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1.
Nature ; 555(7696): 363-366, 2018 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-29513654

RESUMEN

Sustainably feeding a growing population is a grand challenge, and one that is particularly difficult in regions that are dominated by smallholder farming. Despite local successes, mobilizing vast smallholder communities with science- and evidence-based management practices to simultaneously address production and pollution problems has been infeasible. Here we report the outcome of concerted efforts in engaging millions of Chinese smallholder farmers to adopt enhanced management practices for greater yield and environmental performance. First, we conducted field trials across China's major agroecological zones to develop locally applicable recommendations using a comprehensive decision-support program. Engaging farmers to adopt those recommendations involved the collaboration of a core network of 1,152 researchers with numerous extension agents and agribusiness personnel. From 2005 to 2015, about 20.9 million farmers in 452 counties adopted enhanced management practices in fields with a total of 37.7 million cumulative hectares over the years. Average yields (maize, rice and wheat) increased by 10.8-11.5%, generating a net grain output of 33 million tonnes (Mt). At the same time, application of nitrogen decreased by 14.7-18.1%, saving 1.2 Mt of nitrogen fertilizers. The increased grain output and decreased nitrogen fertilizer use were equivalent to US$12.2 billion. Estimated reactive nitrogen losses averaged 4.5-4.7 kg nitrogen per Megagram (Mg) with the intervention compared to 6.0-6.4 kg nitrogen per Mg without. Greenhouse gas emissions were 328 kg, 812 kg and 434 kg CO2 equivalent per Mg of maize, rice and wheat produced, respectively, compared to 422 kg, 941 kg and 549 kg CO2 equivalent per Mg without the intervention. On the basis of a large-scale survey (8.6 million farmer participants) and scenario analyses, we further demonstrate the potential impacts of implementing the enhanced management practices on China's food security and sustainability outlook.


Asunto(s)
Agricultura/métodos , Conservación de los Recursos Naturales , Productos Agrícolas/crecimiento & desarrollo , Eficiencia Organizacional , Agricultores , China , Técnicas de Apoyo para la Decisión , Grano Comestible/crecimiento & desarrollo , Política Ambiental , Fertilizantes/estadística & datos numéricos , Abastecimiento de Alimentos/métodos , Efecto Invernadero , Nitrógeno/metabolismo , Oryza/crecimiento & desarrollo , Triticum/crecimiento & desarrollo , Zea mays/crecimiento & desarrollo
2.
Nature ; 537(7622): 671-674, 2016 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-27602513

RESUMEN

Sustainably feeding the world's growing population is a challenge, and closing yield gaps (that is, differences between farmers' yields and what are attainable for a given region) is a vital strategy to address this challenge. The magnitude of yield gaps is particularly large in developing countries where smallholder farming dominates the agricultural landscape. Many factors and constraints interact to limit yields, and progress in problem-solving to bring about changes at the ground level is rare. Here we present an innovative approach for enabling smallholders to achieve yield and economic gains sustainably via the Science and Technology Backyard (STB) platform. STB involves agricultural scientists living in villages among farmers, advancing participatory innovation and technology transfer, and garnering public and private support. We identified multifaceted yield-limiting factors involving agronomic, infrastructural, and socioeconomic conditions. When these limitations and farmers' concerns were addressed, the farmers adopted recommended management practices, thereby improving production outcomes. In one region in China, the five-year average yield increased from 67.9% of the attainable level to 97.0% among 71 leading farmers, and from 62.8% to 79.6% countywide (93,074 households); this was accompanied by resource and economic benefits.


Asunto(s)
Producción de Cultivos/métodos , Producción de Cultivos/estadística & datos numéricos , Agricultores/estadística & datos numéricos , Triticum/crecimiento & desarrollo , Zea mays/crecimiento & desarrollo , China , Cambio Climático , Producción de Cultivos/economía , Ecología , Política Ambiental , Nitrógeno , Población Rural , Semillas , Factores Socioeconómicos , Factores de Tiempo , Agua
3.
Glob Chang Biol ; 25(12): 4273-4281, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31418955

RESUMEN

Sustainably feeding the growing population amid a changing climate and dwindling resources is a grand challenge facing mankind. Decades-long advancement in crop breeding has progressively elevated yield potential, markedly enhancing global food production capacity. However, relevant impact on reactive N (Nr) emissions associated with crop variety improvement has not been explicitly described. Here, we report multitiered evidence that newer and select maize, wheat, and rice varieties developed in China have the capacity to substantially lower Nr losses while producing more grain. First, we pooled studies featuring side-by-side comparison of different varieties, totaling 269 paired observations, to demonstrate that collectively, relatively newer varieties of maize, wheat, and rice had less Nr emissions (9.6%-23.5%) while yielding more grains (7.3%-11.2%) compared to older varieties under wide-ranging conditions. Next, we built an extended database (142 field studies with 833 observations) and comprehensively evaluated the Nr-loss reduction potential of newer varieties (2000 and after) versus older ones (1985-1999). We found that newer varieties had Nr emission factors (N loss as a percentage of N applied after correcting for background emissions) 18.2%-75.7% less for N2 O, 18.3%-75.7% less for NO 3 - , and -8.5% to 22.8% less for NH3 , while producing more grains (16.0%-24.4%). Individual varieties differed markedly in yield-emission scores. A nationwide farmer survey (2.47 million responses) indicated tremendous opportunities for a new way of management intervention. Coupling variety selection with sound N and other agronomic management can help lower N footprint while producing more grain.


Asunto(s)
Oryza , Triticum , China , Nitrógeno , Zea mays
4.
Glob Chang Biol ; 24(2): e511-e521, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28973790

RESUMEN

Improving nitrogen (N) management for greater agricultural output while minimizing unintended environmental consequences is critical in the endeavor of feeding the growing population sustainably amid climate change. Enhanced-efficiency fertilizers (EEFs) have been developed to better synchronize fertilizer N release with crop uptake, offering the potential for enhanced N use efficiency (NUE) and reduced losses. Can EEFs play a significant role in helping address the N management challenge? Here we present a comprehensive analysis of worldwide studies published in 1980-2016 evaluating four major types of EEFs (polymer-coated fertilizers PCF, nitrification inhibitors NI, urease inhibitors UI, and double inhibitors DI, i.e. urease and nitrification inhibitors combined) regarding their effectiveness in increasing yield and NUE and reducing N losses. Overall productivity and environmental efficacy depended on the combination of EEF type and cropping systems, further affected by biophysical conditions. Best scenarios include: (i) DI used in grassland (n = 133), averaging 11% yield increase, 33% NUE improvement, and 47% decrease in aggregated N loss (sum of NO3- , NH3 , and N2 O, totaling 84 kg N/ha); (ii) UI in rice-paddy systems (n = 100), with 9% yield increase, 29% NUE improvement, and 41% N-loss reduction (16 kg N/ha). EEF efficacies in wheat and maize systems were more complicated and generally less effective. In-depth analysis indicated that the potential benefits of EEFs might be best achieved when a need is created, for example, by downward adjusting N application from conventional rate. We conclude that EEFs can play a significant role in sustainable agricultural production but their prudent use requires firstly eliminating any fertilizer mismanagement plus the implementation of knowledge-based N management practices.


Asunto(s)
Agricultura/métodos , Cambio Climático , Fertilizantes , Nitrógeno , Productos Agrícolas/crecimiento & desarrollo , Productos Agrícolas/metabolismo
5.
Proc Natl Acad Sci U S A ; 110(21): 8375-80, 2013 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-23671096

RESUMEN

Synthetic nitrogen (N) fertilizer has played a key role in enhancing food production and keeping half of the world's population adequately fed. However, decades of N fertilizer overuse in many parts of the world have contributed to soil, water, and air pollution; reducing excessive N losses and emissions is a central environmental challenge in the 21st century. China's participation is essential to global efforts in reducing N-related greenhouse gas (GHG) emissions because China is the largest producer and consumer of fertilizer N. To evaluate the impact of China's use of N fertilizer, we quantify the carbon footprint of China's N fertilizer production and consumption chain using life cycle analysis. For every ton of N fertilizer manufactured and used, 13.5 tons of CO2-equivalent (eq) (t CO2-eq) is emitted, compared with 9.7 t CO2-eq in Europe. Emissions in China tripled from 1980 [131 terrogram (Tg) of CO2-eq (Tg CO2-eq)] to 2010 (452 Tg CO2-eq). N fertilizer-related emissions constitute about 7% of GHG emissions from the entire Chinese economy and exceed soil carbon gain resulting from N fertilizer use by several-fold. We identified potential emission reductions by comparing prevailing technologies and management practices in China with more advanced options worldwide. Mitigation opportunities include improving methane recovery during coal mining, enhancing energy efficiency in fertilizer manufacture, and minimizing N overuse in field-level crop production. We find that use of advanced technologies could cut N fertilizer-related emissions by 20-63%, amounting to 102-357 Tg CO2-eq annually. Such reduction would decrease China's total GHG emissions by 2-6%, which is significant on a global scale.


Asunto(s)
Huella de Carbono , Industria Química/métodos , Industria Química/tendencias , Conservación de los Recursos Naturales/métodos , Fertilizantes , Efecto Invernadero/prevención & control , Nitrógeno , Industria Química/economía , Industria Química/legislación & jurisprudencia , China , Conservación de los Recursos Naturales/economía , Conservación de los Recursos Naturales/tendencias
6.
Foodborne Pathog Dis ; 13(6): 296-302, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27046731

RESUMEN

Antimicrobial resistance (AR) is a global problem with serious implications for public health. AR genes are frequently detected on animal farms, but little is known about their origin and distribution patterns. We hypothesized that AR genes can transfer from animal feces to the environment through manure, and to this end, we characterized and compared the resistomes (collections of AR genes) of animal feces, manure, and soil samples collected from five dairy farms using a metagenomics approach. Resistomes constituted only up to 1% of the total gene content, but were variable by sector and also farm. Broadly, the identified AR genes were associated with 18 antibiotic resistances classes across all samples; however, the most abundant genes were classified under multidrug transporters (44.75%), followed by resistance to vancomycin (12.48%), tetracycline (10.52%), bacitracin (10.43%), beta-lactam resistance (7.12%), and MLS efflux pump (6.86%) antimicrobials. The AR gene profiles were variable between farms. Farm 09 was categorized as a high risk farm, as a greater proportion of AR genes were common to at least three sectors, suggesting possible horizontal transfer of AR genes. Taxonomic characterization of AR genes revealed that a majority of AR genes were associated with the phylum Proteobacteria. Nonetheless, there were several members of Bacteroidetes, particularly Bacteroides genus and several lineages from Firmicutes that carried similar AR genes in different sectors, suggesting a strong potential for horizontal transfer of AR genes between unrelated bacterial hosts in different sectors of the farms. Further studies are required to affirm the horizontal gene transfer mechanisms between microbiomes of different sectors in animal agroecosystems.


Asunto(s)
Enfermedades de los Bovinos/epidemiología , Industria Lechera , Farmacorresistencia Bacteriana/genética , Microbiología de Alimentos , Crianza de Animales Domésticos , Animales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Bacteroides/efectos de los fármacos , Bovinos , Enfermedades de los Bovinos/tratamiento farmacológico , Enfermedades de los Bovinos/microbiología , Heces/microbiología , Femenino , Estiércol/microbiología , Pennsylvania/epidemiología , Prevalencia , Microbiología del Suelo
7.
J Environ Qual ; 42(4): 972-81, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24216349

RESUMEN

China has made remarkable strides in recent decades to grow enough food to feed 20% of the world's population with only 9% of the world's arable land. Meanwhile, the nation is experiencing exacerbated air and water pollution problems. Agricultural growth and the pollution aggravation are closely linked with policies affecting fertilizer production and use. Essentially nonexistent in 1950, China's fertilizer industry is now a robust conglomerate producing fertilizers in amounts that not only meet domestic demand but also contribute to international trade. The industry's growth stemmed from a series of policy progressions, featuring (i) a total control system with state ownership and central planning (1949-1984), (ii) a dual system of central planning and market adjustment (1985-1997), (iii) a market-driven system with government-mandated price caps (1998-2009), and (iv) a complete market-oriented system (since 2009). In conjunction with the policy changes were massive subsidy programs totaling more than $18 billion in 2010. The support policies and subsidies helped grow the industry and safeguard an adequate supply of fertilizers at affordable costs to farmers, but the artificially low-priced fertilizers also contributed to a nationwide trend of fertilizer overuse, leading to nutrient pollution. China needs innovative policies and programs to address food security and sustainability challenges. In this study, we review and analyze policies and programs related to China's fertilizer production and use in a 60-yr span (1950-2010) and discuss its impact on the development of the industry, food security, and pressing environmental issues. Finally, our study analyzes long-term trends in fertilizer use in China and offers some key viewpoints to stimulate debates among all stakeholders.


Asunto(s)
Fertilizantes , Abastecimiento de Alimentos , Agricultura/economía , China , Conservación de los Recursos Naturales , Ambiente
8.
J Environ Qual ; 42(4): 982-9, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24216350

RESUMEN

China's vegetable production has experienced a rapid growth in recent years. Total production amounted to 522.7 million Mg (1 Mg = 10 g) in 2009, which was more than nine times that in 1980 and represented >50% of the world production. Meanwhile, excessive use of animal manures and chemical fertilizers in vegetable fields has brought various production and environmental challenges, including excessive accumulation of nutrients in soils and accelerated water pollution problems. In this study, we have evaluated the current status of phosphorus (P) in China's intensive vegetable production systems based on data summarized from nearly 100 publications plus results from our recent experiments. Gross overfertilization occurred in greenhouse (571 kg P ha) and open-field (117 kg P ha) vegetable systems compared with P removal in harvested crops (44 and 25 kg P ha) per season. Excess P input led to soil enrichment of labile P, measured as Olsen-P, averaging 179 (greenhouses) and 100 mg P kg (open fields) in the 0- to 20-cm soil depth, and in some cases led to P leaching, as evidenced by increases in Olsen-P and CaCl-P at the 40- to 60-cm soil depth. The vast majority of vegetable soils had Olsen-P exceeding the critical level (46.0-58.0 mg P kg) for optimum vegetable yield. Innovative policies and strategies are urgently needed to implement science-based nutrient management practices to attain sustainable vegetable production while protecting natural and environmental resources.


Asunto(s)
Fósforo , Suelo , Animales , Fertilizantes , Contaminantes del Suelo , Verduras
9.
Sci Total Environ ; 902: 166105, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37582443

RESUMEN

To develop new animal feed sources and establish a sustainable food upcycling system, the material feasibility and feeding potential of fresh vegetable waste (FVW) were clarified in this study. First, the FVW output of wet markets in Hangzhou, China was tracked and predicted. The results showed that the retail waste ratio of FVW in wet markets reached 9.3 %, predicting that China's FVW will reach 9034 kt in 2030. Second, the study revealed that the nutritive value of FVW was comparable to that of traditional alfalfa feed, suitable for use as animal feed. However, we found a high probability of microbial contamination. Therefore, FVW should have stricter classification and collection methods. Under this premise, the feeding utilization potential of FVW in wet markets is large. In 2030, the crude protein content may replace 2737 kt of alfalfa, saving 7.7 E + 08 m3 of water and 75,018 ha of land.


Asunto(s)
Alimentación Animal , Frutas , Verduras , Animales , Alimentación Animal/análisis , Estudios de Factibilidad , China , Abastecimiento de Alimentos
10.
Nat Food ; 4(11): 1007-1017, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37828076

RESUMEN

Eliminating both overt and hidden hunger is at the core of the global food and nutrition security agenda. Yet, the collective state of nutrition security at the population level is not known. Here we quantify food-based availability of 11 essential nutrients for 156 countries using a food production-consumption-nutrition model, followed by assessment of the nutrient availability status as a ratio of recommended intake. For the baseline year 2017, global per capita availability was adequate for calorie and protein but in severe deficit for vitamin A and calcium (intake ratios, <0.60, where 1.0 is adequate) and moderate deficit for vitamin B12 (intake ratio, 0.76). At the country level, more than half of the 156 countries were in various degrees of deficit for all nine micronutrients. Disparities across regions or countries were enormous. We explore intervention strategies from an agriculture-food system perspective and discuss the daunting challenges of addressing nutrition security broadly.


Asunto(s)
Nutrientes , Estado Nutricional , Humanos , Micronutrientes , Ingestión de Energía , Agricultura
11.
Nat Food ; 3(9): 741-752, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-37118141

RESUMEN

Compost represents an important input for sustainable agriculture, but the use of diverse compost types causes uncertain outcomes. Here we performed a global meta-analysis with over 2,000 observations to determine whether a precision compost strategy (PCS) that aligns suitable composts and application methods with target crops and growth environments can advance sustainable food production. Eleven key predictors of compost (carbon-to-nutrient ratios, pH and salt content electric conductivity), management (nitrogen N supply) and biophysical settings (crop type, soil texture, soil organic carbon, pH, temperature and rainfall) determined 80% of the effect on crop yield, soil organic carbon and nitrous oxide emissions. The benefits of a PCS are more pronounced in drier and warmer climates and soils with acidic pH and sandy or clay texture, achieving up to 40% higher crop yield than conventional practices. Using a data-driven approach, we estimate that a global PCS can increase the production of major cereal crops by 96.3 Tg annually, which is 4% of current production. A global PCS has the technological potential to restore 19.5 Pg carbon in cropland topsoil (0-20 cm), equivalent to 26.5% of current topsoil soil organic carbon stocks. Together, this points to a central role of PCS in current and emerging agriculture.

12.
Sci Rep ; 12(1): 13630, 2022 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-35948608

RESUMEN

Modern agri-food systems generate large amounts of crop-based biomass that are unfit for direct human consumption but potentially suitable for livestock feeding in production of meats, milk, and eggs. This study aims to develop novel feeds for cattle from some of those biomass materials through the natural microbial-driven processes of ensiling. Fruit and vegetables resembling supermarket discards were ensiled alone or co-ensiled with corn crop residues, mushroom wastes, etc. via laboratory experiments. Longitudinal sample analyses showed that (co-)ensiling was successful, with pH and fermentation acids changing rapidly into desirable ranges (pH < 4.5, the acids 5-13% DM with lactic acid dominating). The (co-)ensiled products had key nutritional parameters comparable to those of good quality forages commonly used on dairy farms. Additionally, in vitro incubation experiments indicated that the ensiled products could substitute certain conventional feeds while maintaining diet digestibility. Findings from this pilot study provide a proof of principle that quality novel feeds for cattle can be generated by co-ensiling food discards and low-value crop residues. Future research and animal feeding trials to demonstrate the utility of this approach can help societies more effectively utilize untapped biomass resources, strengthening the regenerative capacity of agri-food systems towards a more sustainable food future.


Asunto(s)
Leche , Ensilaje , Animales , Biomasa , Bovinos , Digestión , Fermentación , Humanos , Ganado , Proyectos Piloto , Ensilaje/análisis , Zea mays/química
13.
PLoS One ; 16(12): e0260244, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34919561

RESUMEN

The COVID-19 pandemic brought profound changes to all corners of society and affected people in every aspect of their lives. This survey-based study investigated how household food related matters such as food sourcing and consumption behaviors of 2,126 Chinese consumers in different age groups changed approximately two months into the COVID-19 quarantine. A new food sourcing mechanism, community-based online group grocery-ordering (CoGGO), was widely adopted by households, particularly among the youngest group studied (18-24 years of age). The same group showed a higher confidence in the food supply system during the quarantine and a greater propensity for weight gain while staying-at-home. The more mature age group (≥35 years of age) showed heightened vigilance and awareness, with fewer grocery-shopping trips, a higher tendency for purchasing extra food, and less tendency to waste food. Survey findings of the new food-sourcing mechanism, attitudes to food, and changes in behavior among different age groups provide valuable insights to guide policies and management interventions to address matters pertaining to food supply and distribution, food access and household food security, and food waste reduction.


Asunto(s)
COVID-19/epidemiología , Comportamiento del Consumidor/estadística & datos numéricos , Abastecimiento de Alimentos/estadística & datos numéricos , Pandemias , Cuarentena , Eliminación de Residuos/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Adulto Joven
14.
Nat Food ; 2(7): 519-528, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37117678

RESUMEN

Food loss and waste (FLW) hampers global food security, human health and environmental sustainability. However, monitoring and benchmarking FLW reduction is often constrained by the lack of reliable and consistent data, especially for emerging economies. Here we use 6 yr large-scale field surveys and literature data to quantify the FLW of major agrifood products along the entire farm-to-fork chain in China. We show that 27% of food annually produced for human consumption in the country (349 ± 4 Mt) is lost or wasted; 45% of this is associated with postharvest handling and storage and 13% with out-of-home consumption activities. We also show that the land, water, carbon, nitrogen and phosphorus footprints associated with total FLW are similar to those of a medium-sized country (such as the United Kingdom's in the case of carbon footprint). These results highlight the importance of better primary data to inform FLW reduction actions and ensure food security and sustainability.

15.
Nat Food ; 2(6): 426-433, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37118228

RESUMEN

China purchases around 66% of the soy that is traded internationally. This strains the global food supply and contributes to greenhouse gas emissions. Here we show that optimizing the maize and soy production of China can improve its self-sufficiency and also alleviate adverse environmental effects. Using data from more than 1,800 counties in China, we estimate the area-weighted yield potential (Ypot) and yield gaps, setting the attainable yield (Yatt) as the yield achieved by the top 10% of producers per county. We also map out county-by-county acreage allocation and calculate the attainable production capacity according to a set of sustainability criteria. Under optimized conditions, China would be able to produce all the maize and 45% of the soy needed by 2035-while reducing nitrogen fertilizer use by 26%, reactive nitrogen loss by 28% and greenhouse gas emissions by 19%-with the same acreage as 2017, our reference year.

16.
Nat Food ; 2(1): 47-53, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37117651

RESUMEN

China produces half of the world's vegetables. The production uses 1.7% of the global harvest area of crops but accounts for 7.8% of the chemical fertilizers and 6.6% of crop-sourced greenhouse gas (GHG) emissions worldwide. Using an innovative management programme, the integrated knowledge and products strategy (IKPS), we demonstrate opportunities for producing more vegetables with lower environmental impacts in China's vegetable production systems. Combining soil-crop system management practices with enhanced-efficiency fertilizer products, IKPS was tested through 54 site-year field experiments in China's major agro-ecological zones by a national research network over 12 years. Compared with current farming practices, the adoption of IKPS decreased the nitrogen (N) application rate by 38%, N surplus by 65% and GHG emissions by 28%, while increasing yield by 17%. Scenario analyses showed that adoption of IKPS in China's vegetable production could mitigate resource and environmental burdens while enhancing food and nutrition security.

17.
J Environ Qual ; 39(5): 1537-44, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21043259

RESUMEN

China's economic boom in recent decades has stimulated consumer demand for animal products and consequently, a vast expansion in animal production. From 1978 to 2006, the number of animals increased by 322% for pigs, 209% for poultry, and 2770% for dairy cattle. The objective of the present study was to quantify nitrogen mass flow in China's animal production system at the national scale and to elucidate potential environmental implications. A comprehensive analysis was performed combining statistical records with data from the scientific literature and supplemental survey information. Results indicate that approximately 18 Mt of N flowed through the Chinese animal production system in 2006. Nitrogen input to the system was from various feed materials, including 6.8 Mt (38% of total) from roughage, 4.4 Mt (24%) from byproducts, 2.3 Mt (13%) from cereal grains, and 1.6 Mt (9%) each from crop residues and oilseed cakes, with the remaining N (16%) obtained from other feedstuffs. Nitrogen outputs from the system included edible animal products (2.4 t, 13% of total), nonedible animal parts (e.g., bones, skins) (3.8 Mt, 21%), and excreta (12 Mt, 66%). At the national level, the excreta would average 28 Mg (as excreted) and 90 kg N ha(-1) of cropland. However, at the provincial level, it varied from 1 Mg ha(-1) (5 kg N ha(-1)) in Qinghai to 97 Mg ha(-1) (243 kg N ha(-1)) in Sichuan. In regions with excreta in the intermediate rate (e.g., Hebei Province, 115 kg N ha(-1)) or high rare (e.g., Sichuan Province, 243 kg N ha(-1)), animal manure contributes significantly to nutrients polluting groundwater and/or surface waters. It is crucial for China to develop and implement proper management practices to maximum the beneficial use of the 12 Mt excreta N while minimizing its environmental footprint.


Asunto(s)
Crianza de Animales Domésticos , Ambiente , Nitrógeno , Animales , China , Estiércol
18.
Environ Microbiome ; 15(1): 21, 2020 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-33902716

RESUMEN

BACKGROUND: Antimicrobial resistance is a serious concern. Although the widespread use of antimicrobials in livestock has exacerbated the emergence and dissemination of antimicrobial resistance genes (ARG) in farm environments, little is known about whether antimicrobial use affects distribution of ARG in livestock systems. This study compared the distribution of microbiomes and resistomes (collections of ARG) across different farm sectors in dairy herds that differed in their use of antimicrobials. Feces from heifers, non-lactating, and lactating cows, manure storage, and soil from three conventional (antimicrobials used to treat cows) and three organic (no antimicrobials used for at least four years) farms in Pennsylvania were sampled. Samples were extracted for genomic DNA, processed, sequenced on the Illumina NextSeq platform, and analyzed for microbial community and resistome profiles using established procedures. RESULTS: Microbial communities and resistome profiles clustered by sample type across all farms. Overall, abundance and diversity of ARG in feces was significantly higher in conventional herds compared to organic herds. The ARG conferring resistance to betalactams, macrolide-lincosamide-streptogramin (MLS), and tetracyclines were significantly higher in fecal samples of dairy cows from conventional herds compared to organic herds. Regardless of farm type, all manure storage samples had greater diversity (albeit low abundance) of ARG conferring resistance to aminoglycosides, tetracyclines, MLS, multidrug resistance, and phenicol. All soil samples had lower abundance of ARG compared to feces, manure, and lagoon samples and were comprised of ARG conferring resistance to aminoglycosides, glycopeptides, and multi-drug resistance. The distribution of ARG is likely driven by the composition of microbiota in the respective sample types. CONCLUSIONS: Antimicrobial use on farms significantly influenced specific groups of ARG in feces but not in manure storage or soil samples.

19.
J Environ Qual ; 38(5): 1909-18, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19643757

RESUMEN

Organic dairy production has increased rapidly in recent years. Organic dairy cows (Bos taurus) generally eat different diets than their conventional counterparts. Although these differences could impact availability, utilization, and cycling of manure nutrients, little such information is available to aid organic dairy farmers in making nutrient and manure management decisions. In this study, we comparatively characterized P in organic and conventional dairy manure using solution and solid state (31)P NMR spectroscopic techniques. Phosphorus in both types of dairy manure was extracted with water, Na acetate buffer (100 mmol L(-1), pH 5.0) plus 20 mg Na dithionite mL(-1), or 0.025 mol L(-1) NaOH with 50 mmolL(-1) EDTA. Solution NMR analysis revealed that organic dairy manure contained about 10% more inorganic phosphate than conventional dairy manure. Whereas organic dairy manure did contain slightly more phytate P, it contained 30 to 50% less monoester P than conventional dairy manure. Solid state NMR spectroscopy revealed that mono-, di-, and trivalent metal P species with different stabilities were present in the two dairy manures. Conventional dairy manure contained relatively higher contents of soluble inorganic P species and stable metal phytate species. In contrast, organic dairy manure contained more Ca and Mg species of P. These results indicate that P transformation rates and quantities should be expected to differ between organic and conventional dairy manures.


Asunto(s)
Estiércol , Fósforo/análisis , Animales , Bovinos , Productos Lácteos , Femenino , Alimentos Orgánicos , Resonancia Magnética Nuclear Biomolecular , Fósforo/química , Isótopos de Fósforo
20.
J Hazard Mater ; 341: 346-354, 2018 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-28802245

RESUMEN

A two-compartment microcosm was used to investigate the role of arbuscular mycorrhizal fungus (AMF) hyphae and earthworm in altering soil microbial community and OTC degradation. Treatments comprised OTC-contaminated hyphal compartments with or without AMF hyphae and with or without earthworms. Results indicated both AMF hyphae and earthworms accelerated OTC degradation; two degradation products were identified as 4-epi-oxytetracycline (EOTC) and 2-acetyl-2-decarboxamido-oxytetracycline (ADOTC). Q-PCR results indicated that both earthworms and AMF hyphae increased 16s rDNA gene, enhancing OTC degradation consequently. Illumina sequencing of the 16S rRNA genes showed that AMF hyphae and earthworm altered bacterial community. Earthworms stimulated the growth of class Anaerolineae, family Flavobacteriaceae, Genus Pseudomonas, reducing OTC residues. AMF hyphae significantly increased the abundance of family Pirellulaceae, genus Glycomyces, and Nonomuraea which had a negative correlation with EOTC, accelerating OTC degradation. When used together, AMF hyphae and earthworms enhanced OTC degradation by stimulating class Anaerolineae and family Flavobacteriaceae.


Asunto(s)
Antibacterianos/metabolismo , Micorrizas , Oligoquetos , Oxitetraciclina/metabolismo , Microbiología del Suelo , Contaminantes del Suelo/metabolismo , Animales , Bacterias/genética , Bacterias/metabolismo , Biodegradación Ambiental , Medicago/microbiología , ARN Ribosómico 16S/genética , Zea mays/microbiología
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