Fertilizer use in Africa as compared to other developing regions has been limited. What types of policies and programs are needed to realize the potential benefits of fertilizer in African ...agriculture? This book summarizes key lessons learned from past efforts to promote fertilizer in Africa, provides an overview of the current state of knowledge concerning technical aspects of fertilizer use in Africa, and presents good practice guidelines for promoting sustainable increases in fertilizer use.
The excessive use of inorganic fertilizers causes serious environmental degradation, resulting in lower crop yields in Bangladesh. Seventy percent of Bangladesh farmers practice traditional ...fertilizer broadcasting. In the 1960s, the Bangladesh state authority launched a ‘Grow More Food’ campaign to feed the country’s increasing population. Farmers were supplied with chemical fertilizers and pesticides at a subsidized price. Farmers increased the frequency of fertilizer applications to enhance yields. These practices are still used and have caused significant environmental degradation. In this study, we examined the effects of fertilizer broadcasting on excessive use of fertilizer and environmental risks. We collected data from 211 Bangladesh infield farmers in 2016. Respondents were interviewed using a semi-structured questionnaire. Data were analyzed by applying a binary logistic regression model to test the degree of effects between the testable variables. The study found that the effect of broadcasting on the excessive use of fertilizers is strongly significant, at 1%. It also found that younger farmers have a significant effect at 10% on the excessive use of fertilizers. Bangladesh policymakers can formulate policy on sustainable fertilizer management, introducing different placement methods on the basis of this finding. After that, the Directorate of Agricultural Extension (DAE) can carry out the policy at the field level.
•The emission of greenhouse gases are particular important for the environmental impact of fertilizers.•By choosing the appropriate basic material reduction of emission in all important impact ...categories (climate change, terrestrial acidification, freshwater eutrophication, fossil fuel depletion and resource depletion) are possible.•Up-to-date data on emissions along the whole fertilizer value chain are necessary to achieve reliable LCA calculations.
Appropriate use of fertilizer in crop production to limit the environmental impact is essential for sustainable agriculture. While much is known about the environmental impact of fertilizer production only a limited amount of data is available covering the whole fertilizer supply chain. Up to now no comparison was done on the environmental impact of different fertilizer types (i.e., complex fertilizer, bulk blend fertilizer and single nutrient fertilizer). A cradle-to-field life cycle assessment (LCA) for the fertilizer supply chain in Germany, from extraction of raw materials, via fertilizer production, transportation and storage until final application in the field was carried out. Two different complex fertilizers were compared with single nutrient fertilizers (containing only one nutrient) and bulk blend fertilizers (containing more than one nutrient as a dry mixture). The five most relevant impact categories (i.e., climate change, acidification, eutrophication, fossil fuel depletion and resource depletion) were selected to cover different environmental impacts. Additionally, a scenario analysis was carried out focusing on nitrous oxide (N2O) emissions, as new catalytic reduction techniques for the manufacturing of nitrogen (N) containing fertilizers are available that can lead to drastic reductions of N2O emissions.
Production of fertilizers causes high values in the impact categories climate change, fossil fuel depletion and acidification, whereas resource depletion is dominant for production and transportation. For the impact category eutrophication, the application of fertilizer is the most important factor.
For a fertilizer strategy with low phosphorus application rate, a bulk blend or single nutrient fertilizer with calcium ammonium nitrate is the most sustainable choice, while for a fertilizer strategy with a balanced nutrient formula, a bulk blend or single nutrient fertilizer with calcium ammonium nitrate or a standard complex fertilizer are sustainable options. Scenario calculations with reduced N2O emission during the production process reveals that this reduction technique is not relevant for urea based fertilizers leading to the conclusion that products containing urea need different emission reduction techniques to keep up with the environmental improvements of other nitrogen fertilizers.
With an optimized fertilization strategy the environmental burden can be reduced up to 15%. As nitrogen application rates strongly affect the LCA results it is essential that the right amounts of N are used and that for N fertilizer production the best available technique should be installed. Furthermore, a careful consideration concerning the fertilizer product type should be part of every LCA of food and agricultural products, as this has a great impact on LCA results.
Fertilizers and microbial communities that determine fertilizer efficiency are key to sustainable agricultural development. Sugarcane is an important sugar cash crop in China, and using ...bio-fertilizers is important for the sustainable development of China’s sugar industry. However, information on the effects of bio-fertilizers on sugarcane soil microbiota has rarely been studied. In this study, the effects of bio-fertilizer application on rhizosphere soil physicochemical indicators, microbial community composition, function, and network patterns of sugarcane were discussed using a high-throughput sequencing approach. The experimental design is as follows: CK: urea application (57 kg/ha), CF: compound fertilizer (450 kg/ha), BF1: bio-fertilizer (1500 kg/ha of bio-fertilizer + 57 kg/ha of urea), and BF2: bio-fertilizer (2250 kg/ha of bio-fertilizer + 57 kg/ha of urea). The results showed that the bio-fertilizer was effective in increasing sugarcane yield by 3–12% compared to the CF treatment group, while reducing soil acidification, changing the diversity of fungi and bacteria, and greatly altering the composition and structure of the inter-root microbial community. Variance partitioning canonical correspondence (VPA) analysis showed that soil physicochemical variables explained 80.09% and 73.31% of the variation in bacteria and fungi, respectively. Redundancy analysis and correlation heatmap showed that soil pH, total nitrogen, and available potassium were the main factors influencing bacterial community composition, while total soil phosphorus, available phosphorus, pH, and available nitrogen were the main drivers of fungal communities. Volcano plots showed that using bio-fertilizers contributed to the accumulation of more beneficial bacteria in the sugarcane rhizosphere level and the decline of pathogenic bacteria (e.g.,
Leifsonia
), which may slow down or suppress the occurrence of diseases. Linear discriminant analysis (LDA) and effect size analysis (LEfSe) searched for biomarkers under different fertilizer treatments. Meanwhile, support vector machine (SVM) assessed the importance of the microbial genera contributing to the variability between fertilizers, of interest were the bacteria
Anaerolineace
,
Vulgatibacter
, and
Paenibacillus
and the fungi
Cochliobolus
,
Sordariales
, and
Dothideomycetes
between CF and BF2, compared to the other genera contributing to the variability. Network analysis (co-occurrence network) showed that the network structure of bio-fertilizers was closer to the network characteristics of healthy soils, indicating that bio-fertilizers can improve soil health to some extent, and therefore if bio-fertilizers can be used as an alternative to chemical fertilizers in the future alternative, it is important to achieve green soil development and improve the climate.
Nutrients released into soils from uncoated fertilizer granules are lost continuously due to volatilization, leaching, denitrification, and surface run-off. These issues have caused economic loss due ...to low nutrient absorption efficiency and environmental pollution due to hazardous emissions and water eutrophication. Controlled-release fertilizers (CRFs) can change the release kinetics of the fertilizer nutrients through an abatement strategy to offset these issues by providing the fertilizer content in synchrony with the metabolic needs of the plants. Parametric analysis of release characteristics of CRFs is of paramount importance for the design and development of new CRFs. However, the experimental approaches are not only time consuming, but they are also cumbersome and expensive. Scientists have introduced mathematical modeling techniques to predict the release of nutrients from the CRFs to elucidate fundamental understanding of the dynamics of the release processes and to design new CRFs in a shorter time and with relatively lower cost. This paper reviews and critically analyzes the latest developments in the mathematical modeling and simulation techniques that have been reported for the characteristics and mechanisms of nutrient release from CRFs. The scope of this review includes the modeling and simulations techniques used for coated, controlled-release fertilizers.
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► Information about N2O emissions from Mediterranean crops was analyzed. ► Direct N2O fluxes are generally lower for organic than for synthetic fertilizers. ► Irrigation highly increased emissions, ...but the increase was lower with drip irrigation. ► The most promising practices, constraints and research gaps have been summarized. ► Further research is needed to fully understand and develop N2O mitigation potential.
Environmental problems related to the use of synthetic fertilizers and to organic waste management have led to increased interest in the use of organic materials as an alternative source of nutrients for crops, but this is also associated with N2O emissions. There has been an increasing amount of research into the effects of using different types of fertilization on N2O emissions under Mediterranean climatic conditions, but the findings have sometimes been rather contradictory. Available information also suggests that water management could exert a high influence on N2O emissions. In this context, we have reviewed the current scientific knowledge, including an analysis of the effect of fertilizer type and water management on direct N2O emissions.
A meta-analysis of compliant reviewed experiments revealed significantly lower N2O emissions for organic as opposed to synthetic fertilizers (23% reduction). When organic materials were segregated in solid and liquid, only solid organic fertilizer emissions were significantly lower than those of synthetic fertilizers (28% reduction in cumulative emissions). The EF is similar to the IPCC factor in conventionally irrigated systems (0.98% N2O-N N applied−1), but one order of magnitude lower in rainfed systems (0.08%). Drip irrigation produces intermediate emission levels (0.66%). Differences are driven by Mediterranean agro-climatic characteristics, which include low soil organic matter (SOM) content and a distinctive rainfall and temperature pattern. Interactions between environmental and management factors and the microbial processes involved in N2O emissions are discussed in detail.
Indirect emissions have not been fully accounted for, but when organic fertilizers are applied at similar N rates to synthetic fertilizers, they generally make smaller contributions to the leached NO3− pool. The most promising practices for reducing N2O through organic fertilization include: (i) minimizing water applications; (ii) minimizing bare soil; (iii) improving waste management; and (iv) tightening N cycling through N immobilization. The mitigation potential may be limited by: (i) residual effect; (ii) the long-term effects of fertilizers on SOM; (iii) lower yield-scaled performance; and (iv) total N availability from organic sources. Knowledge gaps identified in the review included: (i) insufficient sampling periods; (ii) high background emissions; (iii) the need to provide N2O EF and yield-scaled EF; (iv) the need for more research on specific cropping systems; and (v) the need for full GHG balances.
In conclusion, the available information suggests a potential of organic fertilizers and water-saving practices to mitigate N2O emissions under Mediterranean climatic conditions, although further research is needed before it can be regarded as fully proven, understood and developed.
Excessive ammonia (NH3) emitted from nitrogen (N) fertilizer applications in global croplands plays an important role in atmospheric aerosol production, resulting in visibility reduction and regional ...haze. However, large uncertainty exists in the estimates of NH3 emissions from global and regional croplands, which utilize different data and methods. In this study, we have coupled a process‐based Dynamic Land Ecosystem Model (DLEM) with the bidirectional NH3 exchange module in the Community Multiscale Air‐Quality (CMAQ) model (DLEM‐Bi‐NH3) to quantify NH3 emissions at the global and regional scale, and crop‐specific NH3 emissions globally at a spatial resolution of 0.5° × 0.5° during 1961–2010. Results indicate that global NH3 emissions from N fertilizer use have increased from 1.9 ± 0.03 to 16.7 ± 0.5 Tg N/year between 1961 and 2010. The annual increase of NH3 emissions shows large spatial variations across the global land surface. Southern Asia, including China and India, has accounted for more than 50% of total global NH3 emissions since the 1980s, followed by North America and Europe. Rice cultivation has been the largest contributor to total global NH3 emissions since the 1990s, followed by corn and wheat. In addition, results show that empirical methods without considering environmental factors (constant emission factor in the IPCC Tier 1 guideline) could underestimate NH3 emissions in context of climate change, with the highest difference (i.e., 6.9 Tg N/year) occurring in 2010. This study provides a robust estimate on global and regional NH3 emissions over the past 50 years, which offers a reference for assessing air quality consequences of future nitrogen enrichment as well as nitrogen use efficiency improvement.
Based on the process‐based DLEM‐Bi‐NH3 module, global NH3 emissions from N fertilizer use have increased by 14.8 Tg N/year during the period 1961–2010. At the regional scale, southern Asia, including China and India, has accounted for more than 50% of total global NH3 emissions since the 1980s. Rice cultivation has been the largest contributor to total global NH3 emissions since the 1990s, followed by corn and wheat. In addition, results show that empirical methods without considering environmental factors (constant emission factor in the IPCC Tier 1 guideline) could underestimate NH3 emissions in the context of climate change, with the highest difference (i.e., 6.9 Tg N/year) occurring in 2010.
Crystallization of struvite‐K from pumpkin wastes Atalay, Sema; Sargin, Idris; Arslan, Gulsin
Journal of the science of food and agriculture,
30 January 2022, Letnik:
102, Številka:
2
Journal Article
Anthropogenic activities, and in particular the use of synthetic nitrogen (N) fertilizer, have doubled global annual reactive N inputs in the past 50–100 years, causing deleterious effects on the ...environment through increased N leaching and nitrous oxide (N₂O) and ammonia (NH₃) emissions. Leaching and gaseous losses of N are greatly controlled by the net rate of microbial nitrification. Extensive experiments have been conducted to develop ways to inhibit this process through use of nitrification inhibitors (NI) in combination with fertilizers. Yet, no study has comprehensively assessed how inhibiting nitrification affects both hydrologic and gaseous losses of N and plant nitrogen use efficiency. We synthesized the results of 62 NI field studies and evaluated how NI application altered N cycle and ecosystem services in N‐enriched systems. Our results showed that inhibiting nitrification by NI application increased NH₃emission (mean: 20%, 95% confidential interval: 33–67%), but reduced dissolved inorganic N leaching (−48%, −56% to −38%), N₂O emission (−44%, −48% to −39%) and NO emission (−24%, −38% to −8%). This amounted to a net reduction of 16.5% in the total N release to the environment. Inhibiting nitrification also increased plant N recovery (58%, 34–93%) and productivity of grain (9%, 6–13%), straw (15%, 12–18%), vegetable (5%, 0–10%) and pasture hay (14%, 8–20%). The cost and benefit analysis showed that the economic benefit of reducing N's environmental impacts offsets the cost of NI application. Applying NI along with N fertilizer could bring additional revenues of $163 ha⁻¹ yr⁻¹for a maize farm, equivalent to 8.95% increase in revenues. Our findings showed that NIs could create a win‐win scenario that reduces the negative impact of N leaching and greenhouse gas production, while increases the agricultural output. However, NI's potential negative impacts, such as increase in NH₃emission and the risk of NI contamination, should be fully considered before large‐scale application.
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