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1.
Sci Adv ; 7(6)2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33547077

RESUMEN

Despite numerous journalistic accounts, systematic quantitative evidence on economic conditions during the ongoing COVID-19 pandemic remains scarce for most low- and middle-income countries, partly due to limitations of official economic statistics in environments with large informal sectors and subsistence agriculture. We assemble evidence from over 30,000 respondents in 16 original household surveys from nine countries in Africa (Burkina Faso, Ghana, Kenya, Rwanda, Sierra Leone), Asia (Bangladesh, Nepal, Philippines), and Latin America (Colombia). We document declines in employment and income in all settings beginning March 2020. The share of households experiencing an income drop ranges from 8 to 87% (median, 68%). Household coping strategies and government assistance were insufficient to sustain precrisis living standards, resulting in widespread food insecurity and dire economic conditions even 3 months into the crisis. We discuss promising policy responses and speculate about the risk of persistent adverse effects, especially among children and other vulnerable groups.


Asunto(s)
/economía , Países en Desarrollo/economía , Empleo/tendencias , Renta/tendencias , Pandemias/economía , Adulto , África/epidemiología , Agricultura/economía , Asia/epidemiología , Niño , Colombia/epidemiología , Violencia Doméstica , Recesión Económica , Composición Familiar , Femenino , Programas de Gobierno/economía , Humanos , Masculino , Estaciones del Año , Encuestas y Cuestionarios
2.
Environ Monit Assess ; 193(1): 26, 2021 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-33389231

RESUMEN

Soil and water are vital natural resources. However, due to their indiscriminate use, these resources are being seriously threatened. Therefore, it is essential to manage them in a sustainable way and leave them for future generations. Population and agricultural areas have expanded, deforesting native landscapes for cultivation and pastures. As a result, soil loss from agricultural areas is increasing the amount of sediment transport in water courses. The objective of this study was to quantify soil loss and sediment yield from the Corrente dos Matões sub-basin (CMSB). These measurements are essential to quantify the environmental impact of advancing agricultural frontiers. The Universal Soil Loss Equation (USLE) was applied due to its wide use, compatibility with GIS, and data availability. The suspended sediment transport was calculated by collecting samples with DH-48 sampler. From the application of USLE, the average soil erosion contributed very little to sediment delivery in the watercourse, with a magnitude of only 0.37 t ha-1 year-1. The highest soil loss was associated with greater slope and was observed in areas with agriculture or under the absence of vegetation cover. The low transport of suspended sediments in CMSB is due to the existence of preserved sites. About 99% of the sub-basin had a low degree of erosion. The high degree of soil loss was attributed to the cliffs and the development of agricultural activities leaving the soil uncovered. This work will help identify the most susceptible areas to water erosion for optimizing the allocation of financial resources for the preservation of this natural resource.


Asunto(s)
Conservación de los Recursos Naturales , Suelo , Agricultura , Brasil , Monitoreo del Ambiente , Sedimentos Geológicos
3.
Environ Monit Assess ; 193(1): 40, 2021 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-33409758

RESUMEN

Salinity is one of the main causes of soil degradation, which reduces the capacity for biomass production. Naturally, saline soil is related to climatic, hydrogeological, and edaphic processes. Evaporite rocks are a potential source of gypsum and anhydrite in climates where annual rainfall does not exceed 400 mm. Like any salt, anhydrite contributes to salinity processes that reduce osmotic potential in plants, giving rise to water stress that reduces turgor in plants. In the Zona Media of San Luis Potosí, soil salinity is not homogeneous but rather varies spatially and is associated with soil genesis, agricultural irrigation water quality, and climate. Water sodicity (% Na), toxicity (pH, B3+ y Cl-), and salinity hazards were evaluated by applying agricultural water quality indices. Low sodicity hazard was found at all sample points; chloride and boron did not pose toxicity hazards, but high sulfate concentrations can lead to toxicity and calcium and magnesium deficiency. The salinity hazard was high, identified using OP, EC, TDS, ES, and PS indices. This condition is related to the region's evaporite soils and semi-arid climate.


Asunto(s)
Monitoreo del Ambiente , Calidad del Agua , Riego Agrícola , Agricultura , México , Salinidad , Suelo
4.
Environ Monit Assess ; 193(2): 52, 2021 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-33423184

RESUMEN

Land use and land cover changes over 1973-2017 period in peripheral Delhi were mapped based on digital classification of satellite data and their driving forces ascertained. Urban area expanded and agricultural area diminished at annual rates of 38.6% and 2.1%, respectively, during the 1973-2017 period. Urban expansion occurred more in scrub and sparse vegetation areas than in cultivated lands or ponds. Loss of cultivated land happened mostly due to abandonment of cropping and tree planting in farmhouses developed by the urban elites. Improvement in the state of forests in terms of their expansion as well as densification offsets their loss due to urbanisation, encroachment and logging. The increment in the green cover was due to strict enforcement of compensatory afforestation/forest conservation law, growing demand of ecotourism, emergence of tree-clad farmhouses and increased environmental awareness and surveillance. This research will help in comprehending policies favouring sustainable urban development.


Asunto(s)
Conservación de los Recursos Naturales , Monitoreo del Ambiente , Agricultura , Bosques , India , Urbanización
5.
Ecotoxicol Environ Saf ; 208: 111586, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396109

RESUMEN

This research studies a typical landscape of an agricultural area separated from the road by a ditch with trees. Soils were sampled at 1, 2, 7, 25, and 50 m from the road. The concentrations of polycyclic aromatic hydrocarbons (PAH), total and phyto-available heavy metals (HM), total petroleum hydrocarbons (TPH), and de-icing salts (DS, Cl-) were determined using standard techniques. A set of higher plants (Lepidium sativum L., Sinapis alba L., Raphanus sativus L., Hordeum vulgare L., Avena sativa L.) was applied for toxicity evaluation of soils. The objective of this research is to find correlations between pollution of roadside soils and their phytotoxicity. HM, TPH and DS contamination of soils was observed in the 0-25 m zone, and PAH contamination was found up to the 50 m. Soil toxicity was declining from the road to the 50 m. Phytotoxicity related to majority of plants performed correlations with the same set of contaminants: TPH, 2-rings PAH, phyto-available Zn, Cu, Pb, and total Zn. No any correlations demonstrated Avena sativa L., being not applicable for ecotoxicological assessment of roadside soils. Despite the phytotoxicity was generally in line with contaminants loads, surprisingly low values were indicated in the ditch characterized by the strong pollution. We attribute this to the contrasting properties of soils there - the higher content of organics and clay. Sensitivity of plants to roadside pollution decreased in the row Lepidium sativum L. > Hordeum vulgare L. > Sinapis alba L. > Raphanus sativus L. The most reliable test-parameters for toxicity estimation were the root and the shoot length, germination rate was not informative indicating low phytotoxicity values. The research showed the importance of the right choice of test-cultures and test-parameters to judge phytotoxicity correctly. Linking the contaminants loads and phytotoxicity effects is valuable for comprehensive ecotoxicological assessment.


Asunto(s)
Plantas/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Agricultura , Ecotoxicología , Monitoreo del Ambiente/métodos , Contaminación Ambiental , Hordeum , Hidrocarburos , Lepidium sativum , Metales Pesados/análisis , Petróleo/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Sinapis , Suelo/química , Microbiología del Suelo , Contaminantes del Suelo/análisis
6.
Ecotoxicol Environ Saf ; 208: 111622, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396142

RESUMEN

The continuous growth in global population since the beginning of the 20th century result in the necessity of food and energy provision favoring the intensive use of agricultural products such as pesticides. Although pesticides are important to prevent losses in the conventional chemically based agriculture, they frequently present side effects, which goes against agricultural production. The use of pesticides cause direct and indirect effects to soil organisms unbalancing essential soil processes (e.g. primary production, organic matter decomposition, nutrient cycling). Under tropical conditions, very little is known regarding the effects of pesticides to terrestrial organisms. Hence, the aim of the present study was to assess the ecotoxicological effects of the herbicide DMA® 806 BR (active ingredient: 2,4-D) and the insecticide Regent® 800 WG (active ingredient: fipronil), on terrestrial plant species (the dicot Raphanus sativus var. acanthioformis and the monocot Allium cepa), and soil invertebrates (the collembolan Folsomia candida and the enchytraeid Enchytraeus crypticus), using natural (NS) and artificial soils (TAS). For both pesticides, negative effects on non-target species were observed at concentrations lower than the doses recommended to prevent pests in sugarcane fields. For both soils, the dicot species was the most affected by the herbicide (R. sativus > A. cepa > F. candida > E. crypticus) and the collembolan species was the most affected by the insecticide (F. candida > E. crypticus = R. sativus = A. cepa). Although the order of the organisms' sensitivity for both pesticides was the same in both soils, results showed that the extent of the effects was soil dependent. Considering the ecologically relevant concentrations tested, and their severe effects to non-target organisms, it may be concluded that the use of fipronil and 2,4-D under recommended conditions may pose a risk to the terrestrial environment.


Asunto(s)
Ácido 2,4-Diclorofenoxiacético/toxicidad , Plaguicidas/toxicidad , Pirazoles/toxicidad , Saccharum/fisiología , Contaminantes del Suelo/análisis , Agricultura , Animales , Artrópodos/efectos de los fármacos , Artrópodos/fisiología , Ecotoxicología , Insecticidas/toxicidad , Oligoquetos/efectos de los fármacos , Oligoquetos/fisiología , Suelo/química
7.
J Environ Manage ; 278(Pt 2): 111550, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33129030

RESUMEN

Agriculture is responsive to weather and climate variability. In addition to the climatic stressors, coastal agriculture is influenced by non-climatic factors. Therefore, understanding farmers' perception of the causes of their changes in farm management plays a key role in motivating them to adopt agricultural adaptations. The aim of this study was to investigate the changes in coastal farm management in Bangladesh over the last decade compared to the previous one. We explored whether the causes of those changes were climatic or non-climatic as perceived by the farmers and the factors that shaped their perceptions. We interviewed 381 farmers sampled from ten subdistricts along the coast of Bangladesh. Descriptive statistics showed that the farmers had changed on average 10 to 11 farm management practices. Though the average value was 67%, a higher number of farmers in the western coastal zone mentioned that climate change had impacts on their farm management. Adoption of rice crop-related adaptations was greater than livestock, fisheries or general agricultural practices. According to the discriminant function analysis, discriminative variables were perception of climatic impacts on farm productivity, climate change awareness, involvement with non-farm jobs, age, education, organizational affiliation, number of changed farm practices, and meteorologically consistent perception of rainfall and temperature. Lessons learned from this research are that the farmers should better understand the link between climate change and farm management practices while motivating them to implement adaptation strategies. This could be achieved by improving farmers' climate change awareness, perceptions of changes in climatic parameters and involvement with farm-related associations.


Asunto(s)
Agricultura , Agricultores , Animales , Bangladesh , Cambio Climático , Granjas , Humanos , Percepción
8.
J Environ Manage ; 278(Pt 2): 111559, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33137686

RESUMEN

Given rapid environmental change, the development of new, data-driven, interdisciplinary approaches is essential for improving assessment and management of river systems, especially with respect to flooding. In the world's extensive drylands, difficulties in obtaining field observations of major hydrological events mean that remote sensing techniques are commonly used to map river floods and assess flood impacts. Such techniques, however, are dependent on available cloud-free imagery during or immediately after peak discharge, and single images may omit important flood-related hydrogeomorphological events. Here, we combine multiple Landsat images from Google Earth Engine (GEE) with precipitation datasets and high-resolution (<0.65 m) satellite imagery to visualise flooding and assess the associated channel-floodplain dynamics along a 25 km reach of the unvegetated, ephemeral Río Colorado, Bolivia. After cloud and shadow removal, Landsat surface reflectance data were used to calculate the Modified Normalized Difference Water Index (MNDWI) and map flood extents and patterns. From 2004 through 2016, annual flooding area along the narrow (<30 m), shallow (<1.7 m), fine-grained (dominantly silt/clay) channels was positively correlated (R2 = 0.83) with 2-day maximum precipitation totals. Rapid meander bend migration, bank erosion, and frequent overbank flooding was associated with formation of crevasse channels, splays, and headward-eroding channels, and with avulsion (shifting of flow from one channel to another). These processes demonstrate ongoing, widespread channel-floodplain dynamics despite low stream powers and cohesive sediments. Application of our study approaches to other dryland rivers will help generate comparative data on the controls, rates, patterns and timescales of channel-floodplain dynamics under scenarios of climate change and direct human impacts, with potential implications for improved river management.


Asunto(s)
Inundaciones , Ríos , Agricultura , Colorado , Humanos , Hidrología
9.
J Environ Manage ; 278(Pt 2): 111535, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33142149

RESUMEN

To better inform land management decisions, we explored relationships between land use data and stream nitrate-nitrite (NO3NO2) concentration data in the Yahara River Watershed (YRW) in south-central Wisconsin, USA. Three metrics were used to evaluate the extent of different land uses in the watershed: (1) the area percentage of each land use in both the watershed and in a range of riparian zone widths, (2) the area factor, which refers to the ratio of the area of woodland, recreational, open and vacant subdivided land, or wetlands in the riparian zone (6.1-213.4 m widths) to agricultural areas in the rest of watershed, which indicates the buffering capacity of the riparian zone, and (3) the inverse-distance-weighted (IDW) area percentage with proximity to sub-watershed outlet and to stream, which characterizes spatial arrangement in the watershed by assigning a higher weight to patches closer to the outlet or stream and a lower weight to those farther away. We found significant, positive correlations between the extent of agricultural areas and stream NO3NO2 concentrations. NO3NO2 concentrations were highly correlated to area factor metrics for all riparian zone widths such that as area factor decreased, NO3NO2 concentrations increased. There was also a marked increase in NO3NO2 concentrations at a threshold of approximately 60% agricultural area with IDW proximity to stream. Wetland area percentage in the entire watershed and IDW wetland area percentage with proximity to stream were negatively correlated to stream NO3NO2 concentrations. Compared to the simple area percentage metric, area factor and IDW wetland area percentage with proximity to stream were better indicators of stream NO3NO2 concentrations. Results from this study indicate that, in addition to land use area percentage, spatial distributions of land uses should be considered when managing watersheds. This study also demonstrates the value of citizen-based sampling data and reveals opportunities to improve the utility of such data.


Asunto(s)
Nitratos , Ríos , Agricultura , Nitratos/análisis , Nitritos , Wisconsin
10.
Chemosphere ; 262: 128059, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33182110

RESUMEN

Bioaccumulation of mercury in freshwater fish is a complex process driven by environmental and biological factors. In this study, we assessed mercury in fish from four tributaries to the Red Deer River, Alberta, Canada, which are characterized by high surface water mercury concentrations. We used carbon (δ13C) and nitrogen (δ15N) stable isotopes to examine relationships between fish total mercury (THg) concentrations, food web dynamics and patterns in unfiltered THg and methylmercury (MeHg) concentrations. We found that THg concentrations exceeded the tissue residue quality guideline for the protection of wildlife consumers in 99.7% of fish sampled. However, while the surface water THg concentration was highest in Michichi Creek and the MeHg concentration was consistent across streams, patterns of fish THg concentrations varied depending on species. Furthermore, body size and trophic level were only correlated with THg concentrations in white sucker (Catostomus commersoni) and Prussian carp (Carrasius gibelio). The results of this study suggest that mercury poses a risk to the health of piscivorous wildlife in the Red Deer River watershed. Despite high THg concentrations in these streams, mercury bioaccumulation is not driven by environmental inorganic mercury concentrations. Additionally, commonly cited factors associated with mercury concentrations in fish, such as body size and trophic level, may not strongly influence bioaccumulation in these stream ecosystems.


Asunto(s)
Bioacumulación , Monitoreo del Ambiente/métodos , Peces/metabolismo , Mercurio/análisis , Compuestos de Metilmercurio/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , Agricultura , Alberta , Animales , Cadena Alimentaria , Mercurio/metabolismo , Compuestos de Metilmercurio/metabolismo , Contaminantes Químicos del Agua/metabolismo
11.
Chemosphere ; 262: 128387, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33182114

RESUMEN

Soil degradation caused by watermelon continuous cropping obstacle is a serious problem in China. Compost, as a soil conditioner, has great potential in improving soil degradation. In order to explore how compost affects the soil quality under continuous cropping obstacle, associations among soil chemical characteristics, microbial community structures and agronomic variables were analyzed and compared. Results showed that soil pH, available potassium, alkali-hydrolyzable nitrogen and organic matter changed significantly after using maize straw compost and sludge compost, which indicated the feasibility of composts as soil remediations. This is also reflected on the significant changes of soil microbial community. Mizugakiibacter, as the main reason of watermelon continuous cropping obstacle, decreased significantly after using compost products. It also showed a negative connection with most chemical characteristics. Rhodanobacter and Galbibacter increased significantly after using compost products, which were positively related to most chemical characteristics. The increase of them was helpful to reduce Mizugakiibacter. Beneficial bacteria were positively related to beneficial fungi (Chaetomium and Chrysosporium). The increase of them and the decrease of Verticillium also helped to improve microbial community structure. The results indicated that compost as a useful and inexpensive technique could alleviate soil degradation caused by watermelon continuous cropping obstacle.


Asunto(s)
Agricultura , Citrullus , Microbiota , Microbiología del Suelo , Álcalis , Bacterias , China , Compostaje , Hongos , Estudios Longitudinales , Nitrógeno/análisis , Aguas del Alcantarillado/química , Suelo/química , Zea mays
12.
GM Crops Food ; 12(1): 25-35, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-32687427

RESUMEN

The importance of food security and nourishment is recognized in Southern African region and in many communities, globally. However, the attainment of food security in Southern African countries is affected by many factors, including adverse environmental conditions, pests and diseases. Scientists have been insistently looking for innovative strategies to optimize crop production and combat challenges militating against attainment of food security. In agriculture, strategies of increasing crop production include but not limited to improved crop varieties, farming practices, extension services, irrigation services, mechanization, information technology, use of fertilizers and agrochemicals. Equally important is genetic modification (GM) technology, which brings new prospects in addressing food security problems. Nonetheless, since the introduction of genetically modified crops (GMOs) three decades ago, it has been a topic of public discourse across the globe, conspicuously so in Southern African region. This is regardless of the evidence that planting GMOs positively influenced farmer's incomes, economic access to food and increased tolerance of crops to various biotic and abiotic stresses. This paper looks at the issues surrounding GMOs adoption in Southern Africa and lack thereof, the discourse, and its potential in contributing to the attainment of food security for the present as well as future generations.


Asunto(s)
Productos Agrícolas/genética , Alimentos Modificados Genéticamente , África Austral , Agricultura , Abastecimiento de Alimentos , Plantas Modificadas Genéticamente
13.
J Environ Manage ; 280: 111710, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33308931

RESUMEN

Reducing harmful algal blooms in Lake Erie, situated between the United States and Canada, requires implementing best management practices to decrease nutrient loading from upstream sources. Bi-national water quality targets have been set for total and dissolved phosphorus loads, with the ultimate goal of reaching these targets in 9-out-of-10 years. Row crop agriculture dominates the land use in the Western Lake Erie Basin thus requiring efforts to mitigate nutrient loads from agricultural systems. To determine the types and extent of agricultural management practices needed to reach the water quality goals, we used five independently developed Soil and Water Assessment Tool models to evaluate the effects of 18 management scenarios over a 10-year period on nutrient export. Guidance from a stakeholder group was provided throughout the project, and resulted in improved data, development of realistic scenarios, and expanded outreach. Subsurface placement of phosphorus fertilizers, cover crops, riparian buffers, and wetlands were among the most effective management options. But, only in one realistic scenario did a majority (3/5) of the models predict that the total phosphorus loading target would be met in 9-out-of-10 years. Further, the dissolved phosphorus loading target was predicted to meet the 9-out-of-10-year goal by only one model and only in three scenarios. In all scenarios evaluated, the 9-out-of-10-year goal was not met based on the average of model predictions. Ensemble modeling revealed general agreement about the effects of several practices although some scenarios resulted in a wide range of uncertainty. Overall, our results demonstrate that there are multiple pathways to approach the established water quality goals, but greater adoption rates of practices than those tested here will likely be needed to attain the management targets.


Asunto(s)
Monitoreo del Ambiente , Lagos , Agricultura , Canadá , Eutrofización , Fósforo/análisis , Calidad del Agua
14.
J Environ Manage ; 279: 111632, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33309111

RESUMEN

After press separation of the liquid and solid digestate from an agricultural biogas plant, pyrolysis of solid anaerobic digestate was carried out (i.e., at 500 °C, 1h, and 10 °C/min) to produce biochar (37.6 wt%), bio-oil (33.7 wt%) and syngas (29.3 wt%). The organic phase of bio-oil and syngas exhibited high and low heating values of 28.4 MJ/kg and 12.9 MJ/Nm3, respectively. Then, the synergy of coupling biochar with liquid digestate for agronomic purposes was investigated by leaching experiment and growth plant tests on wheat. Leaching experiments using combination of liquid digestate (170 kg N/ha) and biochar demonstrated that biochar addition increases the cumulative leaching of all nutrients, except nitrate, that have a significant decrease of 82% and 91%, respectively at 50 and 100 t/ha, compared to soil treated only with liquid digestate. The co-application of biochar with liquid digestate on growth wheat plant tests demonstrated that biochar application at 50 t/ha did not exhibit a negative impact on the relative seed germination and improved aerial dry biomass production (up to 27.5%) compared to soil with only liquid digestate addition.


Asunto(s)
Pirólisis , Suelo , Agricultura , Anaerobiosis , Biomasa , Carbón Orgánico
15.
J Environ Manage ; 280: 111798, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33309393

RESUMEN

Agroecosystems are the largest human-natural coupled production system covering ~40% of the planet earth and provide essential ecosystem services for a good quality of life and human wellbeing. The sustainable management of agroecosystems are therefore essential for meeting the food, fuel, fiber, and fodder demands of the rapidly growing human population. Agroecosystems also play a key role in trace gases emission, and also affect the quality and usage of life-supporting resources such as air, water, soil etc. Though the sustainable management of agroecosystems are imperative for achieving UN-Sustainable Development Goals, they are frequently under degradation due to multiple drivers of changes such as unsustainable land-use practices, biodiversity loss, pollution and climate change, etc. Therefore, cordial efforts at national, regional and global levels are essential for managing agroecosystems to meet out the global goals and also the targets of the United Nations- Decade o-n Ecosystem Restoration (2021-2030). Here we opined various strategies for restoring degraded agroecosystems for sustainable development including the adoption of emerging paradigms such as micro-agriculture, urban agriculture, and landless agriculture for averting the mounting pressure on agroecosystems for the benefit of both people and the planet.


Asunto(s)
Ecosistema , Calidad de Vida , Agricultura , Conservación de los Recursos Naturales , Humanos , Suelo , Naciones Unidas
16.
Environ Pollut ; 269: 116143, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33310496

RESUMEN

The combined application of organic and synthetic nitrogen (N) fertilizers is being widely recommended in China's vegetable systems to reduce reliance on synthetic N fertilizer. However, the effect of substituting synthetic fertilizer with organic fertilizer on vegetable productivity (yield, N uptake and nitrogen use efficiency) and reactive nitrogen (Nr) losses (N2O emission, N leaching and NH3 volatilization) remains unclear. A meta-analysis was performed using peer-reviewed papers published from 2000 to 2019 to comprehensively assess the effects of combined application of organic and synthetic N fertilizers. The results indicate that overall, the vegetable yield, N2O emission and NH3 volatilization were not significantly changed, whereas N leaching was reduced by 44.6% and soil organic carbon (SOC) concentration increased by 12.5% compared to synthetic N fertilizer alone. Specifically, when synthetic N substitution rates (SRs) were ≤70%, vegetable yields and SOC concentration were increased by 5.5%-5.6% and 13.1-18.0%, and N leaching was reduced by 41.6%-48.1%. At the high substitution rate (SR>70%), vegetable yield was reduced by 13.6%, N2O emission was reduced by 14.3%, and SOC concentration increased by 16.4%. Mixed animal-plant sources of organic N preferentially increased vegetable yield and SOC concentration, and reduced N2O emission and N leaching compared with single sources of organic-N. Greenhouse gas (GHG) emission was decreased by 28.4%-34.9% by combined applications of organic and synthetic N sources, relative to synthetic N fertilizer alone. We conclude that appropriate rates (SR ≤ 70%) of combined applications of organic and synthetic N fertilizers could improve vegetable yields, decrease Nr and GHG emission, and facilitate sustainable development of coupled vegetable-livestock systems.


Asunto(s)
Fertilizantes , Nitrógeno , Agricultura , Animales , Carbono , China , Fertilizantes/análisis , Óxido Nitroso/análisis , Suelo , Verduras
17.
Sci Total Environ ; 757: 143926, 2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33316529

RESUMEN

Tracking the concentration of elements in the organs of endangered animal species can provide significant knowledge about environmental hazards and allows more targeted protective measures to be taken. In this paper the differences in concentrations of 27 elements in the livers of free-ranging European bison were studied. The ICP-OES method was applied to study the four main Polish populations, which live in lowland (Bialowieska, Knyszynska and Borecka forests) and mountain (Bieszczady) habitats. The study was based on a unique and relatively large amount of comparative material. It was found that European bison populations that live in different locations differ from each other in terms of the hepatic concentrations of 17 of the elements studied in this work. The mountain population in Bieszczady was most distinctive due to the higher concentrations of Ba, Ca, Cd, Se, and the lower concentrations of Mo and V (compared to the other populations). Additionally, even geographically close lowland populations sometimes have different hepatic concentrations of particular elements. The sex and age of individuals have a weak effect on mineral status. Although the lithosphere is the primary factor that affects the availability of elements for the European bison, the soil parameters and biosphere can significantly affect the availability of elements, e.g. by accumulation. It was also shown that the anthroposphere plays a role, but this is mainly through agriculture as feeding on arable fields significantly changes the mineral status of European bison. The need for further research, especially on Cd, Se and Cu, was indicated. It was concluded that toxic elements or deficiencies in essential elements in the populations of the studied species should be considered locally as this would allow better understanding of the health condition of individual populations.


Asunto(s)
Bison , Agricultura , Animales , Ecosistema , Humanos , Minerales , Polonia
18.
Waste Manag ; 119: 356-364, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33186829

RESUMEN

Sustainable development goals imply environmentally sound management of all wastes to minimize the waste generation through prevention, reduction, recycling, and reuse. In particular, the poultry industry produces nutrient-rich waste that requires proper management.Additionally, the recycling of bio-wastes in agricultural lands is still a key technology for the sustainable use of nutrients as a renewable fertilizer. Currently, there are very few studies on the utilization of agro-industrial bio-wastes, such as poultry abattoir sludge (PAS), for crop cultivation in soils containing low organic matter and high pH. In this context, it is necessary to make a more particular assessment of poultry industry-oriented and locally available nutrient-rich organic wastes for nodulation, physiological adaptation, and crop yield. Considering the scarcity of the literature in this field, the present study aimed to fulfill the apparent gap by focusing on the applicability of recycled PAS to low fertility soil in the growth of chickpea selected as a model legume, thereby contributing to the development of an agricultural and sustainable industrial management strategy for the relevant sectors. In this study, leaf chlorophyll content and nodule color were also investigated by the image analysis methodology to describe the effects of bio-waste on closing chickpea yield gap in a marginal land with high soil pH and low organic matter. Two-year consecutive field experiments were carried out to explore the effect of the PAS with the application rates of 25 kg N ha-1 (T2), 50 kg N ha-1 (T3), and 100 kg N ha-1 (T4) along with unamended (T0) and fertilized control (T1). The results indicated that the PAS treatments significantly differed in chlorophyll content, nodulation parameters, and biomass and grain yields. The chlorophyll content was correlated (r = 0.910) with the red color value (RGB color model) of nodule image analysis in the response to bio-waste. Based on the two-year average, it was concluded that chickpea yield could be increased 45% by amending with the PAS (T3). The present study clearly demonstrated that the image analysis could be a useful digital tool for the evaluation of chlorophyll content, nitrogen fixation efficiency, and forecasting biomass and grain yields of chickpea. The results also confirmed that the PAS application to low fertility soil could prominently contribute to establish sustainable waste management and crop production alternatives for closing chickpea yield gap.


Asunto(s)
Cicer , Administración de Residuos , Agricultura , Animales , Fertilizantes/análisis , Reciclaje , Suelo
19.
J Environ Manage ; 278(Pt 2): 111446, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33212354

RESUMEN

The rapid increase in global production of and demand for palm oil has resulted in large-scale expansion of oil palm monoculture in the world's tropical regions, particularly in Indonesia. This expansion has led to the conversion of carbon-rich land-use types to oil palm plantations with a range of negative environmental impacts, including loss of carbon from aboveground biomass and soil. Sequestration of soil organic carbon (SOC) in existing oil palm plantations is an important strategy to limit carbon losses. The aim of this study was to investigate SOC stocks of oil palm plantations under different management systems. Soil samples were collected from three different management systems (best management practices (BMP), current management practices typical of large plantations (CMP) and smallholder management practices (SHMP)) in north Sumatra, Indonesia. Plantations were divided into four management zones that were sampled separately with four replicate profiles in the weeded circle, frond stack, harvesting path and interrow zones. All the soil samples were collected from five (0-5, 5-15, 15-30, 30-50 and 50-70 cm) soil depths. Soil samples were analysed for concentration of SOC, soil texture, soil bulk density and pH. Calculations of SOC stocks in the soils were undertaken according to the fixed-depth and equivalent soil mass approaches. Results showed that SOC stocks of plantations under BMP (68 t ha-1) were 31% and 18% higher than under CMP (57 t ha-1) and SHMP (46 t ha-1) respectively. In the BMP system, soils under the interrow zone that received enriched mulch and frond stack positions stored significantly more SOC than the harvesting path of the BMP system (77, 73 and 57 t ha-1 respectively). BMP also had a 33% higher fresh fruit bunch yield compared to the SHMP system. This study shows that residue incorporation or retention as a part of BMP could be an effective strategy for increasing SOC stocks of oil palm plantations and confirms that these management practices could improve yields from SHMP systems.


Asunto(s)
Carbono , Suelo , Agricultura , Carbono/análisis , Bosques , Indonesia
20.
J Environ Manage ; 278(Pt 2): 111407, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33221672

RESUMEN

To adapt is to survive. However, sub-Saharan Africa, although highly dependent on agriculture, is vulnerable, most affected, with low-adaptive capacity. Luckily, the region is blessed with inherent adaptation-related strengths that are within reach, to counteract uncertainty in climatic patterns which are expected to continue well into the future. One such strength is a bimodal rainfall pattern that avails the 'hidden' multiple season-cropping systems that have the potential to produce four types of crops in a single plot in a single year: short-rains crops, long-rains crops, permanent crops and fruit crops. Despite burgeoning literature on adaptation, the impact of multiple season-cropping systems has not been adequately investigated. This study applies a novel approach to measure its impact on productivity of more than 10,000 smallholder plots using an endogenous switching regression framework. The study finds that plots that adopt multiple season-cropping systems produce higher quantities, earn more crop revenue, and are less likely to be affected by rainfall variability in comparison to plots that engage in single season-cropping systems. As the fight against climate change continues, there is need to move the needle on adaptation and consider strategies that are within reach. The multiple season-cropping systems provide this opportunity and emphasises the benefit of engaging in agriculture throughout the year and producing long-rains, short rains, permanent and fruits crops.


Asunto(s)
Productos Agrícolas , Frutas , Agricultura , Granjas , Lluvia , Estaciones del Año
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