RESUMO
The current centralized configuration of the ammonia industry makes the production of nitrogen fertilizers susceptible to the volatility of fossil fuel prices and involves complex supply chains with long-distance transport costs. An alternative consists of on-site decentralized ammonia production using small modular technologies, such as electric Haber-Bosch or electrocatalytic reduction. Here we evaluate the cost-competitiveness of producing low-carbon ammonia at the farm scale, from a solar agrivoltaic system, or using electricity from the grid, within a novel global fertilizer industry. Projected costs for decentralized ammonia production are compared with historical market prices from centralized production. We find that the cost-competitiveness of decentralized production relies on transport costs and supply chain disruptions. Taking both factors into account, decentralized production could achieve cost-competitiveness for up to 96% of the global ammonia demand by 2030. These results show the potential of decentralized ammonia technologies in revolutionizing the fertilizer industry, particularly in regions facing food insecurity.
Assuntos
Amônia , Fertilizantes , Segurança Alimentar , Fertilizantes/análise , Fertilizantes/economia , Amônia/metabolismo , Agricultura/economia , Agricultura/métodos , Nitrogênio/metabolismoRESUMO
Avoiding excessive agricultural nitrogen (N) use without compromising yields has long been a priority for both research and government policy in China1,2. Although numerous rice-related strategies have been proposed3-5, few studies have assessed their impacts on national food self-sufficiency and environmental sustainability and fewer still have considered economic risks faced by millions of smallholders. Here we established an optimal N rate strategy based on maximizing either economic (ON) or ecological (EON) performance using new subregion-specific models. Using an extensive on-farm dataset, we then assessed the risk of yield losses among smallholder farmers and the challenges of implementing the optimal N rate strategy. We find that meeting national rice production targets in 2030 is possible while concurrently reducing nationwide N consumption by 10% (6-16%) and 27% (22-32%), mitigating reactive N (Nr) losses by 7% (3-13%) and 24% (19-28%) and increasing N-use efficiency by 30% (3-57%) and 36% (8-64%) for ON and EON, respectively. This study identifies and targets subregions with disproportionate environmental impacts and proposes N rate strategies to limit national Nr pollution below proposed environmental thresholds, without compromising soil N stocks or economic benefits for smallholders. Thereafter, the preferable N strategy is allocated to each region based on the trade-off between economic risk and environmental benefit. To facilitate the adoption of the annually revised subregional N rate strategy, several recommendations were provided, including a monitoring network, fertilization quotas and smallholder subsidies.
Assuntos
Agricultura , Produtos Agrícolas , Ambientalismo , Nitrogênio , Oryza , Desenvolvimento Sustentável , Agricultura/economia , Agricultura/métodos , China , Fertilizantes/análise , Fertilizantes/economia , Nitrogênio/análise , Nitrogênio/economia , Nitrogênio/metabolismo , Oryza/metabolismo , Solo/química , Produtos Agrícolas/economia , Produtos Agrícolas/metabolismo , Produtos Agrícolas/provisão & distribuição , Ecologia , Fazendeiros , Conjuntos de Dados como Assunto , Abastecimento de AlimentosAssuntos
Fertilizantes , Biologia Marinha , Mineração , Brasil , Fertilizantes/economia , Mineração/economiaRESUMO
Experiments showed that biodiversity increases grassland productivity and nutrient exploitation, potentially reducing fertiliser needs. Enhancing biodiversity could improve P-use efficiency of grasslands, which is beneficial given that rock-derived P fertilisers are expected to become scarce in the future. Here, we show in a biodiversity experiment that more diverse plant communities were able to exploit P resources more completely than less diverse ones. In the agricultural grasslands that we studied, management effects either overruled or modified the driving role of plant diversity observed in the biodiversity experiment. Nevertheless, we show that greater above- (plants) and belowground (mycorrhizal fungi) biodiversity contributed to tightening the P cycle in agricultural grasslands, as reduced management intensity and the associated increased biodiversity fostered the exploitation of P resources. Our results demonstrate that promoting a high above- and belowground biodiversity has ecological (biodiversity protection) and economical (fertiliser savings) benefits. Such win-win situations for farmers and biodiversity are crucial to convince farmers of the benefits of biodiversity and thus counteract global biodiversity loss.
Assuntos
Agricultura/métodos , Biodiversidade , Pradaria , Fósforo/metabolismo , Agricultura/economia , Biomassa , Fertilizantes/economia , Análise de Classes Latentes , Micorrizas/classificação , Micorrizas/metabolismo , Fósforo/análise , Fósforo/economia , Plantas/classificação , Plantas/metabolismo , Plantas/microbiologia , Solo/química , Microbiologia do SoloRESUMO
The North-West (NW) region of Bangladesh is pivotal for the country's agricultural development, mainly in producing irrigated Boro rice. However, increasing cost of irrigation water, fertilizers, labour and other inputs, and the spatio-temporal variation in actual yield, market price and profitability of rice, have added uncertainty to the sustainability of Boro rice cultivation. In this study, we evaluated the productivity, profitability, and prospect of Boro rice production using comprehensive field data collected directly from 420 farmers' fields over two consecutive seasons (2015-16 and 2016-17), across seven geographically distributed locations in the NW region. We also analyzed the risk and return trade of popular Boro rice cultivars using Monte-Carlo simulation. The results show that there were significant (p≤0.05) variations in rice yield between sites, irrigation pump-types, and rice varieties, with Hybrid rice and BRRI dhan29 producing highest yields (6.0-7.5 t/ha). Due to different pricing systems, the cost of irrigation water varied from site to site and from year to year, but always comprised the highest input cost (20-25% of total production). The total paid-out cost, gross benefit, and gross income of rice significantly (p≤0.05) differed between sites, type of irrigation pumps, rice varieties, transplanting dates, and two cropping years. The variations in observed yield and profitability reveal considerable scope to improve rice production systems. Market variation in the price of rice affected overall profitability significantly. Probability and risk analysis results show that Minikit and BRRI dhan29 are the most stable varieties for yield and profitability. Hybrid rice, which has the maximum attainable yield among the cultivated rice varieties, also has the risk of negative net income. Based on the analysis, we discussed ways to improve yield and profitability and the prospect of Boro rice cultivation in the region. The study provides valuable information for policy-makers to sustain irrigated rice cultivation in both the NW region and nationally.
Assuntos
Irrigação Agrícola/economia , Irrigação Agrícola/métodos , Marketing/economia , Oryza/crescimento & desenvolvimento , Bangladesh , Fertilizantes/economia , Marketing/métodos , Método de Monte Carlo , IncertezaRESUMO
We present an easily calibrated spatial modeling framework for estimating location-specific fertilizer responses, using smallholder maize farming in Tanzania as a case study. By incorporating spatially varying input and output prices, we predict the expected profitability for a location-specific smallholder farmer. A stochastic rainfall component of the model allows us to quantify the uncertainty around expected economic returns. The resulting mapped estimates of expected profitability and uncertainty are good predictors of actual smallholder fertilizer usage in nationally representative household survey data. The integration of agronomic and economic information in our framework makes it a powerful tool for spatially explicit targeting of agricultural technologies and complementary investments, as well as estimating returns to investments at multiple scales.
Assuntos
Produção Agrícola/economia , Fertilizantes/economia , Investimentos em Saúde/economia , Modelos Econômicos , Zea mays/crescimento & desenvolvimento , Produção Agrícola/métodos , Fazendas/economia , Fazendas/estatística & dados numéricos , Previsões/métodos , Chuva , Análise Espacial , Processos Estocásticos , Tanzânia , IncertezaRESUMO
Low crop yields in Sub-Saharan Africa are associated with low fertilizer use. To better understand patterns of, and opportunities for, fertilizer use, location specific fertilizer price data may be relevant. We compiled local market price data for urea fertilizer, a source of inorganic nitrogen, in 1729 locations in eighteen countries in two regions (West and East Africa) from 2010-2018 to understand patterns in the spatial variation in fertilizer prices. The average national price was lowest in Ghana (0.80 USD kg-1), Kenya (0.97 USD kg-1), and Nigeria (0.99 USD kg-1). Urea was most expensive in three landlocked countries (Burundi: 1.51, Uganda: 1.49, and Burkina Faso: 1.49 USD kg-1). Our study uncovers considerable spatial variation in fertilizer prices within African countries. We show that in many countries this variation can be predicted for unsampled locations by fitting models of prices as a function of longitude, latitude, and additional predictor variables that capture aspects of market access, demand and environmental conditions. Predicted within-country urea price variation (as a fraction of the median price) was particularly high in Kenya (0.77-1.12), Nigeria (0.83-1.34), Senegal (0.73-1.40), Tanzania (0.90-1.29) and Uganda (0.93-1.30), but much lower in Burkina Faso (0.96-1.04), Burundi (0.95-1.05), and Togo (0.94-1.05). The correlation coefficient of the country level models was between 0.17 to 0.83 (mean 0.52) and the RMSE varies from 0.005 to 0.188 (mean 0.095). In 10 countries, predictions were at least 25% better than a null-model that assumes no spatial variation. Our work indicates new opportunities for incorporating spatial variation in prices into efforts to understand the profitability of agricultural technologies across rural areas in Sub-Saharan Africa.
Assuntos
Agricultura/economia , Fertilizantes/economia , África Subsaariana , Comércio/economia , Produtos Agrícolas/crescimento & desenvolvimento , Fertilizantes/provisão & distribuição , Ureia/economia , Ureia/provisão & distribuiçãoRESUMO
Chemical fertilizer application is the primary method used to maintain tea yield and quality, but has a negative environmental impact owing to its excessive use. This study sought to assess the environmental and economic benefits of three different chemical fertilizer reduction modes: Single reduction of chemical fertilizer (SRCF), combined application of organic and chemical fertilizer (CAOF), and controlled-release fertilizer substitute (CRFS). Differences in soil nutrient content, NP (NH4+-N, NO3-N and total P) runoff loss, tea yield and quality, and the revenue of tea planting across different fertilizer reduction treatments were then discussed. We also analyzed the coupling effects of these different fertilization modes, fertilization rate and time on soil NP runoff loss, which allowed us to determine the optimum fertilization method based on differences in their respective environmental and economic benefits. Our results revealed differences in soil nutrient content, tea yield and quality, NP runoff loss, and revenue owing to tea planting across the different fertilization treatments. Soil pH after fertilization was significantly lower than before fertilization. CAOF was beneficial and improved soil nutrients as well as tea yield and quality. Of the tested methods, 50% combined application of organic and chemical fertilizer (CAOF2) was the best, as it resulted in the best tea quality and yield. CAOF2 also had the highest revenue. In addition, it was beneficial in reducing NP runoff loss. CRFS was advantageous in its persistent fertilizer efficiency and reduction in NP runoff loss. With CAOF, NP runoff loss was primarily caused by quick-acting chemical fertilizer. With extended time, NP runoff loss caused by fertilization was gradually decreased. Given our analysis of the environmental and economic benefits of different fertilizer reduction methods, CAOF2 emerged in this study as the best fertilizer reduction treatment option.
Assuntos
Fertilizantes/economia , Jardins , Agricultura , Nitrogênio , Solo , CháRESUMO
Abstract Improper management degrades the soil, decreases corn productivity and is reflected in the cost of production. The objective of this research was to evaluate the soil recovery in non-conservationist treatments after the change of management and cultivation to the conservation condition direct sowing, and compare these systems to consolidated direct seeding; This evaluation was based on the soil responsiveness to crop production and water erosion control, and based on the financial cost of soil recovery and corn production when soil management was converted from non-conservationist (tillage rotation - RT, minimum tillage - MT, conventional tillage - CT and bare soil - BS) to no-tillage (NT) condition, in a Humic Cambisol. The transition from managements to no-tillage occurred in 2015 year, after 27 years of conducting the preexisting managements. The chemical recovery was carried out with the application of limestone, phosphorus, and potassium. At the end of the research the yield of the corn crop, the cost of recovering the soil fertility and the cost of crop production were evaluated. Previous soil management influenced the cost of soil chemical recovery. The cost of production showed a financial loss for the previous treatments CT and BS, on the average of the three corn crops.
Assuntos
Fósforo/administração & dosagem , Potássio/administração & dosagem , Tratamento do Solo/métodos , Zea mays/crescimento & desenvolvimento , Fertilizantes , Carbonato de Cálcio/administração & dosagem , Tratamento do Solo/economia , Erosão Hídrica/prevenção & controle , Custos e Análise de Custo , Conservação de Terras/economia , Conservação de Terras/métodos , Fertilizantes/economia , Produção Agrícola/economiaRESUMO
Nitrogen (N), phosphorus (P), and potassium (K) exert various effects on adzuki bean yields. Our research was conducted in a semi-arid area, and four test sites were established in environments that have chernozem or sandy loam soils. During a five-year period, the effects of N, P, and K fertilizers on yield were comprehensively investigated in field trials (2014-2016) and for model-implementation trials (2017-2018), with models established prior to the latter. In the field trials, 23 treatments comprising different N, P, and K combinations significantly affected both yield and yield components, and regression analysis indicated that the experimental results were suitable for model establishment. The model subsequently demonstrated that the yield and the yield components were more sensitive to N and K fertilizer than to P fertilizer. Moreover, the yield and yield components increased. These yield increases were intense in response to the 0.5 to 1.34 levels in terms of the single effects; interaction effects; and the effects of combinations of N, P, and K fertilizers. Moreover, the effects of combinations of N, P, and K fertilizers were more significant on yield than were the single or interaction effects of N, P, and K fertilizers. The optimal fertilizer combination that resulted in high yields (≥1941.53 kg ha-1) comprised 57.23-68.43 kg ha-1 N, 36.04-47.32 kg ha-1 P2O5 and 50.29-61.27 kg ha-1 K2O. The fertilizer combination that resulted in the maximum yield was 62.98 kg ha-1 N, 47.04 kg ha-1 P2O5 and 59.95 kg ha-1 K2O (N:P2O5:K2O = 1:0.75:0.95), which produced the model-expected yield in trials at multiple sites. An economical fertilizer combination was determined on the basis of the best fertilizer measures in consideration of the cost of fertilizer and seed; this combination achieved yields of 2236.17 kg ha-1, the profit was 15,653.16 Yuan ha-1, and the corresponding rates were 57.60 kg ha-1 N, 47.03 kg ha-1 P2O5, and 31.64 kg ha-1 K2O (N:P2O5:K2O = 1:0.82:0.55).
Assuntos
Clima Desértico , Fertilizantes , Nitrogênio/farmacologia , Fósforo/farmacologia , Potássio/farmacologia , Vigna/crescimento & desenvolvimento , China , Fertilizantes/economia , Modelos Teóricos , Análise de Regressão , Vigna/efeitos dos fármacosRESUMO
The generation and poor disposal of waste from livestock industries is the major cause of pollution of water sources, soil, and air. Therefore, profitable alternatives are required for their correct disposal and use. Anaerobic digestion plants are a technologically viable solution to overcome this problem. In this study, it is proposed a methodology for the design and economic assessment of projects using anaerobic digestion plants to produce electrical energy, thermal energy, and biofertilizer from livestock waste. The methodology is developed based on the assumption that the process is mainly composed of an anaerobic digester and an electric generator having a Diesel-cycle internal combustion engine. It is programmed in "MS Excel" sheet and assessed using technical and economic data from a three real anaerobic digestion plants. The methodology obtains technical parameters such as energy production efficiency with an average difference of 35% compared to the real plants data. In addition, the unit capital costs are calculated, obtaining a value of 3789/kW with a difference of 21.1%, as well as unit operating costs of 729/kW per year with a difference of 15.2%. The financial viability of the project is assessed by calculating the net present value and obtaining 577,050 with a difference of 17.8% and an internal rate of return with a percentage difference of 3%. The proposed methodology specifies the technical parameters and the basic engineering of an anaerobic digestion plant in a stationary state, where the basic streams and dimensions of primary equipment, such as anaerobic reactors and electric generators, are specified. Moreover, the methodology calculates capital and operating expenses for an anaerobic digestion plant, which may be useful to assess the technical and financial feasibility for a project of this type.
Assuntos
Criação de Animais Domésticos , Fertilizantes/economia , Eliminação de Resíduos Líquidos/métodos , Resíduos/economia , Animais , GadoRESUMO
Modern agriculture needs a paradigm shift to make the world's food production sustainable while mitigating social and environmental externalities. Although various policies to limit the use of agrochemicals have recently been implemented in the European Union, the use of both herbicides and fertilizers has remained fairly constant. Farmers are assumed to behave optimally, producing the best they can, given the agronomic constraints of their fields. Based on this assumption, reducing agrochemicals should inevitably have negative effects on food production, or reduce farmers' incomes. Coupling empirical analysis based on field surveys and experimental trials where weed management and nitrogen input were manipulated in the same production fields and under real farming conditions, we demonstrate that high use of N fertiliser or intense weed control slightly increase yields, but that this increase is not enough to offset the additional costs incurred by their use. Our experimental design allowed inputs to be varied in a two-factor design, along a gradient spanning from organic to highly intensive farming, while holding all other conditions constant and thus avoiding confounding effects. Quantification of crop yields and gross margins from winter cereal farming showed that reducing dependence on weed management may not hamper cereal production in this system, and is economically profitable at the field level on the short term. Our study thus contributes to addressing a key gap in our economic knowledge, and gives hope for implementing win-win strategies for farmers and the environment.
Assuntos
Agricultura/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Grão Comestível/crescimento & desenvolvimento , Fazendeiros , Estações do Ano , Controle de Plantas Daninhas/métodos , Agricultura/economia , Algoritmos , Biomassa , Análise Custo-Benefício , Fertilizantes/economia , França , Geografia , Herbicidas/administração & dosagem , Herbicidas/economia , Nitrogênio/metabolismoRESUMO
Exhaustive crops such as cotton require potassium (K) in copious amounts as compared to other crops. High yielding cultivars in cotton-wheat cropping system, have further increased its demand in cotton growing areas of Pakistan. As cotton is grown in arid and semiarid areas, therefore often prone to water deficiency. The reproductive growth particularly flowering and boll setting are highly sensitive to low soil water potentials, where enough K supply can play a vital role. In this two-year field studies, three cultivars (early, mid and late maturing) were cultivated at two K fertilizer levels 100, 200 kg K ha-1 along with control with no K fertilizer application at two irrigation levels. In first irrigation level, water was applied as per full irrigation schedule, while in water deficit irrigation water was applied at deficit irrigation schedule started after flowering till harvesting. It has been revealed that K application has impact on boll setting as well as seed cotton yield, however early and mid-maturing cultivars are more responsive to K fertilization. Furthermore, irrigation level had significant impact against K fertilization and relatively better response was observed in deficit irrigation as compared to full irrigation. Nevertheless, fiber quality parameters were unaffected by K fertilization. Considering the best benefit cost ratio under water deficiency, it is concluded that 100 kg K2O ha-1 should be applied at the time of seed bed preparation for economical seed-cotton yield of early maturing Bt cotton.
Assuntos
Irrigação Agrícola/métodos , Fertilizantes/economia , Gossypium/crescimento & desenvolvimento , Potássio/metabolismo , Água/metabolismo , Irrigação Agrícola/economia , Análise Custo-Benefício , Fibra de Algodão/economia , Fibra de Algodão/normas , Gossypium/metabolismo , Paquistão , Potássio/análise , Potássio/economia , Sementes/crescimento & desenvolvimento , Solo/química , Fatores de TempoRESUMO
In Palestine, open dumping and/or burning the waste, including agricultural waste, are prevalent practices resulting in emitting leachate and acidifying greenhouse gases. Composting the agricultural waste can reduce emissions and provide 'compost' as an organic fertilizer and soil amendment; yet, it has not been implemented at the national level. To develop a local marketing strategy for compost, this study views a need to identify farmers' perceptions and willingness of compost production and use in agriculture and examine various socioeconomic, agricultural, and individual factors shaping them. The case of Wadi al-Far'a watershed (WFW) is investigated, where farmers practice inappropriate waste disposal and overuse of agrochemicals. A semi-structured questionnaire is administered to 409 farmers through face-to-face interviews. Descriptive statistics, bivariate analyses, Chi-square test, and binary logistic regression are used for data analysis. High acceptance level (84%) is disclosed among farmers in WFW for the hypothetical idea of producing and using compost. Farmers also have high, yet lower, willingness level (63.6%) of the more salient option of producing compost themselves and using it in agriculture. Tenure systems, large cultivated areas, rainfed irrigation, and lack of access to training sessions inhibit farmers' acceptance of the idea of compost production (overall p value = 0.000). Large cultivated areas and rainfed irrigation is also associated with farmers' unwillingness to produce compost, besides high household monthly income, animal or mixed animal-plant farming, experience in compost production, and use of pesticides (overall p value = 0.000).
Assuntos
Compostagem/economia , Monitoramento Ambiental/economia , Fazendeiros/psicologia , Fazendas/economia , Poluição da Água/economia , Animais , Fertilizantes/economia , Humanos , Oriente Médio , Praguicidas/economia , Eliminação de Resíduos/economia , Percepção Social , Fatores Socioeconômicos , Solo/química , Inquéritos e Questionários , Poluição da Água/prevenção & controleRESUMO
Despite the capacity to accumulate ~70% w/w of lipids, commercially produced unicellular green alga A. protothecoides may become compromised due to the high cost of phosphate fertilizers. To address this limitation A. protothecoides was selected for adaptation to conditions of 100× and 5× lower phosphate and peptone, respectively, compared to 'wild-type media'. The A. protothecoides showed initial signs of adaptation by 45-50 days, and steady state growth at ~100 days. The low phosphate (P)-adapted strain produced up to ~30% greater biomass, while total lipids (~10% w/w) remained about the same, compared to the wild-type strain. Metabolomic analyses indicated that the low P-adapted produced 3.3-fold more saturated palmitic acid (16:0) and 2.2-fold less linolenic acid (18:3), compared to the wild-type strain, resulting in an ~11% increase in caloric value, from 19.5kJ/g for the wild-type strain to 21.6kJ/g for the low P-adapted strain, due to the amounts and composition of certain saturated fatty acids, compared to the wild type strain. Biochemical changes in A. protothecoides adapted to lower phosphate conditions were assessed by comparative RNA-Seq analysis, which yielded 27,279 transcripts. Among them, 2,667 and 15 genes were significantly down- and up-regulated, at >999-fold and >3-fold (adjusted p-value <0.1), respectively. The expression of genes encoding proteins involved in cellular processes such as division, growth, and membrane biosynthesis, showed a trend toward down-regulation. At the genomic level, synonymous SNPs and Indels were observed primarily in coding regions, with the 40S ribosomal subunit gene harboring substantial SNPs. Overall, the adapted strain out-performed the wild-type strain by prioritizing the use of its limited phosphate supply for essential biological processes. The low P-adapted A. protothecoides is expected to be more economical to grow over the wild-type strain, based on overall greater productivity and caloric content, while importantly, also requiring 100-fold less phosphate.
Assuntos
Clorófitas/metabolismo , Fosfatos/metabolismo , Adaptação Fisiológica , Biocombustíveis , Biomassa , Calorimetria , Clorófitas/genética , Clorófitas/crescimento & desenvolvimento , Cromatografia Gasosa , Meios de Cultura , Fertilizantes/economia , Regulação da Expressão Gênica de Plantas , Mutação INDEL , Metabolismo dos Lipídeos , Redes e Vias Metabólicas , Polimorfismo de Nucleotídeo Único , RNA de Plantas/biossíntese , Seleção Genética , Análise de Sequência de RNA , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
The change in nitrogen balance causes many environmental and socioeconomic impacts. In relation to food production and nitrogen release in wastewater systems, wastewater and sludge discharge and mineral fertilizer use intensify nitrogen imbalance of a region. The replacement of mineral fertilizer by nitrogen from treated wastewater, biosolids, and treated urine is a promising alternative. This work presents a model to support decision taking for the management of reactive nitrogen flows in wastewater systems based on system dynamics. Six scenarios were simulated for nitrogen flows in wastewater systems and related components.
Assuntos
Sistemas de Apoio a Decisões Administrativas , Fertilizantes/análise , Modelos Teóricos , Nitrogênio/análise , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Fertilizantes/economia , Eliminação de Resíduos Líquidos/economiaRESUMO
Mineral fertilizers are key to food production, despite plant low nutrient uptake efficiencies and high losses. However, nanotechnology can both enhance crop productivity and reduce nutrient losses. This has raised interest in nanoscale and nanoenabled bulk fertilizers, hence the concept of nanofertilizers. Nevertheless, large-scale industrial production of nanofertilizers is yet to be realized. Here, we highlight the science-based evidence and outstanding concerns for motivating fertilizer industry production of nanofertilizers, including the notion of toxicity associated with nanoscale materials; scant nanofertilizer research with key crop nutrients; inadequacy of soil- or field-based studies with nanofertilizers; type of nanomaterials to produce as fertilizers; how to efficiently and effectively apply nanofertilizers at the field scale; and the economics of nanofertilizers. It is anticipated that the development and validation of nanofertilizers that are nondisruptive to existing bulk fertilizer production systems will motivate the industry's involvement in nanofertilizers.
Assuntos
Fertilizantes/análise , Produtos Agrícolas/crescimento & desenvolvimento , Fertilizantes/economia , Indústrias , Minerais/análise , Minerais/economia , Nanopartículas/análise , Nanopartículas/economiaAssuntos
Biocombustíveis/economia , Empreendedorismo , Fezes , Fertilizantes/economia , Reciclagem/economia , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/métodos , Animais , Compostagem/economia , Dípteros/fisiologia , Fezes/microbiologia , Fezes/parasitologia , Fertilizantes/provisão & distribuição , Alimentos/economia , Humanos , Reciclagem/métodos , Esgotos/efeitos adversos , Esgotos/microbiologia , Esgotos/parasitologia , Banheiros/economia , Banheiros/estatística & dados numéricosRESUMO
Currently, the management of urban waste streams in developing countries is not optimized yet, and in many cases these wastes are disposed untreated in open dumps. This fact causes serious environmental and health problems due to the presence of contaminants and pathogens. Frequently, the use of specific low-cost strategies reduces the total amount of wastes. These strategies are mainly associated to the identification, separate collection and composting of specific organic waste streams, such as vegetable and fruit refuses from food markets and urban gardening activities. Concretely, in the Chimborazo Region (Ecuador), more than 80% of municipal solid waste is dumped into environment due to the lack of an efficient waste management strategy. Therefore, the aim of this study was to develop a demonstration project at field scale in this region to evaluate the feasibility of implanting the composting technology not only for the management of the organic waste fluxes from food market and gardening activities to be scaled-up in other developing regions, but also to obtain an end-product with a commercial value as organic fertilizer. Three co-composting mixtures were prepared using market wastes mixed with pruning of trees and ornamental palms as bulking agents. Two piles were created using different proportions of market waste and prunings of trees and ornamental palms: pile 1 (50:33:17) with a C/N ratio 25; pile 2: (60:30:10) with C/N ratio 24 and pile 3 (75:0:25) with C/N ratio 33), prepared with market waste and prunings of ornamental palm. Throughout the process, the temperature of the mixtures was monitored and organic matter evolution was determined using thermogravimetric and chemical techniques. Additionally, physico-chemical, chemical and agronomic parameters were determined to evaluate compost quality. The results obtained indicated that all the piles showed a suitable development of the composting process, with a significant organic matter decomposition, reached in a shorter period of time in pile 3. At the end of the process, all the composts showed absence of phytotoxicity and suitable agronomic properties for their use as organic fertilizers. This reflects the viability of the proposed alternative to be scaled-up in developing areas, not only to manage and recycle urban waste fluxes, but also to obtain organic fertilizers, including added value in economic terms related to nutrient contents.