce environmental pollution caused by animal manure. In this study, the abundance of trophic groups, community structure and ecological indices of soil nematodes were studied over the growing cycle of phytase transgenic corn (ab. transgenic corn) and control conventional parental corn (ab. control corn) in the field. Totally 29 and 26 nematode genera were isolated from transgenic corn and control corn fields, respectively. The abundances of bacterivores and omnivores-predators, the total number of soil nematodes, and the Shannon index (H) were significantly greater under transgenic corn than under control corn, while the opposite trend was found for the relative abundance of herbivores and the maturity index (Sigma MI) of soil nematodes. Repeated-measures analysis of variance (ANOVA) did not detect any significant effects of transgenic corn on the composition and abundance of nematode trophic groups and ecological indices of soil nematodes. Furthermore, the Student-T test showed that the abundances of bacterivores and omnivores-predators and the total number of soil nematodes during the milk-ripe stage were significant higher in the transgenic corn field than in the control corn field. The effects of transgenic corn planting on soil nematodes might be related to the increase in the nitrogen content of field soil under transgenic corn compared to control corn.

  19. Drainage and leaching dynamics in a cropped hummocky soil landscape with erosion-affected pedogenesis

    Science.gov (United States)

    Gerke, Horst H.; Rieckh, Helene; Sommer, Michael

    2016-04-01

    Hummocky soil landscapes are characterized by 3D spatial patterns of soil types that result from erosion-affected pedogenesis. Due to tillage and water erosion, truncated profiles have been formed at steep and mid slopes and colluvial soils at hollows. Pedogenetic variations in soil horizons at the different hillslope positions suggested feedback effects between erosion affected soil properties, the water balances, and the crop growth and leaching rates. Water balance simulations compared uniform with hillslope position-specific crop and root growths for soils at plateau, flat mid slope, steep slope, and hollow using the Hydrus-1D program. The boundary condition data were monitored at the CarboZALF-D experimental field site, which was cropped with perennial lucerne (Medicago sativa L.) in 2013 and 2014. Crop and root growth was assumed proportional to observed leaf area index (LAI). Fluxes of dissolved organic and inorganic carbon (DOC, DIC) were obtained from simulated water fluxes and measured DOC and DIC concentrations. For the colluvic soil, the predominately upward flow led to a net input in DIC and DOC. For the truncated soils at steep slopes, a reduced crop growth caused an relative increase in drainage, suggesting an accelerated leaching, which in the long term could accelerate the soil development and more soil variations along eroding hillslopes in arable soil landscapes.

  20. Potential ecological risk assessment and predicting zinc accumulation in soils.

    Science.gov (United States)

    Baran, Agnieszka; Wieczorek, Jerzy; Mazurek, Ryszard; Urbański, Krzysztof; Klimkowicz-Pawlas, Agnieszka

    2017-02-22

    The aims of this study were to investigate zinc content in the studied soils; evaluate the efficiency of geostatistics in presenting spatial variability of zinc in the soils; assess bioavailable forms of zinc in the soils and to assess soil-zinc binding ability; and to estimate the potential ecological risk of zinc in soils. The study was conducted in southern Poland, in the Malopolska Province. This area is characterized by a great diversity of geological structures and types of land use and intensity of industrial development. The zinc content was affected by soil factors, and the type of land use (arable lands, grasslands, forests, wastelands). A total of 320 soil samples were characterized in terms of physicochemical properties (texture, pH, organic C content, total and available Zn content). Based on the obtained data, assessment of the ecological risk of zinc was conducted using two methods: potential ecological risk index and hazard quotient. Total Zn content in the soils ranged from 8.27 to 7221 mg kg(-1) d.m. Based on the surface semivariograms, the highest variability of zinc in the soils was observed from northwest to southeast. The point sources of Zn contamination were located in the northwestern part of the area, near the mining-metallurgical activity involving processing of zinc and lead ores. These findings were confirmed by the arrangement of semivariogram surfaces and bivariate Moran's correlation coefficients. The content of bioavailable forms of zinc was between 0.05 and 46.19 mg kg(-1) d.m. (0.01 mol dm(-3) CaCl2), and between 0.03 and 71.54 mg kg(-1) d.m. (1 mol dm(-3) NH4NO3). Forest soils had the highest zinc solubility, followed by arable land, grassland and wasteland. PCA showed that organic C was the key factor to control bioavailability of zinc in the soils. The extreme, very high and medium zinc accumulation was found in 69% of studied soils. There is no ecological risk of zinc to living organisms in the study area, and in 90

  1. Pile-soil stress ratio in bidirectionally reinforced composite ground by considering soil arching effect

    Institute of Scientific and Technical Information of China (English)

    邹新军; 杨眉; 赵明华; 杨小礼

    2008-01-01

    To discuss the soil arching effect on the load transferring model and sharing ratios by the piles and inter-pile subsoil in the bidirectionally reinforced composite ground, the forming mechanism, mechanical behavior and its effect factors were discussed in detail. Then, the unified strength theory was introduced to set up the elastoplastic equilibrium differential equation of the subsoil under the limit equilibrium state. And from the equation, the solutions were derived with the corresponding formulas presented to calculate the earth pressure over and beneath the horizontal reinforced cushion or pillow, the stress of inter-pile subsoil and the pile-soil stress ratio. Based on the obtained solutions and measured data from an engineering project, the influence rules by the soil property parameters (i.e., the cohesion c and internal friction angle φ) and pile spacing on the pile-soil stress ratio n were discussed respectively. The results show that to improve the load sharing ratio by the piles, the more effective means for filling materials with a larger value of φ is to increase the ratio of pile cap size to spacing, while to reduce the pile spacing properly and increase the value of cohesion c is advisable for those filling materials with a smaller value of φ.

  2. Effect of Soil Sampling Density on Detected Spatial Variability of Soil Organic Carbon in a Red Soil Region of China

    Institute of Scientific and Technical Information of China (English)

    YU Dong-Sheng; ZHANG Zhong-Qi; YANG Hao; SHI Xue-Zheng; TAN Man-Zhi; SUN Wei-Xia; WANG Hong-Jie

    2011-01-01

    Spatial variability of soil organic carbon (SOC) of different land use patterns and soil types was examined in a county-wide red soil region of South China, using six sampling densities, 14, 34, 68, 130, 255, and 525 samples designed by the method of grid sampling in 6 different grid sizes, labeled as D14, D34, D68, D130, D255, and D525, respectively. The results showed that the coefficients of variation (CVs) of SOC decreased gradually from 62.8% to 47.4% with the increase in soil sampling densities. The SOC CVs in the paddy field change slightly from 30.8% to 28.7%, while those of the dry farmland and forest land decreased remarkably from 58.1%to 48.7% and from 99.3% to 64.4%, respectively. The SOC CVs of the paddy soil change slightly, while those of red soil decreased remarkably from 82.8% to 63.9%. About 604, 500, and 353 (P < 0.05) samples would be needed a number of years later if the SOC change was supposedly 1.52 g kg-2, based on the CVs of SOC acquired from the present sampling densities of D14, D68, and D525,respectively. Moreover, based on the same SOC change and the present time CVs at D255, the ratio of samples needed for paddy field, dry farmland, and forest land should be 1:0.81:3.33, while the actual corresponding ratio in an equal interval grid sampling was 1:0.74:0.46. These indicated that the sampling density had important effect on the detection of SOC variability in the county-wide region, the equal interval grid sampling was not efficient enough, and the respective CV of each land use or soil type should be fully considered when determining the sampling number in the future.

  3. Effect of cassava mill effluent on biological activity of soil microbial community.

    Science.gov (United States)

    Igbinosa, Etinosa O

    2015-07-01

    This study assessed the effect of cassava effluent on soil microbiological characteristics and enzymatic activities were investigated in soil samples. Soil properties and heavy metal concentrations were evaluated using standard soil analytical and spectroscopic methods, respectively. The microbiological parameters measured include microbial biomass carbon, basal soil respiration, catalase, urease, dehydrogenase activities and number of culturable aerobic bacteria, fungi and actinomycetes. The pH and temperature regime vary significantly (p Soil organic carbon content gave significant positive correlations with microbial biomass carbon, basal soil respiration, catalase activity and dehydrogenase activity (r = 0.450, 0.461, 0.574 and 0.591 at p soil microbial density demonstrates a marked decrease in total culturable numbers of the different microbial groups of the polluted soil samples. Soil contamination decreased catalase, urease and dehydrogenase activities. The findings revealed that soil enzymes can be used as indices of soil contamination and bio-indicator of soil quality.

  4. Evaluation of potential effects of soil available phosphorus on soil arsenic availability and paddy rice inorganic arsenic content.

    Science.gov (United States)

    Jiang, Wei; Hou, Qingye; Yang, Zhongfang; Zhong, Cong; Zheng, Guodong; Yang, Zhiqiang; Li, Jie

    2014-05-01

    The transfer of arsenic from paddy field to rice is a major exposure route of the highly toxic element to humans. The aim of our study is to explore the effects of soil available phosphorus on As uptake by rice, and identify the effects of soil properties on arsenic transfer from soil to rice under actual field conditions. 56 pairs of topsoil and rice samples were collected. The relevant parameters in soil and the inorganic arsenic in rice grains were analyzed, and then all the results were treated by statistical methods. Results show that the main factors influencing the uptake by rice grain include soil pH and available phosphorus. The eventual impact of phosphorus is identified as the suppression of As uptake by rice grains. The competition for transporters from soil to roots between arsenic and phosphorus in rhizosphere soil has been a dominant feature.