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1.
Food Chem ; 367: 130667, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34339981

RESUMO

The main purpose of the present study was to investigate the effect of different fertilizers on the physicochemical properties, multi-element and volatile composition of cucumbers. All samples were divided into five groups according to different combinations and amounts of chicken manure, NPK 17-17-17 fertilizer and microbial fertilizer. The co-application of chicken manure (120,000 kg/ha) and NPK 17-17-17 fertilizer (750 kg/ha) achieved the best texture properties, whereas the addition of the microbial fertilizer at 6000 kg/ha significantly improved the color quality of cucumbers. Similarly, the co-application of chicken manure, NPK 17-17-17 fertilizer and microbial fertilizer at 6000 kg/ha enhanced the number and abundance of volatile components detected in the cucumbers. Cucumbers from the control group contained the highest levels of most of the determined elements. Overall, a combination of chicken manure, NPK 17-17-17 fertilizer and 6000 kg/ha microbial fertilizer is recommended as a relatively efficient fertilizer utilization for cucumbers.


Assuntos
Cucumis sativus , Fertilizantes , Agricultura , Fertilizantes/análise , Esterco , Solo
2.
J Environ Manage ; 301: 113818, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34597948

RESUMO

Best management practices that reduce potential phosphorus (P) loss and provide flexibility in P fertilizer management are needed to help producers protect water quality while maintaining crop yield. This study examined the impacts of P fertilizer management (no P, fall broadcast P, and spring injected P) and cover crop use on annual concentrations and loads of sediment, total P, and dissolved reactive P (DRP) in edge-of-field runoff from a no-till corn (Zea mays)-soybean (Glycine max) rotation in the Central Great Plains, USA, from September 2015 through September 2019. The spring injected P fertilizer treatment generally had 19% less total P and 33% less DRP loss compared to the fall broadcast treatment, confirming the importance of P fertilizer management as a practice for reducing P loss. The addition of a cover crop had an inconsistent effect on total P loss, with no effect in 2016 and 2017, increasing loss in 2018 by 56%, and decreasing it in 2019 by 40%. The inconsistent impact of cover crops on total P loss was related to cover crop effects on sediment loss. Although cover crop impacts on total P losses were inconsistent, the addition of a cover crop increased DRP loss in three of four years. Cover crop use consistently reduced sediment loss, with greater sediment reduction when P fertilizer was applied. Results from this study highlight the benefit of cover crops for reducing sediment loss and the continued need for proper fertilizer management to reduce P loss from agricultural fields.


Assuntos
Fertilizantes , Fósforo , Agricultura , Fertilizantes/análise , Fósforo/análise , Soja , Movimentos da Água , Qualidade da Água , Zea mays
3.
J Environ Manage ; 301: 113812, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34601350

RESUMO

Removing vegetation cover from hill-slope land increases risk for soil erosion and delivery of sediment to waterways. In New Zealand's productive landscapes, clear-fell harvesting of forestry blocks and winter forage grazing by agricultural livestock are two significant causes of vegetation removal. Bare ground exposed by these activities varies annually and seasonally in location and spatial extent. Modelling soil erosion therefore requires temporally and spatially explicit mapping of this bare ground. We have developed an automated mapping method using time-series satellite imagery, thereby enabling wide-area coverage and ease of updating. The temporal analysis identifies land use along with the period of vegetation removal. It produces results per land parcel (in vector format) for use in a Geographic Information System. We present a description of our method, national maps and statistics of bare ground extent in New Zealand's hill-country forestry and winter forage grazing land in 2018, and an assessment of accuracy. The attributes of the mapped land parcels are designed for input into a soil erosion estimation model such as the New Zealand Universal Soil Loss Equation.


Assuntos
Agricultura Florestal , Erosão do Solo , Agricultura , Conservação dos Recursos Naturais , Monitoramento Ambiental , Sistemas de Informação Geográfica , Nova Zelândia , Solo
4.
J Environ Manage ; 301: 113813, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34607133

RESUMO

There is a growing interest in including blue carbon ecosystems (i.e., mangroves, tidal marshes and seagrasses) in climate mitigation programs in national and sub-national policies, with restoration and conservation of these ecosystems identified as potential activities to increase carbon accumulation through time. However, there is still a gap on the spatial scales needed to produce carbon offsets comparable with terrestrial or agricultural ecosystems. Here, we used the Coastal Blue Carbon InVEST 3.7.0 model to estimate future net carbon sequestration in blue carbon ecosystems along Australia's Great Barrier Reef (hereafter GBR) catchments, considering different management scenarios (i.e., reintroduction of tidal exchange through the removal of barriers, sea level rise, restoring low lying land) at three different spatial scales: whole GBR coastline, regional (14,000-16,300 ha), and local (335-370 ha) scales. The focus of the restoration (i.e., tidal marshes and/or mangroves) was dependent on data availability for each scenario. Furthermore, we also estimated the monetary value of carbon sequestration under each management scenario and spatial scale assessed in the study. We found that large scale restoration of tidal marshes could potentially sequester an additional ∼800,000 tonnes of CO2e by 2045 (potentially generating AU$12 million based on the average Australia carbon price), with greater opportunities when sea level rise is accounted for in the modelling. Also, we found that regional and local projects would generate up to 23 tonnes CO2e ha-1 by the end of the crediting period. Our results can guide future decisions in the blue carbon market and financing schemes, however, the return on investment is dependent on the carbon price and funding scheme available for project implementation.


Assuntos
Carbono , Ecossistema , Agricultura , Sequestro de Carbono , Áreas Alagadas
5.
J Environ Manage ; 301: 113858, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34607139

RESUMO

The agricultural cooperative may significantly impact the adoption of environmentally friendly production technologies, which eventually help the farmers with better living standards and productivity. However, critical evaluation of how and to what extent the cooperative organization's participation leads the farmer's adoption of environmentally friendly technology (EFT) is relatively unclear. Thus, to critically explore the knowledge gap, the study evaluates the effects of cooperative participation towards adopting environmentally friendly production technologies based on the theory of planned behavior (TPB). The key variables used in the study have been extracted from an extensive literature investigation, while the empirical data has been collected from October to December 2020 from 292 kiwi-fruit farmers within the Shaanxi province of China. Simultaneously, the partial least square of structural equation modeling (PLS-SEM) tools has been utilized to craft the final assessment. The factor loadings of all three latent variables have been statistically significant and interrelated for quantifying the proposed model. The statistically proven framework portrayed that cooperative organizations' participation positively impacts and shapes behavioral factors and facilitates the adoption of environmentally friendly production technologies. The study found the social structure like China, the impacts of cooperation could be crucial. As cooperative participation is an ample predictor for facilitating environmentally friendly technologies, the government should broaden the technical supports, and agricultural extension should also provide extended training for a smooth transition of the cooperatives.


Assuntos
Fazendeiros , Frutas , Agricultura , China , Humanos , Tecnologia
6.
J Environ Manage ; 301: 113886, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34619594

RESUMO

The conversion of primary forests to cultivation brings a significant change in soil carbon (C) forms. In the foothills of the Eastern Himalayan Region of India (Manipur), such conversions are prevalent. However, little is known about the response of C forms, particularly in deep soil, to land use conversion in the region. We evaluated changes in soil C forms (total organic, inorganic, and pools) and microbiological properties (up to 1.0 m depth) mediated by C when the 45-year-old forest had been cultivated for 18-25 years. The cultivated land uses were tree-based agroforestry (LAF: legumes, NAF: non-legumes), horticultural fruits (WHF: woody, NHF: non-wood, mainly vegetables), and paddy agriculture system (AUS: upland, ALS: lowlands). Forest conversion significantly (p < 0.05) decreased the total carbon (TC) in the surface soil (0.0-0.15 m) from 4.88 % to 3.04-3.93 % in the tree-based land uses (LAF, NAF, and WHF). TC further declined to 2.05-2.81 % under seasonal crops (NHF, AUS, and ALS). Seasonal crop cultivation also caused a higher decline in microbial biomass carbon, soil enzymes, and carbon pools (active and passive) than the tree-based land use with the soil depth. The vertical distribution of C in the soil profile was inconsistent: organic C (including C pools) decreased, while inorganic C increased. The profile TC stock to a depth of 1.0 m in the forest was 358.8 Mg ha-1, of which 81 % were organic C, and 19 % were inorganic C. In comparison with forest soil, total soil C stocks (organic and inorganic) decreased more (-44.1 to -55.1 %) in seasonal crops than in tree-based (-15.4 to -36.3 %) land uses. The degradation index (DI) also confirmed that seasonal crop cultivation caused a larger decline in surface soil quality (DI: -423 % to -623 %) than tree-based land use (DI: -243 % to -317 %). The topsoil (up to 0.45 m) of seasonal crops was more degraded than that of the subsoil (>0.45 m-1.0 m). Forests converted to seasonal cultivation (upland rice and vegetables) caused higher degradation of soil C forms and overall soil health in the Himalayan foothills of northeastern India. We suggest the promotion of Agroforestry based on legumes (Parkia spp.) and woody fruits (mango/citrus/guava) in the uplands to minimize soil C degradation while ensuring nutritional security in the hill agro-ecosystems of the Indian Himalayas.


Assuntos
Carbono , Solo , Agricultura , Carbono/análise , Ecossistema , Florestas , Índia
7.
J Environ Manage ; 301: 113909, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34624580

RESUMO

To promote international collaboration on environmental pollution management and human health protection, we conducted a global-level study on the management of pesticides for surface freshwater quality. Prior to actions being taken in terms of water treatment or remediation, it is essential that clear and definite regulations be disseminated. In our study, 3094 surface freshwater quality standards for 184 different pesticides were recorded from 53 countries and categorized according to pesticide types and standard types, as well as diverse use of freshwater by humans, and compared water quality standards related to human health. Our results indicate large variations in pesticide regulations, standard types (i.e., long- or short-term water quality standards), and related numerical values. With regard to the protection of human health, the 10 most frequently regulated pesticides account for approximately 47% of the total number of standards across 184 considered pesticides. The average occurrence-weighted variations of standard values (i.e., numerical values provided in a standard in terms of residue limits of a given pesticide in water) for the 20 most regulated persistent organic pollutants (POPs) and other phase-out pesticides (i.e., pesticides not currently-approved for use in agriculture across various countries) are 4.1 and 2.6 orders of magnitude, respectively, with human-exposure related standard values for some pesticides varying with over 3 orders of magnitude (e.g., lindane). In addition, variations in water quality standard values occurred across standard types (e.g., maximum and average), water use types (e.g., unspecified waters and human consumption), and standard values (e.g., pesticide individuals and groups). We conclude that regulatory inconsistencies emphasize the need for international collaboration on domestic water treatment, environmental management as well as specific water quality standards for the wider range of current-use pesticides, thereby improving global harmonization in support of protecting human health.


Assuntos
Praguicidas , Poluentes Químicos da Água , Purificação da Água , Agricultura , Monitoramento Ambiental , Água Doce , Humanos , Praguicidas/análise , Poluentes Químicos da Água/análise
8.
J Environ Manage ; 301: 113880, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34638042

RESUMO

The dairy industry produces vast quantities of dairy processing sludge (DPS), which can be processed further to develop second generation products such as struvite, biochars and ashes (collectively known as STRUBIAS). These bio-based fertilizers have heterogeneous nutrient and metal contents, resulting in a range of possible application rates. To avoid nutrient losses to water or bioaccumulation of metals in soil or crops, it is important that rates applied to land are safe and adhere to the maximum legal application rates similar to inorganic fertilizers. This study collected and analysed nutrient and metal content of all major DPS (n = 84) and DPS-derived STRUBIAS products (n = 10), and created an application calculator in MS Excel™ to provide guidance on maximum legal application rates for ryegrass and spring wheat across plant available phosphorus (P) deficient soil to P-excess soil. The sample analysis showed that raw DPS and DPS-derived STRUBIAS have high P contents ranging from 10.1 to 122 g kg-1. Nitrogen (N) in DPS was high, whereas N concentrations decreased in thermo-chemical STRUBIAS products (chars and ash) due to the high temperatures used in their formation. The heavy metal content of DPS and DPS-derived STRUBIAS was significantly lower than the EU imposed limits. Using the calculator, application rates of DPS and DPS-derived STRUBIAS materials (dry weight) ranged from 0 to 4.0 tonnes ha-1 y-1 for ryegrass and 0-4.5 tonnes ha-1 y-1 for spring wheat. The estimated heavy metal ingestion to soil annually by the application of the DPS and DPS-derived STRUBIAS products was lower than the EU guideline on soil metal accumulation. The calculator is adaptable for any bio-based fertilizer, soil and crop type, and future work should continue to characterise and incorporate new DPS and DPS-derived STRUBIAS products into the database presented in this paper. In addition, safe application rates pertaining to other regulated pollutants or emerging contaminants that may be identified in these products should be included. The fertilizer replacement value of these products, taken from long-term field studies, should be factored into application rates.


Assuntos
Agricultura , Metais Pesados , Fertilizantes/análise , Metais Pesados/análise , Fósforo , Esgotos , Solo
9.
Chemosphere ; 287(Pt 2): 132107, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34492409

RESUMO

Modern agricultural practices are relying excessively upon the use of synthetic fertilizers to supply essential nutrients to promote crop productivity. Though useful in the short term, their prolonged and persistent applications are harmful to soil fertility and nutrient dynamics of the rhizospheric microbiome. The application of nanotechnology in form of nanofertilizer provides an innovative, efficient, and eco-friendly alternative to synthetic fertilizers. The nanofertilizers allow a slow and sustained release of nutrients that not only supports plant growth but also conserve the diversity of the beneficial microbiome. Such attributes may help the phytomicrobiome to efficiently mitigate both biotic and abiotic stress conditions. Unfortunately, despite, exceptional efficiency and ease of applications, certain limitations are also associated with the nanofertilizers such as their complicated production process, tenuous transport and dosage-sensitive efficiency. These bottlenecks are causing a delay in the large-scale applications of nanofertilizers in agriculture. This review aims to highlight the current trends and perspectives on the use of nanofertilizers for improving soil fertility with a special focus on their effects on beneficial phyromicrobiome.


Assuntos
Microbiota , Solo , Agricultura , Produção Agrícola , Fertilizantes/análise , Microbiologia do Solo
10.
Chemosphere ; 287(Pt 2): 132017, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34509008

RESUMO

The fan nozzle is widely used in the process of pest control in agriculture and forestry. The spray angle of the nozzle is an important characterization parameter in the atomization of liquids. The spray angle of the nozzle is an important characterizing parameter in the liquid atomization process. It affects the flow field at the exit of the nozzle, thereby affecting the size and velocity of the droplets, and further affecting the deposition effect of the droplets on the crop. Therefore, its research is of great significance for improving the deposition of liquid on plants and controlling pests and related diseases. Based on the classical theory of predecessors and considering the parameters of the flat fan nozzle, we further optimized the theory at the structural level by means of a simulation test and built a spray angle theoretical model taking into account the parameters of the inner chamber of the nozzle. We arrived at the following conclusions: (1) the average error of the spray angle measured by the simulation test and the actual test spray angle was 2.95%, the maximum spray angle deviation value was 2.81°, and the result proves that the simulation test parameter setting is accurate; and (2) the average error between the actual measured value and the theoretical model calculation value was 3.56%, the maximum spray angle deviation was 4°, through the actual test comparison, and the spray angle error of the theoretical model was within the allowable error range of industry production. It was proved that the model could effectively reflect the changing law of spray angle of the flat fan nozzle.


Assuntos
Agricultura , Controle de Pragas , Modelos Teóricos , Tamanho da Partícula , Fenômenos Físicos
11.
Chemosphere ; 287(Pt 2): 132080, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34509011

RESUMO

Rhodamine B (RhB) is among the toxic dyes due to the carcinogenic, neurotoxic effects and ability to cause several diseases for humans. The adsorption with agricultural waste adsorbent recorded high performance for the RhB removal. The current review aimed to explore the efficiency of different adsorbents which have been used in the few last years for removing RhB dye from wastewater. The data of adsorption of RhB using agricultural wastes were collected from the Scopus database in the period between 2015 and 2021. The use of agricultural wastes and adsorbents as a replacement for the activated has received high attention among researchers. The RhB removal methods by microbial enzymes and biomass occurred between 76 and 90.1%. In comparison, the adsorption with agricultural wastes such as activated carbon white sugar reached 98% within 12 min. The adsorption process has a wide range of pH (3-10) due to the zwitterionic forms of RhB. Gmelina aborea leaf activated carbon is among the agriculture wastes absorbents that exhibited 1000 mg g-1 of the adsorption capacity. It appeared that the agricultural wastes adsorbents have a high potential for removing RhB from the wastewater.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Agricultura , Corantes , Humanos , Rodaminas , Águas Residuárias
12.
Chemosphere ; 287(Pt 3): 132338, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34563774

RESUMO

Manure fertilization contributes to crop production and sustainable agriculture by introducing large amounts of nutrients and exogenous microbes into soil. However, the contribution of exogenous microbes in shaping soil bacterial community and network structure after fertilization are still controversial. In this study, bacterial communities and network structure that received unsterilized (R + C) or sterilized (R + SC) manure fertilizers, as well as no fertilizer control (R), were characterized using high throughput sequencing. Results showed that the relative abundance of fertilizer-derived OTUs decreased from 10.4% to 4.6% after 90 days incubation, while the Bray-Curtis distance between the control and fertilization group (R + C and R + SC) gradually increased with the culture time. It can be supposed that manure fertilization altered soil bacterial communities by interfering the growth of indigenous bacteria rather than the colonization of fertilizer-derived bacteria. Network analysis showed that a subset of the fertilizer-derived OTUs identified as Xanthomonadales order and Promicromonospora, Constrictibacter genera acted as connectors between modules. They enhanced the interactions not only between soil-derived OTUs and fertilizer-derived OTUs, but also within indigenous bacteria, supported that the introduction of fertilizer-derived exogenous bacteria contributes large to soil bacterial network association. Moreover, fertilizer-derived OTUs presented to be positively correlated with soil pH, while majority soil-derived OTUs presented to be negatively correlated with various physicochemical variables (pH, DOC, NO3-, and LAP). Our study highlighted the critical role of fertilizer-derived bacteria in regulating indigenous soil microbial community and network formation after fertilization.


Assuntos
Fertilizantes , Solo , Agricultura , Bactérias/genética , Fertilizantes/análise , Esterco , Microbiologia do Solo
13.
Chemosphere ; 287(Pt 3): 132321, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34563778

RESUMO

Agroforestry, an integration of farming system with woody perennials leads to the generation of potential agroforestry residues. The conventional treatment of agroforestry waste includes landfilling, thermal management, and decomposition which is accompanied with their own share of disadvantages. The ample amount of residues and products needs effective management to reap the economic and environmental benefits. The channel of waste collection, transportation, and recycle or valorization into products like biofuel, fertilizers, biochar, industrial chemicals is essential to maintain a circular sustainable bioeconomy. Global market value of biowaste to bioenergy (BtB) technology is roughly US $25.32 billion and is projected to enhance to US $40 billion by 2023. Employment of an appropriate pretreatment technology such as fermentation, hydrolysis, gasification etc. is going to elevate the degree of valorization along with surpassing the mobilization barrier. The sustainability assessment of the management process can be achieved with multiple models including technoeconomic analysis, life cycle assessment and multi criteria approach which are dependent on both hard and soft indices. Additionally, the loopholes of the agroforestry sectors would be managed by the introduction of appropriate policies which are undertaken globally by the Orlando and Lugo declarations, food and agriculture organization, Millennium Development Goals, Global Research Alliance and Guidelines for Sustainable Agriculture and Rural Development. The present review envisaged the agroforestry waste management strategy and its sustainability assessment primarily based upon Social, Economic and Environmental parameters without tormenting the future generations.


Assuntos
Agricultura Florestal , Gerenciamento de Resíduos , Agricultura , Biocombustíveis , Reciclagem
14.
Environ Pollut ; 292(Pt A): 118301, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34626716

RESUMO

Almost 81% of nitrogen fertilizers are applied in form of urea but most of it is lost due to volatilization and leaching leading to environmental pollution. In this regard, slow-release nano fertilizers can be an effective solution. Here, we have synthesized different Fe3O4-urea nanocomposites with Fe3O4 NPs: urea ratio (1:1, 1:2, 1:3) ie. NC-1, 2, and 3 respectively, and checked their efficacy for growth and yield enhancement. Oryza sativa L. cv. Swarna seedlings were treated with different NCs for 14 days in hydroponic conditions and significant up-regulation of photosynthetic efficiency and nitrogen metabolism were observed due to increased availability of nitrogen and iron. The discriminant functional analysis confirmed that the NC3 treatment yielded the best results so further gene expression studies were performed for NC-3 treated seedlings. Significant changes in expression profiles of ammonia and nitrate transporters indicated that NC-3 treatment enhanced nitrogen utilization efficiency (NUE) due to sustained slow release of urea. From pot experiments, we found significant enhancement of growth, grain nutrient content, and NUE in NC supplemented sets. 1.45 fold increase in crop yield was achieved when 50% N was supplemented in form of NC-3 and the rest in form of ammonium nitrate. NC supplementation can also play a vital role in minimizing the use of bulk N fertilizers because, when 75% of the recommended N dose was supplied in form of NC-3, 1.18 fold yield enhancement was found. Thus our results highlight that, slow-release NC-3 can play a major role in increasing the NUE of rice.


Assuntos
Nanocompostos , Oryza , Agricultura , Poluição Ambiental , Fertilizantes/análise , Nitrogênio/análise , Nutrientes , Solo , Ureia
15.
Environ Pollut ; 292(Pt A): 118344, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34637831

RESUMO

The effects of combined biochar and double inhibitor application on gaseous nitrogen (N; nitrous oxide [N2O] and ammonia [NH3]) emissions and N leaching in paddy soils remain unclear. We investigated the effects of biochar application at different rates and double inhibitor application (hydroquinone [HQ] and dicyandiamide [DCD]) on NH3 and N2O emissions, N leaching, as well as rice yield in a paddy field, with eight treatments, including conventional urea N application at 280 kg N ha-1 (CN); reduced N application at 240 kg N ha-1 (RN); RN + 7.5 t ha-1 biochar (RNB1); RN + 15 t ha-1 biochar (RNB2); RN + HQ + DCD (RNI); RNB1 + HQ + DCD (RNIB1); RNB2 + HQ + DCD (RNIB2); and a control without N fertilizer. When compared with N leaching under RN, biochar application reduced total N leaching by 26.9-34.8% but stimulated NH3 emissions by 13.2-27.1%, mainly because of enhanced floodwater and soil NH4+-N concentrations and pH, and increased N2O emission by 7.7-21.2%, potentially due to increased soil NO3--N concentrations. Urease and nitrification inhibitor addition decreased NH3 and N2O emissions, and total N leaching by 20.1%, 21.5%, and 22.1%, respectively. Compared with RN, combined biochar (7.5 t ha-1) and double inhibitor application decreased NH3 and N2O emissions, with reductions of 24.3% and 14.6%, respectively, and reduced total N leaching by up to 45.4%. Biochar application alone or combined with double inhibitors enhanced N use efficiency from 26.2% (RN) to 44.7% (RNIB2). Conversely, double inhibitor application alone or combined with biochar enhanced rice yield and reduced yield-scaled N2O emissions. Our results suggest that double inhibitor application alone or combined with 7.5 t ha-1 biochar is an effective practice to mitigate NH3 and N2O emission and N leaching in paddy fields.


Assuntos
Agricultura , Oryza , Carvão Vegetal , Fertilizantes/análise , Óxido Nitroso/análise , Solo
16.
Environ Pollut ; 292(Pt A): 118345, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34648834

RESUMO

Hot moments of nitrous oxide (N2O) emissions induced by interactions between weather and management make a major contribution to annual N2O budgets in agricultural soils. The causes of N2O production during hot moments are not well understood under field conditions, but emerging evidence suggests that short-term fluctuations in soil oxygen (O2) concentration can be critically important. We conducted high time-resolution field observations of O2 and N2O concentrations during hot moments in a dryland agricultural soil in Northern China. Three typical management and weather events, including irrigation (Irr.), fertilization coupled with irrigation (Fer.+Irr.) or with extreme precipitation (Fer.+Pre.), were observed. Soil O2 and N2O concentrations were measured hourly for 24 h immediately following events and measured daily for at least one week before and after the events. Soil moisture, temperature, and mineral N were simultaneously measured. Soil O2 concentrations decreased rapidly within 4 h following irrigation in both the Irr. and Fer.+Irr. events. In the Fer.+Pre. event, soil O2 depletion did not occur immediately following fertilization but began following subsequent continuous rainfall. The soil O2 concentration dropped to as low as 0.2% (with the highest soil N2O concentration of up to 180 ppmv) following the Fer.+Pre. event, but only fell to 11.7% and 13.6% after the Fer.+Irr. and Irr. events, which were associated with soil N2O concentrations of 27 ppmv and 3 ppmv, respectively. During the hot moments of all three events, soil N2O concentrations were negatively correlated with soil O2 concentrations (r = -0.5, P < 0.01), showing a quadratic increase as soil O2 concentrations declined. Our results provide new understanding of the rapid short response of N2O production to O2 dynamics driven by changes in soil environmental factors during hot moments. Such understanding helps improve soil management to avoid transitory O2 depletion and reduce the risk of N2O production.


Assuntos
Óxido Nitroso , Solo , Agricultura , China , Óxido Nitroso/análise , Oxigênio
17.
Sci Total Environ ; 803: 150019, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34500267

RESUMO

Reducing nitrogen (N) losses from cropping systems to aquatic ecosystems is a global priority. In Australia, N losses from sugarcane production in catchments adjacent to the Great Barrier Reef (GBR) are threatening the health of this World Heritage-listed coral reef ecosystem. N losses from sugarcane can be reduced by improving fertiliser management. However, little is known about the contribution of organic sources of N, such as mill mud. We used more than 10 years of data from two of the main Australian sugarcane regions, a high (Wet Tropics) and moderate (Mackay Whitsundays) rainfall area, to calibrate and validate a model to predict dissolved inorganic nitrogen (DIN) losses in runoff from both inorganic and organic fertilisers. DIN losses in runoff were well simulated (RMSE = 0.37 and 2.0 kg N ha-1 for the Wet Tropics and Mackay Whitsunday regions, respectively). Long-term simulations of rate and fertiliser deductions to account for N from organic sources showed that adopting best management practices for organic fertiliser (applying ≤50 wet t ha-1 mill mud) can significantly reduce DIN in runoff losses compared with applications of 150 wet t ha-1. Simulations of typical farmer practices in relation to fallow management (bare fallow vs. legume fallow) and organic fertiliser placement (buried in a fallow but surface applied to a green cane trash blanket in ratoons) showed that inorganic fertiliser rates need to be adjusted to account for N inputs from both mill mud and legume crops. Rates of application of organic N had a larger impact on DIN runoff losses than placement or timing of application. This work presents a DIN in runoff modelling algorithm that can be coupled with nitrogen models readily available in agricultural models to assess the impact of nutrient management on the quality of water leaving agricultural systems.


Assuntos
Nitrogênio , Saccharum , Agricultura , Algoritmos , Austrália , Ecossistema , Monitoramento Ambiental , Nitrogênio/análise , Nutrientes , Fósforo/análise
18.
Sci Total Environ ; 803: 150035, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34500275

RESUMO

The Loess Plateau is China's primary apple-growing area, and the orchard is a significant source of greenhouse gases (GHGs) emissions due to high nitrogen fertilizer input. Thus, a two-year field study was carried out to investigate the effects of apple wood derived biochar on GHGs emissions during apple orchard production, including soil organic carbon sequestration (SOCSR) and net global warming potential (NGWP) assessments. There are four treatments in this study: 20 t ha-1 biochar in a non-fertilized plot (B); no biochar in a fertilized plot (F); 20 t ha-1 biochar in a fertilized plot (FB); no biochar in a non-fertilized plot (CK). Results showed that the combined application of biochar and fertilizer stimulated CO2 emissions by 9.25% and 8.39% than either biochar or fertilizer alone. Meanwhile, biochar in fertilized plot increased annual N2O emissions by 32.6% as compared to fertilized plot without biochar amendment. Compared with CK, biochar had no significant effect on GHG emissions in unfertilized plot. The N2O emission factor of FB and F were 0.91% and 0.45% respectively in 2017-2018 and they were both 0.34% in 2018-2019. Moreover, compared with CK, the FB and B treatments increased the SOCSR by 316.52% and 354.78%, while, decreased the NGWP by 368.93% and 480.91%, respectively. Thus, biochar application may help reduce the impact of apple production on climate change by sequestering more soil organic carbon and decreasing the NGWP.


Assuntos
Malus , Solo , Agricultura , Carbono , Dióxido de Carbono/análise , Sequestro de Carbono , Carvão Vegetal , China , Aquecimento Global , Metano/análise , Óxido Nitroso/análise
19.
Food Chem ; 370: 131025, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34509147

RESUMO

Grape marc is an underutilised waste material that poses significant environmental issues. This study offers the first proof-of-concept investigation into the polymerisation of both crude and purified Sauvignon blanc grape marc extracts using the diacyl chlorides terephthaloyl chloride, succinyl chloride, adipoyl chloride, sebacoyl chloride, and the tartaric acid derivative (4R,5R)-2,2-dimethyl-1,3-dioxolane-4,5-dicarbonyl dichloride to obtain new materials, in what to the best of our knowledge is the first reported example of a direct polymerisation of an agricultural waste extract. A total of 26 novel materials were prepared. It has also shown that quercetin, a phenolic monomer found in grape marc extracts, can be polymerised with (4R,5R)-2,2-dimethyl-1,3-dioxolane-4,5-dicarbonyl dichloride to give a polymer that shows activity towards S. aureus.


Assuntos
Vitis , Agricultura , Antibacterianos , Fenóis , Staphylococcus aureus
20.
Sci Total Environ ; 803: 149844, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34525739

RESUMO

In the EU and world-wide, agriculture is in transition. Whilst we just converted conventional farming imprinted by the post-war food demand and heavy agrochemical usage into integrated and sustainable farming with optimized production, we now have to focus on even smarter agricultural management. Enhanced nutrient efficiency and resistance to pests/pathogens combined with a greener footprint will be crucial for future sustainable farming and its wider environment. Future land use must embrace efficient production and utilization of biomass for improved economic, environmental, and social outcomes, as subsumed under the EU Green Deal, including also sites that have so far been considered as marginal and excluded from production. Another frontier is to supply high-quality food and feed to increase the nutrient density of staple crops. In diets of over two-thirds of the world's population, more than one micronutrient (Fe, Zn, I or Se) is lacking. To improve nutritious values of crops, it will be necessary to combine integrated, systems-based approaches of land management with sustainable redevelopment of agriculture, including central ecosystem services, on so far neglected sites: neglected grassland, set aside land, and marginal lands, paying attention to their connectivity with natural areas. Here we need new integrative approaches which allow the application of different instruments to provide us not only with biomass of sufficient quality and quantity in a site specific manner, but also to improve soil ecological services, e.g. soil C sequestration, water quality, habitat and soil resistance to erosion, while keeping fertilization as low as possible. Such instruments may include the application of different forms of high carbon amendments, the application of macro- and microelements to improve crop performance and quality as well as a targeted manipulation of the soil microbiome. Under certain caveats, the potential of such sites can be unlocked by innovative production systems, ready for the sustainable production of crops enriched in micronutrients and providing services within a circular economy.


Assuntos
Solo , Oligoelementos , Agricultura , Produtos Agrícolas , Ecossistema
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