Carbon turnover in two soils with contrasting mineralogy under long-term maize and pasture

International Nuclear Information System (INIS)

Parfitt, R.L.; Parshotam, A.; Salt, G.J.

2002-01-01

Total organic carbon (C) and natural 13 C abundance were measured in adjacent allophanic soils (Andisols) and non-allophanic soils (Inceptisols) under maize (Zea mays L.) and ryegrass pasture (Lolium perenne L.) to assess the C turnover rate in soils of contrasting mineralogy and specific surface area. The allophanic soil contained more total C than the non-allophanic soil (139v.101t C/ha in the upper 0-35 cm) but neither soil showed a significant difference in C content between pasture and maize, provided maize residue was retained and incorporated. The gross annual inputs under maize and pasture were both estimated to be about 9 t C/ha, consistent with the similar soil total C contents. Since the soil total C content did not appear to change with time, the gross C mineralisation was about 9 t C/ha each year. The proportion of old pasture C remaining in the soil after maize cropping for 25 years was about 78% in the allophanic soils and about 69% in the non-allophanic soils, reflecting the influence of both Al and allophane, with its high specific surface area, on the retention of old C. The maize C retained in 25 years was similar in both the allophanic soil and the non-allophanic soil (29 t/ha). Therefore, the higher total C content of the allophanic soil would appear to arise from stabilisation of old pasture and forest C by Al and allophane. Copyright (2002) CSIRO Publishing

Role of decaying logs and other organic seedbeds in natural regeneration of Hawaiian forest species on abandoned montane pasture

Science.gov (United States)

Paul G. Scowcroft

1992-01-01

Natural regeneration is one mechanism by which native mixed-species forests become reestablished on abandoned pasture. This study was done to determine patterns of and requirement for natural regeneration of native species in an open woodland after removal of cattle. Ten 50- by 50-m quadrats were randomly selected within a 16-ha exclosure located at 1,700-m elevation...

Long-term effects of grazing management and buffer strips on soil erosion from pastures

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High grazing pressure can lead to soil erosion in pastures by compacting soil and increasing runoff and sediment delivery to waterways. Limited information exists on the effects of grazing management and best management practices (BMPs), such as buffer strips, on soil erosion from pastures. The obje...

Managing cultivated pastures for improving soil quality in South ...

African Journals Online (AJOL)

There are concerns that soils under pastures in certain regions of South Africa are degrading as a result of mismanagement, which include practising continuous tillage, improper grazing management, injudicious application of fertilisers and poor irrigation management. Soil quality indicators, which include physical, ...

The transfer of 137Cs through the soil-plant-sheep food chain in different pasture ecosystems

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A. PAASIKALLIO

2008-12-01

Full Text Available A grazing experiment with sheep was carried out in 1990-1993 on natural, semi-natural and cultivated pasture on clay soil. The pastures were located in Southern Finland and were moderately contaminated with 137 Cs by Chernobyl fallout. Natural pasture refers to forest pasture and semi-natural pasture to set-aside field pasture, the latter having been under cultivation about 15 years ago. The transfer of 137 Cs to sheep was clearly higher from forest pasture than from the other two pastures and it was lowest from cultivated pasture. The transfer was higher to muscle and kidney than to liver and heart. The transfer of 137 Cs to plants and to meat varied with years. Seasonal variation in the plant 137 Cs was followed-up on forest and set-aside field pasturerespect to 137 Cs transfer to plants, the mean soil-plant transfer factors of 137 Cs for forest, set-aside field and cultivated pastures were 1.78, 0.36 and 0.09, and soil-meat aggregated transfer factors 11.0, 0.28 and 0.03, respectively.;

The transfer of 137Cs through the soil-plant-sheep food chain in different pasture ecosystems

International Nuclear Information System (INIS)

Paasikallio, Arja; Sormunen-Cristian, Riitta

1996-01-01

A grazing experiment with sheep was carried out in 1990-1993 on natural, semi-natural and cultivated pasture on clay soil. The pastures were located in Southern Finland and were moderately contaminated with 137 Cs by Chernobyl fallout. Natural pasture refers to forest pasture and semi-natural pasture to set-aside field pasture, the latter having been under cultivation about 15 years ago. The transfer of 137 Cs to sheep was clearly higher from forest pasture than from the other two pastures and it was lowest from cultivated pasture. The transfer was higher to muscle and kidney than to liver and heart. The transfer of 137 Cs to plants and to meat varied with years. Seasonal variation in the plant 137 Cs was followed-up on forest and set-aside field pasturerespect to 137 Cs transfer to plants, the mean soil-plant transfer factors of 137 Cs for forest, set-aside field and cultivated pastures were 1.78, 0.36 and 0.09, and soil-meat aggregated transfer factors 11.0, 0.28 and 0.03, respectively

Soil 137Cs activity in a tropical deciduous ecosystem under pasture conversion in Mexico

International Nuclear Information System (INIS)

Garcia-Oliva, F.; Maass, J.M.

1995-01-01

Soil profiles of 137 Cs were measured in a tropical deciduous ecosystem under pasture conversion on the Pacific Coast of Mexico. Soil samples were taken from unperturbed forest, and from pasture plots following forest conversion. The average total 137 Cs areal activity of non-eroded forest sites indicated a base level of 5 315 ± 427 Bq m -2 . On average, total areal activity on hill-tops was significantly higher (range 10-47%) in the forest than in the pastures. A significant correlation was found between the total 137 Cs areal activity and soil organic matter content (r 2 = 0.16). This correlation can be explained by a soil physical-protection hypothesis. The redistribution of 137 Cs in the landscape is explained by soil erosion processes. (author)

Soil carbon sequestration potential of permanent pasture and continuous cropping soils in New Zealand.

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McNally, Sam R; Beare, Mike H; Curtin, Denis; Meenken, Esther D; Kelliher, Francis M; Calvelo Pereira, Roberto; Shen, Qinhua; Baldock, Jeff

2017-11-01

Understanding soil organic carbon (SOC) sequestration is important to develop strategies to increase the SOC stock and, thereby, offset some of the increases in atmospheric carbon dioxide. Although the capacity of soils to store SOC in a stable form is commonly attributed to the fine (clay + fine silt) fraction, the properties of the fine fraction that determine the SOC stabilization capacity are poorly known. The aim of this study was to develop an improved model to estimate the SOC stabilization capacity of Allophanic (Andisols) and non-Allophanic topsoils (0-15 cm) and, as a case study, to apply the model to predict the sequestration potential of pastoral soils across New Zealand. A quantile (90th) regression model, based on the specific surface area and extractable aluminium (pyrophosphate) content of soils, provided the best prediction of the upper limit of fine fraction carbon (FFC) (i.e. the stabilization capacity), but with different coefficients for Allophanic and non-Allophanic soils. The carbon (C) saturation deficit was estimated as the difference between the stabilization capacity of individual soils and their current C concentration. For long-term pastures, the mean saturation deficit of Allophanic soils (20.3 mg C g -1 ) was greater than that of non-Allophanic soils (16.3 mg C g -1 ). The saturation deficit of cropped soils was 1.14-1.89 times that of pasture soils. The sequestration potential of pasture soils ranged from 10 t C ha -1 (Ultic soils) to 42 t C ha -1 (Melanic soils). Although meeting the estimated national soil C sequestration potential (124 Mt C) is unrealistic, improved management practices targeted to those soils with the greatest sequestration potential could contribute significantly to off-setting New Zealand's greenhouse gas emissions. As the first national-scale estimate of SOC sequestration potential that encompasses both Allophanic and non-Allophanic soils, this serves as an informative case study for the international

The transfer of 137Cs through the soil-plant-sheep food chain in different pasture ecosystems

Directory of Open Access Journals (Sweden)

Arja Paasikallio

1996-12-01

Full Text Available A grazing experiment with sheep was carried out in 1990-1993 on natural, semi-natural and cultivated pasture on clay soil. The pastures were located in Southern Finland and were moderately contaminated with 137 Cs by Chernobyl fallout. Natural pasture refers to forest pasture and serai-natural pasture to set-aside field pasture, the latter having been under cultivation about 15 years ago. The transfer of 137Cs to sheep was clearly higher from forest pasture than from the other two pastures and it was lowest from cultivated pasture. The transfer was higher to muscle and kidney than to liver and heart. The transfer of 137Cs to plants and to meat varied with years. Seasonal variation in the plant 137 Cs was followed-up on forest and set-aside field pasture; the activity concentration of plants reached a maximum in June, a lesser increase occurred later in the autumn. In 1993, which was considered an average year with respect to 137Cs transfer to plants, the mean soil-plant transfer factors of 137Cs for forest, set-aside field and cultivated pastures were 1.78, 0.36 and 0.09, and soil-meat aggregated transfer factors 11.0, 0.28 and 0.03, respectively.

Pasture soils contaminated with fertilizer-derived cadmium and fluorine: livestock effects.

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Loganathan, Paripurnanda; Hedley, Mike J; Grace, Neville D

2008-01-01

Fertilizers are indispensable for ensuring sustainability of agricultural production, thereby achieving food and fiber security. Nitrogen, sulfur, and potassium fertilizers are relatively free of impurities, but phosphorus (P) fertilizers, the main fertilizer input for the economic production of legume-based pastures, contain several contaminants, of which F and Cd are considered to be of most concern because they have potentially harmful effects on soil quality, livestock health, and food safety. Incidences of fluorosis in grazing livestock, and accumulation of Cd in the edible offal products of livestock, above the maximum permissible concentration set by food authorities have been reported in many countries. The majority of Cd and F applied to pastures in many countries continues to accumulate in the biologically active topsoil due to strong adsorption to soil constituents. However, the rate of Cd accumulation in the last decade has slowed as a result of selective use of low-Cd fertilizers. Cd and F adsorption in soils increase with increased contents of iron and aluminium oxides, layer silicates and allophane in soils, and increased soil pH. Cadmium adsorption also increases with increased Mn oxides and organic matter in soil. However, some Cd will be released during decomposition of plant and animal remains and organic matter. In most pastoral soils the majority of Cd and F added in fertilizers remains in the topsoil and little moves below 20-30 cm, and therefore these are unlikely to contaminate groundwater. However, F may pose a risk to shallow groundwater in very acidic low-P-fixing soils, and Cd may pose a risk in very acidic soils containing low organic matter and clay contents, or in soils with high chloride concentrations. Research is required both to test whether groundwater beneath farms with long histories of P fertilizer use is contaminated by these elements and also to examine their mechanisms of movement. Cd intake by grazing livestock occurs

Continuous soil carbon storage of old permanent pastures in Amazonia.

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Stahl, Clément; Fontaine, Sébastien; Klumpp, Katja; Picon-Cochard, Catherine; Grise, Marcia Mascarenhas; Dezécache, Camille; Ponchant, Lise; Freycon, Vincent; Blanc, Lilian; Bonal, Damien; Burban, Benoit; Soussana, Jean-François; Blanfort, Vincent

2017-08-01

Amazonian forests continuously accumulate carbon (C) in biomass and in soil, representing a carbon sink of 0.42-0.65 GtC yr -1 . In recent decades, more than 15% of Amazonian forests have been converted into pastures, resulting in net C emissions (~200 tC ha -1 ) due to biomass burning and litter mineralization in the first years after deforestation. However, little is known about the capacity of tropical pastures to restore a C sink. Our study shows in French Amazonia that the C storage observed in native forest can be partly restored in old (≥24 year) tropical pastures managed with a low stocking rate (±1 LSU ha -1 ) and without the use of fire since their establishment. A unique combination of a large chronosequence study and eddy covariance measurements showed that pastures stored between -1.27 ± 0.37 and -5.31 ± 2.08 tC ha -1  yr -1 while the nearby native forest stored -3.31 ± 0.44 tC ha -1  yr -1 . This carbon is mainly sequestered in the humus of deep soil layers (20-100 cm), whereas no C storage was observed in the 0- to 20-cm layer. C storage in C4 tropical pasture is associated with the installation and development of C3 species, which increase either the input of N to the ecosystem or the C:N ratio of soil organic matter. Efforts to curb deforestation remain an obvious priority to preserve forest C stocks and biodiversity. However, our results show that if sustainable management is applied in tropical pastures coming from deforestation (avoiding fires and overgrazing, using a grazing rotation plan and a mixture of C3 and C4 species), they can ensure a continuous C storage, thereby adding to the current C sink of Amazonian forests. © 2016 John Wiley & Sons Ltd.

Microbial Nitrogen-Cycle Gene Abundance in Soil of Cropland Abandoned for Different Periods.

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Huhe; Borjigin, Shinchilelt; Buhebaoyin; Wu, Yanpei; Li, Minquan; Cheng, Yunxiang

2016-01-01

In Inner Mongolia, steppe grasslands face desertification or degradation because of human overuse and abandonment after inappropriate agricultural management. The soils in these abandoned croplands exist in heterogeneous environments characterized by widely fluctuating microbial growth. Quantitative polymerase chain reaction analysis of microbial genes encoding proteins involved in the nitrogen cycle was used to study Azotobacter species, nitrifiers, and denitrifiers in the soils from steppe grasslands and croplands abandoned for 2, 6, and 26 years. Except for nitrifying archaea and nitrous oxide-reducing bacteria, the relative genotypic abundance of microbial communities involved in nitrogen metabolism differed by approximately 2- to 10-fold between abandoned cropland and steppe grassland soils. Although nitrogen-cycle gene abundances varied with abandonment time, the abundance patterns of nitrogen-cycle genes separated distinctly into abandoned cropland versus light-grazing steppe grassland, despite the lack of any cultivation for over a quarter-century. Plant biomass and plant diversity exerted a significant effect on the abundance of microbial communities that mediate the nitrogen cycle (P nitrogen cycle in recently abandoned croplands.

Microbial Nitrogen-Cycle Gene Abundance in Soil of Cropland Abandoned for Different Periods.

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Huhe

Full Text Available In Inner Mongolia, steppe grasslands face desertification or degradation because of human overuse and abandonment after inappropriate agricultural management. The soils in these abandoned croplands exist in heterogeneous environments characterized by widely fluctuating microbial growth. Quantitative polymerase chain reaction analysis of microbial genes encoding proteins involved in the nitrogen cycle was used to study Azotobacter species, nitrifiers, and denitrifiers in the soils from steppe grasslands and croplands abandoned for 2, 6, and 26 years. Except for nitrifying archaea and nitrous oxide-reducing bacteria, the relative genotypic abundance of microbial communities involved in nitrogen metabolism differed by approximately 2- to 10-fold between abandoned cropland and steppe grassland soils. Although nitrogen-cycle gene abundances varied with abandonment time, the abundance patterns of nitrogen-cycle genes separated distinctly into abandoned cropland versus light-grazing steppe grassland, despite the lack of any cultivation for over a quarter-century. Plant biomass and plant diversity exerted a significant effect on the abundance of microbial communities that mediate the nitrogen cycle (P < 0.002 and P < 0.03, respectively. The present study elucidates the ecology of bacteria that mediate the nitrogen cycle in recently abandoned croplands.

Soil carbon sequestration due to post-Soviet cropland abandonment: estimates from a large-scale soil organic carbon field inventory.

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Wertebach, Tim-Martin; Hölzel, Norbert; Kämpf, Immo; Yurtaev, Andrey; Tupitsin, Sergey; Kiehl, Kathrin; Kamp, Johannes; Kleinebecker, Till

2017-09-01

The break-up of the Soviet Union in 1991 triggered cropland abandonment on a continental scale, which in turn led to carbon accumulation on abandoned land across Eurasia. Previous studies have estimated carbon accumulation rates across Russia based on large-scale modelling. Studies that assess carbon sequestration on abandoned land based on robust field sampling are rare. We investigated soil organic carbon (SOC) stocks using a randomized sampling design along a climatic gradient from forest steppe to Sub-Taiga in Western Siberia (Tyumen Province). In total, SOC contents were sampled on 470 plots across different soil and land-use types. The effect of land use on changes in SOC stock was evaluated, and carbon sequestration rates were calculated for different age stages of abandoned cropland. While land-use type had an effect on carbon accumulation in the topsoil (0-5 cm), no independent land-use effects were found for deeper SOC stocks. Topsoil carbon stocks of grasslands and forests were significantly higher than those of soils managed for crops and under abandoned cropland. SOC increased significantly with time since abandonment. The average carbon sequestration rate for soils of abandoned cropland was 0.66 Mg C ha -1  yr -1 (1-20 years old, 0-5 cm soil depth), which is at the lower end of published estimates for Russia and Siberia. There was a tendency towards SOC saturation on abandoned land as sequestration rates were much higher for recently abandoned (1-10 years old, 1.04 Mg C ha -1  yr -1 ) compared to earlier abandoned crop fields (11-20 years old, 0.26 Mg C ha -1  yr -1 ). Our study confirms the global significance of abandoned cropland in Russia for carbon sequestration. Our findings also suggest that robust regional surveys based on a large number of samples advance model-based continent-wide SOC prediction. © 2017 John Wiley & Sons Ltd.

Assessing soil carbon stocks under pastures through orbital remote sensing

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Gabor Gyula Julius Szakács

2011-10-01

Full Text Available The growing demand of world food and energy supply increases the threat of global warming due to higher greenhouse gas emissions by agricultural activity. Therefore, it is widely admitted that agriculture must establish a new paradigm in terms of environmental sustainability that incorporate techniques for mitigation of greenhouse gas emissions. This article addresses to the scientific demand to estimate in a fast and inexpensive manner current and potential soil organic carbon (SOC stocks in degraded pastures, using remote sensing techniques. Four pastures on sandy soils under Brazilian Cerrado vegetation in São Paulo state were chosen due to their SOC sequestration potential, which was characterized for the soil depth 0-50 cm. Subsequently, a linear regression analysis was performed between SOC and Leaf Area Index (LAI measured in the field (LAIfield and derived by satellite (LAIsatellite as well as SOC and pasture reflectance in six spectra from 450 nm - 2350 nm, using the Enhanced Thematic Mapper (ETM+ sensor of satellite Landsat 7. A high correlation between SOC and LAIfield (R² = 0.9804 and LAIsatellite (R² = 0.9812 was verified. The suitability of satellite derived LAI for SOC determination leads to the assumption, that orbital remote sensing is a very promising SOC estimation technique from regional to global scale.

Agricultural land abandonment in Mediterranean environment provides ecosystem services via soil carbon sequestration.

Science.gov (United States)

Novara, Agata; Gristina, Luciano; Sala, Giovanna; Galati, Antonino; Crescimanno, Maria; Cerdà, Artemi; Badalamenti, Emilio; La Mantia, Tommaso

2017-01-15

Abandonment of agricultural land leads to several consequences for ecosystem functions. Agricultural abandonment may be a significant and low cost strategy for carbon sequestration and mitigation of anthropogenic CO 2 emissions due to the vegetation recovery and increase in soil organic matter. The aim of this study was to: (i) estimate the influence of different Soil Regions (areas characterized by a typical climate and parent material association) and Bioclimates (zones with homogeneous climatic regions and thermotype indices) on soil organic carbon (SOC) dynamics after agricultural land abandonment; and (ii) to analyse the efficiency of the agri-environment policy (agri-environment measures) suggested by the European Commission in relation to potential SOC stock ability in the Sicilian Region (Italy). In order to quantify the effects of agricultural abandonment on SOC, a dataset with original data that was sampled in Sicily and existing data from the literature were analysed according to the IPCC (Intergovernmental Panel on Climate Change) methodology. Results showed that abandonment of cropland soils increased SOC stock by 9.03MgCha -1 on average, ranging from 5.4MgCha -1 to 26.7MgCha -1 in relation to the Soil Region and Bioclimate. The estimation of SOC change after agricultural use permitted calculation of the payments for ecosystem service (PES) of C sequestration after agricultural land abandonment in relation to environmental benefits, increasing in this way the efficiency of PES. Considering the 14,337ha of abandoned lands in Sicily, the CO 2 emission as a whole was reduced by 887,745Mg CO 2 . Therefore, it could be concluded that abandoned agricultural fields represents a valid opportunity to mitigate agriculture sector emissions in Sicily. Copyright © 2016 Elsevier B.V. All rights reserved.

Soil quality effects on regeneration of annual Medicago pastures in ...

African Journals Online (AJOL)

Annual medic (Medicago spp.) pastures are widely used as the forage component of crop rotation systems in the Mediterranean region of South Africa. Reliable establishment of medics can be challenging. This may be related to poor soil quality, an inherent problem of soils in the region often aggravated by poor ...

How do soil properties and soil carbon stocks change after land abandonment in Mediterranean mountain areas?

Science.gov (United States)

Nadal Romero, Estela; Cammeraat, Erik; Pérez Cardiel, Estela; Lasanta, Teodoro

2016-04-01

Land abandonment and subsequent revegetation processes (due to secondary succession and afforestation practices) are global issues with important implications in Mediterranean mountain areas. Moreover, the effects of land use changes on soil carbon stocks are a matter of concern stated in international policy agendas on the mitigation of greenhouse emissions, and afforestation practices are increasingly viewed as an environmental restorative land use change prescription and are considered one of the most efficient carbon sequestration strategies currently available. The MED-AFFOREST project aims to gain more insight into the discussion by exploring the following central research questions: (i) what is the impact of land abandonment on soil properties? and (ii) how do soil organic carbon change after land abandonment? The main objective of this study is to assess the effects of land abandonment, land use change and afforestation practices on soil properties and soil organic carbon (SOC) dynamics. For this aim, five different land covers (bare soil, meadows, secondary succession, Pinus sylvestris (PS) and Pinus nigra (PN) afforestation), in the Central Spanish Pyrenees were analysed. Results showed that changes in soil properties after land abandonment were limited, even if afforestation practices were carried out and no differences were observed between natural succession and afforestation. The results on SOC dynamics showed that: (i) SOC contents were higher in the PN sites in the topsoil (10 cm), (ii) when all the profile was considered no significant differences were observed between meadows and PN, (iii) SOC accumulation under secondary succession is a slow process, and (iv) meadows should also be considered due to the relative importance in SOC stocks. The first step of SOC stabilization after afforestation is the formation of macro-aggregates promoted by large inputs of SOC, with a high contribution of labile organic matter. However, our respiration

Soil physical attributes in forms of sowing the annual winter pasture and intervals between grazing

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Milton da Veiga

Full Text Available The sowing of winter pastures in areas used for summer grain production and their management under direct cattle grazing can cause changes in soil physical attributes, whose intensity depends on the degree of soil mobilization, grazing interval, stocking rate and weather. To study these aspects it was conducted over four years an experiment in a randomized block with split plots design and four replications. In the main plots were applied two forms of sowing the annual winter pasture (direct seeding and seeding + harrowing and, in the subplots, four intervals between grazing (7, 14 and 28 days and ungrazed. Undisturbed soil cores were sampled at the end of each grazing cycle, in the 0-0.05 m layer to determine the saturated hydraulic conductivity and aggregate stability and in the layers of 0-0.05, 0.05-0.10, 0.10-0.15 and 0.15-0.20 m depth to determine bulk density and classes of soil pores. The direct seeding of annual winter pasture increases hydraulic conductivity and reduces soil bulk density in relation to seeding + harrowing while dairy cows trampling increases soil density and reduces macroporosity in the most superficial soil layer. The variation in climatic conditions among grazing cycles affects the soil physical attributes more markedly than forms of sowing and intervals between grazing of the annual winter pasture.

Soil, vegetation and total organic carbon stock development in self-restoring abandoned vineyards

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József Novák, Tibor; Incze, József; Spohn, Marie; Giani, Luise

2016-04-01

Abandoned vineyard's soil and vegetation development was studied on Tokaj Nagy-Hill, which is one of the traditional wine-producing regions of Hungary, it is declared as UNESCO World Heritage site as cultural landscape. Spatial distribution and pattern of vineyards were changing during the last several hundreds of years, therefore significant part of abandoned vineyards were subjected to long-term spontaneous secondary succession of vegetation and self-restoration of soils in absence of later cultivation. Two chronosequences of spontaneously regenerating vineyard abandonments, one on south (S-sequence) and one on southwest (SW-sequence) slope with differing times since their abandonment (193, 142, 101, 63, 39 and 14 years), were compiled and studied. The S-sequence was 25-35% sloped and strongly eroded, and the SW-sequence was 17-25% sloped and moderately eroded. The sites were investigated in respect of vegetation characteristics, soil physico-chemical characteristics, total organic carbon stocks (TOC stocks), accumulation rates of total organic carbon (TOC accumulation rates), and soil profiles, which were classified according to the World Reference Base (WRB) 2014. Vegetation development resulted in shrub-grassland mosaics, supplemented frequently by protected forb species and forest development at the earliest abandonment in S-sequence, and predominantly to forest vegetation in SW-sequence, where trees were only absent at the 63 and 14 years old abandonment sites. In all sites soils on level of reference groups according to WRB were classified, and Cambisols, Regosols, Calcisols, Leptosols, Chernozems and Phaeozems were found. Soils of the S-sequence show shallow remnants of loess cover with colluvic and redeposited soil materials containing 15-65% skeletal volcanic rock of weathering products coated by secondary calcium carbonates. The SW-sequence profiles are developed on deep loess or loess derivatives. The calcium-carbonate content was higher in profiles of

Least limiting water range of Udox soil under degraded pastures on different sun-exposed faces

Science.gov (United States)

Passos, Renato Ribeiro; Marciano da Costa, Liovando; Rodrigues de Assis, Igor; Santos, Danilo Andrade; Ruiz, Hugo Alberto; Guimarães, Lorena Abdalla de Oliveira Prata; Andrade, Felipe Vaz

2017-07-01

The efficient use of water is increasingly important and proper soil management, within the specificities of each region of the country, allows achieving greater efficiency. The South and Caparaó regions of Espírito Santo, Brazil are characterized by relief of `hill seas' with differences in the degree of pasture degradation due to sun exposure. The objective of this study was to evaluate the least limiting water range in Udox soil under degraded pastures with two faces of exposure to the sun and three pedoenvironments. In each pedoenvironment, namely Alegre, Celina, and Café, two areas were selected, one with exposure on the North/West face and the other on the South/East face. In each of these areas, undisturbed soil samples were collected at 0-10 cm depth to determine the least limiting water range. The exposed face of the pasture that received the highest solar incidence (North/West) presented the lowest values in least limiting water range. The least limiting water range proved to be a physical quality indicator for Udox soil under degraded pastures.

Soil quality parameters for row-crop and grazed pasture systems with agroforestry buffers

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Incorporation of trees and establishment of buffers are practices that can improve soil quality. Soil enzyme activities and water stable aggregates are sensitive indices for assessing soil quality by detecting early changes in soil management. However, studies comparing grazed pasture and row crop...

Soil phosphorus dynamics in a humid tropical silvopastoral system

Energy Technology Data Exchange (ETDEWEB)

Cooperband, L.R.

1992-01-01

In developing countries of the humid tropics, timber exploitation and agricultural expansion frequently result in deforestation. Extensive land management, coupled with inherently low soil fertility invariably produce declines in agricultural/livestock productivity which eventually lead to land abandonment and further deforestation. Phosphorus is often the major nutrient limiting plant growth in tropical soils. Agroforestry systems have been considered as viable alternatives to current land use practices. Several hypotheses suggest that combining trees with crops or pasture, especially leguminous species will improve soil nutrient cycling, soil structure and soil organic matter. In this experiment Erythrina berteroana (an arboreous legume) was grown in native grass pastures in Costa Rica to determine the effects of tree pruning and cattle grazing on soil P availability. I measured soil P fluxes as well as changes in pasture biomass over an 18-month period. In a separate field experiment, I determined decomposition rates and P release characteristics of Erythrina leaves, pasture grass clippings and cattle dung. Erythrina leaves decomposed faster than both pasture grass and cattle dung. Erythrina and pasture residues released 4-5 times less P than dung. Phosphorus fluxes after tree pruning and grazing were highly dynamic for all treatments. Tree pruning increased labile soil P over time when coupled with grazing. Pasture biomass production was greatest in the grazed tree treatment. Pasture biomass P production and concentration was greatest in the non-grazed treatment. Trees and grazing together tended to increase nutrient (P) turnover which stimulated biomass production. In contrast, trees without grazing promoted nutrient (P) accumulation in pasture biomass.

Soil phosphorus dynamics in a humid tropical silvopastoral system

International Nuclear Information System (INIS)

Cooperband, L.R.

1992-01-01

In developing countries of the humid tropics, timber exploitation and agricultural expansion frequently result in deforestation. Extensive land management, coupled with inherently low soil fertility invariably produce declines in agricultural/livestock productivity which eventually lead to land abandonment and further deforestation. Phosphorus is often the major nutrient limiting plant growth in tropical soils. Agroforestry systems have been considered as viable alternatives to current land use practices. Several hypotheses suggest that combining trees with crops or pasture, especially leguminous species will improve soil nutrient cycling, soil structure and soil organic matter. In this experiment Erythrina berteroana (an arboreous legume) was grown in native grass pastures in Costa Rica to determine the effects of tree pruning and cattle grazing on soil P availability. I measured soil P fluxes as well as changes in pasture biomass over an 18-month period. In a separate field experiment, I determined decomposition rates and P release characteristics of Erythrina leaves, pasture grass clippings and cattle dung. Erythrina leaves decomposed faster than both pasture grass and cattle dung. Erythrina and pasture residues released 4-5 times less P than dung. Phosphorus fluxes after tree pruning and grazing were highly dynamic for all treatments. Tree pruning increased labile soil P over time when coupled with grazing. Pasture biomass production was greatest in the grazed tree treatment. Pasture biomass P production and concentration was greatest in the non-grazed treatment. Trees and grazing together tended to increase nutrient (P) turnover which stimulated biomass production. In contrast, trees without grazing promoted nutrient (P) accumulation in pasture biomass

Soil erosion as a consequence of wildfires on recently abandoned citrus orchards in eastern Spain

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A.Cerdà

2013-05-01

Full Text Available Fire is a natural factor in the evolution of Earth ecosystems. Due to land abandonment wildfire are widespread in Mediterranean Type Ecosystems, which contribute to increase the soil erosion rates. Fire is also found in recently abandoned citrus orchards due to the quick vegetation recovery and the dry biomass found after 2 years of abandonment. Rainfall simulation experiments (1 hour at 45 mm h-1 in a plot of 0.25 m2 show that although land abandonment on irrigated citrus orchards reduces the soil losses to very low values, the fire increase runoff and soil erosion. Water and soil losses are much lower in the fire-affected plots than on the cultivated ones due to the use of herbicides.

Mercury loss from soils following conversion from forest to pasture in Rondonia, Western Amazon, Brazil

International Nuclear Information System (INIS)

Almeida, Marcelo D.; Lacerda, Luiz D.; Bastos, Wanderley R.; Herrmann, Joao Carlos

2005-01-01

This work reports on the effect of land use change on Hg distribution in Amazon soils. It provides a comparison among Hg concentrations and distribution along soil profiles under different land use categories; primary tropical forest, slashed forest prior to burning, a 1-year silviculture plot planted after 4 years of forest removal and a 5-year-old pasture plot. Mercury concentrations were highest in deeper (60-80 cm) layers in all four plots. Forest soils showed the highest Hg concentrations, ranging from 128 ng g -1 at the soil surface to 150 ng g -1 at 60-80 cm of depth. Lower concentrations were found in pasture soils, ranging from 69 ng g -1 at the topsoil to 135 ng g -1 at 60-80 cm of depth. Slashed and silviculture soils showed intermediate concentrations. Differences among plots of different soil-use categories decreased with soil depth, being non-significant below 60 cm of depth. Mercury burdens were only statistically significantly different between pasture and forest soils at the topsoil, due to the large variability of concentrations. Consequently, estimated Hg losses were only significant between these two land use categories, and only for the surface layers. Estimated Hg loss due to forest conversion to pasture ranged from 8.5 mg m -2 to 18.5 mg m -2 , for the first 20 cm of the soil profile. Mercury loss was comparable to loss rates estimated for other Amazon sites and seems to be directly related to Hg concentrations present in soils. - Deforestation can be responsible for maintaining high Hg levels in the Amazon environment, through a grasshopper effect of Hg remobilization from the affected soils

Predicting greenhouse gas emissions and soil carbon from changing pasture to an energy crop.

Directory of Open Access Journals (Sweden)

Benjamin D Duval

Full Text Available Bioenergy related land use change would likely alter biogeochemical cycles and global greenhouse gas budgets. Energy cane (Saccharum officinarum L. is a sugarcane variety and an emerging biofuel feedstock for cellulosic bio-ethanol production. It has potential for high yields and can be grown on marginal land, which minimizes competition with grain and vegetable production. The DayCent biogeochemical model was parameterized to infer potential yields of energy cane and how changing land from grazed pasture to energy cane would affect greenhouse gas (CO2, CH4 and N2O fluxes and soil C pools. The model was used to simulate energy cane production on two soil types in central Florida, nutrient poor Spodosols and organic Histosols. Energy cane was productive on both soil types (yielding 46-76 Mg dry mass · ha(-1. Yields were maintained through three annual cropping cycles on Histosols but declined with each harvest on Spodosols. Overall, converting pasture to energy cane created a sink for GHGs on Spodosols and reduced the size of the GHG source on Histosols. This change was driven on both soil types by eliminating CH4 emissions from cattle and by the large increase in C uptake by greater biomass production in energy cane relative to pasture. However, the change from pasture to energy cane caused Histosols to lose 4493 g CO2 eq · m(-2 over 15 years of energy cane production. Cultivation of energy cane on former pasture on Spodosol soils in the southeast US has the potential for high biomass yield and the mitigation of GHG emissions.

Chemical, Biochemical, and Microbiological Properties of Soils from Abandoned and Extensively Cultivated Olive Orchards

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A. M. Palese

2013-01-01

Full Text Available The abandonment of olive orchards is a phenomenon of great importance triggered mainly by economic and social causes. The aim of this study was to investigate some chemical, biochemical, and microbiological properties in a soil of a southern olive grove abandoned for 25 years. In order to define the effect of the long-term land abandonment on soil properties, an adjacent olive grove managed according to extensive practices was taken as reference (essentially minimum tillage and no fertilization. Soil organic matter, total nitrogen, and pH were significantly higher in the abandoned olive grove due to the absence of tillage and the natural inputs of organic matter at high C/N ratio which, inter alia, increased the number of cellulolytic bacteria and stimulated the activity of β-glucosidase, an indicator of a more advanced stage of soil evolution. The soil of the abandoned olive orchard showed a lower number of total bacteria and fungi and a lower microbial diversity, measured by means of the Biolog method, as a result of a sort of specialization trend towards low quality organic substrates. From this point of view, the extensive cultivation management seemed to not induce a disturbance to microbiological communities.

Chemical, Biochemical, and Microbiological Properties of Soils from Abandoned and Extensively Cultivated Olive Orchards

Science.gov (United States)

Palese, A. M.; Magno, R.; Casacchia, T.; Curci, M.; Baronti, S.; Miglietta, F.; Crecchio, C.; Xiloyannis, C.; Sofo, A.

2013-01-01

The abandonment of olive orchards is a phenomenon of great importance triggered mainly by economic and social causes. The aim of this study was to investigate some chemical, biochemical, and microbiological properties in a soil of a southern olive grove abandoned for 25 years. In order to define the effect of the long-term land abandonment on soil properties, an adjacent olive grove managed according to extensive practices was taken as reference (essentially minimum tillage and no fertilization). Soil organic matter, total nitrogen, and pH were significantly higher in the abandoned olive grove due to the absence of tillage and the natural inputs of organic matter at high C/N ratio which, inter alia, increased the number of cellulolytic bacteria and stimulated the activity of β-glucosidase, an indicator of a more advanced stage of soil evolution. The soil of the abandoned olive orchard showed a lower number of total bacteria and fungi and a lower microbial diversity, measured by means of the Biolog method, as a result of a sort of specialization trend towards low quality organic substrates. From this point of view, the extensive cultivation management seemed to not induce a disturbance to microbiological communities. PMID:24348166

Ammonia emissions from urea application to permanent pasture on a volcanic soil

Science.gov (United States)

Salazar, F.; Martínez-Lagos, J.; Alfaro, M.; Misselbrook, T.

2012-12-01

Agriculture is the largest source of ammonia (NH3) emission to the atmosphere, deriving mainly from livestock urine and manures, but fertilizer applications to pastures and crops also represent an important source. In Chile, where agriculture and cattle production are important activities (accounting for 4.5% of GDP along with the forestry sector), there are very few published data regarding NH3 emissions from pasture and crop fertilization. This study aimed to provide the first empirical field data for Chile on N losses due to NH3 volatilization following urea application to permanent pasture on a volcanic soil and to assess the influence of environmental conditions on emissions. Four field experiments were carried out on a volcanic acid soil using the micrometeorological integrated horizontal flux (IHF) mass balance method. Measurements were made in winter 2005 and 2007, and spring 2007 and 2008 following urea N fertilization to a permanent pasture at a rate equivalent to 100 kg N ha-1. Cumulative NH3 emissions over the measurement period were 1.4 and 7.7 kg N ha-1 for winter applications, and 12.2 and 26.7 kg N ha-1 for spring dressings. These N losses due to NH3 volatilization are within the range of emissions reported elsewhere. Consideration of urea application timing in Chile, with regards to weather and soil conditions, could have important consequences on minimising potential N losses via volatilization with associated financial benefits to farmers.

Soil carbon storage in silvopastoral systems and a treeless pasture in northwestern Spain.

Science.gov (United States)

Howlett, David S; Mosquera-Losada, M Rosa; Nair, P K Ramachandran; Nair, Vimala D; Rigueiro-Rodríguez, Antonio

2011-01-01

Soil particle size and land management practices are known to have considerable influence on carbon (C) storage in soils, but such information is lacking for silvopastoral systems in Spain. This study quantified the amounts of soil C stored at various depths to 100 cm under silvopastoral plots of radiata pine ( D. Don) and birch ( Roth) in comparison to treeless pasture in Galicia, Spain. Soils were fractionated into three size classes (<53, 53-250, and 250-2000 μm), and C stored in them and in the whole (nonfractionated) soil was determined. Overall, the C stock to 1 m ranged from 80.9 to 176.9 Mg ha in these soils. Up to 1 m depth, 78.82% of C was found in the 0- to 25-cm soil depth, with 12.9, 4.92, and 3.36% in the 25- to 50-, 50- to 75-, and 75- to 100-cm depths, respectively. Soils under birch at 0 to 25 cm stored more C in the 250- to 2000-μm size class as compared with those under radiata pine; at that depth, pasture had more C than pine silvopasture in the smaller soil fractions (<53 and 53-250 μm). In the 75- to 100-cm depth, there was significantly more storage of C in the 250- to 2000-μm fraction in both silvopastures as compared with the pasture. The higher storage of soil C in larger fraction size in lower soil depths of silvopasture suggests that planting of trees into traditional agricultural landscapes will promote longer-term storage of C in the soil. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Multiple constraint modeling of nutrient cycling stoichiometry following forest clearing and pasture abandonment in the Eastern Amazon

Science.gov (United States)

Davidson, Eric; Nifong, Rachel

2017-04-01

While deforestation has declined since its peak, land-use change continues to modify Amazonian landscapes. The responses and feedbacks of biogeochemical cycles to these changes play an important role in determining possible future trajectories of ecosystem function and for land stewardship through effects on rates of secondary forest regrowth, soil emissions of greenhouse gases, inputs of nutrients to groundwater and streamwater, and nutrient management in agroecosystems. Here we present a new synthetic analyses of data from the NASA-supported LBA-ECO project and others datasets on nutrient cycling in cattle pastures, secondary forests, and mature forests at Paragominas, Pará, Brazil. We have developed a stoichiometric model relating C-N-P interactions during original forest clearing, extensive and intensive pasture management, and secondary forest regrowth, constrained by multiple observations of ecosystem stocks and fluxes in each land use. While P is conservatively cycled in all land uses, we demonstrate that pyrolyzation of N during pasture formation and during additional burns for pasture management depletes available-N pools, consistent with observations of lower rates of N leaching and trace gas emission and consistent with secondary forest growth responses to experimental N amendments. The soils store large stocks of N and P, and our parameterization of available forms of these nutrients for steady-state dynamics in the mature forest yield reasonable estimates of net N and P mineralization available for grasses and secondary forest species at rates consistent with observed biomass accumulation and productivity in these modified ecosystems. Because grasses and forests have much different demands for N relative to P, the land use has important biogeochemical impacts. The model demonstrates the need for periodic P inputs for sustainable pasture management and for a period of significant biological N fixation for early-to-mid-successional secondary forest

Acacia sieberiana Effects on Soil Properties and Plant Diversity in Songa Pastures, Rwanda

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C. P. Mugunga

2013-01-01

Full Text Available Effects of A. sieberiana trees on soil properties and plant diversity were investigated in Songa pastures, Rwanda. Tree characteristics and crown architecture of A. sieberiana were studied. Soil properties were assessed and plants were identified under and away from tree crowns. Counts of individual plants/species were done only under tree crowns. Nitrogen, P, and K were analysed in the soil, grass, and A. sieberiana leaves. Plant diversity was determined using Simpson's diversity index. Data were subjected to ANOVA. Soil organic carbon (SOC, cation exchange capacity (CEC, Ca2+, N and pH, and plant diversity were higher in soils under tree canopies than in open areas. Tree leaves were significantly richer in N and poorer in P and K as compared to grasses. Tree crowns grew wider and horizontal and developed intertwined secondary branching, reducing light intensity to as low as 38% under tree canopies compared to the open pasture. At 3 trees/ha stocking, A. sieberiana trees shaded 0.18 ha and herbaceous plants and grasses unpalatable to livestock dominated under tree canopies. A tradeoff of A. sieberiana tree value versus the loss of palatable grass due to tree presence needs to be assessed to decide whether the trees should be included in pastures and if yes, the apporpriate stocking identified.

Impact of vineyard abandonment and natural recolonization on metal content and availability in Mediterranean soils

International Nuclear Information System (INIS)

Santiago-Martín, Ana de; Vaquero-Perea, Cristina; Valverde-Asenjo, Inmaculada; Quintana Nieto, Jose R.; González-Huecas, Concepción; Lafuente, Antonio L.; Vázquez de la Cueva, Antonio

2016-01-01

Abandonment of vineyards after uprooting has dramatically increased in last decades in Mediterranean countries, often followed by vegetation expansion processes. Inadequate management strategies can have negative consequences on soil quality. We studied how the age and type of vegetation cover and several environmental characteristics (lithology, soil properties, vineyard slope and so on) after vineyard uprooting and abandonment contribute to the variation patterns in total, HAc (acetic acid-method, HAc) and EDTA-extractable (ethylenediaminetetraacetic acid-method) concentrations of Cd, Cu, Pb and Zn in soils. We sampled 141 points from vineyards and abandoned vineyard Mediterranean soils recolonized by natural vegetation in recent decades. The contribution of several environmental variables (e.g. age and type of vegetation cover, lithology, soil properties and vineyard slope) to the total and extractable concentrations of metals was evaluated by canonical ordination based on redundancy analysis, considering the interaction between both environmental and response variables. The ranges of total metal contents were: 0.01–0.15 (Cd), 2.6–34 (Cu), 6.6–30 (Pb), and 29–92 mg kg −1 (Zn). Cadmium (11–100%) had the highest relative extractability with both extractants, and Zn and Pb the lowest. The total and EDTA-extractable of Cd, Pb and Zn were positively related to the age of abandonment, to the presence of Agrostis castellana and Retama sphaerocarpa, and to the contents of Fe-oxides, clay and organic matter (OM). A different pattern was noted for Cu, positively related to vineyard soils. Soil properties successfully explained HAc-extractable Cd, Cu, Pb and Zn but the age and type of vegetation cover lost significance. Clay content was negatively related to HAc-extractable Cu and Pb; and OM was positively related to HAc-Cd and Zn. In conclusion, the time elapsed after vineyard uprooting, and subsequent land abandonment, affects the soil content and

Impact of vineyard abandonment and natural recolonization on metal content and availability in Mediterranean soils

Energy Technology Data Exchange (ETDEWEB)

Santiago-Martín, Ana de, E-mail: anasanti@ucm.es [Department of Soil Science, Faculty of Pharmacy, Complutense University of Madrid, 28040, Madrid (Spain); Vaquero-Perea, Cristina, E-mail: crvaquer@farm.ucm.es [Department of Soil Science, Faculty of Pharmacy, Complutense University of Madrid, 28040, Madrid (Spain); Valverde-Asenjo, Inmaculada, E-mail: inma.valverde@farm.ucm.es [Department of Soil Science, Faculty of Pharmacy, Complutense University of Madrid, 28040, Madrid (Spain); Quintana Nieto, Jose R., E-mail: jrquinta@farm.ucm.es [Department of Soil Science, Faculty of Pharmacy, Complutense University of Madrid, 28040, Madrid (Spain); González-Huecas, Concepción, E-mail: chuecas@farm.ucm.es [Department of Soil Science, Faculty of Pharmacy, Complutense University of Madrid, 28040, Madrid (Spain); Lafuente, Antonio L., E-mail: lopezlafuente@farm.ucm.es [Department of Soil Science, Faculty of Pharmacy, Complutense University of Madrid, 28040, Madrid (Spain); Vázquez de la Cueva, Antonio, E-mail: vazquez@inia.es [INIA, Forest Research Centre, Carretera de A Coruña km 7.5, 28040, Madrid (Spain)

2016-05-01

Abandonment of vineyards after uprooting has dramatically increased in last decades in Mediterranean countries, often followed by vegetation expansion processes. Inadequate management strategies can have negative consequences on soil quality. We studied how the age and type of vegetation cover and several environmental characteristics (lithology, soil properties, vineyard slope and so on) after vineyard uprooting and abandonment contribute to the variation patterns in total, HAc (acetic acid-method, HAc) and EDTA-extractable (ethylenediaminetetraacetic acid-method) concentrations of Cd, Cu, Pb and Zn in soils. We sampled 141 points from vineyards and abandoned vineyard Mediterranean soils recolonized by natural vegetation in recent decades. The contribution of several environmental variables (e.g. age and type of vegetation cover, lithology, soil properties and vineyard slope) to the total and extractable concentrations of metals was evaluated by canonical ordination based on redundancy analysis, considering the interaction between both environmental and response variables. The ranges of total metal contents were: 0.01–0.15 (Cd), 2.6–34 (Cu), 6.6–30 (Pb), and 29–92 mg kg{sup −1} (Zn). Cadmium (11–100%) had the highest relative extractability with both extractants, and Zn and Pb the lowest. The total and EDTA-extractable of Cd, Pb and Zn were positively related to the age of abandonment, to the presence of Agrostis castellana and Retama sphaerocarpa, and to the contents of Fe-oxides, clay and organic matter (OM). A different pattern was noted for Cu, positively related to vineyard soils. Soil properties successfully explained HAc-extractable Cd, Cu, Pb and Zn but the age and type of vegetation cover lost significance. Clay content was negatively related to HAc-extractable Cu and Pb; and OM was positively related to HAc-Cd and Zn. In conclusion, the time elapsed after vineyard uprooting, and subsequent land abandonment, affects the soil content and

Sensitivity of soil phosphorus tests in predicting the potential risk of phosphorus loss from pasture soil

Directory of Open Access Journals (Sweden)

H. SOINNE

2008-12-01

Full Text Available The objective of this study was to examine the effects of urine and dung additions on the phosphorus (P chemistry of pasture land and to compare the sensitivity of two soil extraction methods in assessing the P-loading risk. In a field experiment, urine and dung were added to soil in amounts corresponding to single excrement portions and the soil samples, taken at certain intervals, were analysed for pHH2O, acid ammonium acetate extractable P (PAc and water extractable total P (TPw, and molybdate reactive P (MRPw. Urine additions immediately increased soil pH and MRPw, but no such response was observed in PAc extraction due to the low pH (4.65 of the extractant enhancing the resorption of P. The PAc responded to the dunginduced increase in soil total P similarly as did Pw, which suggests that both tests can serve to detect areas of high P concentration. However, water extraction was a more sensitive method for estimating short-term changes in P solubility. In pasture soils, the risk of P loss increases as a result of the interaction of urination and high P concentration in the topsoil resulting from continuous dung excretion.;

Soil Carbon and Nutrient Changes Associated with Deforestation for Pasture in Southern Costa Rica

Science.gov (United States)

Huth, Timothy J.; Porder, Stephen; Chaves, Joaquin; Whiteside, Jessica H.

2012-01-01

We assessed the effects of deforestation on soil carbon (C) and nutrient stocks in the premontane landscape near Las Cruces Biological Station in southern Costa Rica, where forests were cleared for pasture in the mid-1960s. We excavated six soil pits to a depth of 1 m in both pasture and primary forest, and found that C stocks were 20 kg C per square meters in both settings. Nevertheless, soil delta C-13 suggests 50 percent of the forest-derived soil C above 40 cm depth has turned over since deforestation. Soil nitrogen (N) and phosphorus (P) stocks derived from the soil pits were not significantly different between land uses (P = 0.43 and 0.61, respectively). At a larger spatial scale, however, the ubiquity of ruts produced by cattle-induced erosion indicates that there are substantial soil effects of grazing in this steep landscape. Ruts averaged 13 cm deep and covered 45 percent of the landscape, and thus are evidence of the removal of 0.7 Mg C/ ha/yr, and 70, 9 and 40 kg/ha/yr of N, P and potassium (K), respectively. Subsoils in this region are 10 times less C- and N-rich, and 2 times less P- and K-rich than the topsoil. Thus, rapid topsoil loss may lead to a decline in pasture productivity in the coming decades. These data also suggest that the soil C footprint of deforestation in this landscape may be determined by the fate of soil C as it is transported downstream, rather than C turnover in situ.

Arsenic distribution in a pasture area impacted by past mining activities.

Science.gov (United States)

Abad-Valle, P; Álvarez-Ayuso, E; Murciego, A; Muñoz-Centeno, L M; Alonso-Rojo, P; Villar-Alonso, P

2018-01-01

Former mine exploitations entail a serious threat to surrounding ecosystems as after closure of mining activities their unmanaged wastes can be a continuous source of toxic trace elements. Quite often these mine sites are found within agricultural farming areas, involving serious hazards as regards product (feed/food) quality. In this work a grazing land impacted by the abandoned mine exploitation of an arsenical deposit was studied so as to evaluate the fate of arsenic (As) and other trace elements and the potential risks involved. With this aim, profile soil samples (0-50cm) and pasture plant species (Agrostis truncatula, Holcus annus and Leontodon longirostris) were collected at different distances (0-100m) from the mine waste dump and analyzed for their trace element content and distribution. Likewise, plant trace element accumulation from impacted grazing soils and plant trace element translocation were assessed. The exposure of livestock grazing animals to As was also evaluated, establishing its acceptability regarding food safety and animal health. International soil guideline values for As in grazing land soils (50mgkg -1 ) resulted greatly exceeded (up to about 20-fold) in the studied mining-affected soils. Moreover, As showed a high mobilization potential under circumstances such as phosphate application or establishment of reducing conditions. Arsenic exhibited relatively high translocation factor (TF) values (up to 0.32-0.89) in pasture plant species, reaching unsafe concentrations in their above-ground tissues (up to 32.9, 16.9 and 9.0mgkg -1 in Agrostis truncatula, Leontodon longirostris and Holcus annus, respectively). Such concentrations represent an elevated risk of As transfer to the high trophic-chain levels as established by international legislation. The limited fraction of arsenite found in plant roots should play an important role in the relatively high As root-to-shoot translocation shown by these plant species. Both soil ingestion and

Forest-to-pasture conversion increases the diversity of the phylum Verrucomicrobia in Amazon rainforest soils.

Science.gov (United States)

Ranjan, Kshitij; Paula, Fabiana S; Mueller, Rebecca C; Jesus, Ederson da C; Cenciani, Karina; Bohannan, Brendan J M; Nüsslein, Klaus; Rodrigues, Jorge L M

2015-01-01

The Amazon rainforest is well known for its rich plant and animal diversity, but its bacterial diversity is virtually unexplored. Due to ongoing and widespread deforestation followed by conversion to agriculture, there is an urgent need to quantify the soil biological diversity within this tropical ecosystem. Given the abundance of the phylum Verrucomicrobia in soils, we targeted this group to examine its response to forest-to-pasture conversion. Both taxonomic and phylogenetic diversities were higher for pasture in comparison to primary and secondary forests. The community composition of Verrucomicrobia in pasture soils was significantly different from those of forests, with a 11.6% increase in the number of sequences belonging to subphylum 3 and a proportional decrease in sequences belonging to the class Spartobacteria. Based on 99% operational taxonomic unit identity, 40% of the sequences have not been detected in previous studies, underscoring the limited knowledge regarding the diversity of microorganisms in tropical ecosystems. The abundance of Verrucomicrobia, measured with quantitative PCR, was strongly correlated with soil C content (r = 0.80, P = 0.0016), indicating their importance in metabolizing plant-derived carbon compounds in soils.

LBA-ECO ND-10 Soil Properties of Pasture Chronosequences, Para, Brazil: 1997

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: This data set provides the results of soil physical property and chemical measurements of samples collected from two pasture chronosequences (years since...

LBA-ECO ND-10 Soil Properties of Pasture Chronosequences, Para, Brazil: 1997

Data.gov (United States)

National Aeronautics and Space Administration — This data set provides the results of soil physical property and chemical measurements of samples collected from two pasture chronosequences (years since conversion...

National-Scale Changes in Soil Profile C and N in New Zealand Pastures are Determined by Land Use

Science.gov (United States)

Schipper, L. A.; Parfitt, R.; Ross, C.; Baisden, W. T.; Claydon, J.; Fraser, S.

2010-12-01

Grazed pasture is New Zealand’s predominant agricultural land-use and has been relatively recently developed from forest and native grasslands/shrub communities. From the 1850s onwards, land was cleared and exotic pastures established. Phosphorus fertilizer was increasingly used after 1950 which accelerated N fixation by clover. In the last two decades N fertilizers have been used, and grazing intensity has increased, thus affecting soil C and N. Re-sampling of 31 New Zealand soil profiles under grazed pasture measured surprisingly large losses of C and N over the last 2-3 decades (Schipper et al., 2007 Global Change Biology 13:1138-1144). These profiles were predominantly on the most intensively grazed flat land. We extended this re-sampling to 83 profiles (to 90 cm depth), to investigate whether changes in soil C and N stocks also occurred in less intensively managed pasture. Archived soils samples were analysed for total soil C and N alongside the newly collected samples. Intact cores were collected to determine bulk density through the profile. Over an average of 27 years, soils (0-30 cm) in flat dairy pastures significantly lost 0.73±0.16 Mg C ha-1y-1 and 57±16 kg N ha-1y-1 while we observed no change in soil C or N in flat pasture grazed by “dry stock” (e.g., sheep, beef), or in grazed tussock grasslands. Grazed hill country soils (0-30 cm) gained 0.52±0.18 Mg C ha-1y-1 and 66±18 kg N ha-1y-1. The losses of C and N were strongly correlated and C:N ratio has generally declined suggesting soils are becoming N saturated. Losses and gains also occurred in soil layers below 30 cm demonstrating that organic matter throughout the profile was responding to land use. The losses under dairying may be due to greater grazing pressure, fertilizer inputs and exports of C and N. There is evidence that grazing pressure reduces inputs of C below ground, reduces soil microbial C, and that dairy cow urine can mobilise C and N. Gains in hill country pastures may be due

Soil-plant-transfer factors for I-129 and pasture vegetation

International Nuclear Information System (INIS)

Haisch, A.; Schuettelkopf, H.

1993-07-01

The transfer factors for soil/plant, I-129 and I-127 and pasture vegetation have been measured with soils developed by wethering of granite, jura and cretaceous formations. Greenhouse (Karlsruhe) and field experiments (Munich) have been performed using lysimeters. Three ground water levels and the influence of a six weeks flooding was measured. About 90% of the transfer factors ranged from 0.000 to 0.020. The highest values have been determined with soils from granite wethering. The flooding of the lysimeters caused an important increase of the transfer factors after the end of flooding. (orig.) [de

Modeling and Mapping Soil Moisture of Plateau Pasture Using RADARSAT-2 Imagery

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Xun Chai

2015-01-01

Full Text Available Accurate soil moisture retrieval of a large area in high resolution is significant for plateau pasture. The object of this paper is to investigate the estimation of volumetric soil moisture in vegetated areas of plateau pasture using fully polarimetric C-band RADARSAT-2 SAR (Synthetic Aperture Radar images. Based on the water cloud model, Chen model, and Dubois model, we proposed two developed algorithms for soil moisture retrieval and validated their performance using experimental data. We eliminated the effect of vegetation cover by using the water cloud model and minimized the effect of soil surface roughness by solving the Dubois equations. Two experimental campaigns were conducted in the Qinghai Lake watershed, northeastern Tibetan Plateau in September 2012 and May 2013, respectively, with simultaneous satellite overpass. Compared with the developed Chen model, the predicted soil moisture given by the developed Dubois model agreed better with field measurements in terms of accuracy and stability. The RMSE, R2, and RPD value of the developed Dubois model were (5.4, 0.8, 1.6 and (3.05, 0.78, 1.74 for the two experiments, respectively. Validation results indicated that the developed Dubois model, needing a minimum of prior information, satisfied the requirement for soil moisture inversion in the study region.

Greenhouse gases fluxes and soil thermal properties in a pasture in central Missouri.

Science.gov (United States)

Nkonglolo, Nsalambi Vakanda; Johnson, Shane; Schmidt, Kent; Eivazi, Frieda

2010-01-01

Fluctuations of greenhouse gases emissions and soil properties occur at short spatial and temporal scales, however, results are often reported for larger scales studies. We monitored CO2, CH4, and N2O fluxes and soil temperature (T), thermal conductivity (K), resistivity (R) and thermal diffusivity (D) from 2004 to 2006 in a pasture. Soil air samples for determination of CO2, CH4 and N20 concentrations were collected from static and vented chambers and analyzed within two hours of collection with a gas chromatograph. T, K, R and D were measured in-situ using a KD2 probe. Soil samples were also taken for measurements of soil chemical and physical properties. The pasture acted as a sink in 2004, a source in 2005 and again a sink of CH4 in 2006. CO2 and CH4 were highest, but N2O as well as T, K and D were lowest in 2004. Only K was correlated with CO2 in 2004 while T correlated with both N2O (r = 0.76, p = 0.0001) and CO2 (r = 0.88, p = 0.0001) in 2005. In 2006, all gases fluxes were significantly correlated with T, K and R when the data for the entire year were considered. However, an in-depth examination of the data revealed the existence of month-to-month shifts, lack of correlation and differing spatial structures. These results stress the need for further studies on the relationship between soil properties and gases fluxes. K and R offer a promise as potential controlling factors for greenhouse gases fluxes in this pasture.

Spatial variability of chemical properties of soil under pasture

Directory of Open Access Journals (Sweden)

Samuel Ferreira da Silva

2016-04-01

Full Text Available The objective of this study was to analyze the spatial variability of soil chemical attributes under pasture, as well as lime and fertilizer recommendations based on the interpretation of soil chemical analysis from two sampling methods: conventional and systematic depths of 0 to 10 and 10 to 20 cm. The study was conducted at IFES-campus Alegre-ES. Data analysis was performed using descriptive statistics and geostatistics. Results indicate that the spatial method enabled the identification of deficit areas and excessive liming and fertilization, which could not be defined by the conventional method.

Soil structure and earthworm activity in an marine silt loam under pasture versus arable land

NARCIS (Netherlands)

Jongmans, A.G.; Pulleman, M.M.; Marinissen, J.C.Y.

2001-01-01

Agricultural management influences soil organic matter (SOM) and earthworm activity which interact with soil structure. We aimed to describe the change in earthworm activity and related soil (micro)structure and SOM in a loamy Eutrodept as affected by permanent pasture (PP) and conventional arable

Development of spatial heterogeneity in vegetation and soil properties after land abandonment in a semi-arid ecosystem

NARCIS (Netherlands)

Lesschen, J.P.; Cammeraat, L.H.; Kooijman, A.M.; van Wesemael, B.

2008-01-01

To mitigate erosion on abandoned fields in semi-arid ecosystems, it is important to understand how vegetation and soil properties and patterns develop after land abandonment. Our objective was to investigate the development of spatial heterogeneity in vegetation and soil properties after land

Sensitivity of soil phosphorus tests in predicting the potential risk of phosphorus loss from pasture soil

OpenAIRE

H. SOINNE; K. SAARIJÄRVI; M. KARPPINEN

2008-01-01

The objective of this study was to examine the effects of urine and dung additions on the phosphorus (P) chemistry of pasture land and to compare the sensitivity of two soil extraction methods in assessing the P-loading risk. In a field experiment, urine and dung were added to soil in amounts corresponding to single excrement portions and the soil samples, taken at certain intervals, were analysed for pHH2O, acid ammonium acetate extractable P (PAc) and water extractable total P (TPw), and mo...

An attempt and significance of using scandium (Sc) indication for quantitative estimation of soil ingested by pastured cattle

International Nuclear Information System (INIS)

Koyama, Takeo; Sudo, Madoka; Miyamoto, Susumu; Kikuchi, Takeaki; Takahashi, Masayoshi; Kuma, Tadashi.

1985-01-01

Pastured beef cattle constantly ingest soil together with grass. Dried grass and silage used in winter also contain some soil. Sc occurs in soil in much greater amounts than in grass and is not absorbed by digestive canals, and the Sc content can be determined accuretely by the activation analysis method. In view of this, a technique is devised which uses Sc as an indication in estimating the amount of soil ingested by cattle, and this new method is found to be better than the conventional one with Ti indication. Accordingly, dung is collected from the same cattle at the end of the pastured and housed periods. The dung samples are dried, ground, activated and analysed. On the basis of results of this analysis, the amount of soil ingested at the end of the pastured and housed periods is estimated at 106 +- 120 and 129 +- 171 g/day, respectively, which broadly agree with values previously reported. An evaluation of the amounts of Se and Zn taken by cattle from soil is also carried out. (Nogami, K.)

Soil fauna as an indicator of soil quality in forest stands, pasture and secondary forest

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Felipe Vieira da Cunha Neto

2012-11-01

Full Text Available The interactions between soil invertebrates and environmental variations are relatively unknown in the assessment of soil quality. The objective of this study was to evaluate soil quality in areas with different soil management systems, based on soil fauna as indicator, in Além Paraíba, Minas Gerais, Brazil. The soil invertebrate community was sampled using pitfall traps, in the dry and rainy seasons, from areas with five vegetation types (acacia, mimosa, eucalyptus, pasture, and secondary forest. The abundance of organisms and the total and average richness, Shannon's diversity index, the Pielou uniformity index, and change index V were determined. The fauna was most abundant in the areas of secondary forest and mimosa plantations in the dry season (111.3 and 31.7 individuals per trap per day, respectively. In the rainy season, the abundance of organisms in the three vegetation types did not differ. The highest values of average and total richness were recorded in the secondary forest in the dry season and in the mimosa stand in the rainy season. Shannon's index ranged from 1.57 in areas with acacia and eucalyptus in the rainy season to 3.19 in the eucalyptus area in the dry season. The uniformity index was highest in forest stands (eucalyptus, acacia and mimosa in the dry season, but higher in the rainy season in the pasture and secondary forest than in the forest stands. The change index V indicated that the percentage of extremely inhibited groups was lowest in the area with mimosa, both in the dry and rainy season (36 and 23 %, respectively. Of all forest stands, the mimosa area had the most abundant soil fauna.

Effect of biochar produced at different pyrolysis temperature on the soil respiration of abandoned mine soil

Science.gov (United States)

Kim, Yong Seong; Kim, Juhee; Hwang, Wonjae; Hyun, Seunghun

2015-04-01

Contaminated soils near an abandoned mine site included the high acidic mine tailing have received great interest due to potential risk to human health, because leachable elements in low pH continuously release from mine site soil with ground water and precipitation event. Biochar, which is the obtained pyrolysis process of biomass, is used as a soil amendments and carbon storage. Especially, many researchers report that the biochar application to soil show increasing soil pH, CEC, adsorption capacity of various elements, as well as, enhanced microbial activity. Therefore, biochar application to contaminated soil near abandoned mine site is expected to have a positive effects on management of these site and soils through the decreased leachability of contaminants. However, effects of biochar application to these site on the soil respiration, as a common measure of soil health, are poorly understood. The objective of this study is to evaluate the effects of biochar application to abandoned mine site soil on the microbial activity with soil respiration test. Biochar was obtained from giant Miscanthus in a slow pyrolysis process (heating rate of 10° C min-1 and N2 gas flow rate of 1.2 L min-1) at the temperature of 400° C (BC4) and 700° C (BC7), respectively. All biochar samples were prepared with grinding and sieving for particle size control (150~500μm). Soil sample was collected from abandoned mine site at Korea (36° 58'N, 128° 10'E). Main contaminants of this soil were As (12.5 g kg-1), Pb (7.3 g kg-1), and Zn (1.1 g kg-1). Biochars were applied (5% by dry weight) to the soil (final mixture weight were 800g), and then moisture contents were adjusted to 100% field capacity (-0.33 bar) in the respirometer with vacuum pump. CO2 efflux of each samples was continuously assessed using continuous aeration system (air flow rate 25 cc min-1) using air cylinder during 130hr (at 20° C and darkness condition). The CO2 emitted from the samples were carried to the

Mineral content in soil and pasture in bovine dairy herds of the Andean region of Ecuador

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Luís Rodrigo Balarezo Urresta

2017-10-01

Full Text Available The objective of this research was to characterize the mineral status of the soil and pasture in of the Andean Ecuadorian region, during the rainy and dry periods, three dairy farms were used as study cases investigated him three dairy farms of the El Carchi province. They determined the chemical indicators of the soil and the pasture, the descriptive statisticians were calculated themselves and it was used a multifactorial ANOVA to determine the main factors affecting them on them, comparing means with Bonferroni and Duncan test. The soil classified as acid lightly, 100 % of the samples presented elevated levels of organic matter, NH4+, Mg, Cu, Zn, Fe and Mn. The farm had a significant effect on the pH, Ca, Mg, K, Cu, Fe, Mg and P, and the climatic period on the organic matter, NH4+, S, Cu and P. Pasture presented deficiencies of Mg, Zn and Na, the other minerals were above the critical limits. The farm affected the Ca, P, Mg, Na and Mn, and the climatic period the levels of Ca, K, Cu y Zn. In conclusion, 100 % soil samples presented high OM, slight acidity, low levels of Ca and high concentrations of NH4+, S, Mg, Cu, Zn and Mn. In pastures, there were diagnosed deficiencies of P, Cu and Zn, and their concentrations differed among farms and the two climatic periods of the year.

Soil organic matter in fire-affected pastures and in an Araucaria forest in South-Brazilian Leptosols

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Mariana da Luz Potes

2012-05-01

Full Text Available The objective of this work was to evaluate the distribution pattern and composition of soil organic matter (SOM and its physical pools of Leptosols periodically affected by fire over the last 100 years in South Brazil. Soil samples at 0-5, 5-10, and 10-15 cm depths were collected from the following environments: native pasture without burning in the last year and grazed with 0.5 livestock per hectare per year (1NB; native pasture without burning in the last 23 years and grazed with 2.0 livestock per hectare per year (23NB; and an Araucaria forest (AF. Physical fractionation was performed with the 0-5 and 5-10 cm soil layers. Soil C and N stocks were determined in the three depths and in the physical pools, and organic matter was characterized by infrared spectroscopy and thermogravimetry. The largest C stocks in all depths and physical pools were found under the AF. The 23NB environment showed the lowest soil C and N stocks at the 5-15 cm depth, which was related to the end of burning and to the higher grazing intensity. The SOM of the occluded light fraction showed a greater chemical recalcitrance in 1NB than in 23NB. Annual pasture burning does not affect soil C stocks up to 15 cm of depth.

Changes in Soil Quality and Hydrological Connectivity Caused by the Abandonment of Terraces in a Mediterranean Burned Catchment

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Aleix Calsamiglia

2017-09-01

Full Text Available Wildfires and agricultural activities are relevant factors affecting soil quality, hydrological cycle and sedimentary dynamics. Land abandonment leads to afforestation, which increases fire risk and land degradation. However, no studies have yet evaluated the effect of combining the two factors, which occur frequently in Mediterranean ecosystems. This study assessed the changes in soil quality caused by the abandonment of terraces in two microcatchments (<2.5 ha affected distinctly by wildfires (once and twice burned and in an unburned control microcatchment by analyzing soil quality parameters, biochemical indices and spatial patterns of hydrological and sediment connectivity. Soil samples were collected in thirty-six plots (25 m2 representing terraced and non-terraced areas within these microcatchments. Unburned non-terraced plots had higher organic matter content and higher microbiological and enzymatic activities than other plots. Plots in abandoned terraces had lower soil quality indices, regardless of the fire effect. Land abandonment induced changes in the spatial patterns of hydrological connectivity, leading to concentrated runoff, enhanced erosion and soil degradation. Fire also negatively affected soil quality in both terraced and non-terraced plots. However, microbiological communities had different positive post-fire recovery strategies (growth and activity, depending on the previous soil conditions and land uses, which is indicative of the resilience of Mediterranean soil ecosystems.

Quantifying phosphorus levels in soils, plants, surface water, and shallow groundwater associated with bahiagrass-based pastures.

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Sigua, Gilbert C; Hubbard, Robert K; Coleman, Samuel W

2010-01-01

Recent assessments of water quality status have identified eutrophication as one of the major causes of water quality 'impairment' not only in the USA but also around the world. In most cases, eutrophication has accelerated by increased inputs of phosphorus due to intensification of crop and animal production systems since the early 1990 s. Despite substantial measurements using both laboratory and field techniques, little is known about the spatial and temporal variability of phosphorus dynamics across landscapes, especially in agricultural landscapes with cow-calf operations. Critical to determining environmental balance and accountability is an understanding of phosphorus excreted by animals, phosphorus removal by plants, acceptable losses of phosphorus within the manure management and crop production systems into soil and waters, and export of phosphorus off-farm. Further research effort on optimizing forage-based cow-calf operations to improve pasture sustainability and protect water quality is therefore warranted. We hypothesized that properly managed cow-calf operations in subtropical agroecosystem would not be major contributors to excess loads of phosphorus in surface and ground water. To verify our hypothesis, we examined the comparative concentrations of total phosphorus among soils, forage, surface water, and groundwater beneath bahiagrass-based pastures with cow-calf operations in central Florida, USA. Soil samples were collected at 0-20; 20-40, 40-60, and 60-100 cm across the landscape (top slope, middle slope, and bottom slope) of 8 ha pasture in the fall and spring of 2004 to 2006. Forage availability and phosphorus uptake of bahiagrass were also measured from the top slope, middle slope, and bottom slope. Bi-weekly (2004-2006) groundwater and surface water samples were taken from wells located at top slope, middle slope, and bottom slope, and from the runoff/seepage area. Concentrations of phosphorus in soils, forage, surface water, and shallow

Phosphorus, carbon- and nitrogen interactions in productive and degraded tropical pastures

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Oberson, A.; Hegglin, D. D.; Nesper, M.; Rao, I.; Fonte, S.; Ramirez, B.; Velasquez, J.; Tamburini, F.; Bünemann, E. K.; Frossard, E.

2011-12-01

Pastures are the main land use in deforested areas of tropical South America. The highly weathered soils of these regions usually have low total and available phosphorus (P) contents. Low P availability can strongly limit plant and animal productivity and other soil ecosystem functions. Most introduced pastures of Brachiaria spp. are grass-alone (GA) while some are grass-legume (GL) pastures. The majority of the introduced pastures, particularly the grass-alone are at some state of degradation (GD). Pasture degradation induces severe loss of plant biomass production, with drastic ecological and economic implications. Although the importance of P deficiency in pasture degradation has been recognized, the knowledge generated on stoichiometry of carbon (C), nitrogen (N) and P along pathways of the nutrient cycles of pastures, with different botanical composition and productivity, has been very limited. We will present results of a case study realized during 2010 to 2011 in the forest margins agro-ecosystem of the department of Caquetá, Colombia. Our objectives were to determine: i) whether P availability is lower in degraded compared to productive pastures, and ii) whether the introduction of legumes in the pasture increases P availability through enhanced biological P cycling through plant growth, plant litter decomposition and the soil microbial biomass; and iii) whether pasture types (GA vs GL) and the state of pasture degradation affect the C:N:P ratios in nutrient pools of the soil-plant system. An on-farm study was conducted on nine farms in the department of Caquetá, Colombia. On every farm three different pasture types were studied: degraded grass alone pastures (GD), productive grass-alone pastures (GA) and productive grass-legume pastures (GL). Basic soil characteristics and indicators on soil P status, microbial P cycling, plant biomass production, plant litter deposition and nutrient concentrations in plant tissue were determined. Analysis of P, C and N

Physical soil stability under different management of extensive pasture in haplumbrept soils /Estabilidade física de solo sob diferentes manejos de pastagem extensiva em cambissolo

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Ricardo Ralisch

2010-09-01

Full Text Available In the dairy cattle production of the small region of São João Del Rei (MG - Brazil it is common to manage extensive native pastures with annual fires on low natural fertility Haplumbrept soils. The objective of this work was to evaluate the physical stability by measuring the degree of clay flocculation of a Haplumbrept soil under different management systems of extensive pastures. The evaluations were done using three types of managements: native pasture without fire; native pasture with fire, and recovered pasture. For each treatment it was selected one “sub area” of 1 hectare, located at the middle hillside with declivity between 10 and 12%, where, in the month of June 2007, 50 randomized deformed soil samples were collected/studied, in the layer of 0-10 cm to evaluate the degree of clay flocculation, pH, DpHH2O, pHKCl (1N, zero point charge (PCZ. The systems of soil management did influence the degree of clay flocculation, with the lowest values found in pasture with annual burning and recovered pasture. The recovery of pasture in this fragile soil requires care with physical and chemical soil management.Na pecuária leiteira da Microrregião de São João Del Rei (MG é comum o manejo de pastagem nativa extensiva com utilização de queimadas anuais em Cambissolo, considerados de baixa fertilidade natural. O objetivo deste trabalho foi avaliar a estabilidade física a partir da determinação do grau de floculação da argila de Cambissolo sob diferentes manejos de pastagem extensiva. As avaliações foram realizadas em três tipos de manejos: pastagem nativa manejada sem queimada; passagem nativa manejada com queimada e pastagem recuperada. Em cada manejo selecionou-se uma “sub área” de 1 hectare, situada em meia encosta com declive entre 10 – 12%. Em junho / 2007, foram coletadas 50 amostras deformadas de solo de forma inteiramente casualizada, na camada de 0-10 cm, para determinação do grau de floculação da argila, pHH2

Recovery of 15N-urea in soil-plant system of tanzania grass pasture

International Nuclear Information System (INIS)

Martha Junior, Geraldo Bueno; Vilela, Lourival; Corsi, Moacyr; Trivelin, Paulo Cesar Ocheuze

2009-01-01

The economic attractiveness and negative environmental impact of nitrogen (N) fertilization in pastures depend on the N use efficiency in the soil-plant system. However, the recovery of urea- 15 N by Panicum maximum cv. Tanzania pastures, one of the most widely used forage species in intensified pastoral systems, is still unknown. This experiment was conducted in a randomized complete block design with four treatments (0, 40, 80 and 120 kg ha-1 of N-urea) and three replications, to determine the recovery of 15 N urea by Tanzania grass. Forage production, total N content and N yield were not affected by fertilization (p > 0.05), reflecting the high losses of applied N under the experimental conditions. The recovery of 15 N urea (% of applied N) in forage and roots was not affected by fertilization levels (p > 0.05), but decreased exponentially in the soil and soil-plant system (p 15 N (kg ha -1 ) in forage and roots (15 to 30 cm) increased with increasing urea doses (p < 0.05). (author)

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

Short- and long-term temporal changes in soil concentrations of selected endocrine disrupting compounds (EDCs) following single or multiple applications of sewage sludge to pastures

International Nuclear Information System (INIS)

Rhind, S.M.; Kyle, C.E.; Ruffie, H.; Calmettes, E.; Osprey, M.; Zhang, Z.L.; Hamilton, D.; McKenzie, C.

2013-01-01

Temporal changes in soil burdens of selected endocrine disrupting compounds were determined following application to pasture of either sewage sludge or inorganic fertilizer. Soil polycyclic aromatic hydrocarbon and polychlorinated biphenyl concentrations were not altered. Changes in concentrations of diethylhexyl phthalate (DEHP) and PBDEs 47 and 99 differed with season but concentrations remained elevated for more than three weeks after application, when grazing animals are normally excluded from pasture. It is concluded that single applications of sewage sludge can increase soil concentrations of some, but not all classes of EDCs, possibly to concentrations sufficient to exert biological effects when different chemicals act in combination, but patterns of change depend on season and soil temperature. Analysis of soil from pasture subjected to repeated sludge applications, over 13 years, provided preliminary evidence of greater increases in soil burdens of all of the EDC groups measured, including all of the PBDE congeners measured. -- Highlights: •Sewage sludge or inorganic fertilizer was applied to pasture. •Soil PAH and PCB concentrations were not altered by sludge treatment. •Temporal changes in soil phthalate and PBDE differed with season. •Some soil EDC levels were elevated for more than three weeks after application. -- Effects of sewage sludge application to pastures on temporal changes in soil concentrations of endocrine disrupting compounds differ with chemical class and season

Long-term effect of land use change on soil quality: Afforestation and land abandonment in semi-arid Spain

Science.gov (United States)

Zethof, Jeroen; Cammeraat, Erik; Nadal-Romero, Estela

2016-04-01

Soils under the Mediterranean climate are vulnerable for degradation, especially after land abandonment. Abandonment is an important factor in the Mediterranean landscape as vegetation regeneration is hampered due to the characteristic semi-arid and sub-humid Mediterranean climate regime. During the past 70 year extensive afforestation projects have been conducted with the aim to protect landscapes and soils against degradation. While large investments are still being made, little is known about the impact of afforestation on soil quality on a longer time scale. During the past decade, there is a growing interest in qualifying and quantifying the carbon storage in soils by such afforestation projects, to get a better understanding of the carbon cycle and look for possibilities to fixate atmospheric CO2 in the soil. It is generally accepted that afforestation projects will increase the soil carbon pool, but data on this process is scarce. Therefore an intensive fieldwork has been carried out in Murcia, southeastern Spain to study the effects of land abandonment and afforestation on soil quality along a chronosequence and included two afforested areas (from the early '70s and 1993). The Pinus halepensis trees were planted in rows, for which the underlying calcrete was broken. Samples were taken to study changes in soil quality (Aggregate stability, Corg, N, P, K, Na), Soil Organic Carbon (SOC) stocks and soil hydraulic properties, such as infiltration and water retention, between the afforestation projects, abandoned agricultural plots of similar age, semi-natural vegetation, cereal crop fields and almond orchards. As the natural vegetation is characterized by a spotted pattern of bare areas and trees, forming so-called "islands of fertility", both bare and vegetation covered sub-sites were sampled. First results showed a positive effect of both land abandonment and afforestation on the soil aggregation. Especially the 40-year-old plots showed underneath trees

Soil seed-bank germination patterns in natural pastures under different mineral fertilizer treatments

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Anna Iannucci

2014-11-01

Full Text Available Degraded native grasslands in Mediterranean areas can be improved by encouraging seedling regeneration from soil seed banks using chemical fertilization. The effect of mineral fertilizers on soil seed banks was studied in natural pastures at two locations in southern Italy: Carpino and Rignano Garganico. The aim was to determine if nitrogen (N, phosphorus (P and combined nitrogen and phosphorus (NP fertilization can promote increased soil seed density. The seed-bank size and composition were analysed over two growth cycles (2004-2006 at two periods of the year: at the early summer and at the early autumn. The plant species were classified into three functional groups: grasses, legumes and other species (all other dicots. A two-pool model (ephemeral and base pools derived from the germination patterns was developed to quantify the dynamics of the germinated seed populations. The mean total seed number in the seed bank ranged from 2,915 to 4,782 seed m-2 with higher values in early summer than in early autumn. Mineral fertilizer applications increased the seed-bank size (by 27%, 23% and 46%, for N, P and NP, respectively and modified the composition in both localities. The three plant functional groups showed different potentials for ephemeral and persistent seed-bank production; however, within each plant group, the proportion between the ephemeral and base pool fractions did not change with fertilizer application. These data show that mineral fertilization can have positive effects on the seed-bank size of ungrazed natural pastures, and can be used to improve degraded Mediterranean pastures.

Identifying functional groups for response to disturbance in an abandoned pasture

Science.gov (United States)

Lavorel, Sandra; Touzard, Blaise; Lebreton, Jean-Dominique; Clément, Bernard

1998-06-01

In an abandoned pasture in Brittany, we compared artificial small-scale disturbances to natural disturbances by wild boar and undisturbed vegetation. We developed a multivariate statistical approach which analyses how species biological attributes explain the response of community composition to disturbances. This technique, which reconciles the inductive and deductive approaches for functional classifications, identifies groups of species with similar responses to disturbance and characterizes their biological profiles. After 5 months of recolonization, artificial disturbances had a greater species richness than undisturbed vegetation as a result of recruitment of new species without the exclusion of pre-existing matrix species. Species morphology, described by canopy structure, canopy height and lateral spread, explained a large part (16 %) of community response to disturbance. Regeneration strategies, described by life history, seed mass, dispersal agent, dormancy and the existence of vegetative multiplication, explained a smaller part of community response to disturbance (8 %). Artificial disturbances were characterized by therophyte and compact rosettes with moderately dormant seeds, including a number of Asteraceae and other early successional species. Natural disturbances were colonized by leafy guerrilla species without seed dormancy. Few species were tightly related to undisturbed vegetation and were essentially grasses with a phalanx rosette morphology. The functional classification obtained is consistent with the classification of the community into fugitives, regenerators and persistors. These groups are structured according to Grubb's model for temperate grasslands, with regenerators and persistors in the matrix and fugitives taking advantage of gaps open by small-scale disturbances. The conjunction of functional diversity and species diversity within functional groups is the key to resilience to disturbance, an important ecosystem function.

LBA-ECO ND-01 Forest and Pasture Soil and Grass Analyses, Rondonia, Brazil: 2003-2004

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: This data set provides soil physical and chemical properties, and grass nutrient measurements of samples collected from 17 pasture sites located within the...

LBA-ECO ND-01 Forest and Pasture Soil and Grass Analyses, Rondonia, Brazil: 2003-2004

Data.gov (United States)

National Aeronautics and Space Administration — This data set provides soil physical and chemical properties, and grass nutrient measurements of samples collected from 17 pasture sites located within the state of...

Influence of tree canopy on N{sub 2} fixation by pasture legumes and soil rhizobial abundance in Mediterranean oak woodlands

Energy Technology Data Exchange (ETDEWEB)

Carranca, C., E-mail: corina.carranca@iniav.pt [INIAV, Qta Marquês, 2784-505 Oeiras (Portugal); Castro, I.V.; Figueiredo, N. [INIAV, Qta Marquês, 2784-505 Oeiras (Portugal); Redondo, R. [Laboratorio de Isotopos Estables, Universidade Autonoma, Madrid (Spain); Rodrigues, A.R.F. [Centro de Estudos Florestais, ISA/UL, Tapada Ajuda, 1349-017 Lisboa (Portugal); Saraiva, I.; Maricato, R. [INIAV, Qta Marquês, 2784-505 Oeiras (Portugal); Madeira, M.A.V. [Centro de Estudos Florestais, ISA/UL, Tapada Ajuda, 1349-017 Lisboa (Portugal)

2015-02-15

Symbiotic N{sub 2} fixation is of primordial significance in sustainable agro-forestry management as it allows reducing the use of mineral N in the production of mixed stands and by protecting the soils from degradation. Thereby, on a 2-year basis, N{sub 2} fixation was evaluated in four oak woodlands under Mediterranean conditions using a split-plot design and three replicates. {sup 15}N technique was used for determination of N{sub 2} fixation rate. Variations in environmental conditions (temperature, rainfall, radiation) by the cork tree canopy as well as the age of stands and pasture management can cause great differences in vegetation growth, legume N{sub 2} fixation, and soil rhizobial abundance. In the present study, non-legumes dominated the swards, in particular beneath the tree canopy, and legumes represented only 42% of total herbage. A 2-fold biomass reduction was observed in the oldest sown pasture in relation to the medium-age sward (6 t DW ha{sup −1} yr{sup −1}). Overall, competition of pasture growth for light was negligible, but soil rhizobial abundance and symbiotic N{sub 2} fixation capacity were highly favored by this environmental factor in the spring and outside the influence of tree canopy. Nitrogen derived from the atmosphere was moderate to high (54–72%) in unsown and sown swards. Inputs of fixed N2 increased from winter to spring due to more favorable climatic conditions (temperature and light intensity) for both rhizobia and vegetation growths. Assuming a constant fixation rate at each seasonal period, N{sub 2} fixation capacity increased from about 0.10 kg N ha{sup −1} per day in the autumn–winter period to 0.15 kg N ha{sup −1} per day in spring. Belowground plant material contributed to 11% of accumulated N in pasture legumes and was not affected by canopy. Size of soil fixing bacteria contributed little to explain pasture legumes N. - Highlights: • Legumes fixation in oak woodlands was quantified in terms of biomass and N

Spatial variability and response of soil organic carbon stocks to land abandonment and erosion in mountainous drylands (Invited)

Science.gov (United States)

De Baets, S. L.; Meersmans, J.; Vanacker, V.; Quine, T. A.; van oost, K.

2013-12-01

This research focuses on understanding the impact of human activities on C dynamics in a mountainous and semi-arid environment. Despite the low C status of drylands, soil organic carbon (SOC) is the largest C pool in these systems and hence possess a large restoration capacity. Still, regional estimates of SOC stocks and insights in their determining factors are lacking. This study therefore aims 1) to interpret the variability of soil organic carbon in relation to key soil, topographical and land use variables and 2) to quantify the effects of land regeneration following abandonment on SOC stocks. Soil profiles were taken in the Sierra de los Filabres (SE Spain) in different land units along geomorphic and degradation gradients. SOC contents were modelled using recovery period, soil and topographical variables. Sample depth, topographical position, altitude, recovery period and stone content are identified as the main factors for predicting SOC concentrations. SOC stocks in 1 m depth of soil vary between 3.16 and 76.44 t ha-1. Recovery period (years since abandonment), topographical position and altitude were used to predict and map SOC stocks in the top 0.2 m. The results show that C accumulates fast during the first 10-50 years following abandonment, whereafter the stocks evolve towards a steady state level. The erosion zones in the study area demonstrate a higher potential to increase their SOC stocks when abandoned. Deposition zones have higher SOC stocks, although their C accumulation rate is lower compared to erosion dominated landscapes in the first 10-50 years following abandonment. Therefore, full understanding of the C sequestration potential of land use change in areas of complex topography requires knowledge of spatial variability in soil properties and in particular SOC.

Relationship between plant biodiversity and heavy metal bioavailability in grasslands overlying an abandoned mine.

Science.gov (United States)

Hernández, A J; Pastor, J

2008-04-01

Abandoned metal mines in the Sierra de Guadarrama, Madrid, Spain, are often located in areas of high ecological value. This is true of an abandoned barium mine situated in the heart of a bird sanctuary. Today the area sustains grasslands, interspersed with oakwood formations of Quercus ilex and heywood scrub (Retama sphaerocarpa L.), used by cattle, sheep and wild animals. Our study was designed to establish a relationship between the plant biodiversity of these grasslands and the bioavailability of heavy metals in the topsoil layer of this abandoned mine. We conducted soil chemical analyses and performed a greenhouse evaluation of the effects of different soil heavy metal concentrations on biodiversity. The greenhouse bioassays were run for 6 months using soil samples obtained from the mine polluted with heavy metals (Cu, Zn, Pb and Cd) and from a control pasture. Soil heavy metal and Na concentrations, along with the pH, had intense negative effects on plant biodiversity, as determined through changes in the Shannon index and species richness. Numbers of grasses, legumes, and composites were reduced, whilst other species (including ruderals) were affected to a lesser extent. Zinc had the greatest effect on biodiversity, followed by Cd and Cu. When we compared the sensitivity of the biodiversity indicators to the different metal content variables, pseudototal metal concentrations determined by X-ray fluorescence (XRF) were the most sensitive, followed by available and soluble metal contents. Worse correlations between biodiversity variables and metal variables were shown by pseudototal contents obtained by plasma emission spectroscopy (ICP-OES). Our results highlight the importance of using as many different indicators as possible to reliably assess the response shown by plants to heavy metal soil pollution.

Soil Physical and Chemical Properties in Epigeal Termite Mounds in Pastures

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Sandra Santana de Lima

2018-03-01

Full Text Available ABSTRACT We characterized soil physical and chemical properties and soil organic matter in epigeal termite mounds in pastures to evaluate the changes promoted by termites in comparison to an adjacent area. We selected seven active epigeal termite mounds in the municipality of Seropédica, state of Rio de Janeiro, Brazil. Soil samples were collected from top, center and base positions of each mound, at 0.50 and 1.50 m distance from the base of the mound. We identified individuals of the genus Embiratermes, Velocitermes, and Orthognathotermes. The humin fraction predominated over the humic and fulvic acid fractions both in mounds and adjacent soil. The amount of organic matter and the mineral fractions (mineral-associated organic carbon - MOC varied among builder species. The studied chemical attributes point to a higher concentration of nutrients in the mounds than in the adjacent soil.

Soil restoration under pasture after lignite mining - management effects on soil biochemical properties and their relationships with herbage yields

Energy Technology Data Exchange (ETDEWEB)

Ross, D.J.; Speir, T.W.; Cowling, J.C.; Feltham, C.W. (DSIR, Lower Hutt (New Zealand))

1992-01-01

The recovery of soil biochemical properties under grazed, grass-clover pasture after simulated lignite mining was studied over a 5-year period in a mesic Typic Dystrochrept soil at Waimumu, Southland, New Zealand. Restoration procedures involved four replacement treatments, after A,B and C horizon materials had been separately removed, from all except the control, and stockpiled for 2-3 weeks. Replacement treatment markedly influenced the recovery of herbage production and soil organic C and total N contents, N mineralization, microbial biomass (as indicated by mineral-N flush) and invertase and sulphatase activities. The effectiveness of replacement treatments decreased in the order: 1. control (no stripping or replacement). 2. A,B and C horizon materials replaced in the same order. 3. A,B and C horizon materials each mixed with an equal amount of siltstone overburden and replaced in order, 4. A and B horizon materials mixed before replacing over C horizon materials. Ripping increased herbage production, net N mineralization and microbial biomass. Fertilizer N also stimulated herbage production but depressed clover growth. Increases in soil invertase and, to a lesser extent, sulphatase activity were closely related to changes in herbage production. Microbial biomass increased more rapidly than soil organic C in early stages in the trial. Rates of net N mineralization suggest that N availability would have limited pasture growth.

Carbohydrates and thermal analysis reflects changes in soil organic matter stability after forest expansion on abandoned grassland

Science.gov (United States)

Guidi, Claudia; Vesterdal, Lars; Cannella, David; Leifeld, Jens; Gianelle, Damiano; Rodeghiero, Mirco

2014-05-01

Grassland abandonment, followed by progressive forest expansion, is the dominant land-use change in the Southern Alps, Europe. Land-use change can affect not only the amount of organic matter (OM) in soil but also its composition and stability. Our objective was to investigate changes in organic matter properties after forest expansion on abandoned grasslands, combining analysis of carbohydrates, indicative of labile OM compounds with prevalent plant or microbial origin, with thermal analysis. Thermal analysis was used as a rapid assessment method for the characterization of SOM stability. A land-use gradient was investigated in four land-use types in the subalpine area of Trentino region, Italy: i) managed grassland, mown and fertilized for the past 100 years; ii) grassland abandoned since 10 years, with sparse shrubs and Picea abies saplings; iii) early-stage forest, dominated by P. abies and established on a grassland abandoned around 1970; iv) old forest, dominated by Fagus sylvatica and P. abies. Mineral soil was sampled at three subplots in each land use type with eight soil cores, which were subsequently pooled by depth (0-5 cm, 5-10 cm, 10-20 cm). Sugars were extracted from bulk soil samples through acid hydrolysis with H2SO4 (0.5 M). The analytical composition of sugar monomers was performed with HPAEC technology (Dionex ICS5000), equipped with PAD-detection. Thermal stability was assessed with a differential scanning calorimeter DSC100, heating soil samples up to 600°C at a heating rate of 10°C min-1 in synthetic air. Peak height (W g OC-1) of 1st DSC exotherm, dominated by burning of labile OM compounds, was used as thermal stability index. In the abandoned grassland, carbohydrates compounds accounted for a greater proportion of soil OC than in other land use types. Microbially derived sugars, as rhamnose and galactose, were more abundant in managed and abandoned grasslands compared with early-stage and old forest. The amount of thermally labile sugars

Dissipation of sulfamethoxazole in pasture soils as affected by soil and environmental factors.

Science.gov (United States)

Srinivasan, Prakash; Sarmah, Ajit K

2014-05-01

The dissipation of sulfamethoxazole (SMO) antibiotic in three different soils was investigated through laboratory incubation studies. The experiments were conducted under different incubation conditions such as initial chemical concentration, soil depth, temperature, and with sterilisation. The results indicate that SMO dissipated rapidly in New Zealand pasture soils, and the 50% dissipation times (DT50) in Hamilton, Te Kowhai and Horotiu soils under non-sterile conditions were 9.24, 4.3 and 13.33 days respectively. During the incubation period for each sampling event the soil dehydrogenase activity (DHA) and the variation in microbial community were monitored thorough phospholipid fatty acid extraction analysis (PLFA). The DHA data correlated well with the dissipation rate constants of SMO antibiotic, an increase in the DHA activity resulted in faster antibiotic dissipation. The PLFA analysis was indicative of higher bacterial presence as compared to fungal community, highlighting the type of microbial community responsible for dissipation. The results indicate that with increasing soil depth, SMO dissipation in soil was slower (except for Horotiu) while with increase in temperature the antibiotic loss was faster, and was noticeable in all the soils. Both the degree of biological activity and the temperature of the soil influenced overall SMO dissipation. SMO is not likely to persist more than 5-6 months in all three soils suggesting that natural biodegradation may be sufficient for the removal of these contaminants from the soil. Its dissipation in sterile soils indicated abiotic factors such as strong sorption onto soil components to play a role in the dissipation of SMO. Copyright © 2014 Elsevier B.V. All rights reserved.

A comparison of dung beetle assemblage structure (Coleoptera: Scarabaeidae: Scarabaeinae between an Atlantic forest fragment and adjacent abandoned pasture in Paraná, Brazil

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José Lopes

2011-02-01

Full Text Available The study was conducted at the Mata dos Godoy State Park in Londrina, state of Paraná, Brazil. Baited pitfall traps were installed in the forest, in adjacent abandoned pasture land, and on the borders between these two environments. Every two weeks, from June 1999 to May 2000, the traps were placed for 24 hours and the material was collected every 12 hours. The 4687 specimens of Scarabaeinae collected belong to 13 genera and 27 species. The most frequent species were Onthophagus catharinensis (Paulian, 1936 (22.1%, Onthophagus hirculus (Mannerhein, 1829 (20.1%, Dichotomius mormon (Ljungh, 1799 (13.1%, Sulcophanaeus menelas (Laporte, 1840 (12.8%, and Eurystemus parallelus (Dalman, 1824 (10.6%. The other species collected amounted to less than 4.7%. The difference in numbers of specimens collected in the three environments was not significant (K(2.72 = 0.63, p = 0.729. The distribution patterns of species composition for the different environments (ANOSIM R = 0.29, p < 0.01 and activity periods (ANOSIM R = 0.18, p < 0.01 were different. Sulcophanaeus menelas, Canthidium aff. trinodosum, O. hirculus, and E. parallelus were the most abundant species, being predominantly diurnal; the first three species were more active on abandoned pasture. Most of the Dichothomius assifer (Eschscholtz, 1822 and D. mormon specimens were captured at night. The latter species was the most abundant in edges, whereas D. assifer, Scybalochantum aff. zischkai, and O. catharinensis can be considered bioindicators because they were either exclusively or highly predominant in the best preserved areas. A larger number of individuals was observed from December 1999 through March 2000, which is the time of the year when adults of Scarabaeinae normally emerge and fly, in the studied region. The highest diversity (88.89% was observed in February.

Soil, water, and nutrient losses from management alternatives for degraded pasture in Brazilian Atlantic Rainforest biome.

Science.gov (United States)

Rocha Junior, Paulo Roberto da; Andrade, Felipe Vaz; Mendonça, Eduardo de Sá; Donagemma, Guilherme Kangussú; Fernandes, Raphael Bragança Alves; Bhattharai, Rabin; Kalita, Prasanta Kumar

2017-04-01

The objective of this study was to evaluate sediment, water and nutrient losses from different pasture managements in the Atlantic Rainforest biome. A field study was carried out in Alegre Espiríto Santo, Brazil, on a Xanthic Ferralsol cultivated with braquiaria (Brachiaria brizantha). The six pasture managements studied were: control (CON), chisel (CHI), fertilizer (FER), burned (BUR), plowing and harrowing (PH), and integrated crop-livestock (iCL). Runoff and sediment samples were collected and analyzed for calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P) and organic carbon contents. Soil physical attributes and above and below biomass were also evaluated. The results indicated that higher water loss was observed for iCL (129.90mm) and CON (123.25mm) managements, and the sediment losses were higher for CON (10.24tha -1 ) and BUR (5.20tha -1 ) managements when compared to the other managements. Majority of the nutrients losses occurred in dissolved fraction (99% of Ca, 99% of Mg, 96% of K, and 65% of P), whereas a significant fraction of organic carbon (80%) loss occurred in a particulate form. Except for P, other nutrients (Ca, Mg and K) and organic carbon losses were higher in coarse sediment compared to fine sediment. The greater losses of sediment, organic carbon, and nutrients were observed for CON followed by BUR management (plosses from various practices, to reduce pasture degradation, farmers should adopt edaphic practices by applying lime and fertilize to improve pasture growth and soil cover, and reducing soil erosion in the hilly Brazilian Atlantic Rainforest biome. Copyright © 2016. Published by Elsevier B.V.

Soil organic carbon pool's contribution to climate change mitigation on marginal land of a Mediterranean montane area in Italy.

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Tommaso, Chiti; Emanuele, Blasi; Guido, Pellis; Lucia, Perugini; Vincenza, Chiriacò Maria; Riccardo, Valentini

2018-07-15

To evaluate the mitigation potential provided by the SOC pool, we investigated the impact of woody encroachment in the 0-30 cm depth of mineral soil across a natural succession from abandoned pastures and croplands to broadleaves forests on the central Apennine in Italy. In parallel, to assess the effect of the land use change (LUC) from cropland to pasture, a series of pastures established on former agricultural sites, abandoned at different time in the past, were also investigated. Our results show that woody encroachment on former pastures and croplands contributes largely to mitigate climate change, with an increase of the original SOC stock of 45% (40.5 Mg C ha -1 ) and 120% (66.5 Mg C ha -1 ), respectively. Also the LUC from croplands to pastures, greatly contributes to climate change mitigation trough a SOC increase of about 80% of the original SOC (45.9 Mg C ha -1 ). The management of abandoned lands represent a crucial point in the mitigation potential of agriculture and forestry activities, and particularly the role of the SOC pool. A policy effort should focus on minimizing the risk of speculative management options, particularly when the value of woody biomass become convenient to supply new energy systems allowing monetizing a long term forests productivity. In conclusion, despite both the land abandonment and the LUC can have a different impact on the SOC pool under different climatic conditions, these results can be useful to improve the SOC estimates in the National greenhouse gases Inventory at country level. Copyright © 2018 Elsevier Ltd. All rights reserved.

Assessing the bioavailability of dissolved organic phosphorus in pasture and cultivated soils treated with different rates of nitrogen fertiliser

NARCIS (Netherlands)

McDowell, R.W.; Koopmans, G.F.

2006-01-01

A proportion of dissolved organic phosphorus (DOP) in soil leachates is readily available for uptake by aquatic organisms and, therefore, can represent a hazard to surface water quality. A study was conducted to characterise DOP in water extracts and soil P fractions of lysimeter soils (pasture

Pasture degradation modifies soil organic matter properties and biochemical functioning in Tibetan grasslands

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Spielvogel, Sandra; Steingräber, Laura; Schleuß, Per; Kuzyakov, Yakov; Guggenberger, Georg

2015-04-01

Kobresia pastures of the Tibetan Plateau represent the world's largest alpine ecosystem. Moderate husbandry on Kobresia pastures is beneficial for the storage of soil organic carbon (OC), nitrogen (N) and other nutrients and prevents erosion by establishment of sedge-turf root mats with high OC allocation rates below ground. However, undisturbed root mats are affected by freezing and thawing processes, which cause initial ice cracks. As a consequence decomposition of root mat layers will be accelerated and current sedentarization programs with concomitant increased grazing intensity may additionally enhance root mat degradation. Finally, cracks are enlarged by water and wind erosion as well as pika activities until bare soil surface areas without root mat horizons occur. The aim of this study was to understand the impact of the root mat layer on soil organic carbon stabilization and microbial functioning depending on soil depths and to predict future changes (OC, N and nutrient losses, soil microbial functioning in SOM transformation) by overgrazing and climate change. We investigated the mineral soil below Kobresia root mats along a false time degradation sequence ranging from stage 1 (intact root mat) to stage 4 (mats with large cracks and bare soil patches). Vertical gradients of δ13C values, neutral sugar, cutin and suberin contents as well as microbial biomass estimated by total phospholipid fatty acid (PLFA), microbial community composition (PLFA profiles) and activities of six extracellular enzymes involved in the C, N, and P cycle were assessed. Soil OC and N contents as well as C/N ratios indicate an increasing illuviation of topsoil material into the subsoil with advancing root mat degradation. This was confirmed by more negative δ13C values as well as significantly (p ≤ 0.05) increasing contributions of cutin derived hydroxy fatty acids to OC in the subsoils from degradation stages 1 to 4. PLFA profiles were surprisingly similar in the subsoils of

Soil bioengineering methods for abandoned mine land surface drainage channels

Energy Technology Data Exchange (ETDEWEB)

Sotir, R.B.; Simms, A.P.; Sweigard, R.J.; Hammer, P.; Graves, D.H.; Adkins, M. [Robbin B. Sotir & Associates, Marietta, GA (USA)

1999-07-01

Research to determine the suitability of soil bioengineering for slope stabilization at abandoned surface mining sites is described. The technology uses live woody plant material as a structural component, in this case live fascine with coir erosion control fabric made from coconut. A large water collection pond draining to nine channels on the slope below was constructed as a test site. The pond has drainage channels for testing at low, intermediate, and steep slope grades. Each group of three channels is composed of one riprap rock channel, one gabion channel, and one soil bioengineering channel. The channels will be tested summer 1999. 11 refs., 5 figs., 2 tabs., 8 photos.

Soil organic carbon in riparian forests, rice fields, and pastures in Piedras, Tolima, Colombia.

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Hernán Jair Andrade-Castañeda

2016-06-01

Full Text Available The aim of the study was to estimate the soil organic carbon (SOC storage in the interface between riparian forests and a matrix of rice fields and pastures with organic management. The study took place in Piedras, Tolima, Colombia. Two plots in production (rice and pasture were selected and SOC was estimated in these areas and in the edge and the interior of adjacent riparian forests at a depth of 0 to 20 cm. Bulk density and SOC concentration were quantified between May and July, 2013. Potential change in SOC storage due to land use change among rice fields, pastures, and riparian forests was estimated. The interfaces rice field-riparian forest and pasture-riparian forest stored an average of 65.6 and 61.3 t C/ha, respectively, with no statistical differences (p>0.05. Statistical differences were not detected (p>0.05 between agricultural matrices (rice fields and pastures in any of the variables. The sampling position (matrix and the edge and interior of forests had a significant impact (p<0.05 just in bulk density: 1.7 vs 1.1 vs 1.0 g/cm3 in interior and edge of the riparian forests and the matrix, respectively. SOC was not statistically affected (p>0.05 by the position in the riparian forest-matrix interface. Conversion from riparian forests to rice fields or pastures with organic management is not emitting greenhouse gases, on the contrary, it is increasing SOC in 3.2 t C/ha. 

Effects of Biosolids Application on Pasture and Grape Vines in South-Eastern Australia

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David Nash

2011-01-01

Full Text Available Biosolids were applied to a pasture and a vineyard in south-eastern Australia. At both sites, soil Cd, Cu, and Zn concentrations linearly increased with biosolids application rates although not to the extent of exceeding soil quality guidelines. Biosolids marginally increased soil C and N concentrations at the pasture site but significantly increased P concentrations. With lower overall soil fertility at the vineyard, biosolids increased C, N, and P concentrations. At neither site did biosolids application affect soil microbial endpoints. Biosolids increased pasture production compared to the unfertilised control but had little effect on grape production or quality. Interestingly, over the 3-year trial, there was no difference in pasture production between the biosolids treated plots and plots receiving inorganic fertiliser. These results suggest that biosolids could be used as a fertiliser to stimulate pasture production and as a soil conditioner to improve vineyard soils in this region.

Organic Carbon and Physical Properties in Sandy Soil after Conversion from Degraded Pasture to Eucalyptus in the Brazilian Cerrado

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Karla Nascimento Sena

Full Text Available ABSTRACT Soil is currently seen as the most relevant carbon sink and the most effective carbon stabilizer. In contrast, agriculture is the second largest C emitter, after burning of fossil fuels. This organic carbon (OC introduced into the soil, mainly via organic matter (OM, is essential for several soil properties and plays an extremely important role in sandy soils. The objective of this study was to describe the changes in the amounts and pools of OC and the influence thereof on some physical soil properties in areas converted from pasture to eucalyptus. The following areas were analyzed: a degraded pasture (PAST, two areas of pasture-eucalyptus conversion after 2 and 15 years (EU02 and EU15, respectively and a preserved Cerrado area (CER in the east of the state of Mato Grosso do Sul. Soil samples were taken from the 0.00-0.05, 0.05-0.10, and 0.10-0.30 m layers. The OC was measured and analyzed, the carbon pool (CP calculated, aggregate stability, bulk density (BD, and macro- and microporosity determined, and total porosity (TP calculated to analyze the influence of land use on soil properties. The experimental design was completely randomized, and four clusters per area were established, with nine subsampling points, for a total of 36 subsamples per area, organized in 20 × 20 m grids, The soil under natural vegetation (preserved Cerrado was used as a control. The change from CER to commercial cultivation accelerates the process of OC loss (reductions of 25-35 % and reductions in soil physical quality. In the PAST area, OC was reduced by 30 % in the 0.00-0.05 m layer. Cumulative OC and CP were highest in the 0.00-0.05 m layer and decreased in the deeper layers in all land use treatments. Organic C in the 0.10-0.30 m layer was not influenced by land use, indicating the possibility of OC persistence in the soil for longer periods. Macroporosity and total porosity may be considered appropriate in CER and EU15, whereas the conditions for plant

Use of cesium-137 to assess soil erosion rates under soybean, coffee and pasture

International Nuclear Information System (INIS)

Andrello, A.C.; Appoloni, C.R.; Guimaraes, M.F.

2003-01-01

The methodology cesium-137 was used to assess soil erosion and deposition rates in a small watershed with varied crops, at 23 deg 16' S and 51 deg 17' W, in a district of Cambe, Parana State, Brazil. A theoretical equation which considers soil loss or gain directly proportional to the cesium-137 redistribution was utilized in this study. In the watershed, soil redistribution was assessed by transect sampling, and the regional input of cesium-137 by radioactive rainfall determined based on samples from a point in the native forest. Most sampled pasture points presented soil loss, as well as the points in the soybean area under conventional tillage, while in the coffee crop there was neither soil loss nor gain. (author)

Nitrous oxide fluxes and nitrogen cycling along a pasture chronosequence in Central Amazonia, Brazil

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B. Wick

2005-01-01

Full Text Available We studied nitrous oxide (N2O fluxes and soil nitrogen (N cycling following forest conversion to pasture in the central Amazon near Santarém, Pará, Brazil. Two undisturbed forest sites and 27 pasture sites of 0.5 to 60 years were sampled once each during wet and dry seasons. In addition to soil-atmosphere fluxes of N2O we measured 27 soil chemical, soil microbiological and soil physical variables. Soil N2O fluxes were higher in the wet season than in the dry season. Fluxes of N2O from forest soils always exceeded fluxes from pasture soils and showed no consistent trend with pasture age. At our forest sites, nitrate was the dominant form of inorganic N both during wet and dry season. At our pasture sites nitrate generally dominated the inorganic N pools during the wet season and ammonium dominated during the dry season. Net mineralization and nitrification rates displayed large variations. During the dry season net immobilization of N was observed in some pastures. Compared to forest sites, young pasture sites (≤2 years had low microbial biomass N and protease activities. Protease activity and microbial biomass N peaked in pastures of intermediate age (4 to 8 years followed by consistently lower values in older pasture (10 to 60 years. The C/N ratio of litter was low at the forest sites (~25 and rapidly increased with pasture age reaching values of 60-70 at pastures of 15 years and older. Nitrous oxide emissions at our sites were controlled by C and N availability and soil aeration. Fluxes of N2O were negatively correlated to leaf litter C/N ratio, NH4+-N and the ratio of NO3--N to the sum of NO3--N + NH4+-N (indicators of N availability, and methane fluxes and bulk density (indicators of soil aeration status during the wet season. During the dry season fluxes of N2O were positively correlated to microbial biomass N, β-glucosidase activity, total inorganic N stocks and NH4+-N. In our study region, pastures of all age emitted less N2O than

The importance of ingested soils in supplying fluorine and lead to sheep grazing contaminated pastures in the Peak District mining area of Derbyshire, UK.

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Abrahams, Peter W; Blackwell, Nia L

2013-12-01

For sheep grazing pastures in areas of mineralisation and former metalliferous mining activity, an excessive intake of potentially harmful elements (PHEs) such as fluorine (F) and lead (Pb) can result in clinical and subclinical toxicity. The prime aim of our work was to calculate the intakes of both of these PHEs by sheep grazing pastures in the mineralised/mined Peak District area of Derbyshire. The bi-monthly sampling of topsoils (0-15 cm depth) and the faeces of sheep from fields at seven farms was undertaken for a 1-year period. These samples were analysed for titanium that allowed the rates of soil ingestion (and hence also herbage ingestion since we assume that the sheep have an overall diet of 1 kg dry matter (DM)/day) to be determined. Our findings were then combined with previously published soil and soil-free pasture herbage F and Pb concentrations determined from the seven farms to calculate the intakes of both PHEs. The results show seasonal variations of soil ingestion at the seven farms ranging from toxic impact. Because the soil concentrations are greater than those associated with soil-free pasture herbage, ingested soils are the main dietary source of Pb and (especially) F to sheep. However, subjecting freshly sampled topsoils to sequential extraction procedures undertaken in the laboratory indicates that the majority of Pb and (especially) F may not be readily soluble in the ovine digestion system, so reducing the quantities of both PHEs available for absorption.

Reviving wood-pastures for biodiversity and people: A case study from western Estonia.

Science.gov (United States)

Roellig, Marlene; Sutcliffe, Laura M E; Sammul, Marek; von Wehrden, Henrik; Newig, Jens; Fischer, Joern

2016-03-01

Wood-pastures are associated with high cultural and biodiversity values in Europe. However, due to their relatively low productivity, large areas of wood-pastures have been lost over the last century. In some areas, incentive schemes have been developed to revive wood-pastures. We investigated the effects of one such scheme in western Estonia. We compared the structure of grazed wood-pastures (old and restored) to those of abandoned wood-pastures and ungrazed forest stands to explore the effects of management, and conducted interviews with 24 farmers to investigate their motivations to carry out the management. We found a positive influence of active management on the semi-open structure of wood-pastures. Financial support was vital for management, but personal values related to tradition also played an important role. The interviewees differed widely in their range of motivations, suggesting that other strategies in addition to financial incentives would further improve the management of wood-pastures in the region.

Conversion of grazed pastures to energy cane as a biofuel feedstock alters the emission of GHGs from soils in Southeastern United States

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The cultivation of energy cane throughout the Southeastern United States may displace grazed pastures on organic soil (Histosols) to meet growing demands for biofuels. We combined results from a field experiment with a biogeochemical model to improve our understanding of how the conversion of pastur...

Diazotrophic Bacterial Community of Degraded Pastures

OpenAIRE

João Tiago Correia Oliveira; Everthon Fernandes Figueredo; Williane Patrícia da Silva Diniz; Lucianne Ferreira Paes de Oliveira; Pedro Avelino Maia de Andrade; Fernando Dini Andreote; Júlia Kuklinsky-Sobral; Danúbia Ramos de Lima; Fernando José Freire

2017-01-01

Pasture degradation can cause changes in diazotrophic bacterial communities. Thus, this study aimed to evaluate the culturable and total diazotrophic bacterial community, associated with regions of the rhizosphere and roots of Brachiaria decumbens Stapf. pastures in different stages of degradation. Samples of roots and rhizospheric soil were collected from slightly, partially, and highly degraded pastures. McCrady’s table was used to obtain the Most Probable Number (MPN) of bacteria per gram ...

Soil Microbial Community Changes in Wooded Mountain Pastures due to Simulated Effects of Cattle Grazing

NARCIS (Netherlands)

Kohler, F.; Hamelin, J.; Gillet, F.; Gobat, J.M.; Buttler, A.

2005-01-01

The effect of cattle activity on pastures can be subdivided into three categories of disturbances: herbage removal, dunging and trampling. The objective of this study was to assess separately or in combination the effect of these factors on the potential activities of soil microbial communities and

Yield and soil carbon sequestration in grazed pastures sown with two or five forage species

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Increasing plant species richness is often associated with an increase in productivity and associated ecosystem services such as soil C sequestration. In this paper we report on a nine-year experiment to evaluate the relative forage production and C sequestration potential of grazed pastures sown to...

Canopy seed banks as time capsules of biodiversity in pasture-remnant tree crowns.

Science.gov (United States)

Nadkarni, Nalini M; Haber, Willam A

2009-10-01

Tropical pastures present multiple barriers to tree regeneration and restoration. Relict trees serve as "regeneration foci" because they ameliorate the soil microclimate and serve as safe spots for dispersers. Here, we describe another mechanism by which remnant trees may facilitate pasture regeneration: the presence of seed banks in the canopy soil that accumulates from decomposing epiphytes within the crowns of mature remnant trees in tropical cloud forest pastures. We compared seed banks of canopy soils (histosols derived from fallen leaves, fruits, flower, and twigs of host trees and epiphytes, dead bryophytes, bark, detritus, dead animals, and microorganisms, and dust that accumulate on trunks and the upper surfaces of large branches) in pastures, canopy soils in primary forest trees, and soil on the forest floor in Monteverde, Costa Rica. There were 5211 epiphytic and terrestrial plant seeds in the three habitats. All habitats were dominated by seeds in a relatively small number of plant families, most of which were primarily woody, animal pollinated, and animal dispersed. The density of seeds on the forest floor was greater than seed density in either pasture-canopy or forest-canopy soils; the latter two did not differ. Eight species in 44 families and 61 genera from all of the habitats were tallied. There were 37 species in the pasture-canopy soil, 33 in the forest-canopy soil, and 57 on the forest floor. Eleven species were common to all habitats. The mean species richness in the pasture canopy was significantly higher than the forest canopy (F =83.38; p banks of pasture trees can function as time capsules by providing propagules that are removed in both space and time from the primary forest. Their presence may enhance the ability of pastures to regenerate more quickly, reinforcing the importance of trees in agricultural settings.

Sampling methods for pasture, soil and deposition for radioactivity emergency preparedness in the Nordic countries

International Nuclear Information System (INIS)

Isaksson, M.

2002-01-01

The aim of this work was to compare sampling techniques for pasture, soil and deposition, planned for radioactivity surveillance in emergency situations in the Nordic countries. The basis of the survey was a questionnaire, sent to radiation protection authorities and laboratories. Sampling of pasture is performed with a cutting height between 1 and 5 cm above the ground from an area of about 1 m 2 . The sampling plots are usually randomly positioned. Soil samples, 3 to 20 cores in various patterns, are generally taken by a corer of varying diameter. For deposition sampling, precipitation collectors of different sizes are used. When comparing results, the differences between laboratories should be borne in mind so that proper corrections can be made. It is, however, important to consider that, especially in an emergency situation, the use of standardised methods may worsen the results if these methods are not part of the daily work. (orig.)

Distribution of Diverse Escherichia coli between Cattle and Pasture.

Science.gov (United States)

NandaKafle, Gitanjali; Seale, Tarren; Flint, Toby; Nepal, Madhav; Venter, Stephanus N; Brözel, Volker S

2017-09-27

Escherichia coli is widely considered to not survive for extended periods outside the intestines of warm-blooded animals; however, recent studies demonstrated that E. coli strains maintain populations in soil and water without any known fecal contamination. The objective of this study was to investigate whether the niche partitioning of E. coli occurs between cattle and their pasture. We attempted to clarify whether E. coli from bovine feces differs phenotypically and genotypically from isolates maintaining a population in pasture soil over winter. Soil, bovine fecal, and run-off samples were collected before and after the introduction of cattle to the pasture. Isolates (363) were genotyped by uidA and mutS sequences and phylogrouping, and evaluated for curli formation (Rough, Dry, And Red, or RDAR). Three types of clusters emerged, viz. bovine-associated, clusters devoid of cattle isolates and representing isolates endemic to the pasture environment, and clusters with both. All isolates clustered with strains of E. coli sensu stricto, distinct from the cryptic species Clades I, III, IV, and V. Pasture soil endemic and bovine fecal populations had very different phylogroup distributions, indicating niche partitioning. The soil endemic population was largely comprised of phylogroup B1 and had a higher average RDAR score than other isolates. These results indicate the existence of environmental E. coli strains that are phylogenetically distinct from bovine fecal isolates, and that have the ability to maintain populations in the soil environment.

Relationships among Contrasting Measurements of Microbial Dynamics in Pasture and Organic Farm Soils

International Nuclear Information System (INIS)

Edenborn, S.L; Sexstone, A.J; Sutanto, Y; Chapman, J.A

2011-01-01

Soil bacteria exhibit short-term variations in community structure, providing an indication of anthropogenic disturbances. In this study, microbial biomass carbon (MBC), potentially mineralizable nitrogen (PMN), community level physiological profiling (CLPP), and culture-dependent DGGE (CD DGGE) fingerprinting of the 16 S r RNA gene were used to compare microbial communities in organic farm and pasture soils subjected to differing agronomic treatments. Correlation analyses revealed significant relationships between MBC, PMN, and data derived from microbial community analyses. All measures separated soil types but varied in their ability to distinguish among treatments within a soil type. Overall, MBC, PMN, and CLPP were most responsive to compost and manure amendments, while CD DGGE resolved differences in legume cropping and inorganic fertilization. The results support the hypothesis that culturable soil bacteria are a responsive fraction of the total microbial community, sensitive to agronomic perturbations and amenable to further studies aimed at linking community structure with soil functions.

Effects of Bio solids Application on Pasture and Grape Vines in South-Eastern Australia

International Nuclear Information System (INIS)

Nash, D.; Butler, C.; Cody, J.; Warne, M.S.J.; McLaughlin, M.J.; Heemsbergen, D.; Broos, K.; McLaughlin, M.J.; Heemsbergen, D.; Broos, K.; Bell, M.; Barry, G.; Pritchard, D.; Penny, N.; Penny, N.

2011-01-01

Bio solids were applied to a pasture and a vineyard in south-eastern Australia. At both sites, soil Cd, Cu, and Zn concentrations linearly increased with bio solids application rates although not to the extent of exceeding soil quality guidelines. Bio solids marginally increased soil C and N concentrations at the pasture site but significantly increased P concentrations. With lower overall soil fertility at the vineyard, bio solids increased C, N, and P concentrations. At neither site did bio solids application affect soil microbial endpoints. Bio solids increased pasture production compared to the unfertilised control but had little effect on grape production or quality. Interestingly, over the 3-year trial, there was no difference in pasture production between the bio solids treated plots and plots receiving inorganic fertiliser. These results suggest that bio solids could be used as a fertiliser to stimulate pasture production and as a soil conditioner to improve vineyard soils in this region.

Soil properties impacting denitrifier community size, structure, and activity in New Zealand dairy-grazed pasture

Science.gov (United States)

Jha, Neha; Saggar, Surinder; Giltrap, Donna; Tillman, Russ; Deslippe, Julie

2017-09-01

Denitrification is an anaerobic respiration process that is the primary contributor of the nitrous oxide (N2O) produced from grassland soils. Our objective was to gain insight into the relationships between denitrifier community size, structure, and activity for a range of pasture soils. We collected 10 dairy pasture soils with contrasting soil textures, drainage classes, management strategies (effluent irrigation or non-irrigation), and geographic locations in New Zealand, and measured their physicochemical characteristics. We measured denitrifier abundance by quantitative polymerase chain reaction (qPCR) and assessed denitrifier diversity and community structure by terminal restriction fragment length polymorphism (T-RFLP) of the nitrite reductase (nirS, nirK) and N2O reductase (nosZ) genes. We quantified denitrifier enzyme activity (DEA) using an acetylene inhibition technique. We investigated whether varied soil conditions lead to different denitrifier communities in soils, and if so, whether they are associated with different denitrification activities and are likely to generate different N2O emissions. Differences in the physicochemical characteristics of the soils were driven mainly by soil mineralogy and the management practices of the farms. We found that nirS and nirK communities were strongly structured along gradients of soil water and phosphorus (P) contents. By contrast, the size and structure of the nosZ community was unrelated to any of the measured soil characteristics. In soils with high water content, the richnesses and abundances of nirS, nirK, and nosZ genes were all significantly positively correlated with DEA. Our data suggest that management strategies to limit N2O emissions through denitrification are likely to be most important for dairy farms on fertile or allophanic soils during wetter periods. Finally, our data suggest that new techniques that would selectively target nirS denitrifiers may be the most effective for limiting N2O

Mobility and toxicity of heavy metal(loid)s arising from contaminated wood ash application to a pasture grassland soil.

Science.gov (United States)

Mollon, L C; Norton, G J; Trakal, L; Moreno-Jimenez, E; Elouali, F Z; Hough, R L; Beesley, L

2016-11-01

Heavy metal(loid) rich ash (≤10,000 mg kg -1 total As, Cr, Cu and Zn) originating from the combustion of contaminated wood was subjected to several experimental procedures involving its incorporation into an upland pasture soil. Ash was added to soil that had been prior amended with local cattle manure, replicating practices employed at the farm scale. Metal(loid) concentrations were measured in soil pore water and ryegrass grown on soil/manure plus ash mixtures (0.1-3.0% vol. ash) in a pot experiment; toxicity evaluation was performed on the same pore water samples by means of a bacterial luminescence biosensor assay. Thereafter a sequential extraction procedure was carried out on selected soil, manure and ash mixtures to elucidate the geochemical association of ash derived metal(loid)s with soil constituents. Predictive modelling was applied to selected data from the pot experiment to determine the risk of transfer of As to meat and milk products in cattle grazing pasture amended with ash. The inclusion of manure to soils receiving ash reduced phyto-toxicity and increased ryegrass biomass yields, compared to soil with ash, but without manure. Elevated As and Cu concentrations in pore water and ryegrass tissue resulting from ash additions were reduced furthest by the inclusion of manure due to an increase in their geochemical association with organic matter. Zinc was the only measured metal(loid) to remain uniformly soluble and bioavailable regardless of the addition of ash and manure. Risk modelling on pot experimental data highlighted that an ash addition of >1% (vol.) to this pasture soil could result in As concentrations in milk and meat products exceeding acceptable limits. The results of this study therefore suggest that even singular low doses of ash applied to soil increase the risk of leaching of metal(loid)s and intensify the risk of As transfer in the food chain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fractionation of Pb in Soil of Abandoned Pb Mine by SEM-EDX and ...

African Journals Online (AJOL)

Therefore, scanning electron microscopy coupled with energy dispersive X-ray spectrometer (SEM-EDX) were used for the identification of fractional forms of Pb that are liable to leach out/down from the soil matrix of the abandoned mine site to surface-andunderground water bodies of the nearby localities, and to determine ...

Effects of pasture renovation on hydrology, nutrient runoff, and forage yield.

Science.gov (United States)

de Koff, J P; Moore, P A; Formica, J; Van Eps, M; DeLaune, P B

2011-01-01

Proper pasture management is important in promoting optimal forage growth and reducing runoff and nutrient loss. Pasture renovation is a management tool that improves aeration by mechanically creating holes or pockets within the soil. Pasture renovation was performed before manure application (poultry litter or swine slurry) on different pasture soils and rainfall simulations were conducted to identify the effects of pasture renovation on nutrient runoff and forage growth. Renovation of small plots resulted in significant and beneficial hydrological changes. During the first rainfall simulation, runoff volumes were 45 to 74% lower for seven out of eight renovated treatments, and infiltration rates increased by 3 to 87% for all renovated treatments as compared with nonrenovated treatments. Renovation of pasture soils fertilized with poultry litter led to significant reductions in dissolved reactive P (DRP) (74-87%), total P (TP) (76-85%), and total nitrogen (TN) (72-80%) loads in two of the three soils studied during the first rainfall simulation. Renovation did not result in any significant differences in forage yields. Overall, beneficial impacts of renovation lasted up to 3 mo, the most critical period for nutrient runoff following manure application. Therefore, renovation could be an important best management practice in these areas.

Atributos físicos e carbono orgânico em solo sob cerrado convertido para pastagem e sistema misto / Physical attributes and organic carbon in soil under brazilian Savannah converted to pasture and mixed system

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Thalita Mendes Resende

2015-12-01

Full Text Available The pasture is an important economic activity in the brazilian Savannah. From the 1970s and 1980s, the implementation of the programs to improve the productivity of pastures, was introduced grasses, especially Brachiaria. When handled properly, the pasture is an efficient method to contribute to carbon sequestration and to the mitigation of concentrations of greenhouse gases in the atmosphere, which are dependent to the time of the land-use and the properties of each soil type. The microregion of Uberlandia in Triangulo Mineiro (MG is traditionally linked to the pasture. However, the geological and natural soil conditions and climate are factors that can accelerate soil degradation when pasture is not handled properly. The objective of this article was to compare the changes of soil properties and the incorporation of C in covered areas [1] natural brazilian Savannah, [2] mixed system initially converted to agricultural use and the last 15 years of pasture, and [3] pasture cultivated with 30 years of implantation. The results show the influence of the land use on organic matter dynamics, and evaluate the potential degradation of soil by the activity, management and time of land use.

High-Resolution Denitrification Kinetics in Pasture Soils Link N2O Emissions to pH, and Denitrification to C Mineralization.

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Md Sainur Samad

Full Text Available Denitrification in pasture soils is mediated by microbial and physicochemical processes leading to nitrogen loss through the emission of N2O and N2. It is known that N2O reduction to N2 is impaired by low soil pH yet controversy remains as inconsistent use of soil pH measurement methods by researchers, and differences in analytical methods between studies, undermine direct comparison of results. In addition, the link between denitrification and N2O emissions in response to carbon (C mineralization and pH in different pasture soils is still not well described. We hypothesized that potential denitrification rate and aerobic respiration rate would be positively associated with soils. This relationship was predicted to be more robust when a high resolution analysis is performed as opposed to a single time point comparison. We tested this by characterizing 13 different temperate pasture soils from northern and southern hemispheres sites (Ireland and New Zealand using a fully automated-high-resolution GC detection system that allowed us to detect a wide range of gas emissions simultaneously. We also compared the impact of using different extractants for determining pH on our conclusions. In all pH measurements, soil pH was strongly and negatively associated with both N2O production index (IN2O and N2O/(N2O+N2 product ratio. Furthermore, emission kinetics across all soils revealed that the denitrification rates under anoxic conditions (NO+N2O+N2 μmol N/h/vial were significantly associated with C mineralization (CO2 μmol/h/vial measured both under oxic (r2 = 0.62, p = 0.0015 and anoxic (r2 = 0.89, p<0.0001 conditions.

Structure, Variation, and Co-occurrence of Soil Microbial Communities in Abandoned Sites of a Rare Earth Elements Mine.

Science.gov (United States)

Chao, Yuanqing; Liu, Wenshen; Chen, Yanmei; Chen, Wenhui; Zhao, Lihua; Ding, Qiaobei; Wang, Shizhong; Tang, Ye-Tao; Zhang, Tong; Qiu, Rong-Liang

2016-11-01

Mining activity for rare earth elements (REEs) has caused serious environmental pollution, particularly for soil ecosystems. However, the effects of REEs on soil microbiota are still poorly understood. In this study, soils were collected from abandoned sites of a REEs mine, and the structure, diversity, and co-occurrence patterns of soil microbiota were evaluated by Illumina high-throughput sequencing targeting 16S rRNA genes. Although microbiota developed significantly along with the natural restoration, the microbial structure on the site abandoned for 10 years still significantly differed from that on the unmined site. Potential plant growth promoting bacteria (PGPB) were identified by comparing 16S sequences against a self-constructed PGPB database via BLAST, and it was found that siderophore-producing and phosphorus-solubilizing bacteria were more abundant in the studied soils than in reference soils. Canonical correspondence analysis indicated that species richness of plant community was the prime factor affecting microbial structure, followed by limiting nutrients (total carbon and total nitrogen) and REEs content. Further co-occurring network analysis revealed nonrandom assembly patterns of microbiota in the studied soils. These results increase our understanding of microbial variation and assembly pattern during natural restoration in REE contaminated soils.

Nitrogen soil emissions and belowground plant processes in Mediterranean annual pastures are altered by ozone exposure and N-inputs

Science.gov (United States)

Sánchez-Martín, L.; Bermejo-Bermejo, V.; García-Torres, L.; Alonso, R.; de la Cruz, A.; Calvete-Sogo, H.; Vallejo, A.

2017-09-01

Increasing tropospheric ozone (O3) and atmospheric nitrogen (N) deposition alter the structure and composition of pastures. These changes could affect N and C compounds in the soil that in turn can influence soil microbial activity and processes involved in the emission of N oxides, methane (CH4) and carbon dioxide (CO2), but these effects have been scarcely studied. Through an open top chamber (OTC) field experiment, the combined effects of both pollutants on soil gas emissions from an annual experimental Mediterranean community were assessed. Four O3 treatments and three different N input levels were considered. Fluxes of nitric (NO) and nitrous (N2O) oxide, CH4 and CO2 were analysed as well as soil mineral N and dissolved organic carbon. Belowground plant parameters like root biomass and root C and N content were also sampled. Ozone strongly increased soil N2O emissions, doubling the cumulative emission through the growing cycle in the highest O3 treatment, while N-inputs enhanced more slightly NO; CH4 and CO2 where not affected. Both N-gases had a clear seasonality, peaking at the start and at the end of the season when pasture physiological activity is minimal; thus, higher microorganism activity occurred when pasture had a low nutrient demand. The O3-induced peak of N2O under low N availability at the end of the growing season was counterbalanced by the high N inputs. These effects were related to the O3 x N significant interaction found for the root-N content in the grass and the enhanced senescence of the community. Results indicate the importance of the belowground processes, where competition between plants and microorganisms for the available soil N is a key factor, for understanding the ecosystem responses to O3 and N.

Carbon stocks and dynamics under improved tropical pasture and silvopastoral

NARCIS (Netherlands)

Mosquera Vidal, O.; Buurman, P.; Ramirez, B.L.; Amezquita, M.C.

2012-01-01

To evaluate the effect of land use change on soil organic carbon, the carbon contents and stocks of primary forest, degraded pasture, and four improved pasture systems in Colombian Amazonia were compared in a flat and a sloping landscape. The improved pastures were Brachiaria humidicola, and

Pasture improvement in Spanish Dehesas

Science.gov (United States)

Murillo Vilanova, M.; González López, F.

2009-04-01

In the south-west of the Iberian Peninsula, the dehesa is a widespread agro-silvo-pastoral land use system, characterized by a grassland with a disperse cover of oak trees and shrubs, where the main production is extensive livestock combined with agriculture and forestry. Many years of inappropriate management of dehesas (deforestation, overgrazing, excessive agricultural activities, etc.) has led to the degradation of vegetation and soils in extensive areas, causing reductions in biomass and biodiversity, affecting the permanence of plants and causing important losses of palatable species. As there is growing interest in these wooded rangeland ecosystems due to their economic importance and high environmental value, the recovery of the original pasture biodiversity and the increase of productivity, together with the conservation of the environment, are the main goals in these areas of low productive potential, degraded and subject to soil erosion. Soil and climate conditions have a great influence on grassland production, with rainfall producing strong seasonal and interannual variations. These natural pastures, mainly composed of summer withering annual species, reach maximum productions in spring and register low values in autumn, slowing down in winter. During the summer dry season, the wilting pastures can offer a good forage for animals. Autochthonous annual legumes play an important role because they are well adapted to local edaphic and climatic conditions and produce hard seeds which germinate in autumn. This helps them to survive the frequent droughts and offer a high quality forage, which is a valuable complement to other pasture plants with lower protein content. Therefore, for several decades, legume seeding combined with the application of phosphate fertilizer has been the most common strategy used to improve pastures in SW Spain, where dehesas cover an area of about four million hectares. This paper examines the whole process of pasture improvement

Short Communication: Significance for pasture production in the ...

African Journals Online (AJOL)

Short Communication: Significance for pasture production in the southern Cape coastal region of naturalized rhizobia nodulating the strain specific Medicago ... The significance of naturalized strains of M. polymorpha in the production of medic pastures in some soils of the southern Cape coastal region is discussed.

Soil and pasture P concentration in a Fraxinus excelsior L. silvopastoral system fertilised with different types of sewage sludge

Science.gov (United States)

Ferreiro-Domínguez, Nuria; Nair, Vimala; Rigueiro-Rodríguez, Antonio; Rosa Mosquera-Losada, María

2015-04-01

In Europe, sewage sludge should be stabilised before using as fertiliser in agriculture. Depending on the stabilisation process that is used, sewage sludge has different characteristics, nutrient contents and soil nutrient incorporation rates. Sewage sludge is usually applied on a plant-available N or total metal concentration basic, and therefore, P concentrations can be well above crop needs. Leaching of excess P can threaten surface and ground waters with eutrophication. In this context, recent studies have demonstrated that the implementation of agroforestry systems could reduce the P leaching risk compared with conventional agricultural systems due to the different localisation of tree and crop roots which enhance nutrient uptake. The aim of this study was to evaluate during three consecutive years the effect of municipal sewage sludge stabilised by anaerobic digestion, composting, and pelletisation on concentration of P in soil and pasture compared to control treatments (mineral and no fertilisation) in a silvopastoral system established under Fraxinus excelsior L. in Galicia (Spain). The results showed that at the beginning of the study, the fertilisation with mineral increased more the total and available P in soil than the fertilisation with sewage sludge probably because the sludge nutrient release rate is slower than those from mineral fertilisers. The increment of soil available P caused by the mineral fertiliser implied an improvement of the P concentration in the pasture. However, in the last year of the experiment it was observed a positive effect of the fertilisation with pelletised sludge on the concentration of P in pasture compared with the composted sludge and the mineral fertiliser probably due to the annual application of this type of sludge. Therefore, the establishment of silvopastoral systems and their fertilisation with pelletized sludge should be recommended because the pelletized sludge increases the concentration of P in the pasture and

Arbuscular mycorrhizal propagules in soils from a tropical forest and an abandoned cornfield in Quintana Roo, Mexico: visual comparison of most-probable-number estimates.

Science.gov (United States)

Ramos-Zapata, José A; Guadarrama, Patricia; Navarro-Alberto, Jorge; Orellana, Roger

2011-02-01

The present study was aimed at comparing the number of arbuscular mycorrhizal fungi (AMF) propagules found in soil from a mature tropical forest and that found in an abandoned cornfield in Noh-Bec Quintana Roo, Mexico, during three seasons. Agricultural practices can dramatically reduce the availability and viability of AMF propagules, and in this way delay the regeneration of tropical forests in abandoned agricultural areas. In addition, rainfall seasonality, which characterizes deciduous tropical forests, may strongly influence AMF propagules density. To compare AMF propagule numbers between sites and seasons (summer rainy, winter rainy and dry season), a "most probable number" (MPN) bioassay was conducted under greenhouse conditions employing Sorgum vulgare L. as host plant. Results showed an average value of 3.5 ± 0.41 propagules in 50 ml of soil for the mature forest while the abandoned cornfield had 15.4 ± 5.03 propagules in 50 ml of soil. Likelihood analysis showed no statistical differences in MPN of propagules between seasons within each site, or between sites, except for the summer rainy season for which soil from the abandoned cornfield had eight times as many propagules compared to soil from the mature forest site for this season. Propagules of arbuscular mycorrhizal fungi remained viable throughout the sampling seasons at both sites. Abandoned areas resulting from traditional slash and burn agriculture practices involving maize did not show a lower number of AMF propagules, which should allow the establishment of mycotrophic plants thus maintaining the AMF inoculum potential in these soils.

Grazing alters net ecosystem C fluxes and the global warming potential of a subtropical pasture.

Science.gov (United States)

Gomez-Casanovas, Nuria; DeLucia, Nicholas J; Bernacchi, Carl J; Boughton, Elizabeth H; Sparks, Jed P; Chamberlain, Samuel D; DeLucia, Evan H

2018-03-01

The impact of grazing on C fluxes from pastures in subtropical and tropical regions and on the environment is uncertain, although these systems account for a substantial portion of global C storage. We investigated how cattle grazing influences net ecosystem CO 2 and CH 4 exchange in subtropical pastures using the eddy covariance technique. Measurements were made over several wet-dry seasonal cycles in a grazed pasture, and in an adjacent pasture during the first three years of grazer exclusion. Grazing increased soil wetness but did not affect soil temperature. By removing aboveground biomass, grazing decreased ecosystem respiration (R eco ) and gross primary productivity (GPP). As the decrease in R eco was larger than the reduction in GPP, grazing consistently increased the net CO 2 sink strength of subtropical pastures (55, 219 and 187 more C/m 2 in 2013, 2014, and 2015). Enteric ruminant fermentation and increased soil wetness due to grazers, increased total net ecosystem CH 4 emissions in grazed relative to ungrazed pasture (27-80%). Unlike temperate, arid, and semiarid pastures, where differences in CH 4 emissions between grazed and ungrazed pastures are mainly driven by enteric ruminant fermentation, our results showed that the effect of grazing on soil CH 4 emissions can be greater than CH 4 produced by cattle. Thus, our results suggest that the interactions between grazers and soil hydrology affecting soil CH 4 emissions play an important role in determining the environmental impacts of this management practice in a subtropical pasture. Although grazing increased total net ecosystem CH 4 emissions and removed aboveground biomass, it increased the net storage of C and decreased the global warming potential associated with C fluxes of pasture by increasing its net CO 2 sink strength. © 2017 by the Ecological Society of America.

Effects of irrigation and plastic mulch on soil properties on semi-arid abandoned fields

OpenAIRE

van der Meulen, E.S.; Nol, L.; Cammeraat, L.H.

2006-01-01

The Guadalentín Basin in Spain is one of the driest areas of Europe and has problems with high evaporation rates, and high risks of desertification exist including soil quality loss and soil erosion. Farmers in this semi-arid region use polyethylene covers on their irrigated croplands to reduce evaporation in order to enhance crop yield. When farmers abandon the acres, they leave the plastic covers on the fields. Up to now research has been concentrating on the effects of plastic covers on cr...

Rationally Managed Pastures Stock More Carbon than No-Tillage Fields

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Hizumi L. S. Seó

2017-12-01

Full Text Available A significant share of Greenhouse Gases (GHG produced from agriculture comes from cattle farming. The reduction in GHG emissions from ruminants fed with grains has led some researchers to recommend such a diet as a means of mitigating emissions in the sector. A more accurate balance of emissions, however, must include the carbon (C stocked by feed crops. Within the grain production system, no-tillage (NT cultivation systems have a greater capacity to increase and store soil organic carbon (SOC. Within grazing management systems, the rotation used in Voisin's Rational Grazing (VRG allows the accumulation of SOC through root growth. The objective of this study was to assess the C stock of pasture under VRG and compare soil C stock between VRG pasture and fields under no-tillage management, in two seasons over a period of 1 year. The study included five dairy farms in Santa Catarina State, Brazil. In each property, we collected soil to quantify SOC from VRG pasture and NT fields, in summer and winter. In the pasture, to determine the total stock, we also collected samples from the aerial parts of plants and the roots. Further, we estimated how efficient would be producing milk from those pastures or from those crops. The VRG pasture showed a greater capacity to stock C in the soil than the no-tillage fields (VRG = 115.0 Mg C ha−1; NT = 92.5 Mg C ha−1; p < 0.00009, with the greatest difference at a depth of 0–10 cm (VRG = 41 Mg C ha−1; NT = 32 Mg C ha−1; p < 0.00008. In VRG, 95% of C was in the soil, 1% in the aerial part of plants, and 4% in the roots. On pasture was produced 0.15 kg of milk.kg−1 of C stored, and on NT system 0.13 kg of milk.kg−1 of C stored. In this study, we conclude that independent of season, the soil in well managed pastures had a greater stock of C, produced more milk and produced more milk.kg−1 of stored C than fields under NT management. Therefore, when comparing GHG emissions of ruminants with different

Biomass requirements from natural pastures for livestock grazing ...

African Journals Online (AJOL)

The problem of seasonal shortages of herbage production from natural pastures in the Ethiopian highlands was investigated. This was done by comparing the available biomass amounts on the pastures with biomass amounts required for livestock grazing and for protecting land slope from soil erosion within a given slope ...

The management of pot experiments for fertility studies with pasture ...

African Journals Online (AJOL)

The management of pot experiments for fertility studies with pasture crops. ... Discussions on soil preparation and potting procedure, rates and methods of nutrient addition, indicator crops and the ... species|pastures|crops|moisture gradients ...

Impact of land use change on soil organic matter dynamics in subalpine grassland

Science.gov (United States)

Meyer, Stefanie; Leifeld, Jens; Bahn, Michael; Fuhrer, Jürg

2010-05-01

Information regarding the response of soil organic matter (SOM) in soils to past and expected future land use changes in the European Alps is scarce. Understanding this response requires knowledge of size and residence times of SOM fractions with distinct stabilities. In order to quantify differences between types of land use in the amount, distribution and turnover rates of soil organic carbon (SOC) in subalpine grassland soils, we used soil aggregate and SOM density fractionation in combination with 14C dating. Samples were taken along gradients of different types of land use from meadow (M) to pasture (P) and to abandoned grassland (A) in the Stubai Valley and in the Matsch Valley. Sampling sites in both areas were located at equal altitude (1880 m and 1820 m, respectively) with the same parent material and soil type, but the Matsch Valley receives 400-500 mm less annual rainfall. SOC stocks in the top 10 cm were 2.47 ± 0.32 (M), 2.75 ± 0.32 (P), and 2.50 ± 0.31 kg C/m2 (A) in the Stubai Valley and 2.25 ± 0.14 (M), 3.45 ± 0.22 (P), 3.16 ± 0.27 kg C/m2(A) in the Matsch Valley. Three aggregate size classes were separated by wet sieving: 2 mm. The light floating fraction (wPOM, ρ >1 g/cm3) was included in the analysis. Free (f-) and occluded particulate organic matter (oPOM) were isolated from each aggregate size class (ρ >1.6 g/cm3). At both locations, more than 80% of SOC was stored in small (0.25-2 mm) and large (>2 mm) macroaggregates, but no trend in relation to the different types of land use could be detected. The fraction of C in fPOM and in oPOM in all aggregate size classes was highest for soil from abandoned grasslands. The bulk soil of the abandoned site in the Stubai Valley showed a significantly higher share of fPOM-C and oPOM-C and a higher amount of wPOM-C as compared to the soil from managed grassland, whereas in the Matsch Valley pasture soil had a significantly higher wPOM-C content. At both sites, 13C natural abundance analyses revealed

The intake of lead and associated metals by sheep grazing mining-contaminated floodplain pastures in mid-Wales, UK: I. Soil ingestion, soil-metal partitioning and potential availability to pasture herbage and livestock

International Nuclear Information System (INIS)

Smith, K.M.; Abrahams, P.W.; Dagleish, M.P.; Steigmajer, J.

2009-01-01

This paper first evaluates the relative importance of the soil-plant-animal and soil-animal pathways of Zn, Cu and (especially) Pb investigated over a 15-month study period at 12 floodplain sites located within and downstream of the mineralised and historic mining area of mid-Wales, and secondly considers the implications of a sequential extraction procedure (SEP) undertaken on soils of varying particle size sampled from the study locations. Generally, very good agreement was found between the chemical partitioning of the three metals for each of the physical soil fractions subjected to the SEP. The availability of Pb to pasture vegetation, especially at the contaminated sites, is indicated with its associations with the more soluble (i.e. exchangeable and Fe/Mn oxide) soil phases, yet soil and/or plant barriers effectively restrict above-ground herbage concentrations of this metal. Consequently, with sheep ingesting soil at rates varying according to season from 0.1% to 44% or more of dry matter intake, the soil-animal pathway accounts for the majority of Pb consumption through most of the year, and at moderately and highly contaminated sites significant quantities of relatively soluble soil-Pb can be ingested at rates exceeding safety threshold limits.

Management and productive aspects of a dairy herd in a Valle d’Aosta alpine pasture

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M. Bianchi

2011-03-01

Full Text Available In Western Italia Alps pasture areas utilization ratio is sensibly getting lower both as to surfaces and to mountain livestock resources. Recent researches show that in the valley bottom areas transhumance is progressively being abandoned for a permanent and intensive livestock breeding often made up with non local breeds and anyway no more fit to high altitude grazing (Battaglini et al.,2001. This trend is leading to lose local pastures (referred as to exploitable surfaces and fertility and livestock resources.......

Atmospheric impact of abandoned boreal organic agricultural soils depends on hydrological conditions

Energy Technology Data Exchange (ETDEWEB)

Maljanen, M.; Martikainen, P.J. [Univ. of Eastern Finland, Kuopio (Finland). Dept. of Environmental Science], E-Mail: marja.maljanen@uef.fi; Hytonen, J. [Finnish Forest Research Inst., Kannus (Finland); Makiranta, P.; Minkkinen, K. [Helsinki Univ. (Finland). Dept. of Forest Sciences; Laine, J. [Finnish Forest Research Inst., Parkano (Finland)

2013-09-01

Drained agricultural peat soils are significant sources of carbon dioxide (CO{sub 2}) but also small sinks for methane (CH{sub 4}). Leaving these soils without any cultivation practice could be an option to mitigate GHG emissions. To test this hypothesis, we measured, over a three year period, net CO{sub 2} exchange and fluxes of CH{sub 4} for five agricultural peat soils that had been abandoned for 20-30 years. Annually, the sites were either small net sinks or sources of CO{sub 2} and CH{sub 4} (-7,8 to 530 g CO{sub 2}-Cm {sup -2} and -0,41 to 1,8 g CH{sub 4}m{sup -2}). Including N{sub 2}O emissions from our previous study, the net (CH{sub 4}+CO{sub 2}+N{sub 2}O) emissions as CO{sub 2} equivalents were lower than in cultivated peat soils and were lowest in the wet year. Therefore, high GHG emissions from these soils could be avoided if the water table is maintained close to the soil surface when photosynthesis is favoured over respiration. (orig.)

Phosphorus and Defoliation Interact and Improve the Growth and Composition of the Plant Community and Soil Properties in an Alpine Pasture of Qinghai-Tibet Plateau.

Science.gov (United States)

Qi, Juan; Nie, Zhongnan; Jiao, Ting; Zhang, Degang

2015-01-01

Pasture degradation caused by overgrazing and inappropriate fertiliser management is a major production and environmental threat in Qinghai-Tibet Plateau. Previous research has focused on the effects of mixed nitrogen (N) and phosphorus (P) fertiliser and reduced grazing pressure on the plant community of the grassland; however, the role of P and how it interacts with various defoliation (the process of the complete or partial removal of the above-ground parts of plants by grazing or cutting) intensities on the plant and soil of the grassland ecosystem have not been quantified. A field experiment was conducted to quantify how P application in combination of defoliation pressure could impact the dynamic change of the plant and soil in a native alpine grassland ecosystem of the Qinghai-Tibet Plateau, China, from May 2012 to September 2014. A split-plot design with 4 replicates and repeated measures was used to determine the growth and composition of plant community and soil physical and chemical properties under various levels of P fertiliser and defoliation intensity. The results showed that applying 20 kg P/ha increased the herbage yield of Melissitus ruthenica by 68% and total pasture yield by 25%. Close defoliation favoured the growth and plant frequency of the shorter species, whereas lax defoliation favoured that of the taller plant species. Medium P rate and cutting to 3 cm above ground gave an overall best outcome in pasture yield, quality and frequency and soil moisture and nutrient concentration. Application of P fertiliser with a moderate defoliation pressure to promote legume growth and N fixation has the potential to achieve multiple benefits in increasing pasture and livestock production and improving environmental sustainability in the alpine pasture of Qinghai-Tibet Plateau, a fragile and P-deficient ecosystem zone in China and its western neighbouring countries.

Medição e mapeamento da condutividade eléctrica aparente do solo em pastagens Mesurement and mapping the apparent soil electrical conductivity in pastures

Directory of Open Access Journals (Sweden)

João Manuel Serrano

2010-12-01

Full Text Available O objectivo geral deste estudo foi testar uma sonda de indução electromagnética para avaliar a variabilidade do solo e da pastagem num projecto de agricultura de precisão. Esta avaliação é a base para a gestão diferenciada da fertilização, principal ferramenta utilizada pelos agricultores para melhoria das pastagens permanentes em Portugal. O processo tradicional de amostragem e avaliação do solo e da pastagem é muito exigente em tempo, trabalho e reagentes e pode comprometer um projecto de agricultura de precisão. Este artigo descreve as principais etapas seguidas pelos autores para simplificar a metodologia de avaliação baseada na medição da condutividade eléctrica aparente do solo. Os ensaios foram realizados numa parcela com aproximadamente 6 hectares de área, que foi subdividida em quadrículas de 28 m de lado. As amostras de solo e de pastagem e a avaliação da condutividade eléctrica do solo foram georeferenciadas com um GPS-RTK. Os dados geoespaciais foram processados com o software ARCGIS 9.3 seguido de análise de regressão ponderada geograficamente. Os resultados obtidos conduziram a valores significativos dos coeficientes de regressão entre a condutividade eléctrica e a altimetria, o pH do solo e a produtividade da pastagem, em termos de matéria seca.The general objective of this study was to test a non contact electromagnetic induction probe to evaluate the soil and pasture variability in a precision agriculture project. Assessment of the variability of soil and vegetation in a permanent pasture are the basis for management of variable rate fertilization, which is the main instrument used by farmers for improvements in permanent pasture in Portugal. The traditional process of sampling and evaluation of the soil and pastures is very demanding in terms of time, labour and reagents, and can derail a project of precision agriculture. This paper describes the major steps followed by the author to simplify the

CARBON SEQUESTRATION AND PLANT COMMUNITY DYNAMICS FOLLOWING REFORESTATION OF TROPICAL PASTURE.

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WHENDEE L. SILVER; LARA M. KUEPPERS; ARIEL E. LUGO; REBECCA OSTERTAG; VIRGINIA MATZEK

2004-01-01

Conversion of abandoned cattle pastures to secondary forests and plantations in the tropics has been proposed as a means to increase rates of carbon (C) sequestration from the atmosphere and enhance local biodiversity. We used a long-term tropical reforestation project (55–61 yr) to estimate rates of above- and belowground C sequestration and to investigate the impact...

Pasture establishment and fertiliser requirements on rehabilitated land after opencast coal mining in New Zealand

Energy Technology Data Exchange (ETDEWEB)

Longhurst, R.D.; O`Connor, M.B.; Toxopeus, M.R.J. [Ruakura Agricultural Centre, Hamilton (New Zealand)

1999-03-01

Existing pasture establishment practices to rehabilitate land after opencast mining in the Waikato coal fields area of New Zealand were examined and compared with an alternative method involving different pasture mixtures, seeding rates, and lime and fertiliser requirements. Pasture establishment and production, botanical composition changes, and plant and soil nutrient status were measured during a 2-year field trial. Highly significant pasture responses were obtained to increased fertiliser inputs. An improved seed mixture, containing superior pasture cultivars, established more quickly and out-yielded the existing seed mixture by 58%. The two seed mixtures responded differently to sowing rates; the higher rate increased pasture yields of the improved pasture species but decreased the existing seed mix yields. Liming at 5 t ha{sup -1} significantly increased soil pH and clover content and reduced pasture manganese concentrations from possibly toxic levels. Nitrogen concentrations in pastures were below optimum throughout the trial and the strategic use of nitrogen fertiliser is recommended as a useful management option.

How grazing affects soil quality of soils formed in the glaciated northeastern United States.

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Cox, Alissa H; Amador, José A

2018-02-21

Historically, much of the New England landscape was converted to pasture for grazing animals and harvesting hay. Both consumer demand for local sustainably produced food, and the number of small farms is increasing in RI, highlighting the importance of characterizing the effects livestock have on the quality of pasture soils. To assess how livestock affect pasture on Charlton and Canton soils series in RI, we examined soil quality in farms raising beef cattle (Bos taurus), sheep (Ovis aries), and horses (Equus ferus caballus), using hayed pastures as a control. We sampled three pastures per livestock type and three control hayed pastures in May, August, and October 2012. Hay fields and pastures grazed by sheep had statistically significant (P soil quality than pastures grazed by beef cattle or horses. This was driven by parameters including penetration resistance, bulk density, aggregate stability, and infiltration rate. Hayfields also showed higher soil quality measures than grazed pastures for organic matter content and active C. In addition, significant differences in nitrate and phosphate concentrations were observed among livestock types. Respiration and infiltration rates, pH, and ammonium concentrations, on the other hand, did not differ significantly among pasture types. When all soil quality indicators in this study were weighed equally, soil quality scores followed the order: hay > sheep > beef cattle > horses. The results of our study provide baseline data on the effect different types of livestock have on pasture soil quality in RI, which may be useful in making sound land use and agricultural management decisions.

The Influence of Climate, Soil and Pasture Type on Productivity and Greenhouse Gas Emissions Intensity of Modeled Beef Cow-Calf Grazing Systems in Southern Australia

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Richard J. Eckard

2012-10-01

Full Text Available A biophysical whole farm system model was used to simulate the interaction between the historical climate, soil and pasture type at sites in southern Australia and assess the balance between productivity and greenhouse gas emissions (expressed in carbon dioxide equivalents, CO2-eq. intensity of beef cow-calf grazing systems. Four sites were chosen to represent a range of climatic zones, soil and pasture types. Poorer feed quality and supply limited the annual carrying capacity of the kikuyu pasture compared to phalaris pastures, with an average long-term carrying capacity across sites estimated to be 0.6 to 0.9 cows/ha. A relative reduction in level of feed intake to productivity of calf live weight/ha at weaning by feeding supplementary feed reduced the average CO2-eq. emissions/kg calf live weight at weaning of cows on the kikuyu pasture (18.4 and 18.9 kg/kg with and without supplementation, respectively, whereas at the other sites studied an increase in intake level to productivity and emission intensity was seen (between 10.4 to 12.5 kg/kg without and with supplementary feed, respectively. Enteric fermentation and nitrous oxide emissions from denitrification were the main sources of annual variability in emissions intensity, particularly at the lower rainfall sites. Emissions per unit product of low input systems can be minimized by efficient utilization of pasture to maximize the annual turnoff of weaned calves and diluting resource input per unit product.

Changes in soil carbon cycling accompanying conversion of row-crop fields to grazing dairy pastures

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Thompson, A.; Kramer, M. G.; Hill, N.; Machmuller, M. B.; Cyle, K.

2011-12-01

Increasingly, the dairy industry in the eastern US is transitioning from total confinement dairy systems (TCD) toward pasture-based, management intensive grazing dairy (MiGD) systems. This transition is driven by the fact that MiGDs require substantially less operating capital and are more economically efficient than TCD systems. Consequently, the impact of this transition and shift in land-use practice on carbon dynamics may be considerable. Land-use in a Management intensive Grazing Dairy (MiGD) system is fundamentally different than conventional confinement dairies and conventional no-till pastures. The forage system involves rotational grazing at optimal digestibility, when the plants are immature (~20-days) and consequently protein-rich. MiGD cows spend >90% of their time in the field and deposit > 90% of their waste directly to the soil surface. Thus, little above ground plant residues are directly returned to the soil, but rather substantial C inputs derive from bovine manure. We sampled a MiGD-chronosequence of row-crop to MiGD conversion established in 2007 in eastern Georgia. All soils across the MiGD-chronosequence, all occur in relative (40 km) close proximity to one another, are deep, well-drained, fine and fine sandy loam Ultisols formed on Coastal Plain sediments. Prior to MiGD established, the soils were farmed for > 50 yrs using conventional tillage techniques. Our current sampling to 1m depths captures fields at 0, 2, 3, and 5 yrs since conversion. Total soil carbon (C) and the carbon concentration of the clay fraction increased following conversion, with the greatest increases occurring between 3 and 5 yrs since conversion. These C increases were limited to the upper 40cm of the soil, with minimal change occurring at depth. Characterization of the protein and ligand content of these soils via 13C NMR and chemolytic techniques as a function of soil particle density and size is in progress and will be presented along with estimates of carbon

No evidence of increased fire risk due to agricultural land abandonment in Sardinia (Italy

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C. Ricotta

2012-05-01

Full Text Available Different land cover types are related to different levels of fire hazard through their vegetation structure and fuel load composition. Therefore, understanding the relationships between landscape changes and fire behavior is of crucial importance for developing adequate fire fighting and fire prevention strategies for a changing world. In the last decades the abandonment of agricultural lands and pastoral activities has been the major driver of landscape transformations in Mediterranean Europe. As agricultural land abandonment typically promotes an increase in plant biomass (fuel load, a number of authors argue that vegetation succession in abandoned fields and pastures is expected to increase fire hazard. In this short paper, based on 28 493 fires in Sardinia (Italy in the period 2001–2010, we show that there is no evidence of increased probability of fire ignition in abandoned rural areas. To the contrary, in Sardinia the decreased human impact associated with agricultural land abandonment leads to a statistically significant decrease of fire ignition probability.

Detecting Dewatering of Peatland Pastures Using Sentinel-1 Satellite Radar Interferometry.

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Heuff, F.; Samiei-Esfahany, S.; van Leijen, F. J.; Hanssen, R. F.

2017-12-01

The Netherlands are famous for their polders and the draining of soils to be used as pastures. Around 30% of the pastures are situated on peat soils, mostly in the western part of the Netherlands. Peat is composed of organic materials that oxidize and emit greenhouse gases when exposed to air. Oxidation of peat soils results in volume reduction and subsequent subsidence. As a result, the groundwater level rises relative to the surface. Consequently, the soil needs to be dewatered to keep it sufficiently dry for farming, resulting in more oxidation, and therefore more subsidence. This process is bound to continue until the peat soils have disappeared completely. The societal cost of land subsidence due to peat soils are estimated to be 5200 million euro for urban areas and 200 million euro for peatland pastures, for a period until 2050. Measuring the subsidence is not straightforward, if not impossible, with conventional geodetic means as soft soils make it impossible to install fixed benchmarks for repeated surveying. Also, due to the very fast temporal decorrelation over pastures, conventional InSAR approaches cannot measure a signal due to loss of coherence. Here we deploy a complete set of available SAR data from Sentinel-1, Radarsat-2 and TerraSAR-X to estimate the spatio-temporally varying subsidence signal due to the dewatering of peatland pastures over the western part of the Netherlands. We compute the InSAR coherence matrix for all possible interferometric combination, and compute an equivalent single-master stack to estimate the subsidence. Using terrain and land-use defined coherence estimation areas we optimize the phase estimation over areas severely affected by temporal decorrelation. This leads to a first estimate of deformation signals correlated with ancient shallow soil structures due to fluviatile structures. We use the methodology to investigate the effect of advanced local drainage schemes to slow down the subsidence phenomena.

Differential response of Acidobacteria subgroups to forest-to-pasture conversion and their biogeographic patterns in the western Brazilian Amazon

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Acacio Aparecido Navarrete

2015-12-01

Full Text Available Members of the phylum Acidobacteria are among the most abundant soil bacteria on Earth, but little is known about their response to environmental changes. We asked how the relative abundance and biogeographic patterning of this phylum and its subgroups responded to forest-to-pasture conversion in soils of the western Brazilian Amazon. Pyrosequencing of 16S rRNA genes was employed to assess the abundance and composition of the Acidobacteria community across 54 soil samples taken using a spatially nested sampling scheme at the landscape level. Numerically, Acidobacteria represented 20% of the total bacterial community in forest soils and 11% in pasture soils. Overall, 15 different Acidobacteria subgroups of the current 26 subgroups were detected, with Acidobacteria subgroups 1, 3, 5, and 6 accounting together for 87% of the total Acidobacteria community in forest soils and 75% in pasture soils. Concomitant with changes in soil chemistry after forest-to-pasture conversion - particularly an increase in properties linked to soil acidity and nutrient availability - we observed an increase in the relative abundances of Acidobacteria subgroups 4, 10, 17, and 18, and a decrease in the relative abundances of other Acidobacteria subgroups in pasture relative to forest soils. The composition of the total Acidobacteria community as well as the most abundant Acidobacteria subgroups (1, 3, 5, and 6 was significantly more similar in composition across space in pasture soils than in forest soils. These results suggest that preponderant responses of Acidobacteria subgroups, especially subgroups 1, 3, 4, 5, and 6, to forest-to-pasture conversion effects in soils could be used to define management-indicators of agricultural practices in the Amazon Basin. These acidobacterial responses are at least in part through alterations on acidity- and nutrient-related properties of the Amazon soils.

Differential Response of Acidobacteria Subgroups to Forest-to-Pasture Conversion and Their Biogeographic Patterns in the Western Brazilian Amazon

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Navarrete, Acacio A.; Venturini, Andressa M.; Meyer, Kyle M.; Klein, Ann M.; Tiedje, James M.; Bohannan, Brendan J. M.; Nüsslein, Klaus; Tsai, Siu M.; Rodrigues, Jorge L. M.

2015-01-01

Members of the phylum Acidobacteria are among the most abundant soil bacteria on Earth, but little is known about their response to environmental changes. We asked how the relative abundance and biogeographic patterning of this phylum and its subgroups responded to forest-to-pasture conversion in soils of the western Brazilian Amazon. Pyrosequencing of 16S rRNA genes was employed to assess the abundance and composition of the Acidobacteria community across 54 soil samples taken using a spatially nested sampling scheme at the landscape level. Numerically, Acidobacteria represented 20% of the total bacterial community in forest soils and 11% in pasture soils. Overall, 15 different Acidobacteria subgroups of the current 26 subgroups were detected, with Acidobacteria subgroups 1, 3, 5, and 6 accounting together for 87% of the total Acidobacteria community in forest soils and 75% in pasture soils. Concomitant with changes in soil chemistry after forest-to-pasture conversion—particularly an increase in properties linked to soil acidity and nutrient availability—we observed an increase in the relative abundances of Acidobacteria subgroups 4, 10, 17, and 18, and a decrease in the relative abundances of other Acidobacteria subgroups in pasture relative to forest soils. The composition of the total Acidobacteria community as well as the most abundant Acidobacteria subgroups (1, 3, 5, and 6) was significantly more similar in composition across space in pasture soils than in forest soils. These results suggest that preponderant responses of Acidobacteria subgroups, especially subgroups 1, 3, 4, 5, and 6, to forest-to-pasture conversion effects in soils could be used to define management-indicators of agricultural practices in the Amazon Basin. These acidobacterial responses are at least in part through alterations on acidity- and nutrient-related properties of the Amazon soils. PMID:26733981

Elevated CO2 and nitrogen effects on soil CO2 flux from a pasture upon return to cultivation

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Soil CO2 efflux patterns associated with converting pastures back to row crop production remain understudied in the Southeastern U.S. A 10-year study of bahiagrass (Paspalum notatum Flüggé) response to elevated CO2 was conducted using open top field chambers on a Blanton loamy sand (loamy siliceous,...

Nutrition of intensive pastures in the summer rainfall areas of ...

African Journals Online (AJOL)

Keywords: Fertilizer nitrogen sources; Fertilizers; Grasses; Legumes; Lime; Nitrogen application responses; Phosphorous; Potassium; Soil acidity; cutting; fertilizer; grass; grazing; legume; minerals; nitrogen; persistence; phosphorus; productivity; soil test calibrations; utilization; soils; nutrition; pastures; summer rainfall area; ...

DIAGNOSIS OF ENVIRONMENTAL DEGRADED PASTURES IN AREAS OF MUNICIPAL GURUPI-TO

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Gilson Araújo de Freitas

2016-03-01

Full Text Available Environmental degradation in grassland areas is a major constraint for the performance of ranching, which dominates the extensive grazing system on pasture. Therefore, this study aimed to carry out environmental assessment of pasture degradation areas in the municipality of Gurupi-TO. An environmental diagnosis was conducted in four properties: farm “Morada do Boi III”, farm “Jatobá”, and farm “Nova Esperança”. The environmental degradation was evaluated according to the following methods: (a Interview structured in a questionnaire in order to survey: formation, degradation, rehabilitation and maintenance of pastures; (B Soil sample collecting, 0-20 cm; and (c Visual assessment of the environmental degradation level. With regard to the third method, five different parameters such as: Strength and Quality of pasture, Plant population, Weeds, Ground cover, and Erosion were utilized in this evaluation. According to this, individual keys were set up for each parameter, keys that range from 1 to four 4, in which 1 was 75%. It was observed that the four properties are in degradation, but each at a different level. It was found moderate to very strong degradation, as is the case of farm “Jatobá”. It was observed, in all properties, that the soil fertility in decline is related to pasture degradation. Thus, environmental recovery strategies in the four properties are required. Keywords: soil fertility; degradation of pastures; Brachiaria brizantha.

Restoration of contaminated soils in abandoned mine areas (Tuscany, Italy)

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Bini, Claudio; Wahsha, Mohammad

2016-04-01

In Italy ore research and exploitation have been nearly exhausted since the end of the last century, and have left on the land a huge amount of mine waste, therefore provoking evident environmental damage including surface and groundwater, soils, vegetation and the food chain, and a potential threat to human health. The main processes occurring at these sites are: rock disgregation, fragments migration, dust dispersion, oxidation (Eh>250mV), acidification (pHhazard. The increasing environmental consciousness of general population compelled Public Administrators to set down effective legislation acts on this subject (e.g. D.L. 152/2006), and more generally on environmental contamination. In this work we present the results of a survey carried out at several mixed sulphides mine sites in Tuscany, exploited for at least a millennium, and closed in the last century. Biogeochemical analyses carried out on representative soil profiles (Spolic Technosols) and vegetation in the proximal and distal areas of ore exploitation show heavy metal concentrations (Cd, Cu, Fe, Pb, Zn) overcoming legislation limits on average. Ni, Cr and Mn concentrations, instead, are generally below the reference levels. The results obtained suggest that the abandoned mine sites represent actual natural laboratories where to experiment new opportunities for restoration of anthropogenically contaminated areas, and to study new pedogenetic trends from these peculiar parent materials. Moreover, plants growing on these substrates are genetically adapted to metal-enriched soils, and therefore may be utilized in phytoremediation of contaminated sites. Furthermore, the institution of natural parks in these areas could enhance their educational and scientific value, contributing in the meantime to general population amusement and recreation. Finally, it is the occasion for soil scientists to submit to the scientific community new classification proposals of this new kind of soils. Key-words: mine waste

Helminth eggs as parasitic indicators of fecal contamination in agricultural irrigation water, biosolids, soils and pastures.

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Campos, María Claudia; Beltrán, Milena; Fuentes, Nancy; Moreno, Gerardo

2018-03-15

A very common practice in agriculture is the disposal of wastewater and biosolids from water treatment systems due to their high nutrient content, which substantially improves crop yields. However, the presence of pathogens of fecal origin creates a sanitary risk to farmers and consumers. To determine the presence and concentration of helminth eggs in irrigation waters, biosolids, agricultural soils, and pastures. Water, biosolids, soil, and pasture samples were collected and analyzed for helminth egg detection, total eggs and viable eggs counts. The behavior of helminth eggs was evaluated in irrigation waters and dairy cattle grassland, where biosolids had been used as an organic amendment. Concentrations between 0.1-3 total helminth eggs/L, and 0.1-1 viable helminth eggs/L were found in water. In biosolids and soil, we found 3-22 total helminth eggs/4 g of dry weight, and 2-12 viable helminth eggs/4 g of dry weight, and in grass, we found <2-9 total helminth eggs/g of fresh weight, and <1-3 viable helminth eggs/g of fresh weight. The presence of helminth eggs in each matrix varied from days to months, which may represent a sanitary risk to farmers as well as to consumers. The presence of helminth eggs in the assessed matrixes confirms the sanitary risk of such practices. Therefore, it is important to control and incorporate regulations related to the use of wastewater and biosolids in agriculture.

Water and nitrogen in crop and pasture systems in southern Australia

International Nuclear Information System (INIS)

Angus, J.F.; Peoples, M.B.; Herwaarden, A.F. van

1998-01-01

Recent research on water and N for dryland crops in southern Australia has addressed the need for more efficient and sustainable production. Water-use efficiency is well below the potential and N-use efficiency well below optimum on farms. Excess water and N cause on-site and off-site environmental damage. The most effective means of illustrating these inefficiencies to growers is to present simple benchmarks of water and N-use efficiencies with which farmers can assess and improve the performance of their own crops. The practices shown by our recent research that best support the goals of more efficient and sustainable production are those that maximize extraction of soil water and mineral N, and increase biological N 2 fixation. Wheat growing after a brassica break-crop extract more water and mineral N from the soil than when grown as a continuous cereal, apparently because of a 'biofumigation' effect that reduces the numbers of soil-borne pathogens of wheat and produces a stronger root system. In the case of phased pasture-crop systems, annual pastures do not fully extract subsoil water or mineral N. However, when the grasses are removed from annual pastures with a selective herbicide, the remaining pure clover rapidly decomposes after maturity, leaving a large amount of mineral N for the following crop. Perennial pastures containing lucerne produce more forage and fix more N 2 than do annual pastures, but they dry the soil profile. After removal of the lucerne, the soil may be so dry that mineralization is slow, with the risk of water deficit for the subsequent crop. (author)

An intercomparison of sampling techniques among five European laboratories for measurements of radiocaesium in upland pasture and soil

International Nuclear Information System (INIS)

Nielsen, S.P.; Aarkrog, A.; Colgan, P.A.; McGee, E.; Synnott, H.J.; Johansson, K.J.; Horrill, A.D.; Kennedy, V.H.; Barbayiannis, N.

1992-02-01

An intercomparison of sampling procedures used by five European laboratories for the determination of radiocaesium in vegetation and peaty soil was carried out at two locations in Cumbria. The soil sampling procedures included th ecollection of depth profiles in order to obtain information on the vertical distribution of radiocaesium in addition to the total deposition. The number of samples taken by each laboratory varied from one to five. The multiple sampling has given information on the homogeneity of the parameters studied at each location. The parameters comprise soil bulk densities, total deposition of 137 Cs, deposition of 137 Cs in three soil layers, biomass densities, concentrations of 137 Cs in pasture, and activity ratios ( 134 Cs/ 137 Cs) in soil and vegetation. The determination of total deposition of 137 Cs gave no indication of differences between the laboratories. The total depositions of 134 Cs and 137 Cs observed at one site were compared with levels obtained from another study and the two sets of data were found to be in good agreement. The results from the soil profiles do indicate significant differences between laboratories. This covers the vertical distributions of 137 Cs deposition including the 134 Cs/ 137 Cs-activity ratios as well as the soil bulk densities. One laboratory using a coring technique observed difficulties during sampling due to compression of the soil. The coring technique should thus be avoided or applied with extreme care for the sampling of depth profiles in peaty soil. The results from the sampling of pasture show no indication of differences between the laboratories. For the parameters studied the observed variabilities across soil depths and locations range from 10% to 82% in terms of relative standard deviations. A comparison across all results at the two locations indicate a 50% higher field variability at one of the sites relative to the other. (au) (24 tabs., 9 ills., 3 refs.)

Isotope-aided studies of nutrient cycling and soil fertility assessment in humid pasture systems

International Nuclear Information System (INIS)

Wilkinson, S.R.

1983-01-01

Maintenance of primary productivity in grazed ecosystems depends on the orderly cycling of mineral nutrients. Potential applications of nuclear techniques to the study of soil fertility assessment and nutrient cycling are discussed for the plant nutrients N, P, K and S. The bioavailability of extrinsic and intrinsic sources of mineral nutrients are also discussed. With improvements in analytical technology, it appears feasible to use 15 N in grazed pasture ecosystems for N cycling studies. Sulphur cycling in soil/plant/grazing animal systems has been successfully studied, and further opportunities exist using 35 S to study nutrient flows in grazed grassland systems. Opportunities also appear for increased application of tracer technology in the evaluation of mineral intakes and mineral bioavailability to ruminants grazing semi-arid grassland herbage under native soil fertility, with supplemental fertilization, and in the evaluation of mineral supplementation procedures. Root system distribution and function also can be studied advantageously using tracer techniques. (author)

No signs of soil organic matter accumulation and of changes in nutrient (N-P) limitation during tropical secondary forest succession in the wet tropics of Southwest Costa Rica

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Wanek, Wolfgang; Oberdorfer, Sarah; Oberleitner, Florian; Hietz, Peter; Dullinger, Stefan; Zehetner, Franz

2017-04-01

Secondary forests comprise large tracts of the tropical land area, due to ongoing changes in land-use, including selective logging and agricultural land abandonment. Recent meta-analyses demonstrated that temperature and precipitation are key drivers of forest ecosystem recovery, particularly of soil organic carbon (SOC) build-up, where losses of SOC after deforestation and cultivation (and its recovery after abandonment) were largest in the wet tropical lowlands. However, wet lowland tropical chronosequences are strongly underrepresented (4000 mm) and the large variance in this group may be explained by soil type and soil nutrients. Moreover strong effects of (and changes in) nutrient limitation, with an intermittent change from P to N limitation of plant production in young tropical secondary forests, have been identified in a few studies. For this study we established a tropical secondary forest chronosequence, identifying old pastures (>40 years), young to old secondary forests (1-55 years) and old-growth forests based on aerial photographs and satellite images dating from the 1960s to the 2010s in SW Costa Rica, a region where mean annual temperature is 27°C and mean annual precipitation between 5000 and 6000 mm. Soil samples were taken incrementally to 45 cm depth, sieved and soils and roots collected and analysed. Bulk density decreased and SOC content increased from pastures to secondary forests and old-growth forests, with the net effect on soil C stocks (between 63 and 92 Mg ha-1 (0-45 cm)) being neutral. SOC stocks were generally high, due to high fine root densities and associated high root inputs to mineral soils in pastures and forests. SOC showed relatively slow turnover times, based on root and soil delta13C values, with turnover times of 120 and 210 years in topsoils and subsoils, indicating strong stabilization of SOM due to mineral binding and high aggregate stability (>80%). At the same time we found no change in soil N and P availability, but

Hydrological consequences of land-use change from forest to pasture in the Atlantic rain forest region

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Luiz Antonio Martinelli

2012-12-01

Full Text Available The Atlantic rain forest is the most endangered ecosystem in Brazil. Its degradation has started since 1500 when the European settlers arrived. Despite of all land use changes that have occurred, hydrological studies carried out in this biome have been limited to hydrological functioning of rain forests only. In order to understand the hydrological consequences of land-use change from forest to pasture, we described the hydrological functioning of a pasture catchment that was previously covered by tropical rain forest. To reach this goal we measured the precipitation, soil matric potential, discharge, surface runoff and water table levels during one year. The results indicated that there is a decrease in surface soil saturated hydraulic conductivity. However, as low intensity rainfall prevails, the lower water conductivity does not necessarily leads to a substantially higher surface runoff generation. Regarding soil water matric potential, the pasture presented higher moisture levels than forest during the dry season. This increase in soil moisture implies in higher water table recharge that, in turn, explain the higher runoff ratio. This way, land-use change conversion from forest to pasture implies a higher annual streamflow in pasture catchments. Nonetheless, this increase in runoff due to forest conversion to pasture implies in losses of biological diversity as well as lower soil protection.

Mapping the extent of abandoned farmland in Central and Eastern Europe using MODIS time series satellite data

International Nuclear Information System (INIS)

Alcantara, Camilo; Kuemmerle, Tobias; Griffiths, Patrick; Hostert, Patrick; Knorn, Jan; Müller, Daniel; Sieber, Anika; Baumann, Matthias; Bragina, Eugenia V; Radeloff, Volker C; Prishchepov, Alexander V; Schierhorn, Florian

2013-01-01

The demand for agricultural products continues to grow rapidly, but further agricultural expansion entails substantial environmental costs, making recultivating currently unused farmland an interesting alternative. The collapse of the Soviet Union in 1991 led to widespread abandonment of agricultural lands, but the extent and spatial patterns of abandonment are unclear. We quantified the extent of abandoned farmland, both croplands and pastures, across the region using MODIS NDVI satellite image time series from 2004 to 2006 and support vector machine classifications. Abandoned farmland was widespread, totaling 52.5 Mha, particularly in temperate European Russia (32 Mha), northern and western Ukraine, and Belarus. Differences in abandonment rates among countries were striking, suggesting that institutional and socio-economic factors were more important in determining the amount of abandonment than biophysical conditions. Indeed, much abandoned farmland occurred in areas without major constraints for agriculture. Our map provides a basis for assessing the potential of Central and Eastern Europe’s abandoned agricultural lands to contribute to food or bioenergy production, or carbon storage, as well as the environmental trade-offs and social constraints of recultivation. (letter)

Seasonal and temporal evolution of nutrient composition of pastures grown on remediated and non remediated soils affected by trace element contamination (Guadiamar Valley, SW Spain)

Energy Technology Data Exchange (ETDEWEB)

Madejon, P.; Dominguez, M. T.; Murillo, J. M.

2010-07-01

Elevated trace element concentrations in soils can affect the solubility and uptake of essential elements, resulting in nutrient deficiencies in plant tissues. The present paper deals with nutrient composition of pastures established on polluted and remediated soils (Green Corridor of the Guadiamar river Valley), in order to check the potential nutritional disorders that could derive from the soil pollution. In addition, nutrient composition of a representative grass, Cynodon dactylon, collected in 1999 and 2008 was compared in remediated and non-remediated sites of the polluted area. In general, nutrient concentrations of pastures were similar or even higher in polluted sites compared to control sites. Therefore, the estimated potential ingestion of main nutrients by horses (the most abundant animals in the area) was also greater in the polluted and remediated soils and covered their nutritional requirements (more than 300 (N), 70 (S), 35 (P), 400 (K), 175 (Ca) and 30 (Mg) mg kg{sup -}1 body weight day {sup -}1 in spring and autumn). Temporal evolution of nutrients and physiological ratios (N/S, Ca/P, K/Na, K/Ca+Mg) in C. dactylon showed a significant variation from 1999 to 2008, especially in the non-remediated area, leading to a recovery of the nutritional quality of this grass. The reasonable nutritional quality of pastures and the absence of negative interactions between nutrients and trace elements seem to indicate a stabilisation of soil pollutants in the affected area. (Author) 41 refs.

[Soil anti-erodibility of abandoned lands during different succession stages of plant community in hilly-gullied region of the Loess Plateau: Take Fangta small watershed as an example].

Science.gov (United States)

Yan, Fang-chen; Jiao, Ju-ying; Cao, Bin-ting; Yu, Wei-jie; Wei, Yan-hong; Kou, Meng; Hu, Shu

2016-01-01

Field survey and laboratory experiment were conducted to study the soil anti-erodibility of abandoned croplands during different vegetation succession stages in hilly-gullied region of the Loess Plateau, based on the analysis of soil particle composition, size distribution and group characteristics, soil aggregate fractal dimensions and stability. The results showed that in the earlier stages of succession from annual to perennial herbs in abandoned croplands, soil size distribution changed a little bit, the fractal dimension of soil particle increased, soil structure improved, fractal dimension and damage percent of soil aggregate structure decreased, soil stability increased, thus soil anti-erodibility increased. Therefore, natural restoration of vegetation is of great significance to improve the soil structure, increase soil erosion resistance, reduce soil erosion and promote sustainable development of regional ecological environment.

THE EFFECT OF INTRODUCED FORAGE LEGUMES ON IMPROVEMENT OF SOIL FERTILITY IN NATURAL PASTURES OF SEMI-ARID RANGELANDS OF KAJIADO DISTRICT, KENYA

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Peter N Macharia

2010-11-01

Full Text Available A two phase study was carried out from 2002 to 2005 in the semi-arid rangelands of Kajiado District, Kenya to determine the effect of introduced forage legumes on soil fertility improvement of natural pastures. During legume evaluation phase, Neonotonia wightii (Glycine, Macroptilium atropurpureum (Siratro, Lablab purpureus cv. Rongai (Dolichos, Mucuna pruriens (Velvet bean and Stylosanthes scabra var. Seca (Stylo were screened for adaptability and growth performance under the semi-arid conditions for two years. Results of soil analysis showed there were significant increases in soil pH (4.92 to 5.36, organic carbon (1.17 to 2.57% , nitrogen (0.17 to 0.22% and potassium (1.23 to 1.68 me% probably due to the large amounts of organic residues produced by the legumes (particularly Glycine, Siratro and Stylo which are perennials. The calcium content decreased significantly from 7.97 to 4.50 me% (which was attributed to plant uptake while the decrease of phosphorus was not significant. During the second phase of study for 1½ years Glycine, Siratro and Stylo were integrated into natural pastures. The results showed that only the soil pH significantly increased from 5.23 to 5.31 while all the other nutrients decreased results, which were attributed to production of less organic residues by the legumes compared to the residues produced during the legume evaluation phase. The study concluded that Glycine, Siratro and Stylo were capable of improving the soil fertility of semi-arid natural pastures only if the respective dry matter production was 10.31, 7.81 and 3.52 tha-1, amounts which were able to produce large amounts of organic residues. Â

Naturally occurring radionuclides in pasture soil, feed ingredients and milk of dairy cattle

Energy Technology Data Exchange (ETDEWEB)

Turtiainen, T.; Kostiainen, E.; Solatie, D. [STUK-Radiation and Nuclear Safety Authority (Finland)

2014-07-01

Naturally occurring radionuclides are generally considered being respective part of the environment and hence no statutory monitoring of their levels are required in food products. Therefore, limited data are available on the naturally occurring radionuclides in food. Dairy products constitute a significant portion of Finnish diet (400-500 g/d) and hence it is reasonable to study radionuclide levels in milk in more detail. Contrary to caesium, strontium and iodine, few transfer coefficients are available in the literature for naturally occurring radionuclide transfer to cow's milk. The renaissance of mining industry in Finland has raised a question among the public about the baseline values of naturally occurring radionuclides in Finnish agricultural products. The objective of this study was to investigate naturally occurring radionuclides in the components of dairy cattle diet and milk and calculate their transfer to milk. This information is needed for regulating the permitted discharges to the environment and for setting up monitoring programs if any unplanned discharges are released. In modern dairy farming, cattle are fed a precise diet in order to maximize milk production and quality and to achieve cost-effectiveness. Therefore, several different components are found in dairy cattle's diet and pasture grass concentrations are not sufficient for calculating radionuclide transfer to cow's milk. In this study, we carried out comprehensive sampling at four dairy farms each representing different areas of natural radiation background. The pasture soils were characterized and measured for natural radioactivity. Samples were taken from cattle's total diet (including e.g. pasture grass, water, silage, mineral forage) and milk. Document available in abstract form only. (authors)

Spatial variability of forage yield and soil physical attributes of a Brachiaria decumbens pasture in the Brazilian Cerrado

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Cristiano Magalhães Pariz

2011-10-01

Full Text Available The objective of this study was to analyze variability, linear and spatial correlations of forage dry mass yield (FDM and dry matter percentage (DM% of Brachiaria decumbens with the bulk density (BD, gravimetric (GM and volumetric (VM moisture, mechanical resistance to penetration (RP and organic matter content (OM, at depths 1 (0-0.10 m and 2 (0.10-0.20 m, in a Red Latosol (Oxisol, in order to select an indicator of soil physical quality and identify possible causes of pasture degradation. The geostatistical grid was installed to collect soil and plant data, with 121 sampling points, over an area of 2.56 ha. The linear correlation between FDM × DM% and FDM × BD2 was low, but highly significant. Spatial correlations varied inversely and positively, respectively. Except for DM% and BD, at both depths, the other attributes showed average to high variability, indicating a heterogeneous environment. Thus, geostatistics emerges as an important tool in understanding the interactions in pasture ecosystems, in order to minimize possible causes of degradation and indicate better alternatives for soil-plant-animal management. The decrease in FDM and increased BD1 are indicators of physical degradation (compaction of Red Latosol (Oxisol, particularly in the places with the highest concentration of animals and excessive trampling, in Cerrado conditions, in the municipality of Selvíria, Mato Grosso do Sul State, Brazil.

The impact of land abandonment on species richness and abundance in the Mediterranean Basin

DEFF Research Database (Denmark)

Plieninger, Tobias; Hui, Cang; Gaertner, Mirijam

2014-01-01

species richness and abundance in agroforestry, arable land, pastures, and permanent crops of the Mediterranean Basin. In particular, we investigated (1) which taxonomic groups (arthropods, birds, lichen, vascular plants) are more affected by land abandonment; (2) at which spatial and temporal scales.......0001) plant and animal species richness and abundance overall, though results were heterogeneous, with differences in effect size between taxa, spatial-temporal scales, land uses, landforms, and climate. In conclusion, there is no "one-size-fits-all" conservation approach that applies to the diverse contexts......Land abandonment is common in the Mediterranean Basin, a global biodiversity hotspot, but little is known about its impacts on biodiversity. To upscale existing case-study insights to the Pan-Mediterranean level, we conducted a metaanalysis of the effects of land abandonment on plant and animal...

Co-contaminants and factors affecting the sorption behaviour of two sulfonamides in pasture soils

International Nuclear Information System (INIS)

Srinivasan, Prakash; Sarmah, Ajit K.; Manley-Harris, Merilyn

2013-01-01

We investigated the effect of soil pH, organic carbon, ionic strength and steroid hormones on the sorption of sulfamethoxazole (SMO) and sulfachloropyridazine (SCP) in three pastoral soils of New Zealand. A model linking sorbate speciation with species-specific sorption coefficients describing the pH dependence of the apparent sorption coefficients was used to derive the fraction of each species of SMO. All soils displayed a decrease in sorption when pH was increased, with SMO exhibiting the highest sorption at pH 2. The cationic form of SMO appeared to sorb more close to pH ≥ pK a1 and, when pH ≥ pK a2 (6.5, 7.5 and 8.5) the anionic species seems to dominate, however, its sorption affinity to all soils was low. SMO sorption was affected by ionic strengths and organic carbon content, while the presence of hormones showed only a subtle decrease in SCP sorption in a selected model pasture soil. -- Highlights: •The effect of OC content on sulfamethoxazole sorption is nullified by the pH effect. •Steroid hormone has a subtle influence on the sulfachloropyridazine sorption in pastoral soil. •Increased hormone concentrations decrease sulfachloropyridazine sorption in soils. -- Sorption affinity of SMO and SCP are strongly governed by multitude of factors, and variations in these factors can be significant when manure and fertilisers are added to soil

Relationships between soil parameters and vegetation in abandoned terrace fields vs. non-terraced fields in arid lands (Lanzarote, Spain): An opportunity for restoration

Science.gov (United States)

Arévalo, José Ramón; Fernández-Lugo, Silvia; Reyes-Betancort, J. Alfredo; Tejedor, Marisa; Jiménez, Concepción; Díaz, Francisco J.

2017-11-01

Over 90% of terraced fields have been abandoned on the island of Lanzarote in the last 40 years. The present work analyses the effects of abandonment on the soil and vegetation recovery of terraced field agroecosystems by comparing them with adjacent non-terraced fields in Lanzarote, Canary Islands (Spain). This information is necessary to take the appropriate management actions to achieve goals such as soil protection and biodiversity conservation. Results indicate that terraced fields display better soil quality than non-terraced ones, as shown by the significant differences found in parameters such as SAR, exchangeable Na, CaCO3, B content, moisture content or soil depth. Moreover, the terraced fields' plant community has more species similarities with the native plant community when compared with non-terraced areas. Owing to characteristics such as deeper soils, more water capacity, lower salinity and less sodic soils, terraced soils provide better conditions for passive restoration of both soil and vegetation. Therefore, the recovery and maintenance of wall structures and revegetation with native/endemic species are proposed to promote the restoration of native systems and preserve a landscape with cultural and aesthetic value.

Diazotrophic Bacterial Community of Degraded Pastures

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João Tiago Correia Oliveira

2017-01-01

Full Text Available Pasture degradation can cause changes in diazotrophic bacterial communities. Thus, this study aimed to evaluate the culturable and total diazotrophic bacterial community, associated with regions of the rhizosphere and roots of Brachiaria decumbens Stapf. pastures in different stages of degradation. Samples of roots and rhizospheric soil were collected from slightly, partially, and highly degraded pastures. McCrady’s table was used to obtain the Most Probable Number (MPN of bacteria per gram of sample, in order to determine population density and calculate the Shannon-Weaver diversity index. The diversity of total diazotrophic bacterial community was determined by the technique of Denaturing Gradient Gel Electrophoresis (DGGE of the nifH gene, while the diversity of the culturable diazotrophic bacteria was determined by the Polymerase Chain Reaction (BOX-PCR technique. The increase in the degradation stage of the B. decumbens Stapf. pasture did not reduce the population density of the cultivated diazotrophic bacterial community, suggesting that the degradation at any degree of severity was highly harmful to the bacteria. The structure of the total diazotrophic bacterial community associated with B. decumbens Stapf. was altered by the pasture degradation stage, suggesting a high adaptive capacity of the bacteria to altered environments.

Bacteria diversity and microbial biomass in forest, pasture and fallow soils in the southwestern Amazon basin Diversidade de bacteria e biomassa microbiana em solos sob floresta, pastagem e capoeira no sudoeste da Amazônia

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Karina Cenciani

2009-08-01

Full Text Available It is well-known that Amazon tropical forest soils contain high microbial biodiversity. However, anthropogenic actions of slash and burn, mainly for pasture establishment, induce profound changes in the well-balanced biogeochemical cycles. After a few years the grass yield usually declines, the pasture is abandoned and is transformed into a secondary vegetation called "capoeira" or fallow. The aim of this study was to examine how the clearing of Amazon rainforest for pasture affects: (1 the diversity of the Bacteria domain evaluated by Polymerase Chain Reaction and Denaturing Gradient Gel Electrophoresis (PCR-DGGE, (2 microbial biomass and some soil chemical properties (pH, moisture, P, K, Ca, Mg, Al, H + Al, and BS, and (3 the influence of environmental variables on the genetic structure of bacterial community. In the pasture soil, total carbon (C was between 30 to 42 % higher than in the fallow, and almost 47 % higher than in the forest soil over a year. The same pattern was observed for N. Microbial biomass in the pasture was about 38 and 26 % higher than at fallow and forest sites, respectively, in the rainy season. DGGE profiling revealed a lower number of bands per area in the dry season, but differences in the structure of bacterial communities among sites were better defined than in the wet season. The bacterial DNA fingerprints in the forest were stronger related to Al content and the Cmic:Ctot and Nmic:Ntot ratios. For pasture and fallow sites, the structure of the Bacteria domain was more associated with pH, sum of bases, moisture, total C and N and the microbial biomass. In general microbial biomass in the soils was influenced by total C and N, which were associated with the Bacteria domain, since the bacterial community is a component and active fraction of the microbial biomass. Results show that the genetic composition of bacterial communities in Amazonian soils changed along the sequence forest-pasture-fallow.Os solos da floresta

Using a passive air sampler to monitor air-soil exchange of organochlorine pesticides in the pasture of the central Tibetan Plateau.

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Wang, Chuanfei; Wang, Xiaoping; Ren, Jiao; Gong, Ping; Yao, Tandong

2017-02-15

Air-soil exchange is a key process controlling the fate of persistent organic pollutants (POPs). However, the "sink effect" of soil for POPs in Tibetan pasture has not been clear. In NamCo, in the central Tibetan Plateau (TP) where the land is covered by grass, a modified passive air sampler (PAS) (thickness: 2cm) was tested. Using the PAS, the atmospheric gaseous phase organochlorine pesticides (OCPs) at 11 heights from close-to-surface (2cm) to 200cm above ground, in summer and in winter, were measured. Concentrations of OCPs in summer were higher than those in winter. Both in summer and winter, atmospheric concentrations of OCPs decreased with decreasing height from 200 to 2cm, indicating that OCPs were being deposited from air to soil. Air deposition of OCPs was possibly driven by wind speed. Furthermore, based on air OCPs at 0-3cm near the surface, the interface exchange of OCPs between air and soil was studied by the fugacity method. The results showed that pastural soil in the TP was a "sink" of OCPs even in summer. The mean deposition fluxes of α-HCH, γ-HCH and o,p'-DDT were 0.72, 0.24 and 0.54pg/h/m 2 , respectively, and it was estimated that the level of these pollutants in the soil will double every 24, 66 and 206years, respectively. This study will contribute to the further understanding of global cycling of POPs in different land covers. Copyright © 2016 Elsevier B.V. All rights reserved.

Spatial probability of soil water repellency in an abandoned agricultural field in Lithuania

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Pereira, Paulo; Misiūnė, Ieva

2015-04-01

Water repellency is a natural soil property with implications on infiltration, erosion and plant growth. It depends on soil texture, type and amount of organic matter, fungi, microorganisms, and vegetation cover (Doerr et al., 2000). Human activities as agriculture can have implications on soil water repellency (SWR) due tillage and addition of organic compounds and fertilizers (Blanco-Canqui and Lal, 2009; Gonzalez-Penaloza et al., 2012). It is also assumed that SWR has a high small-scale variability (Doerr et al., 2000). The aim of this work is to study the spatial probability of SWR in an abandoned field testing several geostatistical methods, Organic Kriging (OK), Simple Kriging (SK), Indicator Kriging (IK), Probability Kriging (PK) and Disjunctive Kriging (DK). The study area it is located near Vilnius urban area at (54 49' N, 25 22', 104 masl) in Lithuania (Pereira and Oliva, 2013). It was designed a experimental plot with 21 m2 (07x03 m). Inside this area it was measured SWR was measured every 50 cm using the water drop penetration time (WDPT) (Wessel, 1998). A total of 105 points were measured. The probability of SWR was classified in 0 (No probability) to 1 (High probability). The methods accuracy was assessed with the cross validation method. The best interpolation method was the one with the lowest Root Mean Square Error (RMSE). The results showed that the most accurate probability method was SK (RMSE=0.436), followed by DK (RMSE=0.437), IK (RMSE=0.448), PK (RMSE=0.452) and OK (RMSE=0.537). Significant differences were identified among probability tests (Kruskal-Wallis test =199.7597 ptested technique. Simple Kriging, DK, IK and PK methods identified the high SWR probabilities in the northeast and central part of the plot, while OK observed mainly in the south-western part of the plot. In conclusion, before predict the spatial probability of SWR it is important to test several methods in order to identify the most accurate. Acknowledgments COST action ES

Downward migration of radiocesium in an abandoned paddy soil after the Fukushima Dai-ichi Nuclear Power Plant accident.

Science.gov (United States)

Takahashi, Junko; Wakabayashi, Shokichi; Tamura, Kenji; Onda, Yuichi

2018-02-01

After the Fukushima Dai-ichi Nuclear Power Plant accident on March 2011, continuous monitoring of the detailed vertical distribution of radiocesium in soil is required to evaluate the fate of radiocesium and establish strategies for remediation and management of the contaminated land. It is especially important to investigate paddy soil because little knowledge has been accumulated for paddy soil and wetland rice is a major staple in Japan. Therefore, we monitored the vertical distribution of 137 Cs in abandoned paddy soil in a planned evacuation zone from June 2011 to March 2016. The decontamination works (i.e., 5 cm of surface soil removal and re-covering with uncontaminated soil) were conducted by the government in 2015. As a result of monitoring, the 137 Cs gradually migrated downward with time and the 137 Cs concentration in the 0-10 cm soil was almost homogenous in October 2014, although it was non-cultivated. The liner relationship was obtained between the median depth, which is the thickness of a soil layer containing half of the total 137 Cs inventory, and the time after the accident, indicating the migration rate was constant (1.3 cm y -1 ) before the decontamination works. After the decontamination works, the 137 Cs concentration in the uppermost surface layer was reduced by 90%, however the total 137 Cs inventory was reduced by only 50-70%. It was shown that the efficiency of 137 Cs removal by the decontamination works decrease linearly over time in fields like the studied paddy, in which the homogenization of 137 Cs concentration occurred. Conversely, the downward migration of 137 Cs to subsurface layers deeper than 10 cm (i.e., plowpan layer) with low permeability rarely occurred. It is expected that these unique trends in distribution and migration of 137 Cs would be found in abandoned paddy soils with properties similar to the studied soil, sandy loam but poorly drained because of the low permeable plowpan layer, although further validation is

Natural Radionuclides in Meadow and Pasture land in the Nordic countries

DEFF Research Database (Denmark)

Rosén, Klas; Villanueva, José - Luis Gutiérrez; Sundell-Bergman, Synnöve

transfer for pasture land under the different conditions that prevail in the Nordic countries. The potential health hazards due to chronic ingestion of low concentrations of naturally occurring radionuclides are fairly unknown but the results of this study may provide valuable background information...... for assessing these radiation risks. The aim of this project has been to gain knowledge on the status of natural radionuclides in meadow and pasture land and in grassland plants in different Nordic countries and on the transfer of these radionuclides from soil/water to man via the milk/food chain (soil- meadow/pasture...... grass –cow-milk). Limited data are available on the mobility and the transfer of naturally occurring radionuclides in the ecosystems of the agricultural land. In addition, information concerning the concentrations in meat and dairy products is of interest for assessing exposures of humans to natural...

SOIL FLUXES OF CO2, CO, NO AND N2O FROM AN OLD-PASTURE AND FROM NATIVE SAVANNA IN BRAZIL

Science.gov (United States)

We compared fluxes of CO2, CO, NO and N2O, soil microbial biomass, and N-mineralization rates in a 20-year old Brachiaria pasture and a native cerrado area (savanna in Central Brazil). In order to assess the spatial variability of CO2 fluxes, we tested the relation between elect...

Effect of pH on the denitrifying enzyme activity in pasture soils in relation to the intrinsic differences in denitrifier communities

Czech Academy of Sciences Publication Activity Database

Čuhel, Jiří; Šimek, Miloslav

2011-01-01

Roč. 56, č. 3 (2011), s. 230-235 ISSN 0015-5632 R&D Projects: GA MŠk LC06066; GA AV ČR IAA600660605 Institutional research plan: CEZ:AV0Z60660521 Keywords : pH * denitrifying enzyme activity * pasture soils Subject RIV: EH - Ecology, Behaviour Impact factor: 0.677, year: 2011

Comparison of water soil erosion on Spanish Mediterannean abandoned land and agricultural fields under vine, almond, olives and citrus

Science.gov (United States)

Rodrigo-Comino, Jesús; Martínez-Hernández, Carlos; Iserloh, Thomas; Cerdà, Artemi

2017-04-01

The abandonment of agricultural lands is considered as a global dynamic with on- and off-site consequences on the soil mostly ignored (Vanmaercke et al., 2011), which enhance land degradation processes by increasing water soil erosion (Cammeraat et al., 2010; Keesstra et al., 2012) and by decreasing biodiversity (Brevik et al., 2015; Smith et al., 2015). However, there is a lack of information at pedon scale about the assessment and quantification of which environmental elements activate or avoid water soil erosion after its respective abandonment. Small portable rainfall simulators are considered as useful tool for measuring interrelated soil erosion processes such as splash, initial rainfall-runoff processes, infiltration, sediment yield, water turbidity or nutrient suspensions (Cerdà, 1999; Iserloh et al., 2013; Rodrigo Comino et al., 2016). 105 experiments were conducted with a small portable rainfall simulator (rainfall intensity of 40 mm h-1 in 30 minutes) in four different land uses and their respective abandoned land: i) citrus and olives (Valencia), almonds (Murcia) and vines (Málaga). We studied the main environmental factors that may determine water soil erosion during the performed experiments: slope, vegetation cover, rock fragment cover, soil properties (texture) and hydrological responses (time to runoff and infiltration generation). REFERENCES Brevik, E.C., Cerdà, A., Mataix-Solera, J., Pereg, L., Quinton, J.N., Six, J., Van Oost, K., 2015. The interdisciplinary nature of SOIL. SOIL 1, 117-129. doi:10.5194/soil-1-117-2015 Cammeraat, E.L.H., Cerdà, A., Imeson, A.C., 2010. Ecohydrological adaptation of soils following land abandonment in a semi-arid environment. Ecohydrology 3, 421-430. doi:10.1002/eco.161 Cerdà, A., 1999. Simuladores de lluvia y su aplicación a la Geomorfología: Estado de la cuestión. Cuad. Investig. Geográfica 45-84. Iserloh, T., Ries, J.B., Arnáez, J., Boix-Fayos, C., Butzen, V., Cerdà, A., Echeverría, M.T., Fern

Response of free-living nitrogen-fixing microorganisms to land use change in the Amazon rainforest.

Science.gov (United States)

Mirza, Babur S; Potisap, Chotima; Nüsslein, Klaus; Bohannan, Brendan J M; Rodrigues, Jorge L M

2014-01-01

The Amazon rainforest, the largest equatorial forest in the world, is being cleared for pasture and agricultural use at alarming rates. Tropical deforestation is known to cause alterations in microbial communities at taxonomic and phylogenetic levels, but it is unclear whether microbial functional groups are altered. We asked whether free-living nitrogen-fixing microorganisms (diazotrophs) respond to deforestation in the Amazon rainforest, using analysis of the marker gene nifH. Clone libraries were generated from soil samples collected from a primary forest, a 5-year-old pasture originally converted from primary forest, and a secondary forest established after pasture abandonment. Although diazotroph richness did not significantly change among the three plots, diazotroph community composition was altered with forest-to-pasture conversion, and phylogenetic similarity was higher among pasture communities than among those in forests. There was also 10-fold increase in nifH gene abundance following conversion from primary forest to pasture. Three environmental factors were associated with the observed changes: soil acidity, total N concentration, and C/N ratio. Our results suggest a partial restoration to initial levels of abundance and community structure of diazotrophs following pasture abandonment, with primary and secondary forests sharing similar communities. We postulate that the response of diazotrophs to land use change is a direct consequence of changes in plant communities, particularly the higher N demand of pasture plant communities for supporting aboveground plant growth.

How to determine the GHG budget of a pasture field with grazing animals

Science.gov (United States)

Ammann, Christof; Neftel, Albrecht; Felber, Raphael

2016-04-01

Up to now the scientific investigation and description of the agriculture related greenhouse gas (GHG) exchange has been largely separated into (i) direct animal related and (ii) ecosystem area related processes and measurement methods. An overlap of the two usually separated topics occurs for grazed pastures, where direct animal and pasture area emissions are relevant. In the present study eddy covariance (EC) flux measurements on the field scale were combined with a source location attribution (footprint) model and with GPS position measurements of the individual animals. The experiment was performed on a pasture field in Switzerland under a rotational full grazing regime with dairy cows. The exchange fluxes of CH4, CO2, and N2O were measured simultaneously over the entire year. The observed CH4 emission fluxes correlated well with the presence of cows in the flux footprint. When converted to average emission per cow, the results agreed with published values from respiration chamber experiments with similar cows. For CO2 a sophisticated partitioning algorithm was applied to separate the pasture and animal contributions, because both were in the same order of magnitude. The N2O exchange fully attributable to the pasture soil showed considerable and continuous emissions through the entire seasonal course mainly modulated by soil moisture and temperature. The resulting GHG budget shows that the largest GHG effect of the pasture system was due to enteric CH4 emissions followed by soil N2O emissions, but that the carbon storage change was affected by a much larger uncertainty. The results demonstrate that the EC technique in combination with animal position information allows to consistently quantify the exchange of all three GHG on the pasture and to adequately distinguish between direct animal and diffuse area sources (and sinks). Yet questions concerning a standardized attribution of animal related emissions to the pasture GHG budget still need to be resolved.

Woody plant encroachment effect on soil organic carbon dynamics: results from a latitudinal gradient in Italy

Science.gov (United States)

Pellis, Guido; Chiti, Tommaso; Moscatelli, Maria Cristina; Marinari, Sara; Papale, Dario

2016-04-01

Woody plant encroachment into pastures and grasslands represents a significant land cover change phenomenon, with a considerable impact on carbon dynamics at an ecosystem level. It was estimated that 7.64% of the Southern Europe land was subject to that process between 1950 to 2010. As a result of woody encroachment, changes in vegetation composition can produce substantial changes to the soil organic carbon (SOC) cycle. Despite the numerous papers published on land-use change, an evaluation of the IPCC terrestrial carbon pools changes occurring during woody encroachment on abandoned pastures and grasslands is still lacking, particularly for the Italian territory. Therefore, the aim of this study was to investigate the role of woody encroachment on carbon sequestration over abandoned pastures and grasslands in Alpine and Apennine ecosystems, with a particular focus on the SOC. We applied a chronosequence approach to seven selected sites located along a latitudinal gradient in Italy. Each chronosequence consisted of a pasture currently managed, three sites abandoned at different times in the past and, finally, a mature forest stand representing the last phase of the succession. The European Commission sampling protocols to certify SOC changes was adopted to estimate the variations following woody encroachment. Soil samples were collected at different depths in the topsoil (0-30 cm) and subsoil (30-70 cm), despite the original protocol formulation being limited to the topsoil only. In addition, aboveground living biomass (AGB), dead wood and litter were also measured following international protocols. Considering all C pools together, woody plant encroachment leads to a progressive C stock accumulation in all the chronosequences. The total C stock of mature forest stands ranges from 1.78±0.11 times (Eastern Alps) to 2.48±0.31 times (central Apennine) the initial value on pastures. Unsurprisingly, the C stocks of AGB, dead wood and litter all increase during the

Effects of Weather Variability on Crop Abandonment

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Kelvin Mulungu

2015-03-01

Full Text Available In Zambia, every year some parts of the maize fields are abandoned post-planting. Reasons for this are not clearly known. In this paper, we examine the influence of soil and climatic factors on crop abandonment using a six-year (2007–2012 panel data by modeling the planted-to-harvested ratio (a good indicator of crop abandonment using a fractional and linear approach. Therefore, for the first time, our study appropriately (as supported by the model specification tests that favour fractional probit over linear models the fractional nature of crop abandonment. Regression results, which are not very different between the two specifications, indicate that, more than anything, high rainfall immediately after planting and inadequate fertilizer are the leading determinants of crop abandonment. In the agro-ecological region where dry planting takes place, low temperature during planting months negatively affects the harvested area. The results have implications on the sustainability of farming systems in the face of a changing climate.

Mercury contamination in agricultural soils from abandoned metal mines classified by geology and mineralization.

Science.gov (United States)

Kim, Han Sik; Jung, Myung Chae

2012-01-01

This survey aimed to compare mercury concentrations in soils related to geology and mineralization types of mines. A total of 16,386 surface soils (0~15 cm in depth) were taken from agricultural lands near 343 abandoned mines (within 2 km from each mine) and analyzed for Hg by AAS with a hydride-generation device. To meaningfully compare mercury levels in soils with geology and mineralization types, three subclassification criteria were adapted: (1) five mineralization types, (2) four valuable ore mineral types, and (3) four parent rock types. The average concentration of Hg in all soils was 0.204 mg kg(-1) with a range of 0.002-24.07 mg kg(-1). Based on the mineralization types, average Hg concentrations (mg kg(-1)) in the soils decreased in the order of pegmatite (0.250) > hydrothermal vein (0.208) > hydrothermal replacement (0.166) > skarn (0.121) > sedimentary deposits (0.045). In terms of the valuable ore mineral types, the concentrations decreased in the order of Au-Ag-base metal mines ≈ base metal mines > Au-Ag mines > Sn-W-Mo-Fe-Mn mines. For parent rock types, similar concentrations were found in the soils derived from sedimentary rocks and metamorphic rocks followed by heterogeneous rocks with igneous and metamorphic processes. Furthermore, farmland soils contained relatively higher Hg levels than paddy soils. Therefore, it can be concluded that soils in Au, Ag, and base metal mines derived from a hydrothermal vein type of metamorphic rocks and pegmatite deposits contained relatively higher concentrations of mercury in the surface environment.

Soft X-ray spectromicroscopy study of mineral-organic matter associations in pasture soil clay fractions.

Science.gov (United States)

Chen, Chunmei; Dynes, James J; Wang, Jian; Karunakaran, Chithra; Sparks, Donald L

2014-06-17

There is a growing acceptance that associations with soil minerals may be the most important overarching stabilization mechanism for soil organic matter. However, direct investigation of organo-mineral associations has been hampered by a lack of methods that can simultaneously characterize organic matter (OM) and soil minerals. In this study, STXM-NEXAFS spectroscopy at the C 1s, Ca 2p, Fe 2p, Al 1s, and Si 1s edges was used to investigate C associations with Ca, Fe, Al, and Si species in soil clay fractions from an upland pasture hillslope. Bulk techniques including C and N NEXAFS, Fe K-edge EXAFS spectroscopy, and XRD were applied to provide additional information. Results demonstrated that C was associated with Ca, Fe, Al, and Si with no separate phase in soil clay particles. In soil clay particles, the pervasive C forms were aromatic C, carboxyl C, and polysaccharides with the relative abundance of carboxyl C and polysaccharides varying spatially at the submicrometer scale. Only limited regions in the soil clay particles had aliphatic C. Good C-Ca spatial correlations were found for soil clay particles with no CaCO3, suggesting a strong role of Ca in organo-mineral assemblage formation. Fe EXAFS showed that about 50% of the total Fe in soils was contained in Fe oxides, whereas Fe-bearing aluminosilicates (vermiculite and Illite) accounted for another 50%. Fe oxides in the soil were mainly crystalline goethite and hematite, with lesser amounts of poorly crystalline ferrihydrite. XRD revealed that soil clay aluminosilicates were hydroxy-interlayered vermiculite, Illite, and kaolinite. C showed similar correlation with Fe to Al and Si, implying a similar association of Fe oxides and aluminosilicates with organic matter in organo-mineral associations. These direct microscopic determinations can help improve understanding of organo-mineral interactions in soils.

Adverse impacts of pasture abandonment in Himalayan protected areas: Testing the efficiency of a Natural Resource Management Plan (NRMP)

International Nuclear Information System (INIS)

Nautiyal, Sunil; Kaechele, Harald

2007-01-01

The high elevational areas in the Himalayas of India are dominated by forests and alpine pastures. There are many protected areas in the region, including Nanda Devi Biosphere Reserve (NDBR) and Valley of Flowers (VOF) where natural resource management plan (NRMP) has been implemented for the conservation of biodiversity. This has affected the traditional animal husbandry system, as well as the vegetation dynamics of alpine pastures. An integrated approach to studying the impact of NRMP in the region has been applied by us. First, a survey was conducted regarding livestock management, data pertaining the livestock husbandry, the role of animal husbandry in economics of rural household, and socioeconomics. Second, field based study on phytosociology of some important alpine herbs was done to enumerate the density and species richness in different land mark of the region. Thereafter, satellite data and Geographic Information System (GIS) were used to develop a land cover map of the area and to note changes in the landscape over time after implementation of NRMP. From an economic point of view the implementation of such plan is a setback to the rural economy. However, the ecological perspective of such models is a threat to the diversity of alpine pastures. The invasion of bushes/thorny bushes/shrubs and weeds with their luxuriant growth is changing the vegetation index and dynamics. Consequently, the diversity of herbs in alpine pastures of the Himalayan Mountains is in jeopardy. Overall, the situation is leading to landscape change in the region. This study is helpful for generating useful outcomes and strategies considering the question or debate 'is grazing good or bad for pasture ecosystems in the Himalayas?'

Effects of Grazing Abandoned Grassland on Herbage Production and Utilization, and Sheep Preference and Performance

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Håvard Steinshamn

2018-05-01

Full Text Available Large areas of farmland are abandoned in Norway, which for various reasons are regarded as undesirable. Loss of farmland may have negative implications for biodiversity and ecosystem function and food production potential. The objectives of this study were to assess forage mass production and utilization, botanical composition, lamb performance, and grazing distribution pattern when reintroducing livestock grazing to an abandoned grassland. The study area was located in Central Norway, unmanaged for 12 years. Sheep grazed the area for 10 weeks in 2013 and 4 weeks in spring and autumn, respectively, in 2014 and 2015. During the summer of 2014 and 2015, the area was subjected to the following replicated treatments: (1 No grazing, (2 grazing with heifers, and (3 grazing with ewes and their offspring. The stocking rate was similar in the grazed treatments. Forage biomass production and animal intake were estimated using grazing exclosure cages and botanical composition by visual assessment. Effect on lamb performance was evaluated by live weight gain and slaughter traits in sheep subjected to three treatments: (1 Common farm procedure with summer range pasturing, (2 spring grazing period extended by 1 month on the abandoned grassland before summer range pasturing, and (3 spring and summer grazing on the abandoned grassland. Grazing distribution patterns were studied using GPS position collars on ewes. Total annual biomass production was on average 72% higher with summer grazing than without. Annual consumption and utilization was on average 218 g DM/m2 and 70% when summer grazed, and 25 g DM/m2 and 18% without grazing, respectively. Botanical composition did not differ between treatments. Live weight gain was higher in lambs subjected to an extended spring grazing period (255 g/d compared to common farm practice (228 g/d and spring and summer grazing on the abandoned grassland (203 g/d, and carcass value was 14% higher in lambs on extended spring

Factors associated with profitability in pasture-based systems of milk production.

Science.gov (United States)

Hanrahan, L; McHugh, N; Hennessy, T; Moran, B; Kearney, R; Wallace, M; Shalloo, L

2018-06-01

The global dairy industry needs to reappraise the systems of milk production that are operated at farm level with specific focus on enhancing technical efficiency and competitiveness of the sector. The objective of this study was to quantify the factors associated with costs of production, profitability, and pasture use, and the effects of pasture use on financial performance of dairy farms using an internationally recognized representative database over an 8-yr period (2008 to 2015) on pasture-based systems. To examine the associated effects of several farm system and management variables on specific performance measures, a series of multiple regression models were developed. Factors evaluated included pasture use [kg of dry matter/ha and stocking rate (livestock units/ha)], grazing season length, breeding season length, milk recording, herd size, dairy farm size (ha), farmer age, discussion group membership, proportion of purchased feed, protein %, fat %, kg of milk fat and protein per cow, kg of milk fat and protein per hectare, and capital investment in machinery, livestock, and buildings. Multiple regression analysis demonstrated costs of production per hectare differed by year, geographical location, soil type, level of pasture use, proportion of purchased feed, protein %, kg of fat and protein per cow, dairy farm size, breeding season length, and capital investment in machinery, livestock, and buildings per cow. The results of the analysis revealed that farm net profit per hectare was associated with pasture use per hectare, year, location, soil type, grazing season length, proportion of purchased feed, protein %, kg of fat and protein per cow, dairy farm size, and capital investment in machinery and buildings per cow. Pasture use per hectare was associated with year, location, soil type, stocking rate, dairy farm size, fat %, protein %, kg of fat and protein per cow, farmer age, capital investment in machinery and buildings per cow, breeding season length

Mineralogical and geochemical study of contaminated soils on abandoned Sb deposits Dubrava and Poproc

International Nuclear Information System (INIS)

Klimko, T.; Jurkovic, L.

2010-01-01

In this paper we present initial results of mineralogical and geochemical study of secondary mineral phases, often with a high content of Sb and As, resulting from oxidation of sulphide minerals in the soil environment on two, now abandoned Sb deposits. Dubrava deposit is situated on the northern slopes of the Dumbier Low Tatras and Poproc deposit is located in the eastern part of Spis-Gemer Rudohorie. Both studied sites were in the past (second half of 20 th century) significant producers of antimony ore and Dubrava deposit belonged to medium-sized Sb deposits in the world.

Evaluating pasture and soil allowance of manganese for Kajli rams grazing in semi-arid environment.

Science.gov (United States)

Khan, Zafar Iqbal; Ahmad, Kafeel; Ashraf, Muhammad; Naqvi, Syed Ali Hassan; Seidavi, Alireza; Akram, Nudrat Aisha; Laudadio, Vito; Tufarelli, Vincenzo

2015-03-01

The current research on the manganese (Mn) transfer from soil to plant as well as to grazing Kajli rams in the form of sampling periods was carried out under semi-arid environmental conditions. Forage, soil and blood plasma samples were collected during 4 months of the year after a 1-month interval, and Mn concentrations were assessed after wet digestion using an atomic absorption spectrophotometer. Results showed that Mn concentration in soil ranged from 48.28 to 59.44 mg/kg, with incoherent augment and decline across sampling periods, and effect of sampling period on soil Mn was also found to be significant (P soil appeared higher than the critical value and sufficient for forage crop requirement. The Mn concentration in forage ranged between 24.8 and 37.2 mg/kg, resulting deficient based on the requirement allowance of Mn for livestock grazing animals, therein with almost unchanged forage Mn concentration. The Mn values in blood plasma of rams varied from 0.066 to 0.089 mg/l, with a consistent increase based on sampling period, and the effect of sampling periods on plasma Mn was found to be highly significant (P soil and plant species amassing capability on the transport of Mn in the soil-plant-animal system. Results indicated a much higher accumulation rate at the sampling characterized by vegetation dominated by legumes in comparison to grasses, crop residues and mixed pasture and a pronounced seasonal supply of Mn at the four sampling period of grazing land of diverse botanical composition.

Long-term persistence of polychlorinated dibenzo-p-dioxins and dibenzofurans in air, soil and sediment around an abandoned pentachlorophenol factory in China

International Nuclear Information System (INIS)

Li Cheng; Zheng, Minghui; Zhang Bing; Gao Lirong; Liu Lidan; Zhou Xin; Ma Xiaodong; Xiao Ke

2012-01-01

Air, soils and sediments surrounding an abandoned pentachlorophenol (PCP) factory were sampled to determine the levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), unintentionally formed during PCP production. The mean concentration of PCDD/Fs in ambient air was one order of magnitude higher than that of the reference site. A trend of decreasing concentrations with increasing distance from the factory was observed, suggesting this site has a significant influence on the regional ambient air. As for soil samples collected within 3 km from the factory and sediment samples from the adjacent rivers, high levels of contamination were found with WHO-TEQ concentrations of 193 ± 211 pg/g and 667 ± 978 pg/g, respectively. The PCDD/F homologue profiles of all samples were consistent with those found in the technical product of PCP, with OCDD as the dominant congener. These results indicate PCDD/Fs in the historical contaminated site pose a long-term impact on surrounding environment. - Highlights: ► PCDD/Fs were investigated in various environmental compartments surrounding an abandoned pentachlorophenol (PCP) factory. ► High levels of PCDD/F contamination were found in ambient air, soils and the sediments around this factory. ► PCDD/F homologue profiles were consistent with PCDD/Fs in technical product of PCP. ► PCDD/Fs in this historical contaminated site pose a long-term impact on surrounding environment. - PCDD/Fs around an abandoned pentachlorophenol factory pose a long-term impact on surrounding environment.

Banco de sementes de plantas daninhas em solo cultivado com pastagens de Brachiaria brizantha e Brachiaria humidicola de diferentes idades Weed seed bank in soil cultivated with pasture of Brachiaria brizantha and Brachiaria humidicola of different ages

Directory of Open Access Journals (Sweden)

D.S.M. Silva

2001-08-01

Full Text Available Estudou-se o banco de sementes do solo de uma pastagem de Brachiaria brizantha com 4 anos de idade e de pastagens de Brachiaria humidicola com 4, 15 e 20 anos de idade, localizadas no nordeste do Estado do Pará. Objetivou-se avaliar a influência da espécie forrageira e da idade da pastagem no tamanho e na composição do banco de sementes de plantas daninhas do solo. Cada pastagem foi dividida em cinco áreas de aproximadamente 500 m², sendo retiradas, de cada área, 10 subamostras de solo na profundidade de 0-10 cm. Cada amostra composta das 10 subamostras de solo foi homogeneizada, identificada, distribuída em bandeja de plástico e levada para germinar em casa de vegetação durante um período de 15 meses. O banco de sementes do solo da pastagem de B. brizantha foi em torno de 10 vezes menor que o da pastagem de B. humidicola de mesma idade. Com relação ao efeito da idade da pastagem, entre as pastagens de B. humidicola, o banco de sementes foi menor naquela de 20 anos de idade (1.247 sementes m-2, não tendo sido detectada diferença significativa entre as pastagens de 15 (11.602 sementes m-2 e 4 (9.486 sementes m-2 anos de idade. As famílias botânicas Cyperaceae, Rubiaceae e Labiateae foram as de maior predominância entre as plantas daninhas infestantes da área, em todos os tratamentos estudados.The objective of this work was to study the soil seed bank of a four-year-old Brachiaria brizantha pasture soil, and in pasture soils of four, 15 and 20 year-old Brachiaria humidicola, in northeastern Pará, Brazil, to evaluate the influence of the forage species and pasture age on weed seed bank size and composition. Each pasture area was divided into five plots of about 500 m², from which 10 soil sub-samples were collected at a depth of 0-10 cm. The soil from each plot was mixed, identified, placed in plastic trays, and put to germinate in a greenhouse during a 15-month period. The seed bank of the four-year-old B. brizantha pasture

Relationship between gross nitrogen cycling and nitrous oxide emission in grass-cliver pasture

DEFF Research Database (Denmark)

Ambus, P.

2005-01-01

between 82 and 136 mu g N(2)O-N m(-2) d(-1), independent of pasture age. The (15)N labelling indicated that at least 50% of the N(2)O was derived from the soil NH(4)(+) pool, approaching 100% in June. In the two year old pasture the NH(4)(+) pool contributions to N(2)O emissions varied significantly...... with sampling time. Emission rates of N(2)O correlated positively with soil NH(4)(+) concentrations and the NH(4)(+) supply as expressed by gross mineralization. The N(2)O emissions showed a significant inverse relationship with soil NO(3)(-), but was not correlated with the supply of NO(3)(-) as expressed...

Heavy metal immobilization in soil near abandoned mines using eggshell waste and rapeseed residue.

Science.gov (United States)

Lee, Sang Soo; Lim, Jung Eun; El-Azeem, Samy A M Abd; Choi, Bongsu; Oh, Sang-Eun; Moon, Deok Hyun; Ok, Yong Sik

2013-03-01

Heavy metal contamination of agricultural soils has received great concern due to potential risk to human health. Cadmium and Pb are largely released from abandoned or closed mines in Korea, resulting in soil contamination. The objective of this study was to evaluate the effects of eggshell waste in combination with the conventional nitrogen, phosphorous, and potassium fertilizer (also known as NPK fertilizer) or the rapeseed residue on immobilization of Cd and Pb in the rice paddy soil. Cadmium and Pb extractabilities were tested using two methods of (1) the toxicity characteristics leaching procedure (TCLP) and (2) the 0.1 M HCl extraction. With 5 % eggshell addition, the values of soil pH were increased from 6.33 and 6.51 to 8.15 and 8.04 in combination with NPK fertilizer and rapeseed residue, respectively, compared to no eggshell addition. The increase in soil pH may contribute to heavy metal immobilization by altering heavy metals into more stable in soils. Concentrations of TCLP-extracted Cd and Pb were reduced by up to 67.9 and 93.2 % by addition of 5 % eggshell compared to control. For 0.1 M HCl extraction method, the concentration of 0.1 M HCl-Cd in soils treated with NPK fertilizer and rapeseed residue was significantly reduced by up to 34.01 and 46.1 %, respectively, with 5 % eggshell addition compared to control. A decrease in acid phosphatase activity and an increase in alkaline phosphatase activity at high soil pH were also observed. Combined application of eggshell waste and rapeseed residue can be cost-effective and beneficial way to remediate the soil contaminated with heavy metals.

Distribution and Population Dynamics of Nematodes in a Rice Field and Pasture in India

Science.gov (United States)

Mishra, C. C.; Dash, M. C.

1981-01-01

Ecological studies on soil nematodes were made in a tropical rice field and pasture. Parasitic species were more diversified in the pasture than in the rice field. Eighty-six and sixty percent of total nematodes occurred in the top 10 cm in rice field and pasture, respectively. Nematodes were not randomly or uniformly dispersed but aggregated. Parasitic forms were most abundant and correlated with root biomass in the 0-15-cm soil layer, the greatest number usually occurring at the 10-15-cm depth at both sites. In summer, however, they were densest at the 15-30-cm depth. Microbivores were most frequent in the top 5 cm of both sites. Micellaneous feeders (food sources uncertain) usually occurred in highest densities at the 15-30-cm depth. Predators showed no distinct depth preference. Temperature and moisture of the soil apparently played an important role in regulating nematode population. Peak densities of 31.3 × 10⁴/m² and 21.6 × 10⁴/m² at a 30-cm depth occurred in January, while minimum densities of 5.0-5.3 × 10⁴/m² and 4.1 × 10⁴/m² occurred in July-October and April in rice field and pasture, respectively. Monthly mean biomass of nematodes was 23.8 ± 4.5 mg/m² in rice field and 11.5 ± 1.5 mg/m² in pasture. PMID:19300801

Degradação de pastagens na Região Amazônica: propriedades físicas do solo e crescimento de raízes Pasture degradation in the Amazon region: soil physical properties and root growth

Directory of Open Access Journals (Sweden)

Marcelo Marques Lopes Muller

2001-11-01

studied: productive Guinea grass (Panicum maximum Jacq. pasture; Guinea grass pasture on yield decline; degraded Guinea grass pasture (fallow, and degraded Guinea grass pasture recovered with Gamba grass (Andropogon gayanus Kunth. As reference of the soil original characteristics before clearing, a native forest area was also studied. Burning was an usual practice; moreover, the pastures did not receive fertilizers. Pasture degradation decreased soil covering and exposed the soil surface to the direct impact of rain drops and cattle compaction, what resulted in soil bulk density increase in the superficial layer and decrease in clay flocculation and soil total porosity. Forage yield decline on degraded pasture was accompanied by a decrease on the number of roots on the soil profile, and there was a concentration of the root system close to the surface. Andropogon gayanus showed good potential for the rehabilitation of degraded pastures on the Amazon Region.

Assessing degradation of abandoned farmlands for conservation of the Monte Desert biome in Argentina.

Science.gov (United States)

Yannelli, Florencia A; Tabeni, Solana; Mastrantonio, Leandro E; Vezzani, Nazareth

2014-01-01

Land abandonment is a major issue worldwide. In Argentina, the Monte Desert is the most arid rangeland, where the traditional conservation practices are based on successional management of areas excluded to disturbances or abandoned. Some areas subjected to this kind of management may be too degraded, and thus require active restoration. Therefore, the aim of this study was to assess whether passive succession-based management is a suitable approach by evaluating the status of land degradation in a protected area after 17-41 years of farming abandonment. Soil traits and plant growth forms were quantified and compared between sites according to time since abandonment and former land use (cultivation and grazing). Two variables were calculated using the CORINE-CEC method, i.e., potential (PSER) and actual (ASER) soil erosion risk. PSER indicates the erosion risk when no vegetation is present, while ASER includes the protective role of vegetation cover. Results showed that land use history had no significant effect on plant growth forms or soil traits (p > 0.05). After more than 25 years since abandonment of farming activities, soil conditions and vegetation cover had improved, thus having a lower ASER. Nevertheless, the present soil physical crusts may have delayed the full development of vegetation, enhancing erosion processes. Overall, this study indicates that succession-based management may not be the best practice in terms of conservation. Therefore, any effort for conservation in the Monte Desert should contemplate the current status of land degradation and potential vegetation recovery.

Characterization of an abandoned pastoral area in the Northern Apennines, Italy

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Argenti G

2006-01-01

Full Text Available This paper reports the first results of an investigation carried out within the research project "Study and improvement of woods and shrubbery derived from abandoned agricultural areas" (RiSelvItalia Project. Changes occurred in the past 50 years in the pastoral area of S. Paolo in Alpe (Appennino Romagnolo, Northern Apennines, Italy were described on the grounds of photo-interpretation of three sets of aerial photos (1955, 1976, 1997. A high reduction of the surface of sowable lands and pastures (from 80% to 33% was pointed out, together with an increase of shrubbery (from 5% to 18% and woods (from 0 to 42%. The characterization of woods, shrubbery and pastures was performed through structural transects and phyto-sociological investigations. Thus it was possible to reconstruct the dynamic series of vegetation, from grasslands belonging to the association Centaureo bracteatae-Brometum erecti (Festuco-Brometea to woods referable to the association Aceri obtusati-quercetum cerridis (Querco-Fagetea. Investigations on meadows revealed also a good quality of pastures, not only in open grasslands (mean pastoral value - VP - of 30, but even in partially shrubby areas (VP 21. Some guidelines for a multi-purpose exploitation of the site are suggested, taking into account not only economic aspects, but also the conservation of environment and landscape.

Hazard evaluation of soil contaminants from an abandoned oil refinery site with chemical and biological assays

International Nuclear Information System (INIS)

Ramanathan, A.; Yates, C.W.; Burks, S.L.

1993-01-01

The phytotoxic characteristics of soil and leachates of soil from an abandoned oil refinery site were evaluated with rice (Oryza sativa L.) seed germinations and root elongation assays. Toxicity of soil leachates to aquatic animals was determined with acute and martial chronic toxicity tests with Ceriodaphnia dubia, fathead minnows, and Microtox reg-sign. Soil samples from uncontaminated (control) and selected contaminated areas within the old refinery were extracted with Toxic Characteristics Leachate Procedure (TCLP), an aqueous procedure and a supercritical carbon dioxide method. Aqueous extracts of soil from the oil leaded gasoline storage area exhibited greatest effects in all tests. Aqueous extracts from this site also caused a significant reduction in rice root development. Supercritical carbon dioxide extraction proved to be a quick and non-toxic procedure for isolating non-polar organics for assay with aquatic toxicity tests. Subsequent supercritical extracts collected in solvent can help characterize the class of toxicants through HPLC and Gas Chromatography. The toxic constituents were characterized with a Toxicity Identification/Toxicity Reduction Evaluation protocol to fractionate the contaminants into conventional non-polar organics, weak acids, base-neutrals, or heavy metals for subsequent analysis

137Cs uptake by sheep grazing tidally-inundated and inland pastures near the Sellafield reprocessing plant

International Nuclear Information System (INIS)

Howard, B.J.

1987-01-01

Field investigations into the transfer of 137 Cs from pasture to sheep tissues have been made at two contrasting sites in west Cumbria, close to the nuclear fuel reprocessing plant at Sellafield. These were a saltmarsh bordering on the Esk estuary in 1982 and inland pastures close to the perimeter of the works in 1984. 137 Cs concentrations of sampled vegetation from the saltmarsh were generally two orders of magnitude greater than from the inland pasture due to its inundation with 137 Cs associated with silt. The relatively high 137 Cs content of soil/silt compared to that of vegetation at each site meant that soil contamination of vegetation sometimes accounted for a substantial proportion of its 137 Cs activity (up to 99% on the saltmarsh and 67% on the inland pastures). Considerable seasonal changes occurred in the extent of 137 Cs contamination on the inland pastures, with late winter and early spring levels being up to 20-fold higher than those of the summer. 137 Cs concentrations in tissues of lambs from the saltmarsh were consistently higher than for ewes; this was not true for sheep from the inland pastures. 137 Cs concentrations in kidney were found to be higher than in all other tissues, both in the study flocks and in one of the controls. Transfer coefficients (calculated by dividing the 137 Cs concentration of fresh tissue by the daily intake of 137 Cs) were significantly (P 137 Cs activity due to soil/silt contamination was removed from the estimates of daily intake leaving 137 Cs associated with the vegetation only to contribute to the transfer coefficients. Further studies are required to determine the availability of 137 Cs associated with soil/silt particles which are ingested by animals. (author)

Pipeline abandonment - a discussion paper on technical and environmental issues

International Nuclear Information System (INIS)

1996-11-01

The technical and environmental issues associated with pipeline abandonment were reviewed to provide a basis for the development of guidelines that companies could follow in order to abandon oil and gas pipelines in an environmentally safe and economic manner. Some of the topics discussed include land use management, ground subsidence, soil and groundwater contamination, erosion and the potential to create water conduits. A major issue still to be resolved, i.e., the legal and financial aspects of pipeline abandonment, was addressed. An industry-financed fund has been created to cover the cost of reclamation and abandonment of orphaned pipelines and certain associated pipeline facilities. 30 refs., 4 tabs., 3 figs

Hydrology and Soil Erosion in Tropical Rainforests and Pasture Lands on the Atherton Tablelands, North Queensland, Australia - a rainfall simulator study

Science.gov (United States)

Joanne, Joanne; Ciesiolka, Cyril

2010-05-01

The Barron and Johnstone Rivers rise in the basaltic Atherton Tableland, North Queensland, Australia, and flow into the Coral Sea and Great Barrier Reef World Heritage Area (GBRWHA). Natural rainforest in this region was cleared for settlement in the early 20th century. Rapid decline in soil fertility during the 1940's and 50's forced landholders to turn to pasture based industries from row crop agriculture. Since then, these pasture based industries have intensified. The intensified land use has been linked to increases in sediment and nutrient levels in terrestrial runoff and identified as a major environmental threat to the GBRWHA, which has raised alarm for the tourist industry and resource managers. Studies linking land-use to pollutant discharge are often based on measurements and modelling of end of catchment measurements of water quality. Whilst such measurements can be a reasonable indicator of the effects of land use on pollutant discharge to waterways, they are often a gross assessment. This project used rainfall simulations to investigate the relationship between land use and management with sources and sinks of runoff and soil erosion within the Barron and Johnstone Rivers catchments. Rainfall simulations were conducted and pollutant loads measured in natural rainforest, as well as dairy and beef farming systems. The dairy farming systems included an effluent fed pasture, a high mineral fertilizer and supplementary irrigation farm, and a rainfed organic pasture that relied on tropical legumes and introduced grasses and returned organic material to the soil. One of the beef farming systems used a 7-10 day rotation with a low fertilizer regime (kikuyu mostly), while the other, used a long period- two paddock-rotation with no fertiliser and paspalum pastures. The rainforests were generally small isolated enclaves with a well developed shrub layer (1-3 m), and a presence of scattered, deciduous trees. Simulations were carried out on sites which were

Phosphorus fertilizer and grazing management effects on phosphorus in runoff from dairy pastures.

Science.gov (United States)

Dougherty, Warwick J; Nicholls, Paul J; Milham, Paul J; Havilah, Euie J; Lawrie, Roy A

2008-01-01

Fertilizer phosphorus (P) and grazing-related factors can influence runoff P concentrations from grazed pastures. To investigate these effects, we monitored the concentrations of P in surface runoff from grazed dairy pasture plots (50 x 25 m) treated with four fertilizer P rates (0, 20, 40, and 80 kg ha(-1) yr(-1)) for 3.5 yr at Camden, New South Wales. Total P concentrations in runoff were high (0.86-11.13 mg L(-1)) even from the control plot (average 1.94 mg L(-1)). Phosphorus fertilizer significantly (P pasture biomass (P dairy pastures should be the maintenance of soil P at or near the agronomic optimum by the use of appropriate rates of P fertilizer.

Detection of Beta-lactamase gene in the culturable bacteria isolated from agricultural, pasture and mining soils around mines in Hamedan, Iran

Directory of Open Access Journals (Sweden)

Nayereh Younessi

2017-09-01

Full Text Available Introduction: Growing evidence exists that agriculture affects antibiotic resistance in human pathogens. Beta-lactam antibiotics are the most commonly used antimicrobial agents in many countries. The abundance of beta-lactamase encoding genes can be used as an indicator of antibiotic resistance in the environment. So, to determine the beta-lactamase resistance genes, the abundance of culturable bacteria having bla-TEM genesin the soils under different land uses wasexamined. Materials and methods: 44 Gram-positive and 34 Gram-negative bacteria plated on nutrient agar were isolated from agricultural, pasture and mining soils and selected to study the presence of TEM-class gene using PCR amplification. Antibiotic sensitivity test of bla-TEM+isolateswas done adopting the Kirby-Bauer disk diffusion method and antibiotic discs used were: ampicillin, amoxicillin, vancomicin, streptomycin, tetracycline and gentamicin. Finally, five multi-drug resistant and bla-TEM+ isolates were identified using universal primers. Results: The highest level of beta-lactamase genes was observed in the Gram-positive and Gram-negative isolates from the pasture soils. In the agricultural and mining soils, a high abundance of bla-TEM+ isolateswasfound which also showed resistance to beta-lactam antibiotics. The identified multi-drug resistant and bla-TEM+ isolates were from these genera: Achromobacter, Bacillus, Brevibacillus, Aminobacter and Brevundimonas. Discussion and conclusion: The high number of bla-TEM+ bacteria in all the soils may be attributed to the other important feature of bla genes which is their capability to extrude toxic compounds like heavy metals in contaminated environments. Sensitivity of some bla-TEM+ bacteria to beta-lactam antibiotics was interesting. This result shows that bla-TEM genes confer resistance to beta-lactamase inhibitors in a different degree. Some of the identified isolates were pathogen. These pathogens in soils can transfer to plants

The study of DDT in contaminated soil of abandoned DDT factory area of Amangarh Khyber Pakhtunkhwa

International Nuclear Information System (INIS)

Sanaullah, M.A.; Sabir, M.A.; Arfan, M.

2011-01-01

Dichlorodiphenyl trichloroethane (DDT) is an organo chlorine insecticide mainly used to control mosquito borne diseases and agricultural pests worldwide, including Pakistan. For DDT production a factory was established in 1963 in Amangargh, Nowshehra, KP. Although DDT production and its applications in agriculture have been banned since long and as a result the mentioned factory has also abandoned yet there remains extensive amount of DDT and contaminated sites are still releasing DDT to the environment. As a matter of fact even small amounts of DDT can affect a variety of organisms like small microorganisms, algae and plankton. DDT also causes many problems in fish, birds, mammals and somehow Human Beings. This research examined the soil's DDT concentration and its transformation at various depths of study site. The DDT from each soil sample was extracted using simply solvent extraction method. The residual DDT level found in almost all the soil samples taken was greater than the standard limit (< 17 mgKg/sup -1/). (author)

Erosion and sediment deposition evaluation on a slope under pasture in Jandaia-GO using the '137Cs fallout' technique

International Nuclear Information System (INIS)

Arthur, Robson C.J.; Bacchi, Osny O.S.; Reichardt, Klaus; Oliveira, Carloeme Alves de; Correchel, Vladia

2009-01-01

Water erosion is one of the main forms of soil degradation and among the diverse factors that affect it, two of great importance are the soil cover and slope. Estimates of sediment distribution rates associated to the different uses and soil management practices are scarce and the employed methods in these determinations are in general costly and time consuming. Rates of sediment redistribution evaluated by means of the 137 Cs technique are based on the comparison of inventories of individual points of a given position and an inventory of reference, whose value represents the amount of 137 Cs of 'fallout' origin that was added to the local site. This allows evaluating situations of losses and accumulations of sediments by the erosive process. The objective of the present work was to analyze the sediment production in a pasture area and to measure the efficiency of riparian forests in trapping the erosion sediments coming from pasture, through the ' 137 Cs fallout' redistribution analysis. The study was carried out in Jandaia/GO, Brazil, in two dowslope transects located in a pasture area. Samples were taken from seven points of two 140 m long transects, as well as from three soil profiles of a 15 m transect in the downstream riparian forests of each transect. Soil profiles were sampled in three layers of 20 cm (0-20, 20-40 and 40-60). The soil samples were air dried, sieved and then analyzed for 137 Cs activity by a gamma ray detector (GEM-20180P, EG and ORTEC) coupled to a multichannel analyzer at CENA/USP. The results indicate variations of 137 Cs activity in soil profiles and high erosion rates to the riparian forest to the pasture areas of the two transects, showing sediment movement from the pasture area to the riparian forest, which suggests that the current width of the forest is not wide enough to trap the sediments produced upslope in the pasture area. (author)

Abandonment terraced hillside and answer of the fire system: some results from Mediterranean old fields

Energy Technology Data Exchange (ETDEWEB)

Llovet Lopez, J.; Ruiz Varela, M.; Josa March, R.; Vallejo Calzada, V. R.

2009-07-01

The abandonment of agricultural lands promotes temporal changes both in soil characteristics (i.e., increasing organic matter and other quality indicators) and in plant community (i.e., changing its composition and structure, and increasing the fuel load). As a consequence, we can expect differences in the resilience to fire as succession progresses. The aim of this work is to analyse the capacity of an ecosystem to return to pre-fire conditions as a function of the stage of abandonment of old agricultural lands. The study was carried out in the north of Alicante province (E Spain). In long-term abandoned lands, post-fire modulated plant response, which in turn determined soil crusting, runoff and erosion dynamics. In recently-abandoned lands, the plant community seemed less dependent on ratio to recover. Results show a large increase in soil surface crusting in the short term after the fire and it remained high at medium term in long-abandoned lands colonised by pine forest. Fire scarcely modified runoff and erosion in recently-abandoned lands whereas in forest lands the post-fire values increased by some orders of magnitude and remained highly dependent on rain characteristics in the short and medium term after the fire. The results obtained show evidence of increased vulnerability to fire in long-abandoned lands colonised by pine forests. (Author) 4 refs.

Abandonment terraced hillside and answer of the fire system: some results from Mediterranean old fields

International Nuclear Information System (INIS)

Llovet Lopez, J.; Ruiz Varela, M.; Josa March, R.; Vallejo Calzada, V. R.

2009-01-01

The abandonment of agricultural lands promotes temporal changes both in soil characteristics (i.e., increasing organic matter and other quality indicators) and in plant community (i.e., changing its composition and structure, and increasing the fuel load). As a consequence, we can expect differences in the resilience to fire as succession progresses. The aim of this work is to analyse the capacity of an ecosystem to return to pre-fire conditions as a function of the stage of abandonment of old agricultural lands. The study was carried out in the north of Alicante province (E Spain). In long-term abandoned lands, post-fire modulated plant response, which in turn determined soil crusting, runoff and erosion dynamics. In recently-abandoned lands, the plant community seemed less dependent on ratio to recover. Results show a large increase in soil surface crusting in the short term after the fire and it remained high at medium term in long-abandoned lands colonised by pine forest. Fire scarcely modified runoff and erosion in recently-abandoned lands whereas in forest lands the post-fire values increased by some orders of magnitude and remained highly dependent on rain characteristics in the short and medium term after the fire. The results obtained show evidence of increased vulnerability to fire in long-abandoned lands colonised by pine forests. (Author) 4 refs.

Soil microbial community of abandoned sand fields

Czech Academy of Sciences Publication Activity Database

Elhottová, Dana; Szili-Kovács, T.; Tříska, Jan

2002-01-01

Roč. 47, č. 4 (2002), s. 435-440 ISSN 0015-5632 R&D Projects: GA ČR GA526/99/P033 Grant - others:OTKA(HU) T25739 Institutional research plan: CEZ:AV0Z6066911 Keywords : microbial community * abandoned fields Subject RIV: EH - Ecology, Behaviour Impact factor: 0.979, year: 2002

Restricting daily time at pasture at low and high pasture allowance: effects on pasture intake and behavioral adaptation of lactating dairy cows.

Science.gov (United States)

Pérez-Ramírez, E; Peyraud, J L; Delagarde, R

2009-07-01

In pasture-based dairy systems, daily time at pasture is restricted during several periods of the year. The aim of this experiment was to evaluate the effect of restricting time at pasture on milk yield, pasture dry matter (DM) intake, and grazing behavior of dairy cows according to pasture allowance (PA), which partly defines pasture availability. The experiment was carried out in spring on strip-grazed perennial ryegrass pastures. The 6 treatments consisted of 3 durations of daily time at pasture [U: unrestricted day and night grazing (22 h at pasture); R9: 1 grazing session restricted to 9 h between the 2 milkings; R5: 2 grazing sessions of 2.75 h after each milking) compared at low and high PA (13 and 24 kg of DM/d per cow >5 cm, respectively). Eighteen mid-lactation Holstein dairy cows were used according to a 6 x 4 incomplete Latin square design replicated 3 times with four 14-d periods. Pasture DM intake was measured by the ytterbium-fecal index method and grazing behavior from portable devices. On average, restricting time at pasture from U to R (mean of R5 + R9) decreased pasture intake by 2.9 kg of DM, milk yield by 1.3 kg, and milk protein concentration by 0.11%, and increased milk fat concentration by 0.20%. Pasture intake and milk yield did not differ significantly between R9 and R5. The reduction of pasture intake and milk yield with decreasing time at pasture was greater at high compared with low PA. Grazing times were 536, 414, and 305 min, representing proportions of time spent grazing of 0.40, 0.77, and 0.93 for treatments U, R9, and R5, respectively. The reduction of grazing time with decreasing time at pasture was greater at high compared with low PA. Pasture intake rate greatly increased with decreasing time at pasture, but mainly on R5 (29.8, 31.6, and 42.1 g of DM/min for U, R9, and R5, respectively). The effect of time at pasture on pasture intake rate was unaffected by PA. In conclusion, the effect of restriction of time at pasture on

Parâmetros nutricionais da pastagem natural em diferentes tipos de solos na APA do Ibirapuitã, Rio Grande do Sul - Brasil Nutritional parameters of natural pasture in different soils at APA of Ibirapuitã, Rio Grande do Sul - Brazil

Directory of Open Access Journals (Sweden)

Vicente Celestino Pires Silveira

2006-12-01

Full Text Available O desempenho de ruminantes domésticos é influenciado por fatores intrínsecos ao animal, ao alimento e pela interação entre animal e alimento. O trabalho foi realizado na Estância do 28, pertencente à Fundação Maronna, Alegrete - RS, dentro da APA do Ibirapuitã. Para representar o fator solo, foram escolhidos os três tipos predominantes da APA do Ibirapuitã: Basalto Superficial, Basalto Profundo e Arenito. As amostras da pastagem natural foram retiradas por simulação de pastejo, através de coleta manual. Os parâmetros nutricionais avaliados foram: proteína bruta, fibra em detergente neutro e taxa de degradação da matéria seca. A forragem da pastagem natural oriunda do solo Basalto Superficial apresentou diferença significativa (PIntrinsic animal and food factors and the interaction between them influence the performance of domestic ruminants. This study was done at Estância do 28, property of the Maronna Foundation, Alegrete - RS, inside the Ibirapuitã Area of Environmental Protection. In order to represent soil as a factor, the three main soil types were chosen: Superficial Basalt, Deep Basalt and Sandy. Hand plucking methods were used to obtain samples of natural pasture. Nutritional parameters considered were crude protein, neutral detergent fiber and dry matter degradation rate. The forage from natural pasture of the Superficial Basalt presented significant difference (P<0.05 in crude protein rates over the other two types of soil, which did not differ amongst themselves. The highest rate of neutral detergent fibre (84.54% was obtained in pasture originated from Sandy soil, in relation to Superficial and Deep Basalt, with values of 74.53% and 77.98%, respectively. There was also a significant difference in the degradation rate of dry matter (P<0.05. Sandy soil pasture presented an intermediate degradation value (3.61% h-1, not differing from other soils. The forage from natural pastures present similar degradation rates

Translocation of iodine-129 in soil and transfer to vegetation

International Nuclear Information System (INIS)

Handl, J.

1989-01-01

The translocation of I-129 in the soil and its long-term transfer from soil to plant have been investigated using an undisturbed soil column and a pasture on a river bank. The I-129 profiles in the soils of the monolith and the pasture exhibit clear differences in the distribution of radioiodine after 52 and 47 months, respectively. At those times after surface contamination of both soil types 88% (monolith) and 66% (pasture) of the total I-129 activity were found in the top soil layer of 10 cm, indicating that translocation in the pasture soil is faster than in the monolith. Apart from soil-specific parameters this behaviour may be explained by anaerobic conditions created in the soil due to high water levels in the nearby river attecting the chemical form of iodine. The distribution of stable iodine was found rather homogeneous in both soils with mean contents of 3 mg I-127 kg -1 d.w. in the upper 15 cm and 4 mg I-127 kg -1 d.w. in deeper layers in case of the monolith. For the pasture soil the corresponding values are about 4 and 5 mg I-127 kg -1 d.w. Transfer factors plant/soil (dry weight basis) of I-129 obtained from the monolith 39 g and 52 months after contamination are 1.5x10 -3 and 2.1x10 -3 , respectively. Data from the pasture 35 and 47 months after contamination show values of 9.0x10 -3 and 8.4x10 -3 , respectively. Transfer factors of stable iodine are significantly higher in both soils yielding an average value of 1.0 for the monolith and 0.3 for the pasture. Delay constants (related to a top soil layer of 10 cm) calculated for I-129 using data obtained from the long-term translocation processes to deeper soil layers in the monolith and in the pasture show values of 1x10 -9 s -1 and 4x10 -9 s -1 , respectively. (orig.) [de

Heavy metal contamination of soil and water in the vicinity of an abandoned e-waste recycling site: implications for dissemination of heavy metals.

Science.gov (United States)

Wu, Qihang; Leung, Jonathan Y S; Geng, Xinhua; Chen, Shejun; Huang, Xuexia; Li, Haiyan; Huang, Zhuying; Zhu, Libin; Chen, Jiahao; Lu, Yayin

2015-02-15

Illegal e-waste recycling activity has caused heavy metal pollution in many developing countries, including China. In recent years, the Chinese government has strengthened enforcement to impede such activity; however, the heavy metals remaining in the abandoned e-waste recycling site can still pose ecological risk. The present study aimed to investigate the concentrations of heavy metals in soil and water in the vicinity of an abandoned e-waste recycling site in Longtang, South China. Results showed that the surface soil of the former burning and acid-leaching sites was still heavily contaminated with Cd (>0.39 mg kg(-1)) and Cu (>1981 mg kg(-1)), which exceeded their respective guideline levels. The concentration of heavy metals generally decreased with depth in both burning site and paddy field, which is related to the elevated pH and reduced TOM along the depth gradient. The pond water was seriously acidified and contaminated with heavy metals, while the well water was slightly contaminated since heavy metals were mostly retained in the surface soil. The use of pond water for irrigation resulted in considerable heavy metal contamination in the paddy soil. Compared with previous studies, the reduced heavy metal concentrations in the surface soil imply that heavy metals were transported to the other areas, such as pond. Therefore, immediate remediation of the contaminated soil and water is necessary to prevent dissemination of heavy metals and potential ecological disaster. Copyright © 2014 Elsevier B.V. All rights reserved.

Biomassa e atividades microbianas em solo sob pastagem com diferentes lotações de ovinos Biomass and microbial activity in pasture soil under different sheep grazing pressure

Directory of Open Access Journals (Sweden)

Martha Regina Lucizano Garcia

2007-04-01

Full Text Available Os efeitos da lotação de animais na produção de ovinos têm sido bastante estudados. No entanto, informações sobre seus efeitos na biomassa e nas atividades microbianas e, em conseqüência, na fertilidade do solo de pastagens são escassas. Neste trabalho, os efeitos da lotação de ovinos (LO na biomassa e nas atividades microbianas responsáveis pela transformação dos compostos do C e N em solo de clima subtropical foram avaliados. As amostras de solo foram coletadas nas camadas de 0-10 e 10-20 cm de pastos com baixa LO (5 animais ha-1, alta LO (40-50 animais ha-1 e com ausência de animais, em um delineamento inteiramente casualizado em parcelas subdivididas, com seis repetições. Os maiores valores de biomassa microbiana e das atividades respiratória, nitrificante e enzimática (urease e protease foram encontrados nos solos dos pastos com baixa LO. Estes pastos também acumularam as maiores quantidades de matéria orgânica e N total. Essas variáveis foram reduzidas nos pastos sem animais ou com alta LO. Vegetação descontínua e intensa mineralização podem ter acarretado a diminuição dessas variáveis nos pastos com alta LO. Alta correlação foi obtida entre matéria orgânica, C orgânico e N total com as quantidades de biomassa microbiana e a atividade enzimática. A camada de 0-10 cm apresentou valores maiores das variáveis estudadas do que os encontrados na camada de 10-20 cm.The effect of grazing pressure in sheep production has been studied, but not in relation to soil microbiological parameters or the consequences on soil fertility. The effect of grazing pressure (GP by sheep on biomass and microbial activity related to C and N compounds cycling in subtropical region soil was studied. Soil samples were collected from the 0-10 cm and 10-20 cm layers in pastures with low GP (5 animals ha-1, high GP (40-50 animals ha-1 and in absence of animals, in a completely randomized design with 6 replicates. The highest values

Natural radionuclides in meadow and pasture land in the Nordic countries

International Nuclear Information System (INIS)

Rosen, K.; Gutierrez Villanueva, J.-L.; Sundell-Bergman, S.

2012-06-01

The amount of natural radionuclides in the environment differs between the Nordic countries as shown by previous investigations and also by this study. Agricultural areas of high natural background are predominantly found in Sweden, Southern Finland and Norway while low background areas are typical for Iceland and Denmark. Thus, this study offers possibilities for studying behaviour of natural radionuclides under different conditions such as the influence of different soil types as well as the husbandry. Furthermore the areas also enable studying environmental behaviour of radium and other natural radionuclides under seemingly steady state conditions. However, migration and accumulation of natural radionuclides in cultivated soil is complex involving various processes. Thus, a long term goal of this study was to identify the implications of some of these processes by determining the soil to plant transfer for pasture land under the different conditions that prevail in the Nordic countries. The potential health hazards due to chronic ingestion of low concentrations of naturally occurring radionuclides are fairly unknown but the results of this study may provide valuable background information for assessing these radiation risks. The aim of this project has been to gain knowledge on the status of natural radionuclides in meadow and pasture land and in grassland plants in different Nordic countries and on the transfer of these radionuclides from soil/water to man via the milk/food chain (soil- meadow/pasture grass -cow-milk). Limited data are available on the mobility and the transfer of naturally occurring radionuclides in the ecosystems of the agricultural land. In addition, information concerning the concentrations in meat and dairy products is of interest for assessing exposures of humans to natural radionuclides. Soil characteristics are known to have significant impact on the mobility and uptake of natural radionuclides. Therefore, the uptake in relation to

Natural radionuclides in meadow and pasture land in the Nordic countries

Energy Technology Data Exchange (ETDEWEB)

Rosen, K.; Gutierrez Villanueva, J.-L.; Sundell-Bergman, S. [Swedish Univ. of Agricultural Sciences (SLU) (Sweden)] [and others

2012-06-15

The amount of natural radionuclides in the environment differs between the Nordic countries as shown by previous investigations and also by this study. Agricultural areas of high natural background are predominantly found in Sweden, Southern Finland and Norway while low background areas are typical for Iceland and Denmark. Thus, this study offers possibilities for studying behaviour of natural radionuclides under different conditions such as the influence of different soil types as well as the husbandry. Furthermore the areas also enable studying environmental behaviour of radium and other natural radionuclides under seemingly steady state conditions. However, migration and accumulation of natural radionuclides in cultivated soil is complex involving various processes. Thus, a long term goal of this study was to identify the implications of some of these processes by determining the soil to plant transfer for pasture land under the different conditions that prevail in the Nordic countries. The potential health hazards due to chronic ingestion of low concentrations of naturally occurring radionuclides are fairly unknown but the results of this study may provide valuable background information for assessing these radiation risks. The aim of this project has been to gain knowledge on the status of natural radionuclides in meadow and pasture land and in grassland plants in different Nordic countries and on the transfer of these radionuclides from soil/water to man via the milk/food chain (soil- meadow/pasture grass -cow-milk). Limited data are available on the mobility and the transfer of naturally occurring radionuclides in the ecosystems of the agricultural land. In addition, information concerning the concentrations in meat and dairy products is of interest for assessing exposures of humans to natural radionuclides. Soil characteristics are known to have significant impact on the mobility and uptake of natural radionuclides. Therefore, the uptake in relation to

SOIL CHARACTERISTICS IN DEGRADED AREA RESTORATION AT RESERVA BIOLÓGICA DE POÇO DAS ANTAS, RJ

Directory of Open Access Journals (Sweden)

Luiz Fernando Duarte de Moraes

2009-10-01

Full Text Available A project to restore a degraded area must firstly reestablish organic soil matter and nutrient cycling process. In order to evaluate the influence of indigenous tree plantations on changings in soil fertility and organic matter dynamics, an experiment was installed at the Poço das Antas Biological Reserve, an Atlantic Rain Forest remnant of ca. 5,200. Six treatments involved mature forests (F, 8-year-old mixed plantations of indigenous tree species (P, and abandoned pastures (G, at both the flooding (V and the sloping (M areas of the Reserve. The experimental design was completely randomized. Soil samples were collected at the layers 0-2.5cm; 2-5-7.5cm; and 7.5-20cm to evaluate soil pH, and Al, Ca+Mg, P, K, C and N contents. The PV treatment showed higher values for the exchangeable cátions, C and soil organic matter (SOM contents, indicating high cycling rates and biological activity. Soil stability was considered to be high in all treatments, since C:N ratio was lower than 12:1. Organic matter fragmentation showed a higher amount of fulvic acids (FA, humic acids (HA and humin (HU in the PV treatment, for the three soil layers. The plantation on the sloping areas (PM showed the highest values of (FA+HA/HU ratio, suggesting a lower stability condition. Results suggest indigenous tree plantations have great potential to restore nutrient cycling and soil organic matter contents in short term period in areas where forests have been converted into pastures. Techniques to accelerate the development of trees plantation on the sloping areas must be adopted.

Differential Effects of Legume Species on the Recovery of Soil Microbial Communities, and Carbon and Nitrogen Contents, in Abandoned Fields of the Loess Plateau, China

Science.gov (United States)

Li, Jin Hua; Jiao, Shu Mei; Gao, Rong Qing; Bardgett, Richard D.

2012-12-01

Plant-soil interactions are known to influence a wide range of ecosystem-level functions. Moreover, the recovery of these functions is of importance for the successful restoration of soils that have been degraded through intensive and/or inappropriate land use. Here, we assessed the effect of planting treatments commonly used to accelerate rates of grassland restoration, namely introduction of different legume species Medicago sativa, Astragalus adsurgens, Melilotus suaveolens, on the recovery of soil microbial communities and carbon and nitrogen contents in abandoned fields of the Loess Plateau, China. The results showed effects were species-specific, and either positive, neutral or negative depending on the measure and time-scale. All legumes increased basal respiration and metabolic quotient and had a positive effect on activity and functional diversity of the soil microbial community, measured using Biolog EcoPlate. However, soil under Astragalus adsurgens had the highest activity and functional diversity relative to the other treatments. Soil carbon and nitrogen content and microbial biomass were effectively restored in 3-5 years by introducing Medicago sativa and Astragalus adsurgens into early abandoned fields. Soil carbon and nitrogen content were retarded in 3-5 years and microbial biomass was retarded in the fifth year by introducing Melilotus suaveolens. Overall, the restoration practices of planting legumes can significantly affect soil carbon and nitrogen contents, and the biomass, activity, and functional diversity of soil microbial community. Therefore, we propose certain legume species could be used to accelerate ecological restoration of degraded soils, hence assist in the protection and preservation of the environment.

Banco de sementes no solo em sistemas de cultivo lavoura-pastagem Soil seedbank in integrated crop-pasture systems

Directory of Open Access Journals (Sweden)

Fernanda Satie Ikeda

2007-11-01

Full Text Available O objetivo deste trabalho foi avaliar o efeito de sistemas de cultivo, do preparo do solo e dos níveis de adubação sobre o banco de sementes, em solos de áreas submetidas a: três sistemas de cultivo - lavoura contínua (L, lavoura-pastagem-lavoura (LPL e pastagem-lavoura-pastagem (PLP; dois sistemas de preparo do solo - convencional (C e semeadura direta (D; dois níveis de adubação - manutenção (1 e corretiva gradual (2; e uma área de pastagem contínua, com preparo convencional e adubação corretiva gradual. No sistema de cultivo lavoura-pastagem, a densidade de sementes, excluindo-se as áreas de cultivo de LPLC1 e de LPLC2, foi menor do que nas lavouras contínuas e maior do que na pastagem contínua. Nas áreas de lavoura, o banco de sementes foi menor em áreas com semeadura direta do que com preparo convencional do solo, mas nas áreas de PLP, com adubação corretiva gradual, não houve diferença entre os sistemas de preparo do solo. A adubação causou redução na densidade de sementes apenas nas áreas de cultivo de LPLC e PLPC. A adoção de sistemas de cultivo lavoura-pastagem com semeadura direta pode auxiliar no manejo de plantas daninhas em áreas de lavoura de grãos.The objective of this study was to evaluate the effects of cultivation and tillage systems, and fertilization level, on soil seedbanks of areas submitted to: three cultivation systems - continuous crop (L, crop-pasturecrop (LPL, pasture-crop-pasture (PLP; two tillage systems - tillage (C and no-tillage (D; two fertilization levels - maintenance (1 and gradual corrective (2; and a continuous pasture area under tillage and gradual corrective fertilization. Seed density of crop-pasture cultivation systems, was lower than in continuous crop, and higher compared to continuous pasture system, except for LPLC1 and LPLC2 cultivated areas. The seedbanks in continuous cropping areas was lower in no-tillage than in tillage system areas, but in PLP areas with

Exchange of soil moisture between patches of wild-olive and pasture sustains evapotranspiration of a Mediterranean ecosystem in both wet and dry seasons

Science.gov (United States)

Curreli, M.; Montaldo, N.; Oren, R.

2017-12-01

Partitioning evapotranspiration in water-limited environments, such as Mediterranean ecosystems, could give information on vegetation and hydraulic dynamics. Indeed, in such ecosystems, trees may survive prolonged droughts by uptake of water by dimorphic root system: deep roots and shallower lateral roots, extending beyond the crown into inter-trees grassy areas. The water exchange between under canopy areas and treeless patches plays a crucial role on sustaining tree and grass physiological performance during droughts. The study has been performed at the Orroli site, Sardinia (Italy). The landscape is covered by patchy vegetation: wild olives trees in clumps and herbaceous species, drying to bare soil in summer. The climate is characterized by long droughts from May to October and rain events concentrated in the autumn and winter, whit a mean yearly rain of about 700 mm. A 10 m micrometeorological tower equipped with eddy-covariance system has been used for measuring water and energy surface fluxes, as well as key state variables (e.g. temperature, radiations, humidity and wind velocity). Soil moisture was measured with five soil water reflectometers (two below the olive canopy and three in the pasture). To estimate plant water use in the context of soil water dynamic, 33 Granier-type thermal dissipation probes were installed 40 cm aboveground, in representative trees over the eddy covariance footprint. Early analyses show that wild olive continue to transpire even as the soil dries and the pasture desiccates. This reveled hydraulic redistribution system through the plant and the soil, and allows to quantify the reliance of the system on horizontally and vertically differentiated soil compartments. Results shows that during light hours, until transpiration decreases in midday, shallow roots uptake deplete the shallow water content. As transpiration decreases, hydraulically redistributed water provides for both transpiration of wild olives and recharge of shallow

CO2 and Carbon Balance of an Intensively Grazed Temperate Pasture: Response to Cultivation

Science.gov (United States)

Rutledge, S.; Mudge, P. L.; Wallace, D.; Campbell, D.; Wall, A.; Hosking, C. L.; Schipper, L. A.

2012-12-01

Recent soil resampling studies have shown that soils on flat land used for intensive dairy farming in New Zealand have lost large amounts of carbon (~1 t C ha-1y-1) over the past few decades, and the causes of these losses are poorly understood. One of the management practices potentially contributing to the C losses from these dairy soils is the periodic cultivation commonly associated with pasture renewal or the rotation through summer or winter crops. Here we report the results of three experiments aimed at quantifying the effect of cultivation as part of pasture renewal on the CO2 and C balances of permanent pastures. In the first experiment, the net ecosystem CO2 exchange (NEE) of an intensively grazed dairy pasture was measured before, during and after cultivation using eddy covariance (EC) from 2008 to 2011 at a dairy farm in the Waikato region on the North Island of New Zealand. The net ecosystem carbon balance (NECB) was determined by combining NEE data with measurements and estimates of other C imports (feed) and C exports (milk, methane, silage and leaching). The other two experiments took place on the same farm and monitored two different cultivation events in 2008. We made chamber measurements of soil CO2 losses between spraying and seedling emergence. One of the cultivations took place in summer 2008 during a drought, whereas the other took place in spring 2008 when soil water was not limiting. For the first two years of experiment 1 the site was under permanent pasture and it was a sink for both CO2 (1.6 and 2.3 t C ha-1y-1 for 2008 and 2009, respectively) and C (0.59 and 0.90 t C ha-1y-1 for 2008 and 2009, respectively), despite a severe drought in summer 2008 which had led to a loss of approximately 1.1 t C ha-1 as CO2 over the three summer months. Pasture renewal took place in March 2010 and CO2 losses during this event were approximately 1.7 t C ha-1. However, the site seemed to recover quickly and was a sink of CO2 at an annual time scale of

Source and Fate of Inorganic Soil Contamination Around the Abandoned Phillips Sulfide Mine Hudson Highlands New York

Energy Technology Data Exchange (ETDEWEB)

S Gilchrist; A Gates; E Elzinga; M Gorring; z Szabo

2011-12-31

The abandoned Phillips sulfide mine in the critical Highlands watershed in New York has been shown to produce strongly acidic mine drainage (AMD) with anomalous metal contaminants in first-order streams that exceeded local water standards by up to several orders of magnitude (Gilchrist et al., 2009). The metal-sulfide-rich tailings also produce contaminated soils with pH < 4, organic matter < 2.5% and trace metals sequestered in soil oxides. A geochemical transect to test worst-case soil contamination showed that Cr, Co and Ni correlated positively with Mn, (r = 0.72, r = 0.89, r = 0.80, respectively), suggesting Mn-oxide sequestration and that Cu and Pb correlated with Fe (r = 0.76, r = 0.83, respectively), suggesting sequestration in goethite. Ubiquitous, yellow coating on the mine wastes, including jarosite and goethite, is a carrier of the metals. Geochemical and {mu}-SXRF analyses determined Cu to be the major soil contaminant, {mu}-SXRF also demonstrated that the heterogeneous nature of the soil chemistry at the micro-meter scale is self-similar to those in the bulk soil samples. Generally metals decreased, with some fluctuations, rapidly downslope through suspension of fines and dissolution in AMD leaving the area of substantial contamination << 0.5 km from the source.

Tillage-induced changes to soil structure and organic carbon fractions in New Zealand soils

International Nuclear Information System (INIS)

Shepherd, T. G.; Saggar, S.; Ross, C. W.; Dando, J. L.; Newman, R. H.

2001-01-01

The effects of increasing cropping and soil compaction on aggregate stability and dry-sieved aggregate-size distribution, and their relationship to total organic C (TOC) and the major functional groups of soil organic carbon, were investigated on 5 soils of contrasting mineralogy. All soils except the allophanic soil showed a significant decline in aggregate stability under medium- to long-term cropping. Mica-rich, fine-textured mineral and humic soils showed the greatest increase in the mean weight diameter (MWD) of dry aggregates, while the oxide-rich soils, and particularly the allophanic soils, showed only a slight increase in the MWD after long-term cropping. On conversion back to pasture, the aggregate stability of the mica-rich soils increased and the MWD of the aggregate-size distribution decreased, with the humic soil showing the greatest recovery. Aggregate stability and dry aggregate-size distribution patterns show that soil resistance to structural degradation and soil resilience increased from fine-textured to coarse-textured to humic mica-rich soils to oxide-rich soils to allophanic soils. Coarse- and fine-textured mica-rich and oxide-rich soils under pasture contained medium amounts of TOC, hot-water soluble carbohydrate (WSC), and acid hydrolysable carbohydrate (AHC), all of which declined significantly under cropping. The rate of decline varied with soil type in the initial years of cropping, but was similar under medium- and long-term cropping. TOC was high in the humic mica-rich and allophanic soils, and levels did not decline appreciably under medium- and long-term cropping. 13 C-nuclear magnetic resonance evidence also indicates that all major functional groups of soil organic carbon declined under cropping, with O-alkyl C and alkyl C showing the fastest and slowest rate of decline, respectively. On conversion back to pasture, both WSC and AHC returned to levels originally present under long-term pasture. TOC recovered to original pasture

The pasture-type approach for mountain pasture description and management

Directory of Open Access Journals (Sweden)

Giovanni Argenti

2012-10-01

Full Text Available The study of pastoral resources can take different approaches with the main goal of characterizing pasture vegetation and its potential carrying capacity. In recent times, the pasture-type approach has been developed in several Alpine areas – on a regional and on a district scale – starting from sward surveys carried out taking the approach formerly developed by the French pastoral school. The pasture-type approach may play an important role in defining the management of mountain and marginal environments where grazing pressure reduction remarkably affects the agro-ecosystems functions (production, landscape, wildlife, recreation, etc.. This approach is based on the concept of pasture type, which could be defined as a semi-natural vegetation (mainly exploited by grazing animals, rather homogeneous in terms of botanic composition and influenced by environmental factors and agro-pastoral management. This paper presents the pasture-type approach by discussing the results of two large studies carried out in two areas of the south side of the Alps (Piedmont and Veneto. In order to identify pasture types, the vegetation composition was assessed with a point quadrat method. It allowed the computation of species-specific contribution, and of sward forage value and carrying capacity, after a multivariate statistical procedure for type classification and ordination. The site conditions (altitude, slope, aspect and other environmental variables were surveyed. Moreover, to characterize the pasture types from the point of view of the ecological and management factors affecting vegetation composition, the Landolt indicators were used. The results achieved in the two areas were synthesised and organised into reference technical tools with the aim of using the pasture-type approach for pastoral planning. For each study area an identification key to recognize pasture types was drafted, and a handbook containing the technical sheets for pasture type

Fungal biomass in pastures increases with age and reduced N input.

NARCIS (Netherlands)

Vries, de F.T.; Bloem, J.; Eekeren, van N.J.M.; Brussaard, L.; Hoffland, E.

2007-01-01

Previous studies have shown that soil fungal biomass increases towards more natural, mature systems. Shifts to a fungal-based soil food web have previously been observed with abandonment of agricultural fields and extensification of agriculture. In a previous field experiment we found increased

Mitigating soil contamination at abandoned Moroccan mine sites ...

International Development Research Centre (IDRC) Digital Library (Canada)

2018-02-09

Feb 9, 2018 ... Abandoned mines are putting people and ecosystems at risk in ... environmental and health concerns to surrounding communities. .... carbon-rich phosphate mine waste from the neighboring Youssoufia ... The research team is testing the development of lightweight ceramics by mixing the coal tailings with ...

Nitrous oxide emissions from forests and pastures of various ages in the Brazilian Amazon

Science.gov (United States)

Melillo, J. M.; Steudler, P. A.; Feigl, B. J.; Neill, C.; Garcia, D.; Piccolo, M. C.; Cerri, C. C.; Tian, H.

2001-12-01

Nitrous oxide emissions from tropical forest soils are thought to account for 2.2-3.7 Tg N yr-1 of the total annual global production of 10-17 Tg N yr-1. Recent research suggests that clearing of tropical forest for pasture can increase N2O emissions but that the period of elevated emissions may be limited and fluxes from older pastures may be lower than from the original forest. Here we report N2O emissions from two land-use sequences in the Brazilian Amazon's state of Rondônia. Each sequence includes a forest and a set of pastures of different ages. One sequence contains a newly created pasture that we studied intensively through its first 2 years, including forest cutting, burning, and the planting of forage grasses. Emissions from the newly created pasture were about two and one half times the forest emissions during the first 2 years (5.0 kg N2O-N ha-1 yr-1 versus 1.9 kg N2O-N ha-1 yr-1). Nitrous oxide fluxes from pastures older than 3 years were on average about one third lower than fluxes from uncut forest (1.4 kg N2O-N ha-1 yr-1 versus 1.9 kg N2O-N ha-1 yr-1). The best predictor of N2O flux across the chronosequences was the magnitude of the NO3 pool in the upper 10 cm of soil measured at the time of gas sampling. Using a simple cohort model combined with deforestation rates estimated from satellite images by Brazil's Instituto de Pesquisas Espaciais (INPE) for the period 1978 through 1997, we estimate that for the Brazilian Amazon the basin-wide flux of N2O-N from pasture soils was 0.06 Tg in 1997. This is ˜8% of the combined forest plus pasture flux of 0.78 Tg N2O-N we estimate for the Brazilian part of the basin in 1997. In the absence of any forest-to-pasture conversion in the Brazilian part of the basin, we estimate that the basin-wide flux of N2O-N would have been only slightly larger: 0.80 Tg in 1997. Through a second modeling analysis we estimate that for the whole of the Amazon Basin, including parts of the basin outside of Brazil, the N2O

MULTIFUNCTIONAL UTILIZATION OF PASTURES IN ROMANIA

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N. DRAGOMIR

2009-05-01

Full Text Available Romanian pastures are characterized by a multitude of functions that may be used for human benefit: food and habitat for animals, development of some connected activities (collection and processing of apicultural products, medicinal plants, etc., natural reservoir providing biodiversity for more than 70% of the plant species (the preservation of this may assure an important germplasm fund for the next cultivars, the most efficient method of soil protection against erosion, provider of unconventional energy, accomplishment of efficient biological cycles of nitrogen, phosphorus, potassium and carbon dioxide (CO2, development of landscape tourism due to the plant and animal diversity that ennoble and beautify the environment. If only 60% of the permanent pasture area was used, with the application of minimal technological measures, it would provide the necessary food for at least 1.6 million cattle (57% of the current livestock and 12 million sheep and goats.

Persistence of auxinic herbicides applied on pasture and toxicity for succeeding crops

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ARNON H.C. ANÉSIO

2018-04-01

Full Text Available ABSTRACT The aim of this work was to determine the persistence of auxinic herbicides applied on tropical pasture and toxicity for succeeding crops. The herbicides were applied in an area of dystrophic red‒yellow latosol with pasture infested of weeds. At 40, 80, and 280 days after application of herbicide, the soil samples were collected at depths of 0 to 20 cm. Soil with residues of 2,4-D, 2,4-D + picloram, triclopyr, and a soil without herbicide application were analyzed with six replicates. Seven crops were cultivated in these soils: cucumber (Cucumis sativus L., velvet bean [Mucuna pruriens (L. DC.], pigeon pea [Cajanus cajan (L. Millsp.], alfalfa (Medicago sativa L., lablab bean [Lablab purpureus (L. Sweet], corn (Zea mays L., and sorghum [Sorghum bicolor (L. Moench]. The plants of cucumber, pigeon pea, and alfalfa were the most susceptible to the auxinic herbicide residues. However, the lablab bean was the only one among the dicot evaluated that showed tolerance to the 2,4-D + picloram residual when cultivated in soils at 280 days after application of herbicide. Corn and sorghum showed lower chlorophyll content in soils with 2,4-D + picloram residual up to 80 days after application of herbicide.

Fertility and acidity status of latossolos (oxisols under pasture in the Brazilian Cerrado

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Pedro R.S. Vendrame

2010-12-01

Full Text Available The Cerrado region, with over 50 million hectares of cultivated pasture, provides 55% of Brazilian beef production. Previous investigations have shown that about 70-80% of this pasture is affected by some kind of degradation, leading to low productivity. However, until now, few surveys have been carried out on a regional scale. The aim of the present work is both to assess the fertility and acidity levels of Cerrado soils under pasture and compare the variability of the soils characteristics on a regional scale. Two soil depths were sampled in different places within the studied area: (1 a surface horizon (0.0-0.2 m in order to evaluate its fertility and acidity status for pasture, and (2 a subsurface horizon (0.6-0.8 m, used for classification. Most of soils had levels of nutrients below the reference values for adequate pasture development. Whatever the texture, about 90% of soils had low or very low availability of phosphorus. Only 7 to 14% of soils had low pH, high exchangeable aluminum, and aluminum saturation above the critical acidity level. Except for nitrogen, no significant difference was found between Latossolos Vermelhos and Latossolos Vermelho-Amarelos.A região do Cerrado, com 50 milhões de hectares de pastagens cultivadas, responde por 55% da carne bovina produzida no Brasil. Há estimativas indicando que entre 70 e 80% destas pastagens apresentam algum grau de degradação, o que leva a baixa produtividade. No entanto, até o presente, poucos trabalhos foram desenvolvidos em escala regional. O objetivo deste trabalho foi avaliar a fertilidade e a acidez de Latossolos sob pastagens na região do Cerrado e comparar a variabilidade das características dos solos em escala regional. A amostragem foi realizada em duas profundidades, superficial (0,0-0,2 m para avaliação da fertilidade e acidez e subsuperficial (0,60,8 m, utilizada para classificar os solos. A maioria dos solos apresentou teores de nutrientes abaixo do recomendado

Mitigating soil contamination at abandoned Moroccan mine sites ...

International Development Research Centre (IDRC) Digital Library (Canada)

2018-02-09

Feb 9, 2018 ... Photo credit: Flickr Abandoned mines are putting people and ecosystems at risk in Morocco Since the advent of modern excavation techniques in the ... For example, principal investigators Benzaazoua and Hakkou had a key opportunity to influence practice when they were asked to prepare a course on ...

Survival and development of chicken ascarid eggs in temperate pastures

DEFF Research Database (Denmark)

Thapa, Sundar; Thamsborg, Stig Milan; Meyling, Nicolai Vitt

2017-01-01

Eggs of chicken ascarids (Ascaridia galli and Heterakis spp.) are believed to be hardy and survive for long periods. However, this has not been evaluated quantitatively and our study therefore aimed to determine development and recovery of chicken ascarid eggs after burying in pasture soil...

Carbon sequestration in Himalaya's alpine meadows: Mitigating cropping encroachment on pastures in Northern Pakistan

OpenAIRE

Rueff, Henri; Syed Rehman, Aziz; Rahim, Inam; Maselli, Daniel; Nafees, Mohammad; Wiesmann, Urs

2011-01-01

Rangelands store about 30% of the world’s carbon and support over 120 million pastoralists globally. Adjusting the management of remote alpine pastures bears a substantial climate change mitigation potential that can provide livelihood support for marginalized pastoralists through carbon payment. Landless pastoralists in Northern Pakistan seek higher income by cropping potatoes and peas over alpine pastures. However, tilling steep slopes without terracing exposes soil to erosion. Moreover, yi...

The role of livestock-poached pasture as a sediment source

Science.gov (United States)

Greenwood, Philip; Walling, Desmond; Quine, Timothy

2015-04-01

Historically, the occurrence of sediment-laden runoff has almost exclusively been associated with cultivated hillslopes and particularly with arable land. This association was commonly accompanied by the presumption that, in comparison with cultivated slopes, erosion from intensively-managed lowland pasture was relatively low. Recent developments in sediment source tracing and fingerprinting techniques have, however, challenged these assumptions by demonstrating that soil loss from grasslands may be greater than previously assumed. In attempting to identify potential source areas within grassland environments, attention has frequently focused on areas of livestock poaching where herd animals tend to congregate. However, the role of poached grassland as a sediment-source remains uncertain. Reasons include the difficulties associated with accurately documenting the movement or redistribution of small quantities of fine sediment over relevant spatial and temporal scales. Motivated by an urgent need for such information, this communication presents preliminary results from a tracing study aimed at measuring sediment redistribution within areas of poached pasture over short (i.e. event-based) timescales using the artificial radionuclides, caesium-134 (134Cs) and cobalt-60 (60Co). The approach involved labelling six small areas (0.2 * 0.2 m) of poached soil, each with a contrasting gradient, with either 134Cs or 60Co, and then measuring changes in the radiometric inventory at predetermined points before and after periods of rainfall. Each labelled area of poached pasture was measured on three separate occasions over a 65 day period. At the end of the monitoring phase, the mean net soil redistribution depth (mm) was negative for all plots, with values ranging from -6.8 mm to -15.2 mm. This is interpreted as evidence of the removal, or erosion, of surface material. The findings indicate that areas of livestock-poached pasture can act as significant sediment sources. These

Estimates of Annual Soil Loss Rates in the State of São Paulo, Brazil

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Grasiela de Oliveira Rodrigues Medeiros

Full Text Available ABSTRACT: Soil is a natural resource that has been affected by human pressures beyond its renewal capacity. For this reason, large agricultural areas that were productive have been abandoned due to soil degradation, mainly caused by the erosion process. The objective of this study was to apply the Universal Soil Loss Equation to generate more recent estimates of soil loss rates for the state of São Paulo using a database with information from medium resolution (30 m. The results showed that many areas of the state have high (critical levels of soil degradation due to the predominance of consolidated human activities, especially in growing sugarcane and pasture use. The average estimated rate of soil loss is 30 Mg ha-1 yr-1 and 59 % of the area of the state (except for water bodies and urban areas had estimated rates above 12 Mg ha-1 yr-1, considered as the average tolerance limit in the literature. The average rates of soil loss in areas with annual agricultural crops, semi-perennial agricultural crops (sugarcane, and permanent agricultural crops were 118, 78, and 38 Mg ha-1 yr-1 respectively. The state of São Paulo requires attention to conservation of soil resources, since most soils led to estimates beyond the tolerance limit.

Influence of soil water repellency on runoff and solute loss from New Zealand pasture

Science.gov (United States)

Jeyakumar, P.; Müller, K.; Deurer, M.; van den Dijssel, C.; Mason, K.; Green, S.; Clothier, B. E.

2012-04-01

Soil water repellency (SWR) has been reported in New Zealand, but knowledge on its importance for the country's economy and environment is limited. Our recent survey on the occurrence of SWR under pasture across the North Island of New Zealand showed that most soils exhibited SWR when dry independent of climate but influenced by the soil order. SWR is discussed as an important soil surface condition enhancing run-off and the transfer of fertilizers and pesticides from agricultural land into waterways. So far, the impact of SWR on run-off has rarely been measured. We developed a laboratory-scale run-off measurement apparatus (ROMA) to quantify directly the impact of SWR on run-off from undisturbed soil slabs. We compared the run-off resulting from the run-on of water with that resulting from an ethanol (30% v/v) solution, which is a fully-wetting liquid even in severely hydrophobic soils. Thus, the experiments with the ethanol solution can be understood as a proxy measure of the wetting-up behaviour of hydrophilic soils. We conducted ROMA run-off experiments with air-dried soil slabs (460 mm long x 190 mm wide x 50 mm deep) collected from pastoral sites, representing three major soil orders in the North Island: Recent Soil (Fluvisol), Gley Soil (Gleysol), and Organic Soil (Histosol), with water followed by the ethanol solution at a run-on rate of 60 mm/h. Bromide was applied at 80 kg KBr/ha prior to the water experiments to assess potential solute losses via run-off. The air-dried soils had a high degree and persistence of SWR (contact angles, 97, 98 and 104° , and potential water drop penetration times, 42, 54 and 231 min for the Fluvisol, Gleysol and Histosol, respectively). Under identical soil and experimental conditions, water generated run-off from all soils, but in the experiments with the ethanol solution, the entire ethanol solution infiltrated into the soils. The ranking of the run-off coefficients of the soils directly reflected their ranking in

Best practices for the abandonment of pipelines

Energy Technology Data Exchange (ETDEWEB)

Mackean, M; Reed, R; Snow, B [Nabors Canada, Calgary, AB (Canada). Abandonrite Service

2006-07-01

Pipeline regulations implemented in 2006 require that licensees register all pipelines. Training must also be provided for ground disturbance supervisors. In addition, signage must be maintained on abandoned pipelines, and discontinued pipelines must be properly isolated. Corrosion control and internal inhibition is required for discontinued lines. However, pipelines are often neglected during the well abandonment process. This presentation provided recommendations for coordinating well and pipeline abandonment processes. Pipeline ends can be located, depressurized, flushed and purged while wells are being abandoned. Contaminated soils around the wells can also be identified prior to reclamation activities. Administrative reviews must be conducted in order to provide accurate information on pipeline location, reclamation certification, and line break history. Field operation files must be reviewed before preliminary field work is conducted. Site inspections should be used to determine if all ends of the line are accessible. Landowners and occupants near the line must also be notified, and relevant documentation must be obtained. Skilled technicians must be used to assess the lines for obstructions as well as to cut and cap the lines after removing risers. The presentation also examined issues related to pressure change, movement, cold tapping, and live dead legs. tabs., figs.

Polychlorinated biphenyls (PCBs) in air and soil from a high-altitude pasture in the Italian Alps: evidence of CB-209 contamination.

Science.gov (United States)

Tremolada, Paolo; Guazzoni, Niccolò; Comolli, Roberto; Parolini, Marco; Lazzaro, Serena; Binelli, Andrea

2015-12-01

This study analyses the seasonal trend of polychlorinated biphenyls (PCB) concentrations in air and soil from a high-altitude mountain pasture in the Italian Alps. PCB concentrations in soil were generally comparable to background levels and were lower than those previously measured in the same area. Only CB-209 unexpectedly showed high concentrations with respect to the other congeners. GC-MS-MS identification was very clear, rising a new problem of increasing PCB contamination concerning only CB-209, which is not present in commercial mixtures used in the past in Italy and Europe. Considering all of the congeners, seasonal PCB trends were observed both in air and in soil that were related to the temperature and precipitation measured specifically in the study area. Highly significant relationships were found between the temperature-normalised concentrations in soil and the precipitation amounts. A north/south enrichment factor was present only in soil with rapid early summer re-volatilisation kinetics from soil to air and autumn re-deposition events from air to soil. Fugacity ratio calculations confirmed these trends. Surface soils respond rapidly to meteorological variables, while subsurface soils respond much more slowly. Seasonal trends were different for the northern and southern sides of the mountain. A detailed picture of the interactions among temperature, precipitation, mountain aspects and soil features was obtained.

Improving and disaggregating N_2O emission factors for ruminant excreta on temperate pasture soils

International Nuclear Information System (INIS)

Krol, D.J.; Carolan, R.; Minet, E.; McGeough, K.L.; Watson, C.J.; Forrestal, P.J.; Lanigan, G.J.; Richards, K.G.

2016-01-01

Cattle excreta deposited on grazed grasslands are a major source of the greenhouse gas (GHG) nitrous oxide (N_2O). Currently, many countries use the IPCC default emission factor (EF) of 2% to estimate excreta-derived N_2O emissions. However, emissions can vary greatly depending on the type of excreta (dung or urine), soil type and timing of application. Therefore three experiments were conducted to quantify excreta-derived N_2O emissions and their associated EFs, and to assess the effect of soil type, season of application and type of excreta on the magnitude of losses. Cattle dung, urine and artificial urine treatments were applied in spring, summer and autumn to three temperate grassland sites with varying soil and weather conditions. Nitrous oxide emissions were measured from the three experiments over 12 months to generate annual N_2O emission factors. The EFs from urine treated soil was greater (0.30–4.81% for real urine and 0.13–3.82% for synthetic urine) when compared with dung (− 0.02–1.48%) treatments. Nitrous oxide emissions were driven by environmental conditions and could be predicted by rainfall and temperature before, and soil moisture deficit after application; highlighting the potential for a decision support tool to reduce N_2O emissions by modifying grazing management based on these parameters. Emission factors varied seasonally with the highest EFs in autumn and were also dependent on soil type, with the lowest EFs observed from well-drained and the highest from imperfectly drained soil. The EFs averaged 0.31 and 1.18% for cattle dung and urine, respectively, both of which were considerably lower than the IPCC default value of 2%. These results support both lowering and disaggregating EFs by excreta type. - Highlights: • N_2O emissions were measured from cattle excreta applied to pasture. • N_2O was universally higher from urine compared with dung. • N_2O was driven by rainfall, temperature and soil moisture deficit. • Emission

Relationship between apparent soil electrical conductivity (ECa) and soil attributes at an experimental parcel under pasture in a region of Galicia, Spain.

Science.gov (United States)

Marinho, Mara de A.; Dafonte, Jorge D.; Armesto, Montserrat V.; Paz-González, Antonio; Raposo, Juan R.

2013-04-01

Spatial characterization of the variability of soil properties is a central point in site-specific agricultural management and precision agriculture. Geospatial measures of geophysical attributes are useful not only to rapidly characterize the spatial variability of soil properties but also for soil sampling optimization. This work reports partial results obtained at an experimental parcel under pasture located at Castro de Ribeira do Lea (Lugo/ Galicia/ Spain). An ECa automated survey was conducted in September 2011 employing an EM-38 DD (Geonics Ltd.) installed in a nonmetallic car, according to parallel lines spaced 10m one from each other and oriented at the east-west direction. The ECa values were recorded every second with a field computer and the locations were geo-referenced using a GPS. The entire survey was carried out in 1hour and 45 minutes and corrections due to differences in temperature were made. A total of 9.581 ECa registers were retained, configuring a sampling intensity of approximately 1 register per 1.5 m2. Employing the software ESAP 2.35 and the computational tool ESAP-RSSD, eighty positions were selected at the field to extract disturbed and undisturbed soil samples at two depths: 0.0-0.2m, 0.2-0.4m. Ten physical attributes (clay, silt, total sand, coarse sand and fine sand contents, soil bulk density, particle density, total porosity, soil water content, percentage of gravels) and 17 chemical attributes (soil organic matter-SOM, pH, P, K, Ca, Mg, Al, H+Al, Sum of bases-S, Cation exchange capacity-CEC, Base saturation-V%, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were determined. The relationship between the geophysical variables and the soil attributes was performed using statistical and spatial analysis. There were significant correlations (pmanagement zones in the area. Acknowledgements: This work was funded in part by Spanish Ministry of Science and Innovation (MICINN) in the frame of project CGL2009-13700-C02. Financial support from CAPES

Development of secondary woodland in oak wood pastures reduces the richness of rare epiphytic lichens.

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Heidi Paltto

Full Text Available Wooded pastures with ancient trees were formerly abundant throughout Europe, but during the last century, grazing has largely been abandoned often resulting in dense forests. Ancient trees constitute habitat for many declining and threatened species, but the effects of secondary woodland on the biodiversity associated with these trees are largely unknown. We tested for difference in species richness, occurrence, and abundance of a set of nationally and regionally red-listed epiphytic lichens between ancient oaks located in secondary woodland and ancient oaks located in open conditions. We refined the test of the effect of secondary woodland by also including other explanatory variables. Species occurrence and abundance were modelled jointly using overdispersed zero-inflated Poisson models. The richness of the red-listed lichens on ancient oaks in secondary woodland was half of that compared with oaks growing in open conditions. The species-level analyses revealed that this was mainly the result of lower occupancy of two of the study species. The tree-level abundance of one species was also lower in secondary woodland. Potential explanations for this pattern are that the study lichens are adapted to desiccating conditions enhancing their population persistence by low competition or that open, windy conditions enhance their colonisation rate. This means that the development of secondary woodland is a threat to red-listed epiphytic lichens. We therefore suggest that woody vegetation is cleared and grazing resumed in abandoned oak pastures. Importantly, this will also benefit the vitality of the oaks.

Do agricultural terraces and forest fires recurrence in Mediterranean afforested micro-catchments alter soil quality and soil nutrient content?

Science.gov (United States)

E Lucas-Borja, Manuel; Calsamiglia, Aleix; Fortesa, Josep; García-Comendador, Julián; Gago, Jorge; Estrany, Joan

2017-04-01

Bioclimatic characteristics and intense human pressure promote Mediterranean ecosystems to be fire-prone. Afforestation processes resulting from the progressive land abandonment during the last decades led to greater biomass availability increasing the risk of large forest fires. Likewise, the abandonment and lack of maintenance in the terraced lands constitute a risk of land degradation in terms of soil quantity and quality. Despite the effects of fire and the abandonment of terraced lands on soil loss and physico-chemical properties are identified, it is not clearly understood how wildfires and abandonment of terraces affect soil quality and nutrients content. Microbiological soil parameters and soil enzymes activities are biomarkers of the soil microbial communitýs functional ability, which potentially enables them as indicators of change, disturbance or stress within the soil community. The objective of this study was to investigate the effects of terracing (abandoned and non-abandoned) on the soil enzyme activities, microbiological soil parameters and soil nutrients dynamics in three Mediterranean afforested micro-catchments (i.e., fire recurrence in the last 20 years; i.e., unburned areas, burned once and burned twice. The combination of the presence of terraces and the recurrence of forest fire, thirty-six plots of 25 m2 were sampled along the these three micro-catchments collecting four replicas at the corners of each plot. The results elucidated how non-terraced and unburned plots presented the highest values of soil respiration rate and extracellular soil enzymes. Differences between experimental plots with different forest fire recurrence or comparing terraced and unburned plots with burned plots were weaker in relation to biochemical and microbiological parameters. Soil nutrient content showed an opposite trend with higher values in terraced plots, although differences were weaker. We conclude that terraced landscapes present poorer soil quality

Radioactive pollution investigation and disposal of abandoned uranium mines in Jiangsu province

International Nuclear Information System (INIS)

Zhang Qihong; Zhao Fuxiang; Wang Lihua

2008-01-01

The environment influence of five abandoned uranium mines in Jiangsu province from 1950s to 1960s is introduced. By monitoring air absorbed dose rate of external exposure γ radiation, it is found that the pollution scope of No.1 abandoned uranium mine is the biggest in five abandoned uranium mines. The No. 2 and No. 3 mine areas has achieved the limit use after they were desposed. The radioactivity and the gamma nuclein in solid samples(slag, soil, silt) and liquid samples (the surface water, the well water)of No. 1 abandoned uranium mine were further analyzed and measured, the measured values are higher. The pollution of abandoned uranium mines still exists and diffuses after 30 years. According to the monitoring results and the analysis of pollution present situation, suggestions and measures are proposed for the pollution control. (authors)

Carbon storage of different soil-size fractions in Florida silvopastoral systems.

Science.gov (United States)

Haile, Solomon G; Nair, P K Ramachandran; Nair, Vimala D

2008-01-01

Compared with open (treeless) pasture systems, silvopastoral agroforestry systems that integrate trees into pasture production systems are likely to enhance soil carbon (C) sequestration in deeper soil layers. To test this hypothesis, total soil C contents at six soil depths (0-5, 5-15, 15-30, 30-50, 50-75, and 75-125 cm) were determined in silvopastoral systems with slash pine (Pinus elliottii) + bahiagrass (Paspalum notatum) and an adjacent open pasture (OP) with bahiagrass at four sites, representing Spodosols and Ultisols, in Florida. Soil samples from each layer were fractionated into three classes (250-2000, 53-250, and <53 microm), and the C contents in each were determined. Averaged across four sites and all depths, the total soil organic carbon (SOC) content was higher by 33% in silvopastures near trees (SP-T) and by 28% in the alleys between tree rows (SP-A) than in adjacent open pastures. It was higher by 39% in SP-A and 20% in SP-T than in open pastures in the largest fraction size (250-2000 microm) and by 12.3 and 18.8%, respectively, in the intermediate size fraction (53-250 microm). The highest SOC increase (up to 45 kg m(-2)) in whole soil of silvopasture compared with OP was at the 75- to 125-cm depth at the Spodosol sites. The results support the hypothesis that, compared with open pastures, silvopastures contain more C in deeper soil layers under similar ecological settings, possibly as a consequence of a major input to soil organic matter from decomposition of dead tree-roots.

Extreme phosphorus losses in drainage from grazed dairy pastures on marginal land.

Science.gov (United States)

McDowell, Richard W; Monaghan, Ross M

2015-03-01

With the installation of artificial drainage and large inputs of lime and fertilizer, dairy farming can be profitable on marginal land. We hypothesized that this will lead to large phosphorus (P) losses and potential surface water impairment if the soil has little capacity to sorb added P. Phosphorous was measured in drainage from three "marginal" soils used for dairying: an Organic soil that had been developed out of scrub for 2 yr and used for winter forage cropping, a Podzol that had been developed into pasture for 10 yr, and an intergrade soil that had been in pasture for 2 yr. Over 18 mo, drainage was similar among all sites (521-574 mm), but the load leached to 35-cm depth from the Organic soil was 87 kg P ha (∼89% of fertilizer-P added); loads were 1.7 and 9.0 kg ha from the Podzol and intergrade soils, respectively. Soil sampling to 100 cm showed that added P leached throughout the Organic soil profile but was stratified and enriched in the top 15 cm of the Podzol. Poor P sorption capacity (<5%) in the Organic soil, measured as anion storage capacity, and tillage (causing mineralization and P release) in the Organic and intergrade soils were thought to be the main causes of high P loss. It is doubtful that strategies would successfully mitigate these losses to an environmentally acceptable level. However, anion storage capacity could be used to identify marginal soils with high potential for P loss for the purpose of managing risk. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

THE IMPACT ASSESSMENT OF THE ABANDONED URANIUM MINING EXPLOITATIONS ON ROCKS AND SOILS - ZIMBRU PERIMETER, ARAD COUNTY

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DIANA M. BANU

2016-10-01

Full Text Available The mining exploration and exploitation, especially the activity of uranium mineralization exploration and exploitation has a negative impact on the environment by the alterations of the landscape and the degradation of the environmental factors' quality. The principal environmental factors that could be affected by mining operations resulting from uranium exploitation are: water, air, soil, population, fauna, and flora. The aim of this study is, first, to identify the sources of pollution (natural radionuclides - natural radioactive series of uranium, radium, thorium, potassium and heavy metals that are accompanying the mineralizations for two of the most important environmental factors: rocks and soils: and, second, to assess the pollution impact on those two environmental factors. In order to identify this pollutants and their impact assessment it was selected as a study case an abandoned uranium mining perimeter named the Zimbru perimeter located in Arad County, Romania.

Flora in abandoned fields and adjacent crop fields on rendzina soils in the Zamość region

Directory of Open Access Journals (Sweden)

Marta Ziemińska-Smyk

2015-10-01

Full Text Available A floristic inventory of segetal flora was carried out in abandoned fields and adjacent crop fields on rendzina soils in the Zamość region in the year 2010. This study found a total of 130 weed species belonging to 30 botanical families. The following families were represented most frequently: Asteraceae, Fabaceae, Poaceae, Lamiaceae, Scrophulariaceae, and Brassicaceae. In the segetal flora, apophytes are dominant (55% of the total flora, with the highest number of meadow and xerothermic grassland species among them. Archeophytes (38% predominate in the group of anthropophytes. The species characterized by the highest constancy classes and reaching the highest cover indices posed the greatest threat to crops in the study area. The following weeds are most frequently found in fallow fields: Consolida regalis, Cichorium intybus, and Sinapis arvensis, while Papaver rhoeas is the greatest threat to cereal crops grown on rendzina soils.

Sheep Excreta as Source of Nitrous Oxide in Ryegrass Pasture in Southern Brazil

Directory of Open Access Journals (Sweden)

Michely Tomazi

2015-10-01

Full Text Available ABSTRACT Livestock urine and dung are important components of the N cycle in pastures, but little information on its effect on soil nitrous oxide (N2O emissions is available. We conducted a short-term (39-day trial to quantify the direct N2O-N emissions from sheep excreta on an experimental area of ryegrass pasture growing on a Typic Paleudult in southern Brazil. Four rates of urine-N (161, 242, 323, and 403 kg ha-1 N and one of dung-N (13 kg ha-1 N were applied, as well as a control plot receiving no excreta. The N2O-N emission factor (EF = % of added N released as N2O-N for urine and dung was calculated, taking into account the N2O fluxes in the field, over a period of 39 days. The EF value of the urine and dung was used to estimate the emissions of N2O-N over a 90-day period of pasture in the winter under two grazing intensities (2.5 or 5.0 times the herbage intake potential of grazing lambs. The soil N2O-N fluxes ranged from 4 to 353 µg m-2h-1. The highest N2O-N fluxes occurred 16 days after application of urine and dung, when the highest soil nitrate content was also recorded and the water-filled pore space exceeded 60 %. The mean EF for urine was 0.25 % of applied N, much higher than that for dung (0.06 %. We found that N2O-N emissions for the 90-day winter pasture period were 0.54 kg ha-1 for low grazing intensity and 0.62 kg ha-1 for moderate grazing intensity. Comparison of the two forms of excreta show that urine was the main contributor to N2O-N emissions (mean of 36 %, whereas dung was responsible for less than 0.1 % of total soil N2O-N emissions.

Terraced landscape: from an old best practice to a rising land abandoned-related soil erosion risk

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Tarolli, Paolo; Preti, Federico; Romano, Nunzio

2013-04-01

Among the most evident landscape signatures of human fingerprint during the Holocene, the terraces related to agricultural activities deserve a great importance. Landscape terracing probably represents one of the oldest best practice primarily for crop production, but also for mitigating soil erosion and stabilizing hillslopes in landforms dominated by steep slopes. This technique is widely used in various parts of the world even under different environmental conditions. In some zones, terraced landscapes, because of their history and locations, can also be considered a historical heritage and a sort of "cultural landscape" to preserve, an absolutely value for tourism. To preserve their original role of soil erosion prevention, terraces should be properly designed built according to specific and sustainable engineering rules. Then, their maintenance is the most critical issue to deal with. It is well known from literature that terraced landscapes subject to abandonment would result in an increasing of terrace failure and related land degradation. If not maintained, a progressively increasing of gully erosion affects the structure of the walls. The results of this process is the increasing of connectivity and runoff. During the last few years and partly because of changing in the society perspective and migration toward metropolitan areas, some Countries have been affected by a serious and wider land abandonment with an increasing of soil erosion and derived landslide risk. Italy is one example. In this work, we consider three typical case studies of a terraced landscape where the lack of maintenance characterizing the last few years, increased the landslide risk with several problems to the population. The first case study is located along the renowed "Amalfi Coast" (a portion of land located near Salerno, southern Italy), the second is placed in the north of Toscana (a region located in Central Italy), and the third one along the so-called "Cinque Terre" (a region

CARBON SEQUESTRATION IN PASTURES WITH TREES, TREELESS PASTURES AND DECIDUOUS FOREST FROM HUATUSCO, VERACRUZ

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José Antonio Torres-Rivera

2011-11-01

Full Text Available It was compared the amount of carbon (C sequestered in a pasture with trees (P+Ar and in conventional treeless pastures (P and deciduous forest (BC, typical of the region of Huatusco, Veracruz, Mexico. Total C sequestered by the systems evaluated was 49.9, 63.0 and 469.8 ton ha-1 for P, P+Ar and BC, respectively. The system with the highest amount of C sequestered was BC, with almost equal proportions in the aerial (268.4 ton ha-1 and belowground parts (201.4 ton ha-1. The amount of C sequestered in the livestock systems represented about one tenth of that sequestered in BC, being higher the proportion obtained in P+Ar (13.4 % compared to P (10.6 %. In both livestock systems, a significantly greater amount of C was sequestered in the soil organic matter than in the aerial biomass, with 59.7 and 3.29 ton ha-1 in P+Ar, and with 48.2 and 1.78 ton ha-1 in P, respectively. It is expected that as trees of the P+Ar system gain volume, C sequestration will increase, especially in the aerial biomass.

Alpine meadows and pastures after abandonment. Results of the Austrian MaB-programme and the EC-STEP project INTEGRALP

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Tappeiner, Ulrike

1993-12-01

Full Text Available We present the results of a study on the behaviour of alpine ecosystems after the abandon of farming practices. The work has been carried out in Gastein Valley (Austria, the High Tauern National Park (Austria and the Mt. Bondone (Italy. In the three places different phases of plant succession have been studied, and several ecologic parameters, such as the energy budget, the carbon budget, the canopy structure and many interactions between organisms were measured. Over 20 specialists have worked on the data gathering and analysis. Among the main observed results we can count the relative instability of abandoned plots; the diversity and the specific richness decrease; light becomes there a limiting factor because of the canopy growth; the degradation of litterfall becomes slower than in grazed plots; surface erosion and runoff decrease strongly, and so on. Commonly, the abandoned alpine pastures show a transition situation between the artificial equilibrium status kept by livestock and the natural equilibrium corresponding to climatic communities.

[es] Se presentan los resultados de un análisis sobre el comportamiento de los ecosistemas alpinos durante el abandono de las prácticas agrícolas en los mismos. Los trabajos se han llevado a cabo en el valle de Gastein (Austria, en el Parque Nacional del Alto Tauern (Austria y en el Monte Bondone (Italia. En los tres lugares se han estudiado distintas fases de la sucesión vegetal, midiéndose numerosos parámetros ecológicos, como el balance de carbono, el balance energético, la estructura de la cubierta vegetal y distintas interacciones entre organismos. Más de 20 especialistas han intervenido en la toma y análisis de los datos. Entré los principales resultados observados se cuentan el aumento de diversidad en las áreas abandonadas y su relativa inestabilidad; en ellas la luz se convierte en un factor limitante; la degradación de la hojarasca y la materia muerta se hace más lenta; la

Chemical and physical soil attributes in integrated crop-livestock system under no-tillage

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Hernani Alves da Silva

Full Text Available Although integrated crop-livestock system (ICLS under no-tillage (NT is an attractive practice for intensify agricultural production, little regional information is available on the effects of animal grazing and trampling, particularly dairy heifers, on the soil chemical and physical attributes. The objective of this study was to evaluate the effects of animal grazing on the chemical and physical attributes of the soil after 21 months of ICLS under NT in a succession of annual winter pastures (2008, soybeans (2008/2009, annual winter pastures (2009, and maize (2009/10. The experiment was performed in the municipality of Castro (PR in a dystrophic Humic Rhodic Hapludox with a clay texture. The treatments included a combination of two pasture (annual ryegrass monoculture and multicropping - annual ryegrass, black oat, white clover and red clover with animal grazing during the fall-winter period with two animal weight categories (light and heavy, in a completely randomized block experimental design with 12 replications. After the maize harvest (21 months after beginning, soil samples were collected at 0-10 and 10-20 cm layers to measure soil chemical and physical attributes. The different combinations of pasture and animal weight did not alter the total organic carbon and nitrogen in the soil, but they influence the attributes of soil acidity and exchangeable cations. The monoculture pasture of ryegrass showed greater soil acidification process compared to the multicropping pasture. When using heavier animals, the multicropping pasture showed lesser increase in soil bulk density and greater macroporosity.

Spatial distribution and sources of heavy metals in natural pasture soil around copper-molybdenum mine in Northeast China.

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Wang, Zhiqiang; Hong, Chen; Xing, Yi; Wang, Kang; Li, Yifei; Feng, Lihui; Ma, Silu

2018-06-15

The characterization of the content and source of heavy metals are essential to assess the potential threat of metals to human health. The present study collected 140 topsoil samples around a Cu-Mo mine (Wunugetushan, China) and investigated the concentrations and spatial distribution pattern of Cr, Ni, Zn, Cu, Mo and Cd in soil using multivariate and geostatistical analytical methods. Results indicated that the average concentrations of six heavy metals, especially Cu and Mo, were obviously higher than the local background values. Correlation analysis and principal component analysis divided these metals into three groups, including Cr and Ni, Cu and Mo, Zn and Cd. Meanwhile, the spatial distribution maps of heavy metals indicated that Cr and Ni in soil were no notable anthropogenic inputs and mainly controlled by natural factors because their spatial maps exhibited non-point source contamination. The concentrations of Cu and Mo gradually decreased with distance away from the mine area, suggesting that human mining activities may be crucial in the spreading of contaminants. Soil contamination of Zn were associated with livestock manure produced from grazing. In addition, the environmental risk of heavy metal pollution was assessed by geo-accumulation index. All the results revealed that the spatial distribution of heavy metals in soil were in agreement with the local human activities. Investigating and identifying the origin of heavy metals in pasture soil will lay the foundation for taking effective measures to preserve soil from the long-term accumulation of heavy metals. Copyright © 2018 Elsevier Inc. All rights reserved.

Barium selenate supplementation and its effect on intramammary infection in pasture-based dairy cows.

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Ceballos, A; Kruze, J; Barkema, H W; Dohoo, I R; Sanchez, J; Uribe, D; Wichtel, J J; Wittwer, F

2010-04-01

A significant proportion of cattle receive inadequate dietary Se because of its low content in soils and pastures of various regions of the world. Several economically important diseases in dairy cows, such as mastitis, have been associated with Se deficiency. The objective of this study was to evaluate the effect of a single injection of a long-acting form of Se at drying off on the risk and incidence rate of new intramammary infections and on milk somatic cell count in the subsequent lactation in pasture-based dairy cows. Forty-nine Chilean Holstein-Friesian cows were fed a diet containing pasture-based dairy cows did not affect udder health in the subsequent lactation, indicating that Se basal intake was adequate for preventing subclinical mastitis in pasture-based cows in southern Chile. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The effect of abandoned mining ponds on trace elements dynamics in the soil-plant system

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Gabarrón, María; Faz, Ángel; Zornoza, Raúl; Acosta, Jose A.

2017-04-01

In semiarid climate regions lack of vegetation and dryer climate contribute to erosion of abandoned mining surface areas making them up important potential sources of metal pollution into the environment. The objectives of this study were to determine the influence of mine ponds in agriculture and forest soils, and identify the dynamic of metals in the soil-plant system for native plant species (Ballota hirsuta) and crop species (Hordeum vulgare) in two ancient mining districts: La Unión and Mazarrón. To achieve these objectives, wastes samples from mine ponds and soil samples (rhizosphere and non-rhizosphere soils) from natural and agricultural lands were collected. In addition, six plants (Ballota hirsuta) from natural area and 3 plants (Hordeum vulgare) from crops were collected. Physicochemical properties and total, water soluble and bioavailable metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) and arsenic were measured in waste/soil samples. The chemical speciation of metals in soil was estimated by a sequential extraction procedure. For plants analyses, each plant were divided in roots, stem and leaves and metal content measured by ICP-MS. Results indicated that mine, natural and agricultural soils were contaminated by As, Cd, Cu, Pb, and Zn. Chemical partitioning revealed higher mobility of metals in mine ponds than natural and agriculture soils while only Fe and As are completely bound to the soil matrix due to the mineralogical compositions of soils. The accumulation of metals in Ballota hirsuta in La Union decrease as Fe>As>Cr>Ni>Cu>Zn>Cd>Mn>Co>Pb while in Mazarrón did as As>Fe>Cr>Pb>Cu>Ni>Co>Mn>Zn>Cd. Ballota hirsuta showed high ability to bio-accumulate Cu, Cr, Fe, Ni, and As, transferring a large amount to edible parts without exceeding the toxicity limits for animals. Results for barley plants (Hordeum vulgare) showed the ability to absorb and accumulate As, Fe, Mn, Pb and Zn, although the transfer ability of As, Cd and Pb was lower. Although the

Soil cover by natural trees in agroforestry systems

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Diaz-Ambrona, C. G. H.; Almoguera Millán, C.; Tarquis Alfonso, A.

2009-04-01

The dehesa is common agroforestry system in the Iberian Peninsula. These open oak parklands with silvo-pastoral use cover about two million hectares. Traditionally annual pastures have been grazed by cows, sheep and also goats while acorns feed Iberian pig diet. Evergreen oak (Quercus ilex L.) has other uses as fuelwood collection and folder after tree pruning. The hypothesis of this work is that tree density and canopy depend on soil types. We using the spanish GIS called SIGPAC to download the images of dehesa in areas with different soil types. True colour images were restoring to a binary code, previously canopy colour range was selected. Soil cover by tree canopy was calculated and number of trees. Processing result was comparable to real data. With these data we have applied a dynamic simulation model Dehesa to determine evergreen oak acorn and annual pasture production. The model Dehesa is divided into five submodels: Climate, Soil, Evergreen oak, Pasture and Grazing. The first three require the inputs: (i) daily weather data (maximum and minimum temperatures, precipitation and solar radiation); (ii) the soil input parameters for three horizons (thickness, field capacity, permanent wilting point, and bulk density); and (iii) the tree characterization of the dehesa (tree density, canopy diameter and height, and diameter of the trunk). The influence of tree on pasture potential production is inversely proportional to the canopy cover. Acorn production increase with tree canopy cover until stabilizing itself, and will decrease if density becomes too high (more than 80% soil tree cover) at that point there is competition between the trees. Main driving force for dehesa productivity is soil type for pasture, and tree cover for acorn production. Highest pasture productivity was obtained on soil Dystric Planosol (Alfisol), Dystric Cambisol and Chromo-calcic-luvisol, these soils only cover 22.4% of southwest of the Iberian peninssula. Lowest productivity was

Contamination dynamics in fallouts, pasturable vegetation and milk in Leningrad distrist after Chernobyl accident

International Nuclear Information System (INIS)

Nedbaevskaya, N.A.; Sanzharova, N.I.; Blinova, L.D.; Kryshev, I.I.; Aleksakhin, R.M.

1991-01-01

Radiation monitoring of individual elements of agroecosystem in the area of the Leningrad NPP is carried out with the purpose of studying the concentration dynamics of radioisotopes in the atmosphere resulting from the accident at the Chernobyl NPP. The γ-radiation dose rate on the terrain, content and radionuclide composition of atmospheric fallout, content of γ-emitting isotopes in the soil and plants at pastures is monitored from April up to September 1986; radioisotope content in cow milk by pasturing is determined

Impact of soil characteristics and land use on pipe erosion in a temperate humid climate: Field studies in Belgium

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Verachtert, E.; Van Den Eeckhaut, M.; Martínez-Murillo, J. F.; Nadal-Romero, E.; Poesen, J.; Devoldere, S.; Wijnants, N.; Deckers, J.

2013-06-01

This study investigates the role of soil characteristics and land use in the development of soil pipes in the loess belt of Belgium. First, we tested the hypothesis that discontinuities in the soil profile enhance lateral flow and piping by impeding vertical infiltration. We focus on discontinuities in soil characteristics that can vary with soil depth, including texture, saturated hydraulic conductivity, penetration resistance, and bulk density. These characteristics as well as soil biological activity were studied in detail on 12 representative soil profiles for different land use types. Twelve sites were selected in the Flemish Ardennes (Belgium): four pastures with collapsed pipes (CP), four pastures without CP, two sites under arable land without CP and two sites under forest without CP. Secondly, this study aimed at evaluating the interaction of groundwater table positions (through soil augerings) and CP in a larger area, with a focus on pastures. Pasture is the land use where almost all CP in the study area are observed. Therefore, the position of the groundwater table was compared for 15 pastures with CP and 14 pastures without CP, having comparable topographical characteristics in terms of slope gradient and contributing area. Finally, the effect of land use history on the occurrence of pipe collapse was evaluated for a database of 84 parcels with CP and 84 parcels without CP, currently under pasture. As to the first hypothesis, no clear discontinuities for abiotic soil characteristics in soil profiles were observed at the depth where pipes occur, but pastures with CP had significantly more earthworm channels and mole burrows at larger depths (> 120 cm: mean of > 200 earthworm channels per m2) than pastures without CP, arable land or forest (> 120 cm depth, a few or no earthworm channels left). The land use history appeared to be similar for the pastures with and without CP. Combining all results from soil profiles and soil augering indicates that intense

Improving and disaggregating N{sub 2}O emission factors for ruminant excreta on temperate pasture soils

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Krol, D.J., E-mail: kroldj@tcd.ie [Teagasc, Crops, Land Use and Environment Programme, Johnstown Castle, Co., Wexford (Ireland); Carolan, R. [Agri-Food and Biosciences Institute (AFBI), Belfast BT9 5PX (Ireland); Minet, E. [Teagasc, Crops, Land Use and Environment Programme, Johnstown Castle, Co., Wexford (Ireland); McGeough, K.L.; Watson, C.J. [Agri-Food and Biosciences Institute (AFBI), Belfast BT9 5PX (Ireland); Forrestal, P.J. [Teagasc, Crops, Land Use and Environment Programme, Johnstown Castle, Co., Wexford (Ireland); Lanigan, G.J., E-mail: gary.lanigan@teagasc.ie [Teagasc, Crops, Land Use and Environment Programme, Johnstown Castle, Co., Wexford (Ireland); Richards, K.G. [Teagasc, Crops, Land Use and Environment Programme, Johnstown Castle, Co., Wexford (Ireland)

2016-10-15

Cattle excreta deposited on grazed grasslands are a major source of the greenhouse gas (GHG) nitrous oxide (N{sub 2}O). Currently, many countries use the IPCC default emission factor (EF) of 2% to estimate excreta-derived N{sub 2}O emissions. However, emissions can vary greatly depending on the type of excreta (dung or urine), soil type and timing of application. Therefore three experiments were conducted to quantify excreta-derived N{sub 2}O emissions and their associated EFs, and to assess the effect of soil type, season of application and type of excreta on the magnitude of losses. Cattle dung, urine and artificial urine treatments were applied in spring, summer and autumn to three temperate grassland sites with varying soil and weather conditions. Nitrous oxide emissions were measured from the three experiments over 12 months to generate annual N{sub 2}O emission factors. The EFs from urine treated soil was greater (0.30–4.81% for real urine and 0.13–3.82% for synthetic urine) when compared with dung (− 0.02–1.48%) treatments. Nitrous oxide emissions were driven by environmental conditions and could be predicted by rainfall and temperature before, and soil moisture deficit after application; highlighting the potential for a decision support tool to reduce N{sub 2}O emissions by modifying grazing management based on these parameters. Emission factors varied seasonally with the highest EFs in autumn and were also dependent on soil type, with the lowest EFs observed from well-drained and the highest from imperfectly drained soil. The EFs averaged 0.31 and 1.18% for cattle dung and urine, respectively, both of which were considerably lower than the IPCC default value of 2%. These results support both lowering and disaggregating EFs by excreta type. - Highlights: • N{sub 2}O emissions were measured from cattle excreta applied to pasture. • N{sub 2}O was universally higher from urine compared with dung. • N{sub 2}O was driven by rainfall, temperature

Influence of Deforestation on Infiltration and Erosion in the Brazilian Caatinga

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Leite, P. A.; Souza, E.; Gomes, R. J.; Jacques, Y.; Cantalice, J. R. B.; Wilcox, B. P.

2015-12-01

Population growth and changes in land use are leading to increasing rates of deforestation and land degradation in the Brazilian Caatinga—a semiarid tropical forest. The influence of deforestation and subsequent recovery on soil hydrological properties and erosion are poorly understood. To investigate the influence of forest regeneration stage on soil hydrological processes, we conducted small plot rainfall simulation experiments on (1) a degraded pasture, recently abandoned; (2) an abandoned pasture left for natural recovery in the past seven years; (3) a 40 year old regenerating forestland; and (4) an old-growth forestland. In addition, we determined infiltration rates using single rings (following the Beerkan Method) and in the laboratory we applied the constant head method to soil core samples. Hydraulic parameters will be obtained using the BEST method with SciLab software and statistical analysis of the data will be carried in R. We found that infiltration rates were highest and erosion the lowest in the old-growth forest. Surprisingly, differences in both infiltration and erosion rates were quite small in the other sites. These results suggest that significant time is required following deforestation for recovery of soil hydrological properties.

Afforestation alters community structure of soil fungi.

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Carson, Jennifer K; Gleeson, Deirdre B; Clipson, Nicholas; Murphy, Daniel V

2010-07-01

Relatively little is known about the effect of afforestation on soil fungal communities. This study demonstrated that afforestation altered fungal community structure and that changes were correlated to pools of soil C. Pasture at three locations on the same soil type was afforested with Eucalyptus globulus or Pinus pinaster. The structure of fungal communities under the three land uses was measured after 13y using automated ribosomal intergenic spacer analysis (ARISA). Afforestation significantly altered the structure of fungal communities. The effect of location on the structure of fungal communities was limited to pasture soils; although these contained the same plant species, the relative composition of each species varied between locations. Differences in the structure of fungal communities between pasture, E. globulus and P. pinaster were significantly correlated with changes in the amount of total organic C and microbial biomass-C in soil. Afforestation of patches of agricultural land may contribute to conserving soil fungi in agricultural landscapes by supporting fungal communities with different composition to agricultural soils. Copyright © 2010 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Effects of Climate and Social Change on Pasture Productivity and Area in the Alay Valley, Kyrgyzstan

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Zhang, L.; Smithwick, E. A. H.

2017-12-01

The high elevation Alay Valley, located in the central Asian country of Kyrgyzstan, has experienced substantial socio-political and environmental changes in recent decades, resulting from the collapse of the Soviet Union and an increase in average annual temperature from 1.8 C to 2.7 C between 1990 and 2014. However, the consequences of these changes on pastureland productivity and area has not been previously assessed, despite the critical cultural and economic importance of pasturelands for sustaining livelihoods in this region. We assessed spatial and temporal patterns of soil moisture, pasture productivity and pasture area in the Alay Valley. Supervised classification was performed on Landsat imagery over the study region to distinguish pastures and agricultural land in order to relate changes in soil moisture to specific land classes. Root Zone Soil Moisture (RZSM) was estimated between May 2015 and June 2017 from Soil Moisture Active Passive L4 RZSM product. Average monthly NDVI for 2016 was calculated to obtain seasonal patterns in productivity of the pasturelands in the region. Results show that annual RZSM trends closely matched those of precipitation, as RZSM peaks during May (the wettest month) and decreases during the dry summer. The NDVI trend is also notable as it peaks very early in June before declining due to limited precipitation and grazing practices. There has been a sharp increase in pasturelands encompassing the bank of the Kyzyl Suu river from 1993 to 2016. Likely due to turmoil from collapse of the USSR, the area of pasturelands decreased slightly from 59.98 to 55.99 km^2 from 1993-1994, corresponding with a decline in livestock count and GDP per capita. The area of pasturelands has since recovered and is hovering around 104.47 - 107.95 km^2 between 2009-2016. Overall results highlight both sensitivity and resilience of high elevation pasture to coupled socio-environmental drivers.

Fertilization and oversowing on natural grassland: effects on pasture characteristics and yearling steers performance

Directory of Open Access Journals (Sweden)

Eduardo Tonet Ferreira

2011-09-01

Full Text Available The objective of this study was to evaluate the vegetal and animal production of a natural pasture on a Mollisol soil in the region of Campanha, in RS. The experimental design consisted of complete randomized blocks with three replicates, which enables the comparison between natural unfertilized pastures with fertilized pastures and pastures fertilized and overseeded with Lolium multiflorum, Lotus corniculatus cv. São Gabriel and Trifolium repens cv. Lucero (NPO. Data were submitted to the analyses of variance considering seasons of the year as time repeated measurements. Aberddeen Angus calves of about nine months of age were used in continuous stocking with variable stocking rate in order to maintain forage offer at 13% of live weight. Data were collected between July 7th (2007 and May 3rd (2008, totaling 302 days. Fertilized and oversown pastures showed higher green forage mass mainly in the spring, as result of higher dry matter (DM accumulation rate. Average daily live-weight gain for fertilized pasture (0.581 kg/day was higher than for natural pasture (0.473 kg/day. Higher live-weight gains were obtained in the fall (0.869 kg/day. Stocking rate showed interaction with the seasons of the year, with higher stocking rates obtained in oversown pasture (701 kg of LW/ha and fertilized pasture (667 kg of LW/ha during the spring. Live-weight gain per hectare from natural pasture (224 kg LW/ha was lower than on fertilized (310 kg LW/ha and over-sown pasture (287 kg LW/ha. Forage mass, dry matter content, forage allowance and pasture height explained 61% of the average live weight gain. Despite the good performance of native grasslands in this region in its natural condition, the utilization of different inputs as fertilization and oversowing of winter cultivated species promoted positive differences in forage production and its distribution along the year and in animal yield.

Carbon fluxes of Kobresia pygmaea pastures on the Tibetan Plateau

Science.gov (United States)

Foken, T.; Biermann, T.; Babel, W.; Ma, Y.

2013-12-01

With an approximate cover of 450,000 km2 on the Tibetan Plateau (TP), the Cyperaceae Kobresia pygmaea forms he world's largest alpine ecosystem. This species, especially adapted to grazing pressure, grows to a height of only 2-6 cm and can be found in an altitudinal range of 4000 to 5960 m a.s.l. A special characteristic of this ecosystem is the stable turf layer, which is built up from roots and plays a significant role in protecting soil from erosion. This is of great importance since soils on the TP store 2.5 % of the global soil organic carbon stocks. The aim of the investigation was the study of the carbon storage and the impact of human-induced land use change on these Kobresia pygmaea pastures. We therefore applied eddy-covariance measurements and modelling as a long-term control of the fluxes between the atmosphere and the pastures and 13C labelling for the investigation of flux partitioning, and chamber measurements to investigate the degradation of the pastures. Combining CO2 budgets observed in 2010 with eddy-covariance measurements and relative partitioning of Carbon fluxes estimated with 13C labelling enabled us to characterise the C turnover for the vegetation period with absolute fluxes within the plant-soil-atmosphere continuum. These results revealed that this ecosystem indeed stores a great amount of C in below-ground pools, especially in the root turf layer. To further investigate the importance of the root layer, the experiments in 2012 focused on flux measurements over the different surface types which make up the heterogeneity of the Kobresia pygmaea pastures and might result from degradation due to extensive grazing. The three surface types investigated with a LiCOR long-term monitoring chamber system include Kobresia pygmaea with intact turf layer (IRM), a surface type where the turf layer is still present but the vegetation is sparse and mainly consists of Cryptogam crusts (DRM) and finally areas without the turf layer (BS). According to

Microbiological sanitation of abandoned armament sites - treatment of TNT-contaminated soils. Sanierung von Ruestungsaltlasten durch mikrobiologische Verfahren: Behandlung TNT-kontaminierter Boeden

Energy Technology Data Exchange (ETDEWEB)

Winterberg, R.; Stoffers, H. (Contracon GmbH, Cuxhaven (Germany))

TNT (trinitrotoluene) is the most commonly used military explosive. It is a hazardous material which has been spread over many abandoned armament sites since its production and processing during Wold War II and the subsequent delaboration and dismantling of TNT production plants. The harmful effect of this explosive on man and on the environment calls for the sanitation of TNT-contaminated sites. The microbiological method is among the techniques applied to clean TNT-contaminated soils and waters. (orig.).

Using remotely sensed vegetation indices to model ecological pasture conditions in Kara-Unkur watershed, Kyrgyzstan

Science.gov (United States)

Masselink, Loes; Baartman, Jantiene; Verbesselt, Jan; Borchardt, Peter

2017-04-01

Kyrgyzstan has a long history of nomadic lifestyle in which pastures play an important role. However, currently the pastures are subject to severe grazing-induced degradation. Deteriorating levels of biomass, palatability and biodiversity reduce the pastures' productivity. To counter this and introduce sustainable pasture management, up-to-date information regarding the ecological conditions of the pastures is essential. This research aimed to investigate the potential of a remote sensing-based methodology to detect changing ecological pasture conditions in the Kara-Unkur watershed, Kyrgyzstan. The relations between Vegetation Indices (VIs) from Landsat ETM+ images and biomass, palatability and species richness field data were investigated. Both simple and multiple linear regression (MLR) analyses, including terrain attributes, were applied. Subsequently, trends of these three pasture conditions were mapped using time series analysis. The results show that biomass is most accurately estimated by a model including the Modified Soil Adjusted Vegetation Index (MSAVI) and a slope factor (R2 = 0.65, F = 0.0006). Regarding palatability, a model including the Enhanced Vegetation Index (EVI), Northness Index, Near Infrared (NIR) and Red band was most accurate (R2 = 0.61, F = 0.0160). Species richness was most accurately estimated by a model including Topographic Wetness Index (TWI), Eastness Index and estimated biomass (R2 = 0.81, F = 0.0028). Subsequent trend analyses of all three estimated ecological pasture conditions presented very similar trend patterns. Despite the need for a more robust validation, this study confirms the high potential of a remote sensing based methodology to detect changing ecological pasture conditions.

Loss of soil (macro)fauna due to the expansion of Brazilian sugarcane acreage.

Science.gov (United States)

Franco, André L C; Bartz, Marie L C; Cherubin, Maurício R; Baretta, Dilmar; Cerri, Carlos E P; Feigl, Brigitte J; Wall, Diana H; Davies, Christian A; Cerri, Carlos C

2016-09-01

Land use changes (LUC) from pasture to sugarcane (Saccharum spp.) crop are expected to add 6.4Mha of new sugarcane land by 2021 in the Brazilian Cerrado and Atlantic Forest biomes. We assessed the effects of these LUC on the abundance and community structure of animals that inhabit soils belowground through a field survey using chronosequences of land uses comprising native vegetation, pasture, and sugarcane along a 1000-km-long transect across these two major tropical biomes in Brazil. Macrofauna community composition differed among land uses. While most groups were associated with samples taken in native vegetation, high abundance of termites and earthworms appeared associated with pasture soils. Linear mixed effects analysis showed that LUC affected total abundance (X(2)(1)=6.79, p=0.03) and taxa richness (X(2)(1)=6.08, p=0.04) of soil macrofauna. Abundance increased from 411±70individualsm(-2) in native vegetation to 1111±202individualsm(-2) in pasture, but decreased sharply to 106±24individualsm(-2) in sugarcane soils. Diversity decreased 24% from native vegetation to pasture, and 39% from pasture to sugarcane. Thus, a reduction of ~90% in soil macrofauna abundance, besides a loss of ~40% in the diversity of macrofauna groups, can be expected when sugarcane crops replace pasture in Brazilian tropical soils. In general, higher abundances of major macrofauna groups (ants, coleopterans, earthworms, and termites) were associated with higher acidity and low contents of macronutrients and organic matter in soil. This study draws attention for a significant biodiversity loss belowground due to tropical LUC in sugarcane expansion areas. Given that many groups of soil macrofauna are recognized as key mediators of ecosystem processes such as soil aggregation, nutrients cycling and soil carbon storage, our results warrant further efforts to understand the impacts of altering belowground biodiversity and composition on soil functioning and agriculture performance

Evapotranspiration from a Mediterranean evergreen oak savannah: The role of trees and pasture

Science.gov (United States)

Paço, Teresa A.; David, Teresa S.; Henriques, Manuel O.; Pereira, João S.; Valente, Fernanda; Banza, João; Pereira, Fernando L.; Pinto, Clara; David, Jorge S.

2009-05-01

SummaryMediterranean evergreen oak woodlands of southern Portugal ( montados) are savannah-type ecosystems with a widely sparse tree cover, over extensive grassland. Therefore, ecosystem water fluxes derive from two quite differentiated sources: the trees and the pasture. Partitioning of fluxes according to these different sources is necessary to quantify overall ecosystem water losses as well as to improve knowledge on its functional behaviour. In southern Iberia, these woodlands are subjected to recurrent droughts. Therefore, reaction/resilience to water stress becomes an essential feature of vegetation on these ecosystems. Long-term tree transpiration was recorded for 6 years from a sample of holm oak ( Quercus ilex ssp. rotundifolia) trees, using the Granier sap flow method. Ecosystem transpiration was measured by the eddy covariance technique for an 11-month period (February to December 2005), partly coincident with a drought year. Pasture transpiration was estimated as the difference between ecosystem (eddy covariance) and tree (sap flow) transpiration. Pasture transpiration stopped during the summer, when the surface soil dried up. In the other seasons, pasture transpiration showed a strong dependence on rainfall occurrence and on top soil water. Conversely, trees were able to maintain transpiration throughout the summer due to the deep root access to groundwater. Q. ilex trees showed a high resilience to both seasonal and annual drought. Tree transpiration represented more than half of ecosystem transpiration, in spite of the low tree density (30 trees ha -1) and crown cover fraction (21%). Tree evapotranspiration was dominated by transpiration (76%), and interception loss represented only 24% of overall tree evaporation.

Exchangeable cations in some soils of Mt. Stara planina

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Belanović Snežana

2005-01-01

Full Text Available Land use in forest and pasture ecosystems requires the respecting of ecological and economic interactions between the individual components of these ecosystems. The content of nutrition elements in the soil solution depends on soil types, climate conditions and vegetation species, i.e., it is conditioned by their cycling in the ecosystem. This paper studies the cation exchange capacity in pasture and forest soils of Mt. Stara Planina.

THE DEVELOPMENT OF SYNTHETIC SOIL MATERIALS FOR THE SUCCESSFUL RECLAMATION OF ABANDONED MINED LAND SITES

Energy Technology Data Exchange (ETDEWEB)

Song Jin

2006-03-01

Abandoned mine sites associated with coal and metal mining across the western United States have been left as unproductive wastelands. The availability of soil materials or other materials to support the restoration of the vegetative cover and enhance the recovery of such areas is limited. The restoration of these areas often requires the use of available amendments such as organic waste products or to help stabilize the soil. Many of the organic waste products, including sewage sludge, clarifier sludge, fly ash sludge, and other by-products from the agricultural industries such as compost can be employed for beneficial uses. This study looked at the feasibility of applying organic waste products to a mine soil in Montana to increase soil fertility and enhance plant productivity. Waste rock samples were tested for acid forming potential via acid base accounting. Samples cores were constructed and leached with simulated rainwater to determine amendment affect on metal leaching. A greenhouse study was completed to determine the most suitable amendment(s) for the field mine land site. Results from the acid base accounting indicate that acid formed from the waste rock would be neutralized with the alkalinity in the system. Results also show that metals in solution are easily held by organics from the amendments and not allowed to leach in to the surrounding water system. Data from the greenhouse study indicated that the amendment of sewage sludge was most promising. Application of 2% sewage sludge along with 1% sewage sludge plus 1% clarifier sludge, 2% compost, and no treatment were used for mine land application. Initial results were encouraging and it appears that sewage sludge may be a good reclamation option for mine lands.

Agriculture at the Edge: Landscape Variability of Soil C Stocks and Fluxes in the Tropical Andes

Science.gov (United States)

Riveros-Iregui, D. A.; Peña, C.

2015-12-01

Paramos, or tropical alpine grasslands occurring right above the forest tree-line (2,800 - 4,700 m), are among the most transformed landscapes in the humid tropics. In the Tropical Andes, Paramos form an archipelago-like pattern from Northern Colombia to Central Peru that effectively captures atmospheric moisture originated in the Amazon-Orinoco basins, while marking the highest altitude capable of sustaining vegetation growth (i.e., 'the edge'). This study investigates the role of land management on mediating soil carbon stocks and fluxes in Paramo ecosystems of the Eastern Cordillera of Colombia. Observations were collected at a Paramo site strongly modified by land use change, including active potato plantations, pasture, tillage, and land abandonment. Results show that undisturbed Paramos soils have high total organic carbon (TOC), high soil water content (SWC), and low soil CO2 efflux (RS) rates. However, Paramo soils that experience human intervention show lower TOC, higher and more variable RS rates, and lower SWC. This study demonstrates that changes in land use in Paramos affect differentially the accumulation and exchange of soil carbon with the atmosphere and offers implications for management and protection strategies of what has been deemed the fastest evolving biodiversity ecosystem in the world.

EFFECT OF LEGUME TREES ON SOIL MACROFAUNA OF A Brachiaria brizantha cv. MARANDU PASTURE EFEITO DE LEGUMINOSAS ARBÓREAS SOBRE A MACROFAUNA DO SOLO EM PASTAGEM DE Brachiaria brizantha cv. MARANDU

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Avílio Antonio Franco

2007-09-01

Full Text Available

The objective of this research was to evaluate the effect of four legume tree species in a Brachiaria brizantha cv. Marandu pasture on soil macrofauna density and diversity, in a low natural fertility soil. The tree leguminous species introduced in the pasture were Pseudosamanea guachapele, Mimosa artemisiana, Mimosa tenuiflora, and Enterolobium contortisiliquum. The macrofauna sampling consisted in collecting six soil monoliths with 25 cm x 25 cm x 30 cm under tree canopies or in a transect in the single Brachiaria pasture. The densities varied from 602 individuals.m-2 under the canopy of E. contortisiliquum to two individuals.m-2 in the single pasture. The largest group richness was found under M. tenuiflora canopy (ten groups, followed by P. guachapele (nine groups, E. contortisiliquum (seven groups and M. artemisiana (six groups. The leguminous species influence was related to N content and to C:N ratio of leaf material. M. artemisiana and M. tenuiflora favored the occurrence of Oligochaeta and Coleoptera larvae, while under the P. guachapele and E. contortisiliquum canopies Formicidae activity was more intense.

KEY-WORDS: Soil macrofauna; sivipastoral systems; soil quality.

O objetivou deste trabalho foi avaliar o efeito de quatro espécies leguminosas arbóreas, em uma pastagem de Brachiaria brizantha cv. Marandu, com dois anos de estabelecimento, sobre a densidade e diversidade da macrofauna de um planossolo de baixa fertilidade natural. As espécies arbóreas introduzidas na pastagem foram: Pseudosamanea guachapele, Mimosa artemisiana, Mimosa tenuiflora e Enterolobium contortisiliquum. A amostragem da macrofauna consistiu na retirada de seis monolitos de solo com 25 cm x 25 cm x 30 cm sob a copa das árvores ou em um transecto na pastagem solteira. As densidades variaram de 602

Assessment of abandoned agricultural land resource for bio-energy production in Estonia

Energy Technology Data Exchange (ETDEWEB)

Kukk, Liia; Astover, Alar; Roostalu, Hugo; Suuster, Elsa; Noormets, Merrit; Sepp, Kalev (Estonian Univ. of Life Sciences, Inst. of Agricultural and Environmental Sciences, Tartu (Estonia)); Muiste, Peeter (Estonian Univ. of Life Sciences, Inst. of Forestry and Rural Engineering, Tartu (Estonia))

2010-03-15

The current study locates and quantifies abandoned agricultural areas using the Geographic Information System (GIS) and evaluates the suitability of abandoned fields for bio-energy production in Tartumaa (Tartu County) in Estonia. Soils of abandoned areas are generally of low quality and thereby limited suitability for crop production; as a result soil-crop suitability analyses could form the basis of knowledge-based bio-energy planning. The study estimated suitable areas for bio-energy production using willow (Salix sp), grey alder [Alnus incana (L.) Moench], hybrid aspen (Populus tremuloides Michx.Populus tremula L.), reed canary grass (Phalaris arundinacea L.), and Caucasian goat's rue (Galega orientalis Lam.) in separate plantations. A combined land-use strategy is also presented as these crops are partially suitable to the same areas. Reed canary grass and grey alder have the highest energy potentials and each would re-use more than 80% of the available abandoned agricultural land. Energy grasses and short-rotation forestry in combined land-use strategy represents the opportunity of covering approximately a quarter of county's annual energy demand. The study estimates only agronomic potential, so further bio-energy analysis should take into account technical and economic limitations. Developed framework supports knowledge-based decision-making processes from field to regional scale to achieve sustainable bio-energy production

Environmental and plant effects of sewage sludge application to forests and pastures

International Nuclear Information System (INIS)

Van Miegroet, H.; Boston, H.L.; Johnson, D.W.; Nevada Univ., Reno, NV

1989-01-01

Digested sewage sludge was applied to pastures and tree plantations at 19 to 44 Mg/ha (dry weight) as part of a municipal sludge disposal program. The sludge had low concentrations of heavy metals and traces of 137 Cs and 60 Co. Monitoring of soils, soil solutions, and runoff indicated that N, P, heavy metals, and radionuclides were largely retained in the upper 15cm of the soil. Soil solutions had elevated NO 3 - concentrations often >100 mg/L, but no significant increases in groundwater NO 3 - were found during the first year. Runoff from active sites had elevated concentrations of NO 3 - (20--30 mg/L), soluble P (1 mg/L), BOD 5 (5--30 mg/L), and fecal coliform (up to 14,000 colonies per 100 ml), not unlike runoff from pastures with cattle. Enrichment of organic N (2 times), available (inorganic) N (5 to 10 times), and Bray-P in the upper soils persisted for several years following sludge application. Sludge increased vegetation N concentrations from 1.5% to 2.3% and P concentrations from 0.16% to 0.31%. With the exception of Zn, heavy metals did not accumulate substantially in the vegetation. The sludge addition increased the survival and growth of sycamore (Platanus occidentalis L.). For a loblolly pine (Pinus taeda L.) plantation future growth improvements are expected based on elevated foliar N concentrations. 37 refs., 3 figs., 7 tabs

Carbon budgets for an irrigated intensively grazed dairy pasture and an unirrigated winter-grazed pasture

Science.gov (United States)

Hunt, John E.; Laubach, Johannes; Barthel, Matti; Fraser, Anitra; Phillips, Rebecca L.

2016-05-01

Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. Here, we determined the NECB over one year for an irrigated, fertilised and rotationally grazed dairy pasture and a neighbouring unirrigated, unfertilised, winter-grazed pasture. Primary terms in the NECB calculation were: net ecosystem production (NEP), biomass carbon removed by grazing cows and carbon (C) input from their excreta. Annual NEP was measured using the eddy-covariance method. Carbon removal was estimated with plate-meter measurements calibrated against biomass collections, pre- and post-grazing. Excreta deposition was calculated from animal feed intake. The intensively managed pasture gained C (NECB = 103 ± 42 g C m-2 yr-1) but would have been subject to a non-significant C loss if cattle excreta had not been returned to the pasture. The unirrigated pasture was C-neutral (NECB = -13 ± 23 g C m-2 yr-1). While annual GPP of the former was almost twice that of the latter (2679 vs. 1372 g C m-2 yr-1), ecosystem respiration differed by only 68 % between the two pastures (2271 vs. 1352 g C m-2 yr-1). The ratio of GPP to the total annual water input of the irrigated pasture was 37 % greater than that of the unirrigated pasture, i.e. the former used the water input more efficiently than the latter to produce biomass. The NECB results agree qualitatively with those from many other eddy-covariance studies of grazed grasslands, but they seem to be at odds with long-term carbon-stock studies of other New Zealand pastures.

Eficiência no uso dos nutrientes por espécies pioneiras crescidas em pastagens degradadas na Amazônia central Nutrient use efficiency for pioneer species grown on abandoned pastures in central Amazonia

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Carlos E. M. Silva

2006-12-01

Full Text Available Nas últimas décadas, considerável parcela da floresta amazônica tem sido transformada em pastagens que, em função da baixa fertilidade natural dos solos e do manejo deficiente, decrescem rapidamente em produtividade e são abandonadas, dando lugar a uma sucessão secundária arbórea adaptada à baixa disponibilidade de nutrientes. O objetivo deste estudo foi obter informações sobre a eficiência no uso dos nutrientes por espécies arbóreas freqüentes nesses ambientes degradados, após calagem e aplicação de fosfato. O experimento realizado numa área de sucessão secundária com seis anos de idade, consistiu na aplicação de quatro tratamentos: controle; aplicação de fósforo (P; aplicação de fósforo e calcário (P+Cal; e aplicação de fósforo, calcário e gesso (P+Cal+G. As determinações das taxas de fotossíntese, bem como as coletas de amostras de solo e de folhas foram realizadas oito meses após a aplicação dos tratamentos. A aplicação do corretivo e do fosfato favoreceu o desempenho das espécies nos tratamentos P+Cal e P+Cal+G. Bellucia grossularioides acumulou mais N, P e Zn, enquanto que Laetia procera acumulou mais Ca e Mn. Vismia japurensis foi a espécie mais eficiente no uso dos nutrientes, em função dos altos valores da taxa fotossintética; apresentou baixos teores foliares de P quando comparada com Bellucia grossularioides, sugerindo ser uma espécie bem adaptada a ambientes com baixa disponibilidade de nutrientes, como ocorre em áreas degradadas na Amazônia.Large areas of Amazonian forest have been converted to pastures over the last two decades. Low soil fertility and mismanagement results in a rapid decline in net primary productivity leading the pastures to be abandoned, and woody vegetation adapted to low nutrient conditions colonize the areas. The objective of this study was to examine nutrient use efficiency, following liming (calcium and phosphorus addition by three of the most frequent

Radiocarbon enrichment of soil organic matter fractions in New Zealand soils

International Nuclear Information System (INIS)

Goh, K.M.; Stout, J.D.; Rafter, T.A.

1977-01-01

Soil organic matter was extracted using the classical procedure and fractionated into humin (nonextractable), humic acid, and fulvic acid. The masses of total organic carbon in the whole soil samples and in the fractions, together with their 14 C content and 13 C/ 12 C ratios, were also determined. The following New Zealand soils were studied: a Fluvaquent, with experimental pasture plots, formed from deeply mixing subsoils of low organic carbon content; a Typic Fragiaqualf and a Typic Dystrochrept with moderately productive pastures; and an Umbric Vitrandept at two sites under native tussock and under introduced grasses of low productivity. The degree of radiocarbon enrichment of the different fractions in both topsoil and subsoil samples was examined in relation to differences in soil type, soil biological activity, and vegetation history. There was variation in the distribution and enrichment of the organic matter fractions both within the same soil type and between soil types, as well as between the topsoil and subsoil of the same soil. Differences appeared to be primarily a function of the stage of decomposition and translocation of the fractions through the soil rather than due to vegetation differences

Transpiration efficiency of three Mediterranean annual pasture species and wheat.

Science.gov (United States)

Bolger, T P; Turner, N C

1998-06-01

Attempts to improve water use efficiency in regions with Mediterranean climates generally focus on increasing plant transpiration relative to evaporation from the soil and increasing transpiration efficiency. Our aim was to determine if transpiration efficiency differs among key species occurring in annual pastures in southern Australia. Two glasshouse experiments were conducted with three key pasture species, subterranean clover (Trifolium subterraneum L.), capeweed [Arctotheca calendula (L.) Levyns] and annual ryegrass (Lolium rigidum Gaudin), and wheat (Triticum aestivum L.). Transpiration efficiency was assessed at the levels of␣whole-plant biomass and water use (W), leaf gas exchange measurements of the ratio of CO 2 assimilation to leaf conductance to water vapour (A/g), and carbon isotope discrimination (Δ) in leaf tissue. In addition, Δ was measured on shoots of the three pasture species growing together in the field. In the glasshouse studies, annual ryegrass had a consistently higher transpiration efficiency than subterranean clover or capeweed by all methods of measurement. Subterranean clover and capeweed had similar transpiration efficiencies by all three methods of measurement. Wheat had W values similar to ryegrass but A/g and Δ values similar to subterranean clover or capeweed. The high W of annual ryegrass seems to be related to a conservative leaf gas exchange behaviour, with lower assimilation and conductance but higher A/g than for the other species. In contrast to the glasshouse results, the three pasture species had similar Δ values when growing together in mixed-species swards in the field. Reasons for these differing responses between glasshouse and field-grown plants are discussed in terms of the implications for improving the transpiration efficiency of mixed-species annual pasture communities in the field.

Soil properties relevant to land degradation in abandoned sloping fields in Aisa valley, Central Pyrenees (Spain

Directory of Open Access Journals (Sweden)

Pardini, G.

1991-06-01

Full Text Available A multi-approach characterization of soil properties in abandoned fields in the Aisa valley, at mid mountain in the Central Spanish Pyrenees, demonstrated that the soil's own peculiar characteristics are concerned with conservation problems. Aggregate stability and shrinkage tests pointed to a relatively good soil performance due to the aggregating role of organic matter and calcium carbonates, although calcium ions, in some instances, may exert and additional antagonistic role for a sealed surface, increasing runoff. On the other hand, soil micromorphology suggests that the poor condition of the soils is in some contradiction to paedogenic activity. These findings, together with the presence of ashes, support the hypothesis that land degradation in these areas is mainly related to human activity thought unsuitable management after land abandonment.

[es] La caracterización de diversas propiedades del suelo en campos abandonados del valle de Aisa, montaña media del Pirineo Central, ha mostrado que dichos suelos presentan algunos caracteres de interés desde el punto de vista de la conservación. La estabilidad de los agregados y los test de agrietamiento evidencian un comportamiento aceptable, gracias al papel agregante de la materia orgánica y carbonatos de calcio, a pesar que los iones calcio, en algunas ocasiones, pueden ejercer un papel antagonista adicional y favorecer el sellado de la superficie del suelo, aumentando la escorrentía superficial. Por otra parte, la micromorfología sugiere que el estado de degradación de los suelos contrasta con la actividad pedogénica. Estos resultados, juntamente con la presencia de cenizas, apoyan la hipótesis de que el estado de degradación en estas áreas es consecuencia principalmente de una utilización incorrecta después del abandono de los cultivos.
[fr] Un étude des propriétés des sois dans une zone à cultures en pente abandonnées dans la vallée d'Aisa (Pyr

Distribution of Diverse Escherichia coli between Cattle and Pasture

OpenAIRE

NandaKafle, Gitanjali; Seale, Tarren; Flint, Toby; Nepal, Madhav; Venter, Stephanus N.; Brözel, Volker S.

2017-01-01

Escherichia coli is widely considered to not survive for extended periods outside the intestines of warm-blooded animals; however, recent studies demonstrated that E. coli strains maintain populations in soil and water without any known fecal contamination. The objective of this study was to investigate whether the niche partitioning of E. coli occurs between cattle and their pasture. We attempted to clarify whether E. coli from bovine feces differs phenotypically and genotypically from isola...

CENSUS AND STATISTICAL CHARACTERIZATION OF SOIL AND WATER QUALITY AT ABANDONED AND OTHER CENTRALIZED AND COMMERCIAL DRILLING-FLUID DISPOSAL SITES IN LOUISIANA, NEW MEXICO, OKLAHOMA, AND TEXAS

Energy Technology Data Exchange (ETDEWEB)

Alan R. Dutton; H. Seay Nance

2003-06-01

Commercial and centralized drilling-fluid disposal (CCDD) sites receive a portion of spent drilling fluids for disposal from oil and gas exploration and production (E&P) operations. Many older and some abandoned sites may have operated under less stringent regulations than are currently enforced. This study provides a census, compilation, and summary of information on active, inactive, and abandoned CCDD sites in Louisiana, New Mexico, Oklahoma, and Texas, intended as a basis for supporting State-funded assessment and remediation of abandoned sites. Closure of abandoned CCDD sites is within the jurisdiction of State regulatory agencies. Sources of data used in this study on abandoned CCDD sites mainly are permit files at State regulatory agencies. Active and inactive sites were included because data on abandoned sites are sparse. Onsite reserve pits at individual wells for disposal of spent drilling fluid are not part of this study. Of 287 CCDD sites in the four States for which we compiled data, 34 had been abandoned whereas 54 were active and 199 were inactive as of January 2002. Most were disposal-pit facilities; five percent were land treatment facilities. A typical disposal-pit facility has fewer than 3 disposal pits or cells, which have a median size of approximately 2 acres each. Data from well-documented sites may be used to predict some conditions at abandoned sites; older abandoned sites might have outlier concentrations for some metal and organic constituents. Groundwater at a significant number of sites had an average chloride concentration that exceeded nonactionable secondary drinking water standard of 250 mg/L, or a total dissolved solids content of >10,000 mg/L, the limiting definition for underground sources of drinking water source, or both. Background data were lacking, however, so we did not determine whether these concentrations in groundwater reflected site operations. Site remediation has not been found necessary to date for most abandoned

Phytoremediation of abandoned crude oil contaminated drill sites of Assam with the aid of a hydrocarbon-degrading bacterial formulation.

Science.gov (United States)

Yenn, R; Borah, M; Boruah, H P Deka; Roy, A Sarma; Baruah, R; Saikia, N; Sahu, O P; Tamuli, A K

2014-01-01

Environmental deterioration due to crude oil contamination and abandoned drill sites is an ecological concern in Assam. To revive such contaminated sites, afield study was conducted to phytoremediate four crude oil abandoned drill sites of Assam (Gelakey, Amguri, Lakwa, and Borholla) with the aid of two hydrocarbon-degrading Pseudomonas strains designated N3 and N4. All the drill sites were contaminated with 15.1 to 32.8% crude oil, and the soil was alkaline in nature (pH8.0-8.7) with low moisture content, low soil conductivity and low activities of the soil enzymes phosphatase, dehydrogenase and urease. In addition, N, P, K, and C contents were below threshold limits, and the soil contained high levels of heavy metals. Bio-augmentation was achieved by applying Pseudomonas aeruginosa strains N3 and N4 followed by the introduction of screened plant species Tectona grandis, Gmelina arborea, Azadirachta indica, and Michelia champaca. The findings established the feasibility of the phytoremediation of abandoned crude oil-contaminated drill sites in Assam using microbes and native plants.

Pasture Monitoring Using SAR with COSMO-SkyMed, ENVISAT ASAR, and ALOS PALSAR in Otway, Australia

Directory of Open Access Journals (Sweden)

Xiaojing Li

2013-07-01

Full Text Available Because of all-weather working ability, sensitivity to biomass and moisture, and high spatial resolution, Synthetic aperture radar (SAR satellite images can perfectly complement optical images for pasture monitoring. This paper aims to examine the potential of the integration of COnstellation of small Satellites for the Mediterranean basin Observasion (COSMO-SkyMed, Environmental Satellite Advanced Synthetic Aperture Radar (ENVISAT ASAR, and Advanced Land Observing Satellite Phased Array type L-band Synthetic Aperture Radar (ALOS PALSAR radar signals at horizontally emitted and received polarization (HH for pasture monitoring at the paddock scale in order to guide farmers for better management. The pasture site is selected, in Otway, Victoria, Australia. The biomass, water content of grass, and soil moisture over this site were analyzed with these three bands of SAR images, through linear relationship between SAR backscattering coefficient, and vegetation indices Normalized Differential Vegetation Index (NDVI, Normalized Difference Water Index (NDWI, Enhanced Vegetation Index (EVI, together with soil moisture index (MI. NDVI, NDWI, and MI are considered as proxy of pasture biomass, plant water content, and soil moisture, respectively, and computed from optical images and climate data. SAR backscattering coefficient and vegetation indices are computed within a grass zone, defined by classification with MODIS data. The grass condition and grazing activities for specific paddocks are detectable, based on SAR backscatter, with all three wavelengths datasets. Both temporal and spatial analysis results show that the X-band SAR has the highest correlation to the vegetation indices. However, its accuracy can be affected by wet weather due to its sensitivity to the water on leaves. The C-band HH backscattering coefficient showed moderate reliability to evaluate biomass and water content of grass, with limited influence from rainfall in the dry season

Effects of grazing strategy on limiting nitrate leaching in grazed grass-clover pastures on coarse sandy soil

DEFF Research Database (Denmark)

Hansen, Elly Møller; Eriksen, Jørgen; Søegaard, Karen

2012-01-01

-term mean. The experiment was initiated in a 4-yr-old grass-clover sward in south Denmark. Three treatments were as follows grazing only (G), spring cut followed by grazing (CG) and both spring and autumn cuts with summer grazing (CGC). Nitrate leaching was calculated by extracting water isolates from 80 cm......Urinations of ruminants on grazed pastures increase the risk of nitrate leaching. The study investigated the effect of reducing the length of the grazing season on nitrate leaching from a coarse sandy, irrigated soil during 2006–2007 and 2007–2008. In both years, precipitation was above the long...... depth using ceramic suction cups. Because of considerable variation in measured nitrate concentrations, the 32 installed suction cups per treatment were insufficient to reveal differences between treatments. However, weighted nitrate leaching estimations for G, CG and CGC showed estimated mean nitrate N...

Genome Sequence of “Pedosphaera parvula” Ellin514, an Aerobic Verrucomicrobial Isolate from Pasture Soil▿

Science.gov (United States)

Kant, Ravi; van Passel, Mark W. J.; Sangwan, Parveen; Palva, Airi; Lucas, Susan; Copeland, Alex; Lapidus, Alla; Glavina del Rio, Tijana; Dalin, Eileen; Tice, Hope; Bruce, David; Goodwin, Lynne; Pitluck, Sam; Chertkov, Olga; Larimer, Frank W.; Land, Miriam L.; Hauser, Loren; Brettin, Thomas S.; Detter, John C.; Han, Shunsheng; de Vos, Willem M.; Janssen, Peter H.; Smidt, Hauke

2011-01-01

“Pedosphaera parvula” Ellin514 is an aerobically grown verrucomicrobial isolate from pasture soil. It is one of the few cultured representatives of subdivision 3 of the phylum Verrucomicrobia. Members of this group are widespread in terrestrial environments. PMID:21460084

Pyrolysis of attapulgite clay blended with yak dung enhances pasture growth and soil health: Characterization and initial field trials.

Science.gov (United States)

Rafiq, Muhammad Khalid; Joseph, Stephen D; Li, Fei; Bai, Yanfu; Shang, Zhanhuan; Rawal, Aditya; Hook, James M; Munroe, Paul R; Donne, Scott; Taherymoosavi, Sara; Mitchell, David R G; Pace, Ben; Mohammed, Mohanad; Horvat, Joseph; Marjo, Christopher E; Wagner, Avital; Wang, Yanlong; Ye, Jun; Long, Rui-Jun

2017-12-31

Recent studies have shown that the pyrolysis of biomass combined with clay can result in both lower cost and increase in plant yields. One of the major sources of nutrients for pasture growth, as well as fuel and building materials in Tibet is yak dung. This paper reports on the initial field testing in a pasture setting in Tibet using yak dung, biochar, and attapulgite clay/yak dung biochars produced at ratios of 10/90 and 50/50 clay to dung. We found that the treatment with attapulgite clay/yak dung (50/50) biochar resulted in the highest pasture yields and grass nutrition quality. We also measured the properties and yields of mixtures of clay/yak dung biochar used in the field trials produced at 400°C and 500°C to help determine a possible optimum final pyrolysis temperature and dung/clay ratio. It was observed that increasing clay content increased carbon stability, overall biochar yield, pore size, carboxyl and ketone/aldehyde functional groups, hematite and ferrous/ferric sulphate/thiosulphate concentration, surface area and magnetic moment. Decreasing clay content resulted in higher pH, CEC, N content and an enhanced ability to accept and donate electrons. The resulting properties were a complex function of both processing temperature and the percentage of clay for the biochars processed at both 400°C and 500°C. It is possible that the increase in yield and nutrient uptake in the field trial is related to the higher concentration of C/O functional groups, higher surface area and pore volume and higher content of Fe/O/S nanoparticles of multiple oxidation state in the 50/50 clay/dung. These properties have been found to significantly increase the abundance of beneficial microorganisms and hence improve the nutrient cycling and availability in soil. Further field trials are required to determine the optimum pyrolysis production conditions and application rate on the abundance of beneficial microorganisms, yields and nutrient quality. Copyright © 2017

Grazing management effects on sediment, phosphorus, and pathogen loading of streams in cool-season grass pastures.

Science.gov (United States)

Schwarte, Kirk A; Russell, James R; Kovar, John L; Morrical, Daniel G; Ensley, Steven M; Yoon, Kyoung-Jin; Cornick, Nancy A; Cho, Yong Il

2011-01-01

Erosion and runoff from pastures may lead to degradation of surface water. A 2-yr grazing study was conducted to quantify the effects of grazing management on sediment, phosphorus (P), and pathogen loading of streams in cool-season grass pastures. Six adjoining 12.1-ha pastures bisected by a stream in central Iowa were divided into three treatments: continuous stocking with unrestricted stream access (CSU), continuous stocking with restricted stream access (CSR), and rotational stocking (RS). Rainfall simulations on stream banks resulted in greater ( CSR pastures. Bovine enterovirus was shed by an average of 24.3% of cows during the study period and was collected in the runoff of 8.3 and 16.7% of runoff simulations on bare sites in CSU pastures in June and October of 2008, respectively, and from 8.3% of runoff simulations on vegetated sites in CSU pastures in April 2009. Fecal pathogens (bovine coronavirus [BCV], bovine rotavirus group A, and O157:H7) shed or detected in runoff were almost nonexistent; only BCV was detected in feces of one cow in August of 2008. Erosion of cut-banks was the greatest contributor of sediment and P loading to the stream; contributions from surface runoff and grazing animals were considerably less and were minimized by grazing management practices that reduced congregation of cattle by pasture streams. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Carbon implications of Virgin Lands Campaign cropland expansion and post-Soviet agricultural land abandonment in Russia and Kazakhstan

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Prishchepov, A. V.; Kurganova, I.; Schierhorn, F.; Lopes de Gerenyu, V.; Müller, D.; Kuzyakov, Y.

2015-12-01

Political economy and institutional changes regarding land use play crucial role in shaping land cover worldwide. Among such events was the Soviet Virgin Lands Campaign, when 45.2 million ha of virgin steppes were ploughed up from 1954 to 1963 in northern Eurasia. We took opportunity to evaluate carbon (C) costs of this Campaign, particularly with the account of massive cropland abandonment in the former Campaign area after demise of the Soviet Union in 1991. Within cropland mask produced with remotely sensed data, we spatially disaggregated historical annual sown area statistics at the provincial level for Russia and Kazakhstan based on cropland suitability assessment. We also adjusted our cropland allocation model with the use of 1:3,000,000 map depicting cropland expansion in Northern Kazakhstan. We used C bookkeeping approach to assess C dynamics based on soil stratification and C field measurements. The Campaign resulted in huge C losses from soils, which accounted for 611±47 Mt C in Russia and 241±11 Mt C in Kazakhstan for upper 0-50 cm soil layer during the first 20 years of cultivation. Such C losses could be compared with C losses due to plowing up the prairies in the mid-1930s in USA. Despite the huge C losses from soils during the Campaign, the total C budget in soils of both countries at national level was positive after 1991 due to sequestered C on abandoned lands, albeit the patterns of C loss during the Campaign and C sink in post-Soviet period differed. The C sink from 1991 to 2010 on abandoned croplands in Russia (45.5Mha) comprised 976±108Mt C and Kazakhstan (12.9Mha) comprised 240±34Mt C. However, already ongoing recultivation of abandoned cropland in Kazakhstan and already planned such activities in Russia, can release stored C on abandoned lands. Our study highlights the importance of environmental evaluation of such governmental programs and their alternatives, particularly, since such programs are not rare events in modern land

Effects of Different Treatments of Pasture Restoration on Soil Trace Gas Emissions in the Cerrados of Central Brazil

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Planted pastures ( mainly Brachiaria spp) are the most extensive land use in the cerrado (savannas of central Brazil) with an area of approximately 50 x 10(6) ha. The objective of the study was to assess the effects of pasture restoration on the N dynamics ( net N mineralization/...

Environmental effectiveness of GAEC cross-compliance standard 4.1 (b, c ‘Protection of permanent pasture land’ and economic evaluation of the competitiveness gap for farmers

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Mauro Salis

2015-11-01

Full Text Available The paper presents the main results of the monitoring on the effectiveness of the cross-compliance Standard 4.1 ‘Permanent pasture protection: lett. b, c’ carried out in two case studies within the project MO.NA.CO. Soil, botanical, productive and economic (competitiveness gap parameters have been monitored. In the short term, the Standard 4.1 showed its effectiveness on soil quality, biomass productivity and competitiveness gap in both case studies. Botanical parameters showed differing results, therefore their generalization is not applicable to the heterogeneity of the pasture land Italian system. Shallow soil tillage could be suggested, every 40-50 years, when an appropriate soil organic matter content and the absence of runoff phenomena occur.

A Rapid, Accurate, and Efficient Method to Map Heavy Metal-Contaminated Soils of Abandoned Mine Sites Using Converted Portable XRF Data and GIS

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Jangwon Suh

2016-12-01

Full Text Available The use of portable X-ray fluorescence (PXRF and inductively coupled plasma atomic emission spectrometry (ICP-AES increases the rapidity and accuracy of soil contamination mapping, respectively. In practice, it is often necessary to repeat the soil contamination assessment and mapping procedure several times during soil management within a limited budget. In this study, we have developed a rapid, inexpensive, and accurate soil contamination mapping method using a PXRF data and geostatistical spatial interpolation. To obtain a large quantity of high quality data for interpolation, in situ PXRF data analyzed at 40 points were transformed to converted PXRF data using the correlation between PXRF and ICP-AES data. The method was applied to an abandoned mine site in Korea to generate a soil contamination map for copper and was validated for investigation speed and prediction accuracy. As a result, regions that required soil remediation were identified. Our method significantly shortened the time required for mapping compared to the conventional mapping method and provided copper concentration estimates with high accuracy similar to those measured by ICP-AES. Therefore, our method is an effective way of mapping soil contamination if we consistently construct a database based on the correlation between PXRF and ICP-AES data.

Pasture degradation modifies the water and carbon cycles of the Tibetan highlands

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W. Babel

2014-12-01

Full Text Available The Tibetan Plateau has a significant role with regard to atmospheric circulation and the monsoon in particular. Changes between a closed plant cover and open bare soil are one of the striking effects of land use degradation observed with unsustainable range management or climate change, but experiments investigating changes of surface properties and processes together with atmospheric feedbacks are rare and have not been undertaken in the world's two largest alpine ecosystems, the alpine steppe and the Kobresia pygmaea pastures of the Tibetan Plateau. We connected measurements of micro-lysimeter, chamber, 13C labelling, and eddy covariance and combined the observations with land surface and atmospheric models, adapted to the highland conditions. This allowed us to analyse how three degradation stages affect the water and carbon cycle of pastures on the landscape scale within the core region of the Kobresia pygmaea ecosystem. The study revealed that increasing degradation of the Kobresia turf affects carbon allocation and strongly reduces the carbon uptake, compromising the function of Kobresia pastures as a carbon sink. Pasture degradation leads to a shift from transpiration to evaporation while a change in the sum of evapotranspiration over a longer period cannot be confirmed. The results show an earlier onset of convection and cloud generation, likely triggered by a shift in evapotranspiration timing when dominated by evaporation. Consequently, precipitation starts earlier and clouds decrease the incoming solar radiation. In summary, the changes in surface properties by pasture degradation found on the highland have a significant influence on larger scales.

Methods for assessing the impact of avermectins on the decomposer community of sheep pastures.

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King, K L

1993-06-01

This paper outlines methods which can be used in the field assessment of potentially toxic chemicals such as the avermectins. The procedures focus on measuring the effects of the drug on decomposer organisms and the nutrient cycling process in pastures grazed by sheep. Measurements of decomposer activity are described along with methods for determining dry and organic matter loss and mineral loss from dung to the underlying soil. Sampling methods for both micro- and macro-invertebrates are discussed along with determination of the percentage infection of plant roots with vesicular-arbuscular mycorrhizal fungi. An integrated sampling unit for assessing the ecotoxicity of ivermectin in pastures grazed by sheep is presented.

Novel dry forests in southwestern Puerto Rico

Science.gov (United States)

Sandra Molina Colón; Ariel E. Lugo; Olga Ramos

2011-01-01

We report results of new research on (1) community composition of novel subtropical dry forests developing on abandoned pastures and agricultural fields in both private and protected public lands and (2) seed germination and growth rates of plantings of native tree species on degraded soils. We found that novel dry forests were dominated by introduced species, which...

The influence of land use on soil organic carbon and nitrogen content and redox potential

DEFF Research Database (Denmark)

Kusliene, Gedrime

2010-01-01

different farming systems (conventional and organic) as well as abandoned lands. We choose the plants of two botanical species (Poaceae and Fabaceae) in organic and conventional farming systems as well as abandoned lands. Experimental results show that the best soil organic matter status according...... to the investigated indexes is in the soils of conventional and orgaic farming systems occupied with mixtures of Poaceae and Fabaceae and the worst - in the soils of abandoned Poaceae meadowa. In the abandoned lands, Fabaceae (galega) had better influence on soil organic matter status than Poaceae....

Floristic and phytosociology of weeds in pastures in Maranhão State, Northeast Brazil

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Jaílson Penha Costa

2016-06-01

Full Text Available ABSTRACT Knowledge of weed floristic composition and phytosociology are key factors for improving weed management in pastures. Information on weed species that occur in pastures in Northeast Brazil, particularly in Maranhão State is very limited. It is, therefore, important, to search for information to help farmers to control weeds in livestock farming. This paper describes the weed flora diversity and community structure parameters, including density, frequency, abundance and importance value for each weed species found in five pastures of same age and management in Maranhão State, Northeast Brazil. The weed survey was carried out using a wooden frame (80 cm x 30 cm placed randomly on the soil surface 30 times in each pasture (n = 150. Weeds were pulled out, separated by species and counted. The weed flora was represented by 996 individuals, from nine families, 15 genera and 19 species. Weed density within pastures was of 44.3 plants m-2. The weed flora was dominated by species of the Cyperaceae and Poaceae families. The most important weed species based on Importance Value were Eragrostis ciliaris (IV = 32.97, Cyperus rotundus (IV = 31,95, Cyperus luzulae (IV = 27,50, Cyperus sphacelatus (IV = 27,42, Pycreus lanceolatus (IV = 27,33 Cyperus haspan (IV = 25,72 and Eleusine indica (IV = 23,49. Weed diversity, based on Shannon Diversity Index was very high (H' = 4.37 nats ind-1. Our results could lead to improved weed management in pastures in Maranhão State, Northeast Brazil.

Effect of land use change on the carbon cycle in Amazon soils

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Trumbore, Susan E.; Davidson, Eric A.

1994-01-01

The overall goal of this study was to provide a quantitative understanding of the cycling of carbon in the soils associated with deep-rooting Amazon forests. In particular, we wished to apply the understanding gained by answering two questions: (1) what changes will accompany the major land use change in this region, the conversion of forest to pasture? and (2) what is the role of carbon stored deeper than one meter in depth in these soils? To construct carbon budgets for pasture and forest soils we combined the following: measurements of carbon stocks in above-ground vegetation, root biomass, detritus, and soil organic matter; rates of carbon inputs to soil and detrital layers using litterfall collection and sequential coring to estimate fine root turnover; C-14 analyses of fractionated SOM and soil CO2 to estimate residence times; C-13 analyses to estimate C inputs to pasture soils from C-4 grasses; soil pCO2, volumetric water content, and radon gradients to estimate CO2 production as a function of soil depth; soil respiration to estimate total C outputs; and a model of soil C dynamics that defines SOM fractions cycling on annual, decadal, and millennial time scales.

Improving a native pasture with the legume Arachis pintoi in the humid tropics of México

NARCIS (Netherlands)

Castillo Gallegos, E.

2003-01-01

The objective of this study was to determine the effect of introducing the legume Arachis pintoi CIAT 17434 into a native pasture where native grasses dominated the botanical composition, on establishment, persistence, standing dry matter, botanical composition, soil variables, animal performance,

Radiocesium transport in the pasture-cow-milk food chain; and reply

Energy Technology Data Exchange (ETDEWEB)

Lassey, K R [Department of Scientific and Industrial Research, Lower Hutt (New Zealand). Inst. of Nuclear Sciences; Matthies, M [Gesellschaft fuer Strahlen- und Umweltforschung m.b.H. Muenchen, Neuherberg (Germany, F.R.)

1982-11-01

In this letter Lassey comments on the model analysis of radiocesium transport through the pasture-cow-milk food chain, presented by Matthies et al. This 5-compartmental model extends by one one compartment-soil surface (S), the model, TERMOD, used by Lassey. Matthies model fails to take account of radiocesium 'fixed' for many years in the upper few cm of untilled soil and unavailable for root uptake. This soil sink compartment (D) should really be two compartments, one for 'leached' and one for 'fixed' radiocesium. Matthies replies that radioecological model predictions have a degree of uncertainty because of the large biological variabilities of transfer processes involved, and the results of his stochastic model calculations provide more information than those of Lassey's more deterministic methods.

Land use and surface process domains on alpine hillslopes

Science.gov (United States)

Kuhn, Nikolaus J.; Caviezel, Chatrina; Hunziker, Matthias

2015-04-01

Shrubs and trees are generally considered to protect hillslopes from erosion. As a consequence, shrub encroachment on mountain pastures after abandoning grazing is not considered a threat to soils. However, the abandonment of mown or grazed grasslands causes a shift in vegetation composition and thus a change in landscape ecology and geomorphology. On many alpine slopes, current changes in land use and vegetation cover are accompanied by climate change, potentially generating a new geomorphic regime. Most of the debate focuses on the effect of land abandonment on water erosion rates. Generally, an established perennial vegetation cover improves the mechanical anchoring of the soil and the regulation of the soil water budget, including runoff generation and erosion. However, changing vegetation composition affects many other above- and below-ground properties like root density, -diversity and -geometry, soil structure, pore volume and acidity. Each combination of these properties can lead to a distinct scenario of dominating surface processes, often not reflected by common erosion risk assessment procedures. The study of soil properties along a chronosequence of green alder (alnusviridis) encroachment on the Unteralptal in central Switzerland reveals that shrub encroachment changes soil and vegetation properties towards an increase of resistance to run-off related erosion processes, but a decrease of slope stability against shallow landslides. The latter are a particular threat because of the currently increasing frequency of slide-triggering high magnitude rainfalls. The potential change of process domain on alpine pastures highlights the need for a careful use of erosion models when assessing future land use and climate scenarios. In mountains, but also other intensively managed agricultural landscapes, risk assessment without the appropriate reflection on the shifting relevance of surface processes carries the risk of missing future threats to environmental

Transport of oxytetracycline, chlortetracycline, and ivermectin in surface runoff from irrigated pasture.

Science.gov (United States)

Bair, Daniel A; Popova, Ina E; Tate, Kenneth W; Parikh, Sanjai J

2017-09-02

The transport of oxytetracycline, chlortetracycline, and ivermectin from manure was assessed via surface runoff on irrigated pasture. Surface runoff plots in the Sierra Foothills of Northern California were used to evaluate the effects of irrigation water application rates, pharmaceutical application conditions, vegetative cover, and vegetative filter strip length on the pharmaceutical discharge in surface runoff. Experiments were designed to permit the maximum potential transport of pharmaceuticals to surface runoff water, which included pre-irrigation to saturate soil, trimming grass where manure was applied, and laying a continuous manure strip perpendicular to the flow of water. However, due to high sorption of the pharmaceuticals to manure and soil, less than 0.1% of applied pharmaceuticals were detected in runoff water. Results demonstrated an increase of pharmaceutical transport in surface runoff with increased pharmaceutical concentration in manure, the concentration of pharmaceuticals in runoff water remained constant with increased irrigation flow rate, and no appreciable decrease in pharmaceutical runoff was produced with the vegetative filter strip length increased from 30.5 to 91.5 cm. Most of the applied pharmaceuticals were retained in the manure or within the upper 5 cm of soil directly beneath the manure application sites. As this study evaluated conditions for high transport potential, the data suggest that the risk for significant chlortetracycline, oxytetracycline, and ivermectin transport to surface water from cattle manure on irrigated pasture is low.

Anthropic changes to the biotic factor of soil formation from forests to managed grasslands along summits of the western Pyrenees Mountains, France

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Leigh, David; Gragson, Theodore

2017-04-01

Mounting evidence indicates that highland pastures of the humid-temperate western Pyrenees were converted from mixed forests to managed grasslands thousands of years ago, as early as during the late Neolithic and Bronze age by human actions including use of fire. We observe pronounced differences between soil profiles of ancient pastures and old-growth forests in otherwise similar landscape positions. In order to test physical and chemical differences, we collected paired samples of forest versus grassland soils at four separate hillslope sites where there was a clear boundary between the two vegetation types. Animal trails were excluded from sampling. Factors of climate, topography, parent material, and time of soil formation were essentially identical in the forests and pastures of each site, but the time of soil under grassland vegetation may have varied. Each paired hillslope site included five core samples (7.6 cm diameter) from the upper 7.6 cm of the mineral soil within each vegetation type, and the A horizon thickness was recorded at each core hole site. In addition, one complete soil profile was sampled in each vegetation type at each site, making a total of 20 core samples and 4 complete profiles from each respective vegetation type. In addition, we measured the magnetic susceptibility of the mineral soil surface on two transects crossing the vegetation boundary. Core samples have been measured for bulk density, pH, plant-available nutrients, and organic matter; and tests for total carbon and nitrogen, amorphous silica, charcoal, and other forms of black carbon are ongoing. Preliminary results indicate pastured A horizons are about three times as thick as forested soils, contain more organic matter, have lower soil bulk densities, have much finer and stronger structural development of soil aggregates. These traits favor much greater infiltration and water holding capacities of the pastured soils, which we have validated with saturated hydraulic

Organic Matter Dynamics in Soils Regenerating from Degraded ...

African Journals Online (AJOL)

The area of secondary forest (SF) regenerating from degraded abandoned rubber (Hevea brasiliensis) plantation is increasing in the rainforest zone of south southern Nigeria; however, the build-up of soil organic matter following abandonment is not well understood. This study examined the build-up of soil organic matter in ...

Aspects of a two-pasture — herbivore model

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Jan Åge Riseth

2004-04-01

Full Text Available Pastures for reindeer can be divided into green pastures (mainly herbs and grasses of summer time and more or less snow-covered lichen pastures of winter. Fall and spring pastures have a composition in-between these extremes, but for model purposes bisection is sufficient. For the animals the green-pasture season is an anabolic phase with a physiological building-up of protein reserves, while winter is a catabolic phase where food-intake is reduced and the animals to a considerable extent survive on the accumulated reserves from summer. While protein reserves are stored from summer to winter, lichen pastures are stored from year to year. Grasses and herbs not being grazed are wilting by the end of the growing season, while lichens not grazed can live for many years. This corresponds with fundamental differences in both growth pattern and resilience. The implications of the different features, and their interconnections, are not easy to survey without formal modeling. The point of departure is a simple pasture-herbivore model, well known from the literature building on a set of differential equations. A new two-pasture-herbivore model is developed. The model includes as basic elements the Klein (1968 hypothesis and that a residual lichen biomass is kept ungrazed due to snow-cover protection. Further the annual cycle is divided into four stylized seasons with herd rates of winter survival, spring calving, summer physiological growth and fall slaughtering. Isoclines are derived for summer pasture, winter pasture and herbivores. Stability properties are discussed in relation to various situations of seasonal pasture balance. Empirical examples, particularly that of changes in pasture balance and vegetation cover in Western Finnmark, Norway, are discussed. The article finds that the two-pasture model provides important features of reality, such as the stability aspects of pasture balance, which cannot be displayed by a one-pasture model. It is

Spatial variation in spoil and vegetative characteristics of pastures on reclaimed surface mined land

International Nuclear Information System (INIS)

Teutsch, C.D.; Collins, M.; Ditsch, D.C.

1999-01-01

Kentucky has large areas of reclaimed surface mined land that could provide grazing for livestock. Research is needed to determine optimal stocking densities and to evaluate the sustainability of such grazing systems for this region. A long-term grazing study was initiated in 1997 on 151 ha of reclaimed land near Chavies, KY to determine spatial and temporal variation with stocking densities of 0, 0.28, 0.42, or 0.83 beef cow-calf units/ha. Global Positioning System and GIS technologies were used to establish pasture boundaries, locate permanent sampling markers at a density of 1 per 0.4 ha, and interpolate maps of physical, spoil, and vegetable pasture characteristics. Herbage and spoil samples were collected around the permanent markers in May of 1997. Stepwise regression was used to determine factors affecting the vegetative characteristics of the sites. Biomass density ranged from 0 to 2500 kg/ha with a mean of 570 kg/ha. Factors affecting biomass included legume and weed proportions in the sward, grazing activity, soil potassium, elevation, and potential acidity, cumulatively accounting for 32% of the variation. Ground cover ranged from 10 to 100% with an average of 74%. Soil pH, potassium, and grass in the sward accounted for 14% of the variation in ground cover. Legumes made up 0 to 61% of the sward with a mean of 13% over the pasture area. Variables affecting the amount of legume in the sward included biomass density, slope, elevation, pH, and stocking density, together accounting for 21% of the variation. Spatial variation in the physical, spoil, and vegetative characteristics of the pastures was large. Overall, regression accounted for a limited amount of the variation in the vegetative characteristics of the site indicating that other important variables exist

The Adaptive potential pasture phytocenosis to sole ambience and influence them on speaker of the fertility light-chestnut ground in condition of the natural moistening

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R. Z. Usmanov

2010-01-01

Full Text Available Estimation of the adaptive potential natural phytocenosis is given to soil salinization ground under natural moistening. The Studied general regularities of the operation to pasture vegetation and condition of the renewing the vegetable cover on techno-broken ground (the lands. The analysed role prevail plants in conservation balances conditions pasture.

Agregação e estabilidade de agregados do solo em sistemas agropecuários em Mato Grosso do Sul Soil aggregation and aggregate stability under crop-pasture systems in Mato Grosso do Sul state, Brazil

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Júlio Cesar Salton

2008-02-01

Full Text Available Sistemas de manejo do solo, incluindo lavouras em plantio direto, lavouras (soja em rotação com pastagens em plantio direto e pastagens permanentes (Brachiaria sp., foram avaliados quanto à agregação do solo e estabilidade dos agregados. Em três experimentos de longa duração (9 e 11 anos localizados em Mato Grosso do Sul, o solo foi amostrado nas camadas de 0 a 5, 5 a 10 e 10 a 20 cm, para determinação da estabilidade dos agregados em água e a seco. Foram calculados o diâmetro médio ponderado (DMP e o índice de estabilidade dos agregados (IEA. Em todos os experimentos, nos sistemas com pastagens, seja de forma isolada ou em rotação com lavouras, foi verificado maior volume do solo, constituindo agregados com tamanho superior a 4,76 mm. Os sistemas com pastagens também apresentaram maior DMP e maior IEA em todos os experimentos. O sistema apenas com lavouras apresentou, nos três experimentos, o maior volume de solo com agregados de tamanho entre 0,25 e 2,00 mm. Esses efeitos ocorreram de forma semelhante em todas as profundidades avaliadas. Entre os locais, observou-se o efeito do teor de argila na agregação, sendo maior em Maracaju e menor em Campo Grande. Foi observada estreita relação entre a estabilidade dos agregados e o teor de C no solo. A formação de macroagregados parece estar relacionada à presença de raízes, que são mais abundantes sob pastagem de gramíneas.Soil management systems, with crops under no-tillage (NT, crops (soybean in rotation with pastures under NT and permanent pastures (Brachiaria sp., were evaluated for soil aggregation and aggregate stability. Three long-term experiments (9 and 11 years in the state of Mato Grosso do Sul were sampled in the layers 0-5, 5-10 and 10-20 cm for determination of the aggregate stability in wet and dry sieving. The mean weight diameter (MWD and the aggregate stability index (IAS were calculated. In all experiments, the greatest soil volume was verified in the

Abandoned seasonal livestock migration reflected by plant functional traits: A case study in Kyrgyz rangelands

Science.gov (United States)

Hoppe, Franziska; Zhusui Kyzy, Taalaigul; Usupbaev, Adilet; Schickoff, Udo

2017-04-01

At least 30% of Kyrgyz pasture areas are considered to be subject to vegetation and soil degradation. Since animal husbandry is the economic basis to sustain people's livelihoods, rangeland degradation presents a threat for the majority of the population. Recently, the usage of plant functional traits as a powerful tool for the characterization of vegetation dynamics in response to anthropogenic and natural disturbances has been put forward. Grazing is one of the most severe disturbances on vegetation, which concerns equally the loss of area and biomass. Because grazing is both depending on and affecting plant functional traits, important insights can be generated, based on this codependency. We hypothesized that the contrasting grazing intensity of summer and winter pastures is reflected by the chosen traits. We used traits such as plant height, flowering start, growth form as well as SLA (Specific Leaf Area) and LMA (Leaf Mass per Area). Based on former phytosociological classification of the main pasture types (summer and winter pastures), community structure and the traits of dominant plant species were analyzed. Our results showed that on winter pastures grazing decreased plant height and SLA and favored plants with an earlier flowering start as well as rosette plants and ascending plants. We conclude that the study of trait composition in relation to anthropogenic disturbances can provide important insights into the mechanism of plant response to grazing in high-altitude rangelands.

The role of soil moisture on the coevolution of soil and vegetation in mountain grasslands

Science.gov (United States)

Bertoldi, Giacomo; Claudia, Notarnicola; Brenner, Johannes; Castelli, Mariapina; Greifeneder, Felix; Niedrist, Georg; Seeber, Julia; Tappeiner, Ulrike

2016-04-01

One of the key variables controlling the organization of vegetation and the coevolution of soils and landforms is soil moisture content (SMC). For this reason, understanding the controls on the spatial and temporal patterns of SMC is essential to predict how perturbations in vegetation and climate will affect mountain ecosystem functioning. In this contribution, we focus on the dynamic of surface SMC of water-limited alpine grasslands in the Long Term Ecological Research area Mazia Valley in the European Alps. We analyze the impacts of different land managements (meadows versus pastures) and its relationships with climate and topography. The area has been equipped since 2009 with a network of more than 20 stations, measuring SMC and climatic variables and with two eddy-covariance stations, measuring surface fluxes over meadows and pastures. Monthly biomass production data have been collected and detailed soil and spatial soil moisture surveys are available. Moreover, high spatial resolution SMC maps have been derived from satellites Synthetic Aperture Radar Radar (SAR) images (Sentinel 1 and RADARSAT2 images). Both ground surveys and remote sensing observations show persistent landscape-level patterns. Meadows, in general located in flatter areas, tend to be wetter. This leads to higher vegetation productivity and to the development of soils with higher water holding capacity, thus to a positive feedback on SMC. In contrast, pastures, located on steeper slopes with lower vegetation density and higher soil erosion, tend to be drier, leading to a negative feedback on SMC and soil development. This co-evolution of land cover and SMC leads therefore to persistent spatial patterns. In order to understand quantitatively such linked interactions, a sensitivity analysis has been performed with the GEOtop hydrological model. Results show how both abiotic (mainly slope and elevation) and anthropogenic (irrigation and soil management) factors exert a significant control on

Assessment of the radiocaesium levels in irish soils and its transfer to crops

International Nuclear Information System (INIS)

MacNeill, Geraldine; Duffy, J.T.; Cunningham, J.D.; Coulter, B.; Diamond, S.; McAulay, I.R.; Moran, D.

1991-02-01

The behaviour of radiocaesium deposited by the Chernobyl fall-out was investigated in eleven different permanent pastures and arable lands. Samples of grass and subjacent soil at various depths were collected and analysed for their caesium content during a period extending from the Spring of 1987 (one year after the accident) to the Autumn of 1988. Soil from tillage land along with vegetable and grain crops from this land were also sampled and subjected to gamma spectrometric analysis. The results for the pasture soils show that there has been limited downward migration of Chernobyl caesium. In October 1988 more than 88% of caesium of Chernobyl origin was still retained in the 0-10 cm layer of undisturbed pasture soil. It would also appear that at most sites more than 70% of weapons deposited caesiym is still contained in the 0-15 cm soil layer

137Cs profiles in erosion plots with different soil cultivation

International Nuclear Information System (INIS)

Andrello, A.C.; Appoloni, C.R.; Cassol, E.A.; Melquiades, F.L.

2006-01-01

Cesium-137 methodology has been successfully used to assess soil erosion. Seven erosion plots were sampled to determine the 137 Cs profile and to assess the erosion rates. Cesium-137 profile for native pasture plot showed an exponential decline below 5 cm depth, with little 137 Cs activity in the superficial layer (0-5 cm). Cesium-137 profile for wheat-soybean rotation plot in conventional tillage showed a uniform distribution with depth. For this plot, the soil loss occurs more in middle than upper and lower level. Cesium-137 profile for wheat-soybean rotation and wheat-maize rotation plots in no-tillage showed a similar result to the native pasture, with a minimum soil loss in the superficial layer. Cesium-137 profile for bare soil and cultivated pasture plots are similar, with a soil erosion rate of 229 t ha -1 year -1 . In the plots with a conventional tillage a greater soil loss occur in middle than upper and lower level. In no-tillage cultivation plots occurs soil loss in lower level, but no sign of soil loss neither gain in the upper level is observed. Cesium-137 methodology is a good tool to assess soil erosion and the 137 Cs profile gives a possibility to understand the soil erosion behavior in erosion plots. (author)

European wood-pastures in transition

DEFF Research Database (Denmark)

Wood-pastures are important elements of European cultural identity and have an exceptional ecological value, yet they are in decline all over Europe. The structure of wood-pastures is strongly influenced by grazing and multiple other land uses and by local and regional environmental conditions....... This book examines the diverse expressions of wood-pastures across Europe. It provides a new perspective, using a social-ecological framework to explore social and ecological values, governing institutions, threats and conservation approaches. It explores the major drivers of decline, which are shown...

Influence of management history and landscape variables on soil organic carbon and soil redistribution

Science.gov (United States)

Venteris, E.R.; McCarty, G.W.; Ritchie, J.C.; Gish, T.

2004-01-01

Controlled studies to investigate the interaction between crop growth, soil properties, hydrology, and management practices are common in agronomy. These sites (much as with real world farmland) often have complex management histories and topographic variability that must be considered. In 1993 an interdisiplinary study was started for a 20-ha site in Beltsville, MD. Soil cores (271) were collected in 1999 in a 30-m grid (with 5-m nesting) and analyzed as part of the site characterization. Soil organic carbon (SOC) and 137Cesium (137Cs) were measured. Analysis of aerial photography from 1992 and of farm management records revealed that part of the site had been maintained as a swine pasture and the other portion as cropped land. Soil properties, particularly soil redistribution and SOC, show large differences in mean values between the two areas. Mass C is 0.8 kg m -2 greater in the pasture area than in the cropped portion. The pasture area is primarily a deposition site, whereas the crop area is dominated by erosion. Management influence is suggested, but topographic variability confounds interpretation. Soil organic carbon is spatially structured, with a regionalized variable of 120 m. 137Cs activity lacks spatial structure, suggesting disturbance of the profile by animal activity and past structures such as swine shelters and roads. Neither SOC nor 137Cs were strongly correlated to terrain parameters, crop yields, or a seasonal soil moisture index predicted from crop yields. SOC and 137Cs were weakly correlated (r2 ???0.2, F-test P-value 0.001), suggesting that soil transport controls, in part, SOC distribution. The study illustrates the importance of past site history when interpreting the landscape distribution of soil properties, especially those strongly influenced by human activity. Confounding variables, complex soil hydrology, and incomplete documentation of land use history make definitive interpretations of the processes behind the spatial distributions

Pasture types and Echinococcus multilocularis, Tibetan communities

NARCIS (Netherlands)

Wang, Qian; Vuitton, Dominique A; Xiao, Yongfu; Budke, Christine M; Campos-Ponce, Maiza; Schantz, Peter M; Raoul, Francis; Yang, Wen; Craig, Philip S; Giraudoux, Patrick

Our study showed that open pastures had more small mammal burrows than fenced pastures in Tibetan pastoralist communities in 2003. This characteristic was linked to a higher prevalence of Echinococcus multilocularis in dogs and indicates that pasture type may affect E. multilocularis transmission.

Abandoned works program

International Nuclear Information System (INIS)

Arnott, A.

2007-01-01

Thousands of improperly abandoned or decommissioned oil and gas wells are threatening the purity of Ontario's source water. This presentation discussed an abandoned works program developed by the Ontario Ministry of Natural Resources. The abandoned works program was established in 2005 in order to plug old oil and gas wells. The program was designed to create a list of abandoned wells, develop a coherent policy, and formulate procurement and contracting protocols. Abandoned wells are defined as wells drilled prior to 1963 with no operator other than the current landowner. There are currently over 200 prioritized wells on the list. Twenty-six contracts have been issued for a total of 33 wells, and 19 wells have been plugged since the program's field operations began in 2006. However, the program is often challenged by the difficulties associated with determining where the wells are located. Many of the wells have been cut off and buried, and access is often dependent on weather conditions and road restrictions. There is also a shortage of contractors who have experience working with older wells. It was concluded that the program will expand by obtaining further funding and modifying its qualification criteria. tabs., figs

Phosphorus, iron, and aluminum losses in runoff from a rotationally-grazed pasture in Georgia, USA

Science.gov (United States)

Pastures can be a source of phosphorus (P) contributing to eutrophication and impairment of water resources. Phosphorus is tightly held in soils that are highly weathered, acidic, and with high iron (Fe) and aluminum (Al) content like the Ultisols of southeastern USA. We used 11-yr (1999-2009) of da...

Negative trade-off between changes in vegetation water use and infiltration recovery after reforesting degraded pasture land in the Nepalese Lesser Himalaya

Science.gov (United States)

Ghimire, C. P.; Bruijnzeel, L. A.; Lubczynski, M. W.; Bonell, M.

2014-12-01

This work investigates the trade-off between increases in vegetation water use and rain water infiltration afforded by soil improvement after reforesting severely degraded grassland in the Lesser Himalaya of central Nepal. The hillslope hydrological functioning (surface and subsurface soil hydraulic conductivities and overland flow generation) and the evapotranspiration (rainfall interception and transpiration) of the following contrasting vegetation types were quantified and examined in detail: (i) a nearly undisturbed, natural broadleaved forest; (ii) a 25-year-old, intensively-used pine plantation; and (iii) a highly degraded pasture. Planting pines increased vegetation water use relative to the pasture and natural forest situation by 355 and 55 mm year-1, respectively. On balance, the limited amount of extra infiltration afforded by the pine plantation relative to the pasture (only 90 mm year-1 due to continued soil degradation associated with regular harvesting of litter and understory vegetation in the plantation) proved insufficient to compensate the higher water use of the pines. As such, observed declines in dry season flows in the study area are thought to mainly reflect the higher water use of the pines although the effect could be moderated by better forest and soil management promoting infiltration. In contrast, a comparison of the water use of the natural forest and degraded pasture suggests that replacing the latter by (mature) broadleaved forest would (ultimately) have a near-neutral effect on dry season flows as the approximate gains in infiltration and evaporative losses were very similar (ca. 300 mm year-1 each). The results of the present study underscore the need for proper forest management for optimum hydrological functioning as well as the importance of protecting the remaining natural forests in the region.

Factors associated with the financial performance of spring-calving, pasture-based dairy farms.

Science.gov (United States)

Ramsbottom, G; Horan, B; Berry, D P; Roche, J R

2015-05-01

As land becomes a limiting resource for pasture-based dairy farming, the inclusion of purchased supplementary feeds to increase milk production per cow (through greater dry matter intake) and per hectare (through increased stocking rate) is often proposed as a strategy to increase profitability. Although a plausible proposition, virtually no analysis has been done on the effect of such intensification on the profitability of commercial pasture-based dairy farm businesses. The objective of this study was to characterize the average physical and financial performance of dairy systems differing in the proportion of the cow's diet coming from grazed pasture versus purchased supplementary feeds over 4 yr, while accounting for any interaction with geographic region. Physical, genetic, and financial performance data from 1,561 seasonal-calving, pasture-based dairy farms in Ireland were available between the years 2008 and 2011; data from some herds were available for more than 1 yr of the 4-yr study period, providing data from 2,759 dairy farm-years. The data set was divided into geographic regions, based on latitude, rainfall, and soil characteristics that relate to drainage; these factors influence the length of the pasture growth season and the timing of turnout to pasture in spring and rehousing in autumn. Farms were also categorized by the quantity of feed purchased; farms in which cows received 30% of their annual feed requirements from purchased feed were considered to be categories representative of increasing levels of system intensification. Geographic region was associated with differences in grazing days, pasture harvested per hectare, milk production per cow and per hectare, and farm profitability. Farms in regions with longer grazing seasons harvested a greater amount of pasture [an additional 19kg of dry matter (DM)/ha per grazing day per hectare], and greater pasture harvested was associated with increased milk component yield per hectare (58.4kg of fat

Visual assessment of soil structure quality in an agroextractivist system in Southeastern Amazonia

Science.gov (United States)

Fernanda Simões da Silva, Laura; Stuchi Boschi, Raquel; Ortega Gomes, Matheus; Cooper, Miguel

2016-04-01

Soil structure is considered a key factor in the functioning of soil, affecting its ability to support plant and animal life, and moderate environmental quality. Numerous methods are available to evaluate soil structure based on physical, chemical and biological indicators. Among the physical indicators, the attributes most commonly used are soil bulk density, porosity, soil resistance to penetration, tensile strength of aggregates, soil water infiltration, and available water. However, these methods are expensive and generally time costly for sampling and laboratorial procedures. Recently, evaluations using qualitative and semi-quantitative indicators of soil structure quality have gained importance. Among these methods, the method known as Visual Evaluation of Soil Structure (VESS) (Ball et al., 2007; Guimarães et al., 2011) can supply this necessity in temperate and tropical regions. The study area is located in the Piranheira Praialta Agroextrativist Settlement Project in the county of Nova Ipixuna, Pará, Brazil. Two toposequences were chosen, one under native forest and the other under pasture. Pits were opened in different landscape positions (upslope, midslope and downslope) for soil morphological, micromorphological and physical characterization. The use of the soil visual evaluation method (SVE) consisted in collecting an undisturbed soil sample of approximately 25 cm in length, 20 cm in width and 10 cm in depth. 12 soil samples were taken for each land use. The samples were manually fragmented, respecting the fracture planes between the aggregates. The SVE was done comparing the fragmented sample with a visual chart and scores were given to the soil structure. The categories that define the soil structure quality (Qe) vary from 1 to 5. Lower scores mean better soil structure. The final score calculation was done using the classification key of Ball et al. (2007) adapted by Guimarães (2011). A change in soil structure was observed between forest and

Effect of termite activity on soil under different land management strategies

Directory of Open Access Journals (Sweden)

Liane Barreto Alves Pinheiro

2017-03-01

Full Text Available Mound-building termites are important agents of soil bioperturbation, but these species have not been extensively studied thus far. The present study aimed to evaluate the soil particle-size and the chemical attributes of termite mounds and the surrounding soil under different land use strategies. A one-hectare plot was defined for an unmanaged degraded pasture, planted pasture, and for a eucalyptus Corymbia citriodora plantation. In each plot, the top, center, and base sections of five Cornitermes cumulans mounds, and the surrounding soil at the depths of 0-5; 5-10; 10-20 cm, were sampled in the Pinheiral, Rio de Janeiro state. In the three areas, the center of the mounds contained higher clay content, organic carbon, phosphorous, calcium and magnesium, total bases, and cation exchangeable capacity, when compared to the top, base, and the surrounding soils. However, the center had lower values of exchangeable acidity and potassium, of the three areas. In the eucalyptus plantation, the values of pH, total bases, calcium, and magnesium were lower, whereas aluminum, exchangeable acidity, sodium, and cation exchange capacity were higher both in the mounds and in the surrounding soil, in relation to the pastures. There were no differences among the three areas in terms of organic carbon, potassium, phosphorous, and total bases, in the mounds and adjacent soil. Thus, the termite activity altered the clay content and most of the soil chemical properties in all of the studied areas, but only for the center of the mounds. However, the effect of these organisms was different in the eucalyptus plantation in relation to the pasture areas.

Report on the survey of abandoned uraniferous lignite mines in southwestern North Dakota

International Nuclear Information System (INIS)

Lyon, R.J.; Prochaska, D.; Burgess, J.L.; Patrick, D.

1986-03-01

A radiation survey was conducted in October 1983 as part of the proposed reclamation plan of abandoned uraniferous lignite mines in southwestern North Dakota. The survey was made to determine the extent of contamination caused by mining operations in the 1960's. Radiation measurements were made and soil samples were taken at approximately 300 locations around six mine sites comprising eleven lignite mine pits. Toxic element analysis was also done on 50 of the soil samples

HUMIC SUBSTANCES AND PHOSPHORUS FRACTIONS IN AREAS WITH CROP-LIVESTOCK INTEGRATION, PASTURE AND NATURAL CERRADO VEGETATION IN GOIÁS, BRAZIL

Directory of Open Access Journals (Sweden)

Sidinei Julio Beutler

2015-04-01

Full Text Available Crop-livestock integration (CLI coupled with a no-till planting system (NTS has proven to be an important alternative farming system, promoting efficient land use and soil conservation by maintaining soil organic matter (SOM. The present study quantified the humic fractions of SOM and soil P fractions and analyzed their relationship in CLI, pasture and natural Cerrado areas in Goiás, Brazil. The samples were obtained from a pasture area (covered with Urochloa decumbens grass for 15 years; a CLI area (planted in annual rotation with Urochloa ruziziensis for 13 years; and a native Cerrado area, sampled for comparison purposes. Total organic carbon (TOC and carbon in the fulvic acid fraction (C-FAF, humic acid fraction (C-HAF and humin (C-HUM were evaluated at a depth of 0‑5; 5‑10; 10‑20 and 20‑40 cm; and inorganic (IP and organic (OP P fractions at a depth of 0‑5 and 5‑10 cm. The highest TOC values, humic fractions and OP were found in the Cerrado area. Similarities in relation to the humic fractions and TOC were found between CLI and pasture areas in all the layers between 0 and 40cm. The area currently managed with CLI, but originally covered by Cerrado, had already developed chemical stability (C-FAF, C-HAF, C-HUM and TOC that was similar to that found in the Cerrado area at a depth of 20-40 cm and with higher C-FAF and C-HUM accumulation compared to the pasture area. Compared to pasture and Cerrado, the CLI system favored the increase in labile, moderately labile and moderately resistant P, both for total P (TP and IP. IP fractions were found in areas treated with high doses of phosphate fertilizer, whereas OP fractions corresponded to those under low or null anthropogenic influence. Organic P fractions were directly related to the humic SOM fractions.

Matéria orgânica em Neossolo de altitude: influência do manejo da pastagem na sua composição e teor Soil organic matter in highland Leptosols: influence of pasture management on composition and content

Directory of Open Access Journals (Sweden)

Mariana da Luz Potes

2010-02-01

Full Text Available A queima da pastagem após o inverno é uma prática antiga em solos de altitude, que visa principalmente ao rebrote da vegetação. Entretanto, o impacto do manejo da pastagem na matéria orgânica do solo de Neossolo de altitude ainda é pouco conhecido. O presente trabalho propôs-se a investigar a composição e o teor de matéria orgânica em perfis de Neossolo da região de São José dos Ausentes, RS, e relacionar os resultados com a ocorrência de queimadas e com o pastejo, empregando como comparação solo sob mata nativa. Os ambientes estudados foram: campo nativo pastejado (2 animais ha-1 sem queima há 22 anos, campo nativo pastejado sujeito à queima bienal (0,5 animal ha-1 e mata nativa adjacente à área de pastagem. Foram coletadas amostras compostas nas camadas de 0-5, 5-10, 10-15 e 15-30 cm, sendo determinados os teores de óxidos de Fe (Fe d e Fe o, de C e de N e realizadas análises de espectroscopia de infravermelho e de termogravimetria. O ambiente alterado periodicamente pelo fogo apresentou maior teor de matéria orgânica em camadas subsuperficiais e, em geral, maior proporção de estruturas quimicamente mais lábeis, comparativamente à pastagem sem queima. Nesse ambiente, o menor teor de C foi atribuído ao pastejo mais intensivo do que o da pastagem alterada pelo fogo. A distribuição de C no ambiente de mata nativa assemelhou-se à de pastagem sem queima. No entanto, na mata a proporção de matéria orgânica de baixo peso molecular extraível com solução de HCl 0,1 mol L-1, relacionada principalmente à atividade microbiana, superou aquela encontrada sob pastagem nativa.Burning pastures after the winter is a traditional practice in highland soils, whose main purpose is the regrowth of vegetation. However, the impact of fire, as well as the influence of grazing on the organic matter of Leptosols is still unknown. The purpose of this study was to investigate the composition and content of organic matter in soil

Radioactive contamination of soil-vegetation cover in some southern areas of Semipalatinsk test site

International Nuclear Information System (INIS)

Tuleubaev, B.A.; Zharikov, S.K.

2001-01-01

The nature of radioactive contamination of meadow-pasture lands in the south of the Semipalatinsk test site (STS) has been studied using experimental data. Individual parameters of radionuclide transport from soil into plants depending upon soil type and sub-type, extent of land use for hay-making and pasturing, and other nature-climatic and anthropogenic factors have been determined. (author)

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

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

Directory of Open Access Journals (Sweden)

Laura Delgado-Balbuena

Full Text Available 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

Evaluation of Seed and Forage Yield of Perennial Plants with Low Water Requirement in Abandoned Farming Lands

Directory of Open Access Journals (Sweden)

Ali gazanchian

2017-10-01

Full Text Available Introduction Drought is a natural phenomenon in arid and semi-arid regions of the world. It is created by low precipitation, high evaporation and reduced soil moisture. Today, they are the major threats to agricultural lands due to fluctuations in rainfall, limited water resources, wells salinization and subsequently abandoned farming lands. Iran is located on the world's dry belt and more than 90 percent of its area is located in the arid and semi-arid climatic regions. It has been reported that the annual rate of soil erosion is up to 33 tons per hectare and 5 to 6 times more than the standard limit. Also, 90% of the country's protein production comes from animals sources. Due to the lack of adequate forage production, the main burden of protein production is imposed on the natural resources and pastures. Therefore, In order to enhance soil stabilization and maintain its fertility, optimum use of off-season precipitations, preventing the flow of water and protecting the abandoned farming lands from the flood risk, increasing the water permeability in the soil, and helping to feed the underwater aquifers and finally the production of forage and seeds, the development of perennial plants cultivation is an important conservative practice. The aim of this study is to emphasize on the selection of the best perennial forage species with low water requirements and acceptable performance for renovation of the abandoned farming lands and moving towards sustainable agriculture approaches. Materials and Methods In this experiment, 10 species of perennial grasses (Agropyron elongatum Host., Secale montanum Guss., Festuca arundinaceae Schreb., Dactylis glomerata L., Agropyron intermedium Host., Agropyron repense L., Agropyron cristatum L., Panicum antidutale Retz., Bromus inermis Leyss., Bromus riparius Rehmann, Agropyron cristatum L. and two legumes includes Trifolium pratense L., Onobrychis sativa Lam. were studied at Asatan-e-Ghods Razavi farm in

Host-specific effects of soil microbial filtrates prevail over those of arbuscular mycorrhizae in a fragmented landscape.

Science.gov (United States)

Pizano, Camila; Mangan, Scott A; Graham, James H; Kitajima, Kaoru

2017-09-01

Plant-soil interactions have been shown to determine plant community composition in a wide range of environments. However, how plants distinctly interact with beneficial and detrimental organisms across mosaic landscapes containing fragmented habitats is still poorly understood. We experimentally tested feedback responses between plants and soil microbial communities from adjacent habitats across a disturbance gradient within a human-modified tropical montane landscape. In a greenhouse experiment, two components of soil microbial communities were amplified; arbuscular mycorrhizal fungi (AMF) and a filtrate excluding AMF spores from the soils of pastures (high disturbance), coffee plantations (intermediate disturbance), and forest fragments (low disturbance), using potted seedlings of 11 plant species common in these habitats (pasture grass, coffee, and nine native species). We then examined their effects on growth of these same 11 host species with reciprocal habitat inoculation. Most plant species received a similar benefit from AMF, but differed in their response to the filtrates from the three habitats. Soil filtrate from pastures had a net negative effect on plant growth, while filtrates from coffee plantations and forests had a net positive effect on plant growth. Pasture grass, coffee, and five pioneer tree species performed better with the filtrate from "away" (where these species rarely occur) compared to "home" (where these species typically occur) habitat soils, while four shade-tolerant tree species grew similarly with filtrates from different habitats. These results suggest that pastures accumulate species-specific soil enemies, while coffee plantations and forests accumulate beneficial soil microbes that benefit pioneer native plants and coffee, respectively. Thus, compared to AMF, soil filtrates exerted stronger habitat and host-specific effects on plants, being more important mediators of plant-soil feedbacks across contrasting habitats. © 2017 by

Fate of airborne metal pollution in soils as related to agricultural management. 1. Zn and Pb distributions in soil profiles

NARCIS (Netherlands)

Fernandez, C.; Labanowski, J.; Cambier, P.; Jongmans, A.G.; Oort, van F.

2007-01-01

The fate of airborne metal pollutants in soils is still relatively unknown. We studied the incorporation of such airborne metal pollution in two soils under long-term permanent pasture (PP) and conventional arable land (CA). Both soils were located at an almost equal distance from a former zinc

Biomasa microbiana y actividad ureasa del suelo en una pradera permanente pastoreada de Chile Soil microbial biomass and urease activity in a grazed permanent pasture from Chile

Directory of Open Access Journals (Sweden)

Pedro Antonio Núñez Ramos

2012-12-01

Full Text Available En los sistemas de pasturas; la productividad de la pradera puede estar influenciada por el manejo; debido a su impacto sobre los microorganismos del suelo y el reciclaje de nutrientes. El objetivo de este trabajo fue evaluar la biomasa microbiana (BM del suelo asociada al nitrógeno (BMN; carbono (BMC y la actividad ureasa (AU en una pradera permanente del sur de Chile. Entre la primavera de 2005 y el invierno de 2006 fueron evaluados dos sistemas de pastoreo: pastoreo intenso (PI; pastoreo suave (PS y un tratamiento control (C. El diseño fue en bloques al azar con tres repeticiones. En relación a los valores promedios medidos de las variables en pre y post pastoreo; se produjo un incremento en los contenidos de CB en un 21,8 y 8,6% para PI y PS; mientras que en el control fue sólo de 1,9%. Los contenidos de NB también fueron incrementados en un 16 y 19% para PI y PS; respectivamente en comparación con el control (4%. La actividad ureasa aumentó en 13 y 27% para PI y PS; respectivamente en comparación con el control (5%. El pastoreo; produce un flujo más alto de residuos orgánicos en el suelo; lo que estimula la actividad de la biomasa microbiana y; por tanto; aumentó la AU y los contenidos de CB y NB. Esto sugiere que; en los sistemas de pastoreo; se mejora la fertilidad biológica de los suelos y la disponibilidad de nutrientes.In pasture systems, management practices can affect pasture productivity differently due to their impact on soil microorganisms and nutrient cycling. The objective of this study was to evaluate the relationship between soil microbial biomass (MB nitrogen (MBN, carbon (MBC and urease activity (UA in a permanent pasture in southern Chile. Two grazing systems were evaluated between spring 2005 and winter 2006 : heavy grazing (HG, light grazing (LG and a control treatment (C. Treatments were arranged in a randomized block design with three replications. Concerning the average values of the variables measured at

[Impact of Land Utilization Pattern on Distributing Characters of Labile Organic Carbon in Soil Aggregates in Jinyun Mountain].

Science.gov (United States)

Li, Rui; Jiang, Chang-sheng; Hao, Qing-ju

2015-09-01

Four land utilization patterns were selected for this study in Jinyun mountain, including subtropical evergreen broad-leaved forest (abbreviation: forest), sloping farmland, orchard and abandoned land. Soil samples were taken every 10 cm in the depth of 60 cm soil and proportions of large macroaggregates (> 2 mm), small macroaggregates (0. 25-2 mm), microaggregates (0. 053 - 0. 25 mm) and silt + clay (organic carbon and labile organic carbon in each aggregate fraction and analyze impacts of land uses on organic carbon and labile organic carbon of soil aggregates. LOC content of four soil aggregates were significantly reduced with the increase of soil depth; in layers of 0-60 cm soil depth, our results showed that LOC contents of forest and abandoned land were higher than orchard and sloping farmland. Reserves of labile organic carbon were estimated by the same soil quality, it revealed that forest (3. 68 Mg.hm-2) > abandoned land (1. 73 Mg.hm-2) > orchard (1. 43 Mg.hm-2) >sloping farmland (0.54 Mg.hm-2) in large macroaggregates, abandoned land (7.77, 5. 01 Mg.hm-2) > forest (4. 96, 2.71 Mg.hm-2) > orchard (3. 33, 21. 10 Mg.hm-2) > sloping farmland (1. 68, 1. 35 Mg.hm-2) in small macroaggregates and microaggregates, and abandoned land(4. 32 Mg.hm-2) > orchard(4. 00 Mg.hm-2) > forest(3. 22 Mg.hm-2) > sloping farmland (2.37 Mg.hm-2) in silt + clay, forest and abandoned land were higher than orchard and sloping farmland in other three soil aggregates except silt + clay. It was observed that the level of organic carbon and labile organic carbon were decreased when bringing forest under cultivation to orchard or farmland, and augments on organic carbon and labile organic carbon were found after exchanging farmland to abandoned land. The most reverses of forest and abandoned land emerged in small macroaggregates, orchard and sloping farmland were in microaggregates. That was, during the transformations of land utilization pattern, soil aggregates with bigger size were

Towards a conceptual model of hydrological change on an abandoned cutover bog, Quebec

Science.gov (United States)

van Seters, Tim E.; Price, Jonathan S.

2002-07-01

Cutover bogs do not return to functional peatland ecosystems after abandonment because re-establishment of peat-forming mosses is poor. This paper presents a conceptual model of bog disturbance caused by peat harvesting (1942-1972), and the hydrological evolution that occurred after abandonment (1973-1998). Two adjacent bogs of similar size and origin, one harvested and the other essentially undisturbed, provide the basis for understanding what changes occurred. The model is based on historical trends evident from previous surveys of land-use, bog ecology and resource mapping; and from recent hydrological and ecological data that characterize the current condition. Water balance data and historical information suggest that runoff increased and evapotranspiration decreased following drainage, but tended towards pre-disturbance levels following abandonment, as vegetation recolonized the surface and drainage became less efficient over time. Dewatering of soil pores after drainage caused shrinkage and oxidation of the peat and surface subsidence of approximately 80 cm over 57 years. Comparisons with a nearby natural bog suggest that bulk density in the upper 50 cm of cutover peat increased from 0·07 to 0·13 g cm-3, specific yield declined from 0·14 to 0·07, water table fluctuations were 67% greater, and mean saturated hydraulic conductivity declined from 4·1 × 10-5 to 1·3 × 10-5 cm s-1. More than 25 years after abandonment, Sphagnum mosses were distributed over broad areas but covered less than 15% of the surface. Areas with good Sphagnum regeneration (>10% cover) were strongly correlated with high water tables (mean -22 cm), especially in zones of seasonal groundwater discharge, artefacts of the extraction history. Forest cover expanded from 5 to 20% of the study area following abandonment. The effect of forest growth (transpiration and interception) and drainage on lowering water levels eventually will be countered by slower water movement through the

Mineralogical characterization of tailing dams: incidence of abandoned mining works on soil pollution (Linares, Jaén)

Science.gov (United States)

de la Torre, M. J.; Hidalgo, C.; Rey, J.; Martínez, J.

2012-04-01

The metallogenic district of Linares-La Carolina (Jaén, Spain) consists of dyke mineralizations mainly of galena, accompanied by blende, chalcopyrite and barite. Associated to these abandoned mines, relatively extensive areas occupied by spoil heaps and tailing impoundments exist and constitute potential sources of soil pollution by metals and semimetals. In order to analyze the pollution potential of these mining wastes, we have carried out a mineralogical and geochemical study of seven tailing dams and surrounding soils in the area. The mineralogy of the samples was studied by x-ray diffraction (XRD) and scanning electron microscope (SEM). In addition, the total metal content of samples was determined by inductively coupled plasma mass spectrometry (ICP-MS) analysis. Samples were taken from the first 30 cm of the waste piles and soil deposits and white efflorescences were also obtained from the surface of the tailings. In all analyzed heaps, high to very high total contents in Pb (1220-22890 mg/kg), Zn (150-51280 mg/kg), Mn (2658-4160 mg/kg), Ba (1026-19610 mg/kg) and Fe (19400-138000 mg/kg) were observed. The concentrations for these same elements in the studied soils range from 527-9900 mg/kg for Pb, 27-1700 mg/kg for Zn, 506-2464 mg/kg for Mn, 2832-4306 for Ba and 8642-29753 mg/kg for Fe, and these figures indicate a contamination of the soils, according to the guidelines established by the Spanish law. The XRD and SEM results indicate that the tailings are primarily constituted by gangue of the exploited mineralization: quartz, calcite, ankerite, feldspars and phyllosilicates. They are inherited, primary mineral phases. Galena, also primary, appears in low proportion, as well as lepidocrocite, melanterite and cerussite, being these three last secondary minerals and indicating a certain remobilization of metal cations, especially lead and iron. On the other hand, quartz and phyllosilicates predominate in the soils, in which, in addition, is identified a

Effects of pasture system management on physical properties Efeitos de sistemas de manejo de pastagens nas propriedades físicas do solo

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Vinicius Martins Ferreira

2010-12-01

Full Text Available The soil physical quality is associated with infiltration, retention and availability of water for plants respond to the management and resists degradation, allows the exchange of heat and gases with the atmosphere and allows plant roots and root growth. The objective of this review is to gather information on soil quality and the effects of anthropogenic systems of pasture management on physical properties. Between physical properties proposed for study of soil quality in pastures, to include vegetation, water erosion, organic matter, aggregate stability, soil macrofauna, density, porosity and water retention in soil because they distinguish the effects caused by soil management systems and contribute to the monitoring of pasture management.A qualidade física do solo está associada à infiltração, retenção e disponibilização de água às plantas; responde ao manejo e resiste à degradação; permite as trocas de calor e de gases com a atmosfera e raízes de plantas e permite o crescimento das raízes. Objetivou-se nesta revisão reunir informações sobre a qualidade do solo e os efeitos das ações antrópicas dos sistemas de manejo de pastagens nas propriedades físicas. Dentre os parâmetros propostos para estudo da qualidade do solo com pastagens, incluem-se a cobertura vegetal, a erosão hídrica, a matéria orgânica, a estabilidade de agregados, a macrofauna do solo, a densidade, a porosidade e a retenção de água no solo, pois os mesmos permitem distinguir os efeitos proporcionados pelos sistemas de manejo nos solos e contribuem para o monitoramento do manejo das pastagens.

Seed predation in a Mediterranean pasture: can ants modify the floristic composition of soil seed banks? Depredación de semillas en un pastizal mediterráneo: ¿pueden las hormigas modificar la composición florística de los bancos de semillas?

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TÍSCAR ESPIGARES

2005-12-01

Full Text Available Ants may play an important role on vegetation dynamics, especially in arid and semiarid environments, where they can consume a high proportion of the produced seeds. Although some works have analysed the influence of seed predation by ants on the density of vegetation in Mediterranean pastures, there are no studies on the influence of ant activity upon the floristic composition of the vegetation and the soil seed banks in this kind of ecosystem. We have studied the effect of ant exclusion on the floristic composition of the vegetation and the soil seed bank in a Mediterranean pasture of central Spain. We sampled the floristic composition of the pasture during 2002 and 2003 springs and also we collected soil seed bank samples in autumn 2002. Floristic composition of soil seed banks was estimated by means of greenhouse germination. Cerastium semidecandrum seeds were almost four times more abundant in the plots subjected to ant exclusion than in those with ant activity. Due to the high spatial heterogeneity shown by soil seed banks, we have corrected the differences found between the autumn soil seed banks subjected to different ant treatments by using the floristic composition of the pasture community in the previous spring, as it was the primary source of the seeds collected in autumn. We found significant differences between the floristic composition of the soil seed banks subjected to ant exclusion and control treatments. However, no effects where found when the same procedure was used to detect ant effects on the spring adult community, highlighting the necessity of longer time spans for these pastures to manifest changes taking place at the soil seed bank stageLa mirmecofauna juega un papel fundamental sobre la dinámica de la vegetación, especialmente en zonas de carácter árido o semiárido, donde puede llegar a consumir una elevada proporción de las semillas producidas, condicionando la composición florística de la vegetación. Aunque

Potential for biological nitrification inhibition to reduce nitrification and N2O emissions in pasture crop-livestock systems.

Science.gov (United States)

Subbarao, G V; Rao, I M; Nakahara, K; Sahrawat, K L; Ando, Y; Kawashima, T

2013-06-01

Agriculture and livestock production systems are two major emitters of greenhouse gases. Methane with a GWP (global warming potential) of 21, and nitrous oxide (N2O) with a GWP of 300, are largely emitted from animal production agriculture, where livestock production is based on pasture and feed grains. The principal biological processes involved in N2O emissions are nitrification and denitrification. Biological nitrification inhibition (BNI) is the natural ability of certain plant species to release nitrification inhibitors from their roots that suppress nitrifier activity, thus reducing soil nitrification and N2O emission. Recent methodological developments (e.g. bioluminescence assay to detect BNIs in plant root systems) have led to significant advances in our ability to quantify and characterize the BNI function. Synthesis and release of BNIs from plants is a highly regulated process triggered by the presence of NH4 + in the rhizosphere, which results in the inhibitor being released precisely where the majority of the soil-nitrifier population resides. Among the tropical pasture grasses, the BNI function is strongest (i.e. BNI capacity) in Brachiaria sp. Some feed-grain crops such as sorghum also have significant BNI capacity present in their root systems. The chemical identity of some of these BNIs has now been established, and their mode of inhibitory action on Nitrosomonas has been characterized. The ability of the BNI function in Brachiaria pastures to suppress N2O emissions and soil nitrification potential has been demonstrated; however, its potential role in controlling N2O emissions in agro-pastoral systems is under investigation. Here we present the current status of our understanding on how the BNI functions in Brachiaria pastures and feed-grain crops such as sorghum can be exploited both genetically and, from a production system's perspective, to develop low-nitrifying and low N2O-emitting production systems that would be economically profitable and

Understanding plant-to-plant interactions for soil resources in multilayered Iberian dehesas

Science.gov (United States)

Moreno, G.; Rolo, V.; Cubera, E.; López-Díaz, L.

2009-04-01

Iberian dehesa is usually defined as two-layered silvopastoral system, where native grasses cohabit with a scattered widely-space tree layer. In the last two decades, an intense debate has been developed on the sustainability of this simplified type of dehesa. While some authors argue that that the forest cycle has been disrupted in most dehesas, where the lack of regeneration is an inherent problem to their exploitation, other authors have showed that dehesa degradation is easily reversible if certain abandonment is periodically exerted. The coexistence of two-layered plots with multilayered plots (encroached open woodlands) and mono-layered plots (either closed forest or mono-pasture/monocrops) has been a common feature of dehesas, as result of a systematic combination of agricultural, pastoral, and forestry uses. Different structures of vegetation depend on land use, giving a mosaic at both estate and landscape scales. These mosaic-type systems allow finding several scenarios of plant-to-plant interactions, mostly at belowground level. A key issue for sustainable management of oak woodland is to understand the complexity of the plant-to-plant relationships and their consequences in the ecosystem functioning in terms of productivity and stability. The competitive abilities of component systems are modified by the environment conditions. Dehesas, as most savanna systems, exhibit a low rainfall with high variability within and between years as well as a high evaporative demand during the summer. Indeed, water availability is one of the major ecological factors influencing either natural savannas or man-made open woodlands. Although most of the available studies have focused different aspects of the mature tree-grass interactions, we also present here some recent results on tree-tree, tree-shrub, shrub-seedling and seedling-grass interactions, explained mostly in terms of competition for soil water and nutrients. Trees can modify the soil and microclimate

Vegetation Succession on Degraded Sites in the Pomacochas Basin (Amazonas, N Peru—Ecological Options for Forest Restoration

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Helge Walentowski

2018-02-01

Full Text Available The Andes of northern Peru are still widely covered with forests, but increasingly suffer from habitat fragmentation. Subsequent soil degradation often leads to the abandonment of overused forests and pastures. Ecological knowledge on the restoration potential, e.g., on dependencies of soil conditions and altitude, is scarce. Therefore, we compared soil and vegetation patterns along nine transects within the upper Pomacochas Basin, which is an important biodiversity corridor along the Andes, between remaining forests, succession sites and pastures. Anthropogenic successional and disturbance levels, geological substrate, and altitude have the most important ecological impacts on vegetation and tree species composition. Species responded to sandstone versus calcareous substrates, but also to depths of the organic soil layer, and light conditions. The absence of organic layers under pastures contrasted with the accumulation of thick organic layers under forest cover. Vegetation composition at succession sites revealed certain starting points (herbal stage, bush stage, or secondary forest for restoration that will determine the length of regeneration paths. Pre-forest patches of Alchornea sp. and Parathesis sp. may act as habitat stepping stones for expeditiously restoring biocorridors for wildlife. The key findings can contribute to the sustainable use and conservation of biodiversity in a fragile ecoregion.

Soil chemical atributtes on brachiaria spp in integrated crop livestock system

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Valdinei Tadeu Paulino

2013-12-01

Full Text Available Integrated crop-livestock systems have attracted more interest in the last few years due to their capacity of improving stability and sustainability of agricultural systems when compared to more specialized production ones. The crop-livestock integration is an effective technique, but complex to maintain pasture productivity and its recovery, whose efficiency depends on soil physical management and its chemical fertility. Regarding the soil fertility, the corrective practices generally begin with the liming due to the high acidity of most Brazilian soils and low levels of Ca and Mg in the exchange complex and high Al saturation. In areas of crop-livestock systems, liming corrects the surface acidity potential. However, this practice can leave the subsoil with excess aluminum and lack of calcium, which inhibit root growth and affect the absorption of water and nutrients. The application of gypsum allows the improvement of the subsoil, reducing Al saturation and increasing levels of calcium and sulfur. The aim of this study was to investigate changes in the soil chemical properties of a Haplorthox soil in integrated crop-livestock system (ICL with Brachiaria brizantha cv. Marandu and Piatã, Brachiaria ruziziensis with gypsum and liming application. This study was conducted at the Instituto de Zootecnia, Nova Odessa/SP, a pasture established on a soil with medium texture (61.4% sand, silt 14.6% and 24.0% clay. The treatment plots consisted on integration crop-livestock (ICL cultivated - maize and B. Marandu,  ICL - maize and B. ruziziensis, ICL - maize and B. Piatã and an untreated control group (control - without liming and fertilization grazed pasture throughout the year, located immediately adjacent to the ICL evaluation, which was cultivated for 25 years with B. brizantha cv. Marandu. All pastures were desiccated in October with glyphosate-based herbicide (4 liters per hectare. Then gypsum (1.2 Mg ha-1 and liming (1.2 Mg ha-1 were applied

Network analysis reveals that bacteria and fungi form modules that correlate independently with soil parameters.

Science.gov (United States)

de Menezes, Alexandre B; Prendergast-Miller, Miranda T; Richardson, Alan E; Toscas, Peter; Farrell, Mark; Macdonald, Lynne M; Baker, Geoff; Wark, Tim; Thrall, Peter H

2015-08-01

Network and multivariate statistical analyses were performed to determine interactions between bacterial and fungal community terminal restriction length polymorphisms as well as soil properties in paired woodland and pasture sites. Canonical correspondence analysis (CCA) revealed that shifts in woodland community composition correlated with soil dissolved organic carbon, while changes in pasture community composition correlated with moisture, nitrogen and phosphorus. Weighted correlation network analysis detected two distinct microbial modules per land use. Bacterial and fungal ribotypes did not group separately, rather all modules comprised of both bacterial and fungal ribotypes. Woodland modules had a similar fungal : bacterial ribotype ratio, while in the pasture, one module was fungal dominated. There was no correspondence between pasture and woodland modules in their ribotype composition. The modules had different relationships to soil variables, and these contrasts were not detected without the use of network analysis. This study demonstrated that fungi and bacteria, components of the soil microbial communities usually treated as separate functional groups as in a CCA approach, were co-correlated and formed distinct associations in these adjacent habitats. Understanding these distinct modular associations may shed more light on their niche space in the soil environment, and allow a more realistic description of soil microbial ecology and function. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

FACTORS TO CONSIDER ABOUT MILK PRODUCTION ON PASTURE

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Haroldo Wilson da Silva

2011-12-01

Full Text Available In this review, we addressed issues that permeate discussions related to some factors to consider about milk production on pasture, since the viability of milk production on pasture until the nutritional value of pasture for dairy cows. Analyze the theme of milk production on pasture and how it is inserted within the perspective of the viability of exploiting the cattle dairy pastures in Brazil is the objective of this work. In general, it was observed that the responses of production with grazing animals are conditioned on the rational use of pasture, so this factor of production represents an economical feed source for livestock destined for milk production. For that, it is evident the need to use land intensively, in order to obtain forage quantity and quality necessary to fully meet the nutritional needs of cows, lactating or not. It was observed in this study the great demand for information on pasture as a resource for the production of milk, which justifies this work. It was concluded that grazing managed properly represent a viable, low cost, animal nutrition in the production of bovine milk.

Abandoned Pb−Zn mining wastes and their mobility as proxy to toxicity: A review

Energy Technology Data Exchange (ETDEWEB)

Gutiérrez, Mélida, E-mail: mgutierrez@missouristate.edu [Department of Geography, Geology and Planning, Missouri State University, Springfield, MO 65897 (United States); Mickus, Kevin, E-mail: kevinmickus@missouristate.edu [Department of Geography, Geology and Planning, Missouri State University, Springfield, MO 65897 (United States); Camacho, Lucy Mar, E-mail: lucy.camacho@tamuk.edu [Department of Environmental Engineering, Texas & M University-Kingsville, Kingsville, TX 78363 (United States)

2016-09-15

Lead and zinc (Pb−Zn) mines are a common occurrence worldwide; and while approximately 240 mines are active, the vast majority have been abandoned for decades. Abandoned mining wastes represent a serious environmental hazard, as Pb, Zn and associated metals are continuously released into the environment, threatening the health of humans and affecting ecosystems. Iron sulfide minerals, when present, can form acid mine drainage and increase the toxicity by mobilizing the metals into more bioavailable forms. Remediation of the metal waste is costly and, in the case of abandoned wastes, the responsible party(ies) for the cleanup can be difficult to determine, which makes remediation a complex and lengthy process. In this review, we provide a common ground from a wide variety of investigations about concentrations, chemical associations, and potential mobility of Pb, Zn and cadmium (Cd) near abandoned Pb−Zn mines. Comparing mobility results is a challenging task, as instead of one standard methodology, there are 4–5 different methods reported. Results show that, as a general consensus, the metal content of soils and sediments vary roughly around 1000 mg/kg for Zn, 100 for Pb and 10 for Cd, and mobilities of Cd > Zn > Pb. Also, mobility is a function of pH, particle size, and formation of secondary minerals. New and novel remediation techniques continue to be developed in laboratories but have seldom been applied to the field. Remediation at most of the sites has consisted of neutralization (e.g. lime,) for acid mine discharge, and leveling followed by phytostabilization. In the latter, amendments (e.g. biochar, fertilizers) are added to boost the efficiency of the treatment. Any remediation method has to be tested before being implemented as the best treatment is site-specific. Potential treatments are described and compared. - Highlights: • Abandoned Pb−Zn mine wastes represent a hazard to the environment. • Cd is a toxic metal closely associated to Zn and

Abandoned Pb−Zn mining wastes and their mobility as proxy to toxicity: A review

International Nuclear Information System (INIS)

Gutiérrez, Mélida; Mickus, Kevin; Camacho, Lucy Mar

2016-01-01

Lead and zinc (Pb−Zn) mines are a common occurrence worldwide; and while approximately 240 mines are active, the vast majority have been abandoned for decades. Abandoned mining wastes represent a serious environmental hazard, as Pb, Zn and associated metals are continuously released into the environment, threatening the health of humans and affecting ecosystems. Iron sulfide minerals, when present, can form acid mine drainage and increase the toxicity by mobilizing the metals into more bioavailable forms. Remediation of the metal waste is costly and, in the case of abandoned wastes, the responsible party(ies) for the cleanup can be difficult to determine, which makes remediation a complex and lengthy process. In this review, we provide a common ground from a wide variety of investigations about concentrations, chemical associations, and potential mobility of Pb, Zn and cadmium (Cd) near abandoned Pb−Zn mines. Comparing mobility results is a challenging task, as instead of one standard methodology, there are 4–5 different methods reported. Results show that, as a general consensus, the metal content of soils and sediments vary roughly around 1000 mg/kg for Zn, 100 for Pb and 10 for Cd, and mobilities of Cd > Zn > Pb. Also, mobility is a function of pH, particle size, and formation of secondary minerals. New and novel remediation techniques continue to be developed in laboratories but have seldom been applied to the field. Remediation at most of the sites has consisted of neutralization (e.g. lime,) for acid mine discharge, and leveling followed by phytostabilization. In the latter, amendments (e.g. biochar, fertilizers) are added to boost the efficiency of the treatment. Any remediation method has to be tested before being implemented as the best treatment is site-specific. Potential treatments are described and compared. - Highlights: • Abandoned Pb−Zn mine wastes represent a hazard to the environment. • Cd is a toxic metal closely associated to Zn and

Abandonment (field decommissioning): The legal requirements

International Nuclear Information System (INIS)

Roberts, M.

1994-01-01

The main areas to be considered in relation to the abandonment of offshore installations are: (1) the legal requirements to be imposed in relation to abandonment, this will include consideration of English, Norwegian and Dutch law as well as international law; (2) how licensees may protect themselves against joint and several liability for performance of their legal obligations in relation to abandonment by the provision of security; and (3) consideration of practical examples of abandonment such as the abandonment of the Piper Alpha platform on the UK continental shelf and the K13-D platform on the Dutch continental shelf. This paper considers only abandonment of offshore installations as very different considerations apply onshore and applies only to Europe, though the international treaties will also apply elsewhere

An outline of soil nematode succession on abandoned fields in South Bohemia

Czech Academy of Sciences Publication Activity Database

Háněl, Ladislav

2010-01-01

Roč. 46, č. 3 (2010), s. 355-371 ISSN 0929-1393 R&D Projects: GA ČR GA526/97/0631 Grant - others:MŠMT(CZ) 2004-13 Institutional research plan: CEZ:AV0Z60660521 Keywords : secondary succession * abandoned field * fallow Subject RIV: EH - Ecology, Behaviour Impact factor: 2.399, year: 2010

Mediterranean shrub vegetation: soil protection vs. water availability

Science.gov (United States)

García Estringana, Pablo; Nieves Alonso-Blázquez, M.; Alegre, Alegre; Cerdà, Artemi

2014-05-01

Soil Erosion and Land Degradation are closely related to the changes in the vegetation cover (Zhao et al., 2013). Although other factors such as rainfall intensiy or slope (Ziadat and Taimeh, 2013) the plant covers is the main factor that controls the soil erosion (Haregeweyn, 2013). Plant cover is the main factor of soil erosion processes as the vegetation control the infiltration and runoff generation (Cerdà, 1998a; Kargar Chigani et al., 2012). Vegetation cover acts in a complex way in influencing on the one hand on runoff and soil loss and on the other hand on the amount and the way that rainfall reaches the soil surface. In arid and semiarid regions, where erosion is one of the main degradation processes and water is a scant resource, a minimum percentage of vegetation coverage is necessary to protect the soil from erosion, but without compromising the availability of water (Belmonte Serrato and Romero Diaz, 1998). This is mainly controlled by the vegetation distribution (Cerdà, 1997a; Cammeraat et al., 2010; Kakembo et al., 2012). Land abandonment is common in Mediterranean region under extensive land use (Cerdà, 1997b; García-Ruiz, 2010). Abandoned lands typically have a rolling landscape with steep slopes, and are dominated by herbaceous communities that grow on pasture land interspersed by shrubs. Land abandonment use to trigger an increase in soil erosion, but the vegetation recovery reduces the impact of the vegetation. The goal of this work is to assess the effects of different Mediterranean shrub species (Dorycnium pentaphyllum Scop., Medicago strasseri, Colutea arborescens L., Retama sphaerocarpa, L., Pistacia Lentiscus L. and Quercus coccifera L.) on soil protection (runoff and soil losses) and on rainfall reaching soil surface (rainfall partitioning fluxes). To characterize the effects of shrub vegetation and to evaluate their effects on soil protection, two field experiments were carried out. The presence of shrub vegetation reduced runoff by

Production of N2O in grass-clover pastures

International Nuclear Information System (INIS)

Carter, M.S.

2005-09-01

Agricultural soils are known to be a considerable source of the strong greenhouse gas nitrous oxide (N 2 O), and in soil N 2 O is mainly produced by nitrifying and denitrifying bacteria. In Denmark, grass-clover pastures are an important component of the cropping system in organic as well as conventional dairy farming, and on a European scale grass-clover mixtures represent a large part of the grazed grasslands. Biological dinitrogen (N 2 ) fixation in clover provides a major N input to these systems, but knowledge is sparse regarding the amount of fixed N 2 lost from the grasslands as N2O. Furthermore, urine patches deposited by grazing cattle are known to be hot-spots of N 2 O emission, but the mechanisms involved in the N 2 O production in urine-affected soil are very complex and not well understood. The aim of this Ph.D. project was to increase the knowledge of the biological and physical-chemical mechanisms, which control the production of N2O in grazed grass-clover pastures. Three experimental studies were conducted with the objectives of: 1: assessing the contribution of recently fixed N 2 as a source of N 2 O. 2: examining the link between N 2 O emission and carbon mineralization in urine patches. 3: investigating the effect of urine on the rates and N 2 O loss ratios of nitrification and denitrification, and evaluating the impact of the chemical conditions that arise in urine affected soil. The results revealed that only 3.2 ± 0.5 ppm of the recently fixed N 2 was emitted as N2O on a daily basis. Thus, recently fixed N released via easily degradable clover residues appears to be a minor source of N2O. Furthermore, increased N 2 O emission following urine application at rates up to 5.5 g N m -2 was not caused by enhanced denitrification stimulated by labile compounds released from scorched plant roots. Finally, the increase of soil pH and ammonium following urine application led to raised nitrification rate, which appeared to be the most important factor

Localization of 15N uptake in a Tibetan alpine Kobresia pasture

Science.gov (United States)

Schleuß, Per-Marten; Kuzyakov, Yakov

2014-05-01

The Kobresia Pygmea ecotone covers approximately 450.000 km2 and is of large global and regional importance due several socio-ecological aspects. For instance Kobresia pastures store high amounts of carbon, nitrogen and other nutrients, represent large grazing areas for herbivores, provide a fast regrowth after grazing events and protect against mechanical degradation and soil erosion. However, Kobresia pastures are assumed to be a grazing induced and are accompanied with distinct root mats varying in thickness between 5-30 cm. Yet, less is known about the morphology and the functions of this root mats, especially in the background of a progressing degradation due to changes of climate and management. Thus we aimed to identify the importance of single soil layers for plant nutrition. Accordingly, nitrogen uptake from different soil depths and its remain in above-ground biomass (AGB), belowground biomass (BGB) and soil were determined by using a 15N pulse labeling approach during the vegetation period in summer 2012. 15N urea was injected into six different soil depths (0.5 cm, 2.5 cm, 7.5 cm, 12.5 cm, 17.5 cm, 22.5 cm / for each 4 replicates) and plots were sampled 45 days after the labeling. For soil and BGB samples were taken in strict sample intervals of 0-1 cm, 1-5 cm, 5-10 cm, 10-15 cm, 15-20 cm, 20-25 cm. Results indicate that total recovery (including AGB, BGB and soil) was highest, if tracer was injected into the top 5 cm and subsequently decreased with decreasing injection depth. This is especially the case for the 15N recovery of BGB, which is clearly attributed to the root density and strongly decreased with soil depth. In contrast, the root activity derived from the 15N content of roots increased with soil depth, which is primary associated to a proportionate increase of living roots related to dead roots. However, most 15N was captured in plant biomass (67.5-85.3 % of total recovery), indicating high 15N uptake efficiency possibly due to N limitation

Comparison of Vegetation Indices from Rpas and SENTINEL-2 Imagery for Detecting Permanent Pastures

Science.gov (United States)

Piragnolo, M.; Lusiani, G.; Pirotti, F.

2018-04-01

Permanent pastures (PP) are defined as grasslands, which are not subjected to any tillage, but only to natural growth. They are important for local economies in the production of fodder and pastures (Ali et al. 2016). Under these definitions, a pasture is permanent when it is not under any crop-rotation, and its production is related to only irrigation, fertilization and mowing. Subsidy payments to landowners require monitoring activities to determine which sites can be considered PP. These activities are mainly done with visual field surveys by experienced personnel or lately also using remote sensing techniques. The regional agency for SPS subsidies, the Agenzia Veneta per i Pagamenti in Agricoltura (AVEPA) takes care of monitoring and control on behalf of the Veneto Region using remote sensing techniques. The investigation integrate temporal series of Sentinel-2 imagery with RPAS. Indeed, the testing area is specific region were the agricultural land is intensively cultivated for production of hay harvesting four times every year between May and October. The study goal of this study is to monitor vegetation presence and amount using the Normalized Difference Vegetation Index (NDVI), the Soil-adjusted Vegetation Index (SAVI), the Normalized Difference Water Index (NDWI), and the Normalized Difference Built Index (NDBI). The overall objective is to define for each index a set of thresholds to define if a pasture can be classified as PP or not and recognize the mowing.

COMPARISON OF VEGETATION INDICES FROM RPAS AND SENTINEL-2 IMAGERY FOR DETECTING PERMANENT PASTURES

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M. Piragnolo

2018-04-01

Full Text Available Permanent pastures (PP are defined as grasslands, which are not subjected to any tillage, but only to natural growth. They are important for local economies in the production of fodder and pastures (Ali et al. 2016. Under these definitions, a pasture is permanent when it is not under any crop-rotation, and its production is related to only irrigation, fertilization and mowing. Subsidy payments to landowners require monitoring activities to determine which sites can be considered PP. These activities are mainly done with visual field surveys by experienced personnel or lately also using remote sensing techniques. The regional agency for SPS subsidies, the Agenzia Veneta per i Pagamenti in Agricoltura (AVEPA takes care of monitoring and control on behalf of the Veneto Region using remote sensing techniques. The investigation integrate temporal series of Sentinel-2 imagery with RPAS. Indeed, the testing area is specific region were the agricultural land is intensively cultivated for production of hay harvesting four times every year between May and October. The study goal of this study is to monitor vegetation presence and amount using the Normalized Difference Vegetation Index (NDVI, the Soil-adjusted Vegetation Index (SAVI, the Normalized Difference Water Index (NDWI, and the Normalized Difference Built Index (NDBI. The overall objective is to define for each index a set of thresholds to define if a pasture can be classified as PP or not and recognize the mowing.

[Impact of land use type on stability and organic carbon of soil aggregates in Jinyun Mountain].

Science.gov (United States)

Li, Jian-Lin; Jiang, Chang-Sheng; Hao, Qing-Ju

2014-12-01

Soil aggregates have the important effect on soil fertility, soil quality and the sustainable utilization of soil, and they are the mass bases of water and fertilizer retention ability of soil and the supply or release of soil nutrients. In this paper, in order to study the impact of land use type on stability and organic carbon of soil aggregates in Jinyun Mountain, we separated four land use types of soil, which are woodland, abandoned land, orchard and sloping farmland by wet sieving method, then we got the proportion of large macroaggregates (> 2 mm), small macroaggregates (0.25-2 mm), microaggregates (53 μm-0.25 mm) and silt + clay (soil depth of 0-60 cm and calculated the total content of organic carbon of all aggregates fraction in each soil. The results showed that reclamation of woodland will lead to fragmentation of macroaggregates and deterioration of soil structure, and the proportion of macroaggrgates (> 0.25 mm) were 44.62% and 32.28% respectively in the soils of orchard and sloping farmland, which reduced 38.58% (P soil fraction from silt + clay to large macroaggregates and small macroaggregates, so it will improve the soil structure. MWD (mean weight diameter) and GMD (geometric mean diameter) are important indicators of evaluating the stability of soil aggregates. We found the MWD and GWD in soil depth of 0-60 cm in orchards and sloping farmland were significantly lower than those in woodland (P soil aggregates, and they will be separated more easily by water. However, after changing the sloping farmland to abandoned land will enhance the stability of soil aggregates, and improve the ability of soil to resist external damage. The organic carbon content in each soil aggregate of four land use types decreased with the increase of soil depth. In soil depth of 0-60 cm, the storage of organic carbon of large macroaggregates in each soil are in orders of woodland (14.98 Mg x hm(-2)) > abandoned land (8.71 Mg x hm(-2)) > orchard (5.82 Mg x hm(-2

Sustainable intensification of cultivated pastures using multiple ...

African Journals Online (AJOL)

rangeland and wildlife parks) for guidelines to implementing this approach in cultivated pasture. In rangeland or natural grassland ... Keywords: animal production, biodiversity, cultivated pastures, foraging ecology, plant–herbivore interactions ...

Prevention of Child Abandonment

OpenAIRE

Gaia, A.

2011-01-01

The aim of this work is to analyze the determinants of child abandonment in the city of Bra ov. The research is based on a new dataset collected on the field on mothers and pregnant women at risk of abandoning their child.

Drivers, Constraints and Trade-Offs Associated with Recultivating Abandoned Cropland in Russia, Ukraine and Kazakhstan

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Patrick Meyfroidt

2016-06-01

Full Text Available Further cropland expansion might be unavoidable to satisfy the growing demand for land- based products and ecosystem services. A crucial issue is thus to assess the trade-offs between social and ecological impacts and the benefits of converting additional land to cropland. In the former Soviet Union countries, where the transition from state-command to market-driven economies resulted in widespread agricultural land abandonment, cropland expansion may incur relatively low costs, especially compared with tropical regions. Our objectives were to quantify the drivers, constraints and trade-offs associated with recultivating abandoned cropland to assess the potentially available cropland in European Russia, western Siberia, Ukraine and Kazakhstan - the region where the vast majority of post- Soviet cropland abandonment took place. Using spatial panel regressions, we characterized the socio-economic determinants of cropland abandonment and recultivation. We then used recent maps of changes in cropland to 1 spatially characterize the socio-economic, accessibility and soil constraints associated with the recultivation of abandoned croplands and 2 investigate the environmental trade-offs regarding carbon stocks and habitat for biodiversity. Less cropland abandonment and more recultivation after 2000 occurred in areas with an increasing rural population and a younger labor force, but also improved yields. Synergies were observed between cropland recultivation and intensification over the 2000s. From 47.3 million hectares (Mha of cropland abandoned in 2009, we identified only 8.5 (7.1-17.4 Mha of potentially available cropland with low environmental tradeoffs and low to moderate socio-economic or accessibility constraints that were located on high-quality soils (Chernozems. These areas represented an annual wheat production potential of 14.3 (9.6-19.5 million tons (Mt. Conversely, 8.5 (4.2-12.4 Mha had high carbon or biodiversity trade-offs, of which 10

Historical cropland expansion and abandonment in the continental U.S. during 1850 to 2016

Science.gov (United States)

Yu, Z.; Lu, C.

2017-12-01

Land use and land cover changes (LCLUC) are among the most important driving forces that alter terrestrial ecosystem functions and their feedbacks to climate system, but reliable spatially explicit dataset over century long period is still lacking for fine-scale earth system modeling. In this study, by harmonizing multiple sources of inventory data and high-resolution satellite images, we reconstructed cropland density maps to depict the annual percentage and distribution pattern of cultivated land (excluding summer idle/fallow, cropland pasture) in the conterminous U.S. during 1850 to 2016. We further examined the cropland expansion and abandonment in the U.S. using the newly-developed LCLUC data. In total, national cropland expansion is 104 million hectares (Mha) from 1850 to 2016 and peaked at about 127 Mha in 1920. Forests and shrublands were the dominant land cover types that croplands were converted from during 1850-1880, which may be primarily attributed to agriculture development in Northeast region. Croplands began to expand into grasslands since 1870 and the encroached area dramatically increased, mainly due to cultivation development in the Great Plain and Midwestern area. In comparison, the abandoned cropland in the U.S. is 65 Mha (34% of the maximum crop density) during the study period. We found cropland abandonment mostly occurred in the Central and Southeast U.S., while cropland expansion centered in the Midwestern states, the Central California, and the Mississippi Alluvial Plain. National cultivated lands have shifted from the Eastern to Midwestern U.S., which contributed to the increasingly important role of Midwest in the rise of food and biofuel productions, enhanced GHGs emission, and intensive nitrogen loads into the Gulf of Mexico. Our study provides a reliable database of historical cropland distribution, which is essential for modeling assessments of LCLUC impacts, crop production estimation, and social-economic analysis.

Atributos químicos e físicos de solo sob pastagens perenes de verão Soil chemical and physical attributes under perennial summer pastures

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Henrique Pereira dos Santos

2009-01-01

Full Text Available Atributos químicos e físicos de um Nitossolo Vermelho Eutrófico léptico argiloso foram avaliados em Passo Fundo (RS em um experimento sobre o desempenho agronômico de três gramíneas perenes de verão (capim quicuio, capim elefante e capim Tifton 68 para a produção de leite após duas estações de crescimento. O delineamento experimental foi em blocos ao acaso com quatro repetições. Avaliou-se também o solo sob floresta subtropical em área adjacente ao experimento. Os valores de pH, Al, Ca e Mg trocáveis, e P extraível diferiram, em algumas camadas, entre as pastagens estudadas. Algumas pastagens, em relação à floresta nativa favoreceram a elevação do teor de P, em todas as camadas avaliadas. Entre as pastagens, não houve diferença significativa para o teor de carbono do solo. Sob capins houve maior acúmulo de carbono, na camada de 0-20 cm do solo, em comparação à floresta. A densidade do solo e a resistência à penetração não diferiram entre as pastagens, em ambas as camadas, porém nas camadas de 0 a 5 cm e na de 10 a 15 cm, houve aumento desses valores, em relação à floresta subtropical. As porosidades totais e a macroporosidade não diferiram entre as três espécies de pastagens, mas houve redução dos valores em comparação com a floresta subtropical.Soil chemical and physical characteristics were evaluated on a Rhodic Nitisol Eutrophic clayey located in Passo Fundo, Rio Grande do Sul State, Brazil in a trial of agronomic performance of three perennial summer grasses (kikuyu grass, elephant grass and Tifton 68 grass for milk production after two growing seasons. The trial used a complete randomized block design replicated three times. Soil samples were also taken in a fragment of subtropical forest near the experiment. Soil reaction (pH, aluminum, calcium, magnesium, and phosphorus varied according to the studied soil layer. Some grasses increased the level of phosphorus content in all layers. Pastures

Study on the quality of site in the mining district gangue of abandoned place

Institute of Scientific and Technical Information of China (English)

LU Guo-bin; LI Ying; WU Xiang-yun

2008-01-01

Being as an example of Fuxin, gangue abandoned place was classified gangue hill and dump. It was built 68 piece of temporary standard fields, which physical and chemical character of soil were researched and analyzed. The quality of district site was estimated, and five type abandoned place were gotten. Stopping draining cash less than 7 a and draining cash gangue hill was regarded as Ⅰ gangue hill. Stopping draining gangue age limit 7-15 a and herbage abundance being CO1p level was regarded as Ⅱ gangue hill.Stopping draining gangue age limit 15～25 a and herbage abundance CO2p level was re-garded as Ⅲ gangue hill. Stopping draining cash gangue age limit over 25 a and herbage abundance CO3p level was regarded as Ⅳ gangue hill. Dump being formed the under-ground layer dug up and stacked in the course of mining was regarded asVgangue hill.The results show that every typical abandoned place can plant vegetable.

Decontamination of abandoned sites. An introduction into the problems of land decontamination

International Nuclear Information System (INIS)

Kundt, K.

1991-01-01

Starting from a brief overview of the history of origin of soil and ground water pollution in Berlin and its surroundings by gas, chemical, and petroleum works, old landfills, manufactories of arms and ammunition as well as gasoline depots or sites of gasoline depots, the brochure describes the legal situation and procedure (list of 'intervention' values) and goes on to outline the situation regarding the ground under Berlin, existing pollutants, and methods for dealing with land contamination. In five abandoned sites (waste oil refinery, copper refinery, waste solvent treatment plant, asphalt factory and drugs factory), different methods for eliminating soil and ground water contamination were used. Their efficacy is assessed on the basis of their soil and pollutant-specific suitability; the decontamination achieved is indicated. (BBR) [de

Land-use systems affect Archaeal community structure and functional diversity in western Amazon soils

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Acácio Aparecido Navarrete

2011-10-01

Full Text Available The study of the ecology of soil microbial communities at relevant spatial scales is primordial in the wide Amazon region due to the current land use changes. In this study, the diversity of the Archaea domain (community structure and ammonia-oxidizing Archaea (richness and community composition were investigated using molecular biology-based techniques in different land-use systems in western Amazonia, Brazil. Soil samples were collected in two periods with high precipitation (March 2008 and January 2009 from Inceptisols under primary tropical rainforest, secondary forest (5-20 year old, agricultural systems of indigenous people and cattle pasture. Denaturing gradient gel electrophoresis of polymerase chain reaction-amplified DNA (PCR-DGGE using the 16S rRNA gene as a biomarker showed that archaeal community structures in crops and pasture soils are different from those in primary forest soil, which is more similar to the community structure in secondary forest soil. Sequence analysis of excised DGGE bands indicated the presence of crenarchaeal and euryarchaeal organisms. Based on clone library analysis of the gene coding the subunit of the enzyme ammonia monooxygenase (amoA of Archaea (306 sequences, the Shannon-Wiener function and Simpson's index showed a greater ammonia-oxidizing archaeal diversity in primary forest soils (H' = 2.1486; D = 0.1366, followed by a lower diversity in soils under pasture (H' = 1.9629; D = 0.1715, crops (H' = 1.4613; D = 0.3309 and secondary forest (H' = 0.8633; D = 0.5405. All cloned inserts were similar to the Crenarchaeota amoA gene clones (identity > 95 % previously found in soils and sediments and distributed primarily in three major phylogenetic clusters. The findings indicate that agricultural systems of indigenous people and cattle pasture affect the archaeal community structure and diversity of ammonia-oxidizing Archaea in western Amazon soils.

Soil microbial community as a proxy for the ecological service condition in karst soils of SW China

Science.gov (United States)

Green, Sophie M.; Dungait, Jennifer A. J.; Zhang, Xinyu; Hawkes, Simon; Donovan, Neil; Barrows, Tim; Buss, Heather; Liu, Taoze; Evershed, Richard; Wen, Xuefa; Hartley, Iain; Song, Zhaoliang; Liu, Hongyan; Tu, Chenglong; Johnes, Penny J.; Meersmans, Jeroen; Guo, Dali; Quine, Tim

2017-04-01

Karst is a key landscape covering extensive areas of Southwest China that has undergone rapid intensive land use change and degradation over the last 50 years. Clear evidence of environmental degradation and its damaging consequences for the reduction of intrinsic value of the land for local human populations has led to an increasing focus on landscape rehabilitation. This has included unmanaged abandonment and attempts to re-vegetate denuded surfaces. However, this has achieved limited success and there is a clear need to develop restoration strategies underpinned by robust quantitative and mechanistic understanding of critical zone (CZ) functioning. Thus, a karst Critical Zone Observatory (CZO) was established in June 2016 in Chenqi, Guizhou Province, along a gradient through three levels of human perturbed landscapes: sloping farmland; recovery phase 1 (recently abandoned, within 5 years); and, recovery phase 2 (secondary forest, abandoned > 5 years). We hypothesise that there is a tipping point along the degradation gradient beyond which key biological controls over CZ function are lost, resulting in declining nutrient cycling and rock weathering rates, and increased soil erosion rates. This paper will present preliminary data from the application of the CZ approach using space-for-time substitution. We characterised soil microbial community dynamics along the degradation gradient using geochemical biomarkers and soil properties measured in soil profiles (soil microbes, and pools of soil carbon (C), nitrogen (N) and phosphorus (P), with estimations of soil erosion rates using radionuclide 137Cs/Pb210, within the karst ecosystem to evaluate the status of key ecosystem functions (e.g. nutrient cycling, carbon sequestration, soil stabilisation).

Soil macrofauna in wooded pasture with legume trees

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Lusimar Lamarte Gonzaga Galindo da Silva

2015-07-01

Full Text Available Grasslands afforestation aims at adding different soil uses in a way they become profitable for their owners. As such handling aims at minimizing impacts, the current study had as its goal the use of soil macrofauna in order to evaluate legume afforestation effects on the soil, regardless the depth. Thus, nitrogen fixing species were inserted onto grassland areas and the macrofauna collection was performed 6 years after their planting in the 0-10cm, 10-20cm and 20.30cm layers, in winter and summer. Leguminous influence was different between depths and times of the year. It mostly favors communities under "Mimosa" Genus treetops. Besides, the effects from climatic seasonal variations on invertebrates were mitigated by the implementation of such legume trees

The impact of agriculture terraces on soil organic matter, aggregate stability, water repellency and bulk density. A study in abandoned and active farms in the Sierra de Enguera, Eastern Spain.

Science.gov (United States)

Cerdà, Artemi; Burguet, Maria; Keesstra, Saskia; Prosdocimi, Massimo; Di Prima, Simone; Brevik, Erik; Novara, Agata; Jordan, Antonio; Tarolli, Paolo

2016-04-01

Soil erosion, land degradation, lack of organic matter, erodible soils, rock outcrops… are a consequence of the human abuse and misuse of the soil resources. And this is a worldwide environmental issue (Novara et al., 2011; Vanlauwe et al., 2015; Musinguzi et al., 2015; Pereira et al., 2015; Mwagno et al., 2016). Agriculture terraces are a strategy to reduce the soil erosion, improve the soil fertility and allow the ploughing (Cerdà et al., 2010; Li et al., 2014). Although this idea is well accepted there are few scientific evidences that demonstrate that soils in the terraced areas are more stable, fertile and sustainable that the soil in non terraced areas. In fact, the ploughing in comparison to the abandoned or not ploughed land results in the soil degradation (Lieskovský and Kenderessy, 2014; Gao et al., 2015; Parras-Alcántara et al., 2014). This is mainly due to the lack of vegetation that increase the surface runoff (Cerdà et al., 1998; Keesstra et al., 2007). And why is necessary to develop also in terraced landscapes soil erosion control strategies (Mekonnen et al., 2015a; Mekonnen et al., 2015b; Prosdocimi et al., 2016). Our objective was to assess the soil organic matter content (Walkley and Black, 1934), the soil bulk density (ring method), the aggregate stabilility (drop impact) and the water repellency (Water Drop Penetration Time test) in four study sites in the Sierra de Enguera. Two sites were terraced: one abandoned 40 years before the measurements and the other still active with olive crops. And two control sites non-terraced. We used the paired plot strategy to compare the impact of terracing and abandonment. At each site we collected randomly 50 soil samples at 0-2 cm, 4-6 and 8-10 cm depth. At each sampling point 100 WDPT measurements where carried out, and one sample for the bulk density, and one for the organic matter, and one for the soil aggregate stability were collected. The soil surface samples shown the largest differences. The

CHANGES IN SOIL MACROFAUNA IN AGROECOSYSTEMS DERIVED FROM LOW DECIDUOUS TROPICAL FOREST ON LEPTOSOLS FROM KARSTIC ZONES

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Francisco Bautista

2009-02-01

Full Text Available In Yucatan Mexico the method of slash and burn is used for the establishment of pastures. Pastures are developed for 15 to 20 years, no more because weed control is too expensive. The impact of these practices on soil macrofauna had not been evaluated. Because of its wide distribution, diverse habits and high sensitivity to disturbance, soil macrofauna is considered a valuable indicator of soil health, allowing monitoring of soil sustainability. We studied soil macrofauna communities in low deciduous tropical forest and four livestock agroecosystems with increasing management-derived disturbance including a silvopastoral system, Taiwan grass (Cynodon nlemfuensis and Star grass (Pennisetum purpureum pastures in order to describe community structure across systems, and evaluate disturbance sensitivity of taxonomical groups to detect taxa with potential use as biological indicators of soil health or degradation. Pitfall traps were used at each of the systems to sample soil macrofauna. We estimate their taxonomical abundance, biomass, richness (order, morphospecies, diversity, dominance and response to disturbance on agroecosystems and the forest. We found 133 macrofauna morphospecies of 15 taxa. Groups with more individuals were: Hymenoptera (64.97%, Coleoptera (22.68%, and Orthoptera (3.91%.  Agroecosystem of two-year old Taiwan-grass pasture (TP2 had the highest macrofauna abundances, biomass and richness, low diversity, and a non-homogeneous distribution of individuals among species; in contrast, silvopastoral system (SP, had low abundance and biomass, the lowest specific richness, high diversity and a homogeneous distribution of individuals among species. The discriminant analysis revealed that the agroecosystems and the forest serve to predict the macrofauna communities, since they have particular or typical soil macrofauna. The cases (sampled points with a correct assignation by agroecosystems were: Forest (70%, Sivopastoral system (70

Artificial radioactivity in tide washed pastures in south west Scotland

International Nuclear Information System (INIS)

McKay, W.A.; Bonnett, P.J.P.; Barr, H.M.; Howorth, J.M.

1991-01-01

A study has been carried out to determine the impact of Sellafield discharges on the levels of radioactivity in tide washed pastures in south west Scotland. The likely areas of tidal inundations along the Nith, Urr, Dee, Fleet and Cree (including nearby Bladnoch) rivers were assessed using maps and aerials photographs. These were then visited and gamma radiation measurements taken at regular intervals to enable the external dose from anthropogenic nuclides to be estimated. A further survey followed where soil cores were taken from the areas on each river where the external dose appeared highest and analysed for a range of artificial radionuclides. The levels of 137 Cs, 134 Cs, 238 Pu, 239+240 Pu and 241 Am found, although small, were clearly in excess of the background from other sources. A habit survey was carried out to provide site specific information of tide washed pasture usage, which, with the spatial radionuclide data was used to estimate doses to appropriate critical groups. The maximum annual dose calculated to arise was 60 μSv which is less than 6% of the ICRP principal dose limit of 1 mSv. (author)

Arsenic contamination and potential health risk implications at an abandoned tungsten mine, southern China

International Nuclear Information System (INIS)

Liu Chuanping; Luo Chunling; Gao Yun; Li Fangbai; Lin Lanwen; Wu Changan; Li Xiangdong

2010-01-01

In an extensive environmental study, field samples, including soil, water, rice, vegetable, fish, human hair and urine, were collected at an abandoned tungsten mine in Shantou City, southern China. Results showed that arsenic (As) concentration in agricultural soils ranged from 3.5 to 935 mg kg -1 with the mean value of 129 mg kg -1 . In addition, As concentration reached up to 325 μg L -1 in the groundwater, and the maximum As concentration in local food were 1.09, 2.38 and 0.60 mg kg -1 for brown rice, vegetable and fish samples, respectively, suggesting the local water resource and food have been severely contaminated with As. Health impact monitoring data revealed that As concentrations in hair and urine samples were up to 2.92 mg kg -1 and 164 μg L -1 , respectively, indicating a potential health risk among the local residents. Effective measurements should be implemented to protect the local community from the As contamination in the environment. - It is the first report on arsenic contamination and potential health risk implications at abandoned Lianhuashan tungsten mine.

Microclimate and soil moisture in a silvopastoral system in southeastern Brazil

Directory of Open Access Journals (Sweden)

José Ricardo Macedo Pezzopane

2015-03-01

Full Text Available In this study, the microclimate changes in silvopastoral systems are quantified at different time and spatial scales and compared with single-pasture systems. The study was conducted in a silvopastoral system in São Carlos, Brazil (22°01' South and 47°53' West. The silvopastoral system consisted of grass pastures [Urochloa (sin. Brachiaria decumbens cv. Basilik] lined with strips of native trees spaced at 17 m. Continuous microclimate measurements (air temperature, relative humidity, wind speed, and incident photosynthetically active radiation were carried out from September 2010 to September 2012 at two positions of the silvopastoral system (2.0 and 8.5 m from the rows of trees and at a pasture under full sunlight, located in an adjacent area. The soil moisture was monitored weekly from 24 March 2010 to 1 April 2012 at distances of 0.0, 2.0, 4.75, and 8.5 m from the rows of trees. The rows of native trees reduced wind speeds (46% reduction and changed the photosynthetically active radiation incidence pattern on the pasture (up to 40% reduction of incidence at the point nearest to the trees. The combined action of these factors promoted thermal and air humidity changes on the pasture at the different points measured. With respect to soil moisture, there was greater soil moisture removal at the sampling points near the rows of native trees under the silvopastoral system, mainly due to enhanced exploration by tree roots at greater depths in dry spells or early dry periods, when compared with the midpoints between the rows.

Soil losses in rural watersheds with environmental land use conflicts.

Science.gov (United States)

Pacheco, F A L; Varandas, S G P; Sanches Fernandes, L F; Valle Junior, R F

2014-07-01

Soil losses were calculated in a rural watershed where environmental land use conflicts developed in the course of a progressive invasion of forest and pasture/forest lands by agriculture, especially vineyards. The hydrographic basin is located in the Douro region where the famous Port wine is produced (northern Portugal) and the soil losses were estimated by the Universal Soil Loss Equation (USLE) in combination with a Geographic Information System (GIS). Environmental land use conflicts were set up on the basis of land use and land capability maps, coded as follows: 1-agriculture, 2-pasture, 3-pasture/forest, and 4-forest. The difference between the codes of capability and use defines a conflict class, where a negative or nil value means no conflict and a positive i value means class i conflict. The reliability of soil loss estimates was tested by a check of these values against the frequency of stone wall instabilities in vineyard terraces, with good results. Using the USLE, the average soil loss (A) was estimated in A=12.2 t·ha(-1)·yr(-1) and potential erosion risk areas were found to occupy 28.3% of the basin, defined where soil losses are larger than soil loss tolerances. Soil losses in no conflict regions (11.2 t·ha(-1)·yr(-1)) were significantly different from those in class 2 (6.8 t·ha(-1)·yr(-1)) and class 3 regions (21.3 t·ha(-1)·yr(-1)) that in total occupy 2.62 km(2) (14.3% of the basin). When simulating a scenario of no conflict across the entire basin, whereby land use in class 2 conflict regions is set up to permanent pastures and in class 3 conflict regions to pine forests, it was concluded that A=0.95 t·ha(-1)·yr(-1) (class 2) or A=9.8 t·ha(-1)·yr(-1) (class 3), which correspond to drops of 86% and 54% in soil loss relative to the actual values. Copyright © 2014 Elsevier B.V. All rights reserved.

Land-Use Change, Soil Process and Trace Gas Fluxes in the Brazilian Amazon Basin

Science.gov (United States)

Melillo, Jerry M.; Steudler, Paul A.

1997-01-01

We measured changes in key soil processes and the fluxes of CO2, CH4 and N2O associated with the conversion of tropical rainforest to pasture in Rondonia, a state in the southwest Amazon that has experienced rapid deforestation, primarily for cattle ranching, since the late 1970s. These measurements provide a comprehensive quantitative picture of the nature of surface soil element stocks, C and nutrient dynamics, and trace gas fluxes between soils and the atmosphere during the entire sequence of land-use change from the initial cutting and burning of native forest, through planting and establishment of pasture grass and ending with very old continuously-pastured land. All of our work is done in cooperation with Brazilian scientists at the Centro de Energia Nuclear na Agricultura (CENA) through an extant official bi-lateral agreement between the Marine Biological Laboratory and the University of Sao Paulo, CENA's parent institution.

Influence of Afforestation on the Species Diversity of the Soil Seed Bank and Understory Vegetation in the Hill-Gullied Loess Plateau, China.

Science.gov (United States)

Wang, Ning; Jiao, Juying; Jia, Yanfeng; Wang, Dongli

2017-10-24

The Chinese Loess Plateau region has long been suffering from serious soil erosion. Thus, large-scale afforestation has continued during the past decades in order to control soil erosion. Afforestation can dramatically alter nutrient cycles, affect soil-carbon storage, and change hydrology. However, it is unknown how afforestation influences species diversity of the soil seed bank and understory vegetation compared with spontaneous restoration of abandoned land. Forest land with trees planted 30 years ago, abandoned slope land restored spontaneously for 30 years, and the corresponding slopes with remnant natural vegetation were selected as sampling sites. The species richness both in the soil seed bank and vegetation was significantly higher on the afforested slope compared to the spontaneously restored abandoned land. The species similarity between the afforested slope and the remnant slope land was high both in the soil seed bank and standing vegetation compared to the abandoned land. The soil seed bank density varied from 1778 ± 187 to 3896 ± 221 seeds/m², and more than half of it was constituted by annual and biennial species, with no significant difference among sampling habitats. However, the afforested slope had higher seed density of grass and shrub/subshrubs compared to the abandoned slope. The present study indicates that in the study region, characterized by serious soil erosion, afforestation can better facilitate vegetation succession compared to spontaneously restoration of abandoned slope land.

Distribution of uranium in soil components of agricultural fields after long-term application of phosphate fertilizers

International Nuclear Information System (INIS)

Yamaguchi, N.; Kawasaki, A.; Iiyama, I.

2009-01-01

Long-term application of phosphate fertilizers causes accumulation of U in the surface soil of agricultural fields. We investigated the soil constituents that contribute to the accumulation of U by using chemical extraction methods. Surface soil samples were obtained from upland fields, pastures, and paddy fields cultivated without any phosphate fertilizer (control site), with NPK fertilizer (NPK site), and with both NPK fertilizer and compost (NPK + compost site) for more than 20 years. In addition to the total U (U t ) concentration in soil, the concentrations of pyrophosphate- and acid oxalate-extractable U were determined as a measure of U associated with soil organic matter and poorly crystalline Fe/Al minerals in soil, respectively. The total, pyrophosphate-extractable, and acid oxalate-extractable U concentrations were higher in the soil obtained from the NPK and NPK + compost sites than in that obtained from the control site. The difference in the U concentrations between the NPK or NPK + compost site and the control site corresponded with the increased U concentration observed after the application of the phosphate fertilizer or both the fertilizer and compost. In the upland field and pasture soil, the increase in pyrophosphate-extractable U was 83-94% of that in U t . On the other hand, the increase in acid oxalate-extractable U was 44-58% of that in U t in the upland field and pasture soil, but it was almost equivalent to the increase in U t in the paddy soil with NPK. In conclusion, most of the phosphate fertilizer-derived U was either incorporated into the soil organic matter or poorly crystalline Fe/Al minerals in the surface soil of agricultural fields. Thus, soil organic matter is an important pool of U in upland field and pasture soil, whereas poorly crystalline Fe/Al minerals are important pools of U in paddy soil experiencing alternating changes in redox conditions

Restoring abandoned agricultural lands in cold desert shrublands: Tradeoffs between water availability and invasive species

Science.gov (United States)

Jeanne C. Chambers; Eric P. Eldredge; Keirith A. Snyder; David I. Board; Tara Forbis de Queiroz; Vada Hubbard

2014-01-01

Restoration of abandoned agricultural lands to create resilient ecosystems in arid and semi-arid ecosystems typically requires seeding or transplanting native species, improving plant-soil-water relations, and controlling invasive species. We asked if improving water relations via irrigation or surface mulch would result in negative tradeoffs between native species...

Aboveground and belowground legacies of native Sami land use on boreal forest in northern Sweden 100 years after abandonment.

Science.gov (United States)

Freschet, Grégoire T; Ostlund, Lars; Kichenin, Emilie; Wardle, David A

2014-04-01

Human activities that involve land-use change often cause major transformations to community and ecosystem properties both aboveground and belowground, and when land use is abandoned, these modifications can persist for extended periods. However, the mechanisms responsible for rapid recovery vs. long-term maintenance of ecosystem changes following abandonment remain poorly understood. Here, we examined the long-term ecological effects of two remote former settlements, regularly visited for -300 years by reindeer-herding Sami and abandoned -100 years ago, within an old-growth boreal forest that is considered one of the most pristine regions in northern Scandinavia. These human legacies were assessed through measurements of abiotic and biotic soil properties and vegetation characteristics at the settlement sites and at varying distances from them. Low-intensity land use by Sami is characterized by the transfer of organic matter towards the settlements by humans and reindeer herds, compaction of soil through trampling, disappearance of understory vegetation, and selective cutting of pine trees for fuel and construction. As a consequence, we found a shift towards early successional plant species and a threefold increase in soil microbial activity and nutrient availability close to the settlements relative to away from them. These changes in soil fertility and vegetation contributed to 83% greater total vegetation productivity, 35% greater plant biomass, and 23% and 16% greater concentrations of foliar N and P nearer the settlements, leading to a greater quantity and quality of litter inputs. Because decomposer activity was also 40% greater towards the settlements, soil organic matter cycling and nutrient availability were further increased, leading to likely positive feedbacks between the aboveground and belowground components resulting from historic land use. Although not all of the activities typical of Sami have left visible residual traces on the ecosystem after

Transplantation of subalpine wood-pasture turfs along a natural climatic gradient reveals lower resistance of unwooded pastures to climate change compared to wooded ones.

Science.gov (United States)

Gavazov, Konstantin; Spiegelberger, Thomas; Buttler, Alexandre

2014-04-01

Climate change could impact strongly on cold-adapted mountain ecosystems, but little is known about its interaction with traditional land-use practices. We used an altitudinal gradient to simulate a year-round warmer and drier climate for semi-natural subalpine grasslands across a landscape of contrasting land-use management. Turf mesocosms from three pasture-woodland land-use types-unwooded pasture, sparsely wooded pasture, and densely wooded pasture-spanning a gradient from high to low management intensity were transplanted downslope to test their resistance to two intensities of climate change. We found strong overall effects of intensive (+4 K) experimental climate change (i.e., warming and reduced precipitation) on plant community structure and function, while moderate (+2 K) climate change did not substantially affect the studied land-use types, thus indicating an ecosystem response threshold to moderate climate perturbation. The individual land-use types were affected differently under the +4 K scenario, with a 60% decrease in aboveground biomass (AGB) in unwooded pasture turfs, a 40% decrease in sparsely wooded pasture turfs, and none in densely wooded ones. Similarly, unwooded pasture turfs experienced a 30% loss of species, advanced (by 30 days) phenological development, and a mid-season senescence due to drought stress, while no such effects were recorded for the other land-use types. The observed contrasting effects of climate change across the pasture-woodland landscape have important implications for future decades. The reduced impact of climate change on wooded pastures as compared to unwooded ones should promote the sustainable land use of wooded pastures by maintaining low management intensity and a sparse forest canopy, which buffer the immediate impacts of climate change on herbaceous vegetation.

Soil physical indicators of management systems in traditional agricultural areas under manure application

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Luiz Paulo Rauber

Full Text Available ABSTRACT Studies of the successive application of manure as fertilizer and its combined effect with long-term soil management systems are important to the identification of the interdependence of physical attributes. The aim of this study was to evaluate changes in the physical properties of a Rhodic Kandiudox under management systems employing successive applications of pig slurry and poultry litter, and select physical indicators that distinguish these systems using canonical discriminant analysis (CDA. The systems consisting of treatments including land use, management and the application time of organic fertilizers are described as follows: silage maize under no-tillage (NT-M7 years; silage maize under conventional tillage (CT-M20 years; annual pasture with chisel plowing (CP-P3 years; annual pasture with chisel plowing (CP-P15 years; perennial pasture without tillage (NT-PP20 years; and no-tillage yerba mate (NT-YM20 years and were compared with native forest (NF and native pasture (NP. Soil samples were collected from the layers at the following depths: 0.0-0.05, 0.05-0.10, and 0.10-0.20 m, and were analyzed for bulk density, porosity, aggregation, flocculation, penetration resistance, water availability and total clay content. Canonical discriminant analysis was an important tool in the study of physical indicators of soil quality. Organic fertilization, along with soil management, influences soil structure and its porosity. Total porosity was the most important physical property in the distinction of areas with management systems and application times of manure for the 0.0-0.05 and 0.10-0.20 m layers. Soil aeration and micropores differentiated areas in the 0.05-0.10 m layer. Animal trampling and machinery traffic were the main factors inducing compaction of this clayey soil.

PCBs, HCHs and DDTs in cow's milk and soil of pasture from the Irkutsk region, Russia

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Mamontova, E.A.; Tarasova, E.N.; Mamontov, A.A.; Kuzmin, M.I. [A.P. Vinogradov Inst. of Geochemistry, SB of RAS, Irkutsk (Russian Federation); Chuvashev, I.A. [Inst. of Chemistry, SB of RAS, Irkutsk (Russian Federation); McLachlan, M.S. [Inst. of Applied Environmental Research, Stockholm Univ. (Sweden)

2004-09-15

The main pathway of human exposure to organochlorine compounds is food, especially dairy products. Our previous investigations of PCDD/Fs and PCBs in food produced in the Irkutsk region showed that the average daily intake amounts to 88 pg PCDD/F TEQ per day and 95 pg PCB TEQ per day1. Thus the contribution of PCBs and PCDD/Fs to the total daily intake is 51.7 and 48.3 % respectively. Cow's milk contributes up to 24 % of the daily intake of PCBs, and is exceeded only by fish (64 %). It was shown also that PCDD/F and PCB levels in milk and the daily intake of these compounds depends on the distance of the farms from the largest PCB source in the Irkutsk Region located in the Usol'e-Sibirskoe area. In the previous study milk samples were taken from dairies which collect milk from a lot of farms. The aim of the paper is to investigate the organochlorine contamination in milk from single farms and to see if this is related to the contaminant levels in soil from the farms' pastures.

Runoff and initial erosion assessment in fruit tree crops and improved forage pastures in the slopes of the Irazu Volcano (Costa Rica)

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Marchamalo, Miguel; González-Rodrigo, Beatriz

2017-04-01

Costa Rica is located in the Central American tropical isthmus. It presents high precipitations (ranging from 1400-8500 mm) and protection levels (27% of national territory). However, intensive land use and increasing population in headwaters are major threats for water resource management in this country. Birrís Basin is a 4800 hectares sub-watershed of the River Reventazón Basin, the major hydroelectric source in Costa Rica. Birrís Basin was selected for its high estimated erosion rates and its potential for demonstrative projects (ICE, 1999). Some pilot projects have been developed in this watershed starting from 1999, when major Costa Rican energy producer, Instituto Costarricense de Electricidad, began with a long term watershed management program for the Reventazón Basin. This study aims at measuring runoff and initial splash and sheet erosion to assess the hydrological response of two pilot land use projects. Erosion and runoff plots were established and monitored in a one year period for two pilot projects (fruit trees and forage pastures) and their respective traditional land uses (vegetable crops and extensive pastures). Improved forage pastures showed reduced runoff by 73% and split erosion by 55% compared to prior extensive pastures. Conversion of vegetable crop lands into fruit tree plantations (apricot and avocado) made possible a 97% reduction of soil initial erosion. Land use pilot projects have succeeded in runoff and soil erosion reduction. Now it is time for a wider technology transfer program to expand improved land uses within Birrís Basin.

Variation in important pasture grasses: I. Morphological and ...

African Journals Online (AJOL)

Variation in important pasture grasses: I. Morphological and geographical variation. ... Seven species are important pasture grasses throughout the western Transvaal, Orange Free State, northern Cape and Natal. ... Language: English.

Toxicity assessment using Lactuca sativa L. bioassay of the metal(loid)s As, Cu, Mn, Pb and Zn in soluble-in-water saturated soil extracts from an abandoned mining site

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Bagur-Gonzalez, Maria Gracia [Univ. of Granada, Faculty of Sciences, Dept. of Analytical Chemistry, Granada (Spain); Univ. of Granada-CSIC, Inst. Andaluz de Ciencias de la Tierra, Faculty of Sciences, Granada (Spain); Estepa-Molina, Carmen [Univ. of Granada, Faculty of Sciences, Dept. of Mineralogy and Petrology, Granada (Spain); Martin-Peinado, Francisco [Univ. of Granada, Faculty of Sciences, Dept. of Soil Science, Granada (Spain); Morales-Ruano, Salvador [Univ. of Granada-CSIC, Inst. Andaluz de Ciencias de la Tierra, Faculty of Sciences, Granada (Spain); Univ. of Granada, Faculty of Sciences, Dept. of Mineralogy and Petrology, Granada (Spain)

2011-02-15

We used the different soluble-in-water concentrations of As, Cu, Mn, Pb and Zn from contaminated soils in an abandoned mining area (anthropogenic origin) to assess the phytotoxicity of the abandoned site using the results obtained with a Lactuca sativa L. bioassay. Material and methods The study has been carried out on potentially polluted samples from the Rodalquilar mining district (southern Spain). The area was sampled according to the different metallurgical treatments for gold extraction used in each one: dynamic cyanidation and heap leaching. The saturation extracts were obtained by filtering each saturated paste with a vacuum-extraction pump, in which measurements of metal(loid) concentrations, pH and electrical conductivity were made. The variables evaluated in the bioassay, defined as toxicity indices ranging from -1 (maximum phytotoxicity) to >0 (hormesis), were seed germination (SG) and root elongation (RE) of lettuce seeds. Results and discussion In areas with a low degree of contamination, the most sensitive toxicity index is RE, whereas in highly contaminated areas, both RE and SG are good estimators of soil toxicity. According to these results, samples from the western area showed moderate to low toxicity, which was closely related to water-soluble As concentrations. Samples from the eastern area had a high degree of toxicity in 40% of the soils. Conclusions The comparison of the two indices (SG and RE) defined using the L. sativa L. bioassay indicates that, for areas with a low degree of contamination, the most sensitive toxicity index is RE, whereas in highly contaminated areas, both RE and SG are good estimators of soil phytotoxicity. Unsupervised pattern recognition methods such as HCA and PCA enabled us to conclude that the low/moderate phytotoxicity of the soils is related to the extraction process used for the recovery of gold (mainly dynamic cyanidation in tanks located in the eastern area) and to the As and Pb contents. (orig.)

Study of heavy metals transport by runoff and sediments from an abandoned mine: Alagoa, Portugal

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Gerardo, R.; de Lima, J. L. M. P.; de Lima, M. I. P.

2009-04-01

Over time, several studies have been designed to understand heavy metals fate and its impact on the environment and on human health. However, only a few studies have focused on the transport of heavy metals in mining areas through the various hydrological processes such as runoff, infiltration, and subsurface flow. In particular, heavy rainfall events have a great impact on the dispersion of metals existing in the soil. This problem is often more serious in abandoned and inactive mining sites causing environmental problems. In Portugal, there are 175 identified abandoned mines that continuously threaten the environment through acid drainage waters that pollute the soil as well as surface and groundwater. An example is the abandoned mine of Alagoa, located near the village of Penacova (Centre of Portugal); in this site mining activities ceased about 30 years ago. The area is characterized by very steep slopes that are confining with a small stream; the mining excavation by-products were deposited on these slopes. We have selected this mine as a case study, aiming at understanding the transport mechanisms and dispersion of heavy metals and at contributing to the definition of the most appropriate mitigation measures for this area that is contaminated by heavy metals from the mine tailings. So far a total of 30 soil samples from 3 contaminated zones were collected and analysed for pH, texture and heavy metal content, using atomic absorption spectroscopy. Results indicate that the contents of Zn and Pb in the soil samples are in the range from 95-460 mg/kg and 67-239 mg/kg, respectively, which exceed the critical limit-values defined by the Portuguese legislation. These metals are dispersed downslope and downstream from the mine tailings by storm water. The next step of this work is to investigate the transport of heavy metals by runoff, by mobilization of sediments and by subsurface flow. Three spatial scales tests will be conducted: on the mine tailings, on the slope

Successional and seasonal variations in soil and litter microbial community structure and function during tropical postagricultural forest regeneration: a multiyear study.

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Smith, A Peyton; Marín-Spiotta, Erika; Balser, Teri

2015-09-01

Soil microorganisms regulate fundamental biochemical processes in plant litter decomposition and soil organic matter (SOM) transformations. Understanding how microbial communities respond to changes in vegetation is critical for improving predictions of how land-cover change affects belowground carbon storage and nutrient availability. We measured intra- and interannual variability in soil and forest litter microbial community composition and activity via phospholipid fatty acid analysis (PLFA) and extracellular enzyme activity across a well-replicated, long-term chronosequence of secondary forests growing on abandoned pastures in the wet subtropical forest life zone of Puerto Rico. Microbial community PLFA structure differed between young secondary forests and older secondary and primary forests, following successional shifts in tree species composition. These successional patterns held across seasons, but the microbial groups driving these patterns differed over time. Microbial community composition from the forest litter differed greatly from those in the soil, but did not show the same successional trends. Extracellular enzyme activity did not differ with forest succession, but varied by season with greater rates of potential activity in the dry seasons. We found few robust significant relationships among microbial community parameters and soil pH, moisture, carbon, and nitrogen concentrations. Observed inter- and intrannual variability in microbial community structure and activity reveal the importance of a multiple, temporal sampling strategy when investigating microbial community dynamics with land-use change. Successional control over microbial composition with forest recovery suggests strong links between above and belowground communities. © 2015 John Wiley & Sons Ltd.

Soil Quality Indexing Strategies for Evaluating Sugarcane Expansion in Brazil.