| 1. |
|
|
| 2. |
- Akram, Usman, 1984-
(author)
-
Closing nutrient cycles
- 2020
-
Doctoral thesis (other academic/artistic)abstract
- Adequate and balanced crop nutrition – with nitrogen (N), phosphorus (P), and potassium (K) – is vital for sustainable crop production. Inadequate and imbalanced crop nutrition contributes to the crop yield gaps – a difference in actual and potential crop yield. Yield gap is one of the many causes of insufficient food production, thus aggravating hunger and malnourishment across the globe. On the other hand, an oversupply of nutrients is highly unsustainable, in terms of both resource conservation and global environmental health. A decreasing excreta recycling in crop production is one of the many reasons for nutrient imbalances in agriculture. Previous studies show that increasing agricultural specialization leads to spatial separation of crop and animal production. Increasing distance between excreta production and crop needs is one of the leading factors that cause reduced excreta recycling. Studies focusing on excreta recycling show that a substantial barrier to a more efficient excreta nutrient reuse is the expensive transportation of bulky volumes of excreta over long distances. In order to overcome that barrier, more detailed spatial estimates of distances between excreta production and crop nutrient needs, and the associated costs for complete excreta transport in an entire country are needed. Hence, the overall aim of this thesis was to quantify the amount of nutrients in the excreta resources compared to the crop nutrient needs at multiple scales (global, national, subnational, and local), and to analyze the need for excreta transports, total distances and costs, to meet the crop nutrient needs in a country.On the global scale, annual (2000-2016) excreta supply (livestock and human) could provide at least 48% of N, 57% of P, and 81% of K crop needs. Although excreta supply was not enough to cover the annual crop nutrient needs at the global scale, at least 29 countries for N, 41 for P, and 71 for K had an excreta nutrient surplus. When including the annual use of synthetic fertilizers, at least 42 additional countries had a N surplus, with the equivalent figures for P being 17 countries, whereas 8 additional countries attained a K surplus. At the same time, when accounting for the use of synthetic fertilizers, each year, at least 57 countries had an N deficit, 70 a P deficit, and 51 countries a K deficit, in total equivalent to 14% of global N and 16% of each P and K crop needs. The total surplus in other countries during the period was always higher than the deficit in the countries with net nutrient deficits, except for P for some years. Unfortunately, both the deficits of the deficit countries and surpluses of the surplus countries were increasing substantially during the 17 years. Such global divergence in nutrient deficits and surpluses have clear implications for global food security and environmental health.A district-scale investigation of Pakistan showed that the country had a national deficit of 0.62 million tons of P and 0.59 million tons of K, but an oversupply of N. The spatial separation was not significant at this resolution; only 6% of the excreta N supply needed to be transported between districts. Recycling all excreta, within and between districts, could cut the use of synthetic N to 43% of its current use and eliminate the need for synthetic K, but there would be an additional need of 0.28 million tons of synthetic P to meet the crop nutrient needs in the entire country. The need for synthetic fertilizers to supplement the recycled excreta nutrients would cost USD 2.77 billion. However, it might not be prohibitively expensive to correct for P deficiencies because of the savings on the costs of synthetic N, and K. Excreta recycling could promote balanced crop nutrition at the national scale in Pakistan, which in turn could eliminate the nutrient-related crop yield gaps in the country.The municipal-scale investigation using Swedish data showed that the country had a national oversupply of 110,000 tons of N, 6,000 tons of P, and 76,000 tons of K. Excreta could provide up to 75% of N and 81% of P, and more than 100% of the K crop needs in the country. The spatial separation was pronounced at the municipal scale in the country. Just 40% of the municipalities produced over 50% of the excreta N and P. Nutrient balance calculations showed that excreta recycling within municipalities could provide 63% of the P crop needs. Another 18% of the P crop needs must be transported from surplus municipalities to deficit municipalities. Nationally, an optimized reallocation of surplus excreta P towards the P deficit municipalities would cost USD 192 million for a total of 24,079 km truck transports. The cost was 3.7 times more than the total NPK fertilizer value transported, and that met the crop nutrient needs. It was concluded that Sweden could potentially reduce its dependence on synthetic fertilizers, but to cover the costs of an improved excreta reuse would require valuing the additional benefits of recycling.An investigation was also done to understand the effect of the input data resolution on the results (transport needs and distances) from a model to optimize excreta redistribution. The results showed that the need for excreta transports, distances, and spatial patterns of the excreta transports changed. Increasing resolution of the spatial data, from political boundaries in Sweden and Pakistan to 0.083 decimal grids (approximately 10 km by 10 km at the equator), showed that transport needs for excreta-N increased by 12% in Pakistan, and the transport needs for excreta-P increased by 14% in Sweden. The effect of the increased resolution on transport analysis showed inconsistency in terms of the excreta total nutrient transportation distance; the average distance decreased by 67% (to 44 km) in Pakistan but increased by 1 km in Sweden. A further increase in the data resolution to 5 km by 5 km grids for Sweden showed that the average transportation distance decreased by 9 km. In both countries, increasing input data resolution resulted in a more favorable cost to fertilizer value ratios. In Pakistan, the cost of transport was only 13% of the NPK fertilizer value transported at a higher resolution. In Sweden, the costs decreased from 3.7 (at the political resolution) to slightly higher than three times of the fertilizer value transported in excreta at the higher data resolution.This Ph.D. thesis shows that we could potentially reduce the total use of synthetic fertilizers in the world and still reduce the yield gaps if we can create a more efficient recycling of nutrients both within and between countries, and a more demand adapted use of synthetic fertilizers.
|
|
| 3. |
- Akram, Usman, 1984-, et al.
(author)
-
Closing Pakistan’s yield gaps through nutrient recycling
- 2018
-
In: Frontiers in Sustainable Food Systems. - : Frontiers Media S.A.. - 2571-581X. ; , s. 1-14
-
Journal article (peer-reviewed)abstract
- Achieving food security will require closing yield gaps in many regions, including Pakistan. Although fertilizer subsidies have facilitated increased nitrogen (N) application rates, many staple crop yields have yet to reach their maximum potential. Considering that current animal manure and human excreta (bio-supply) recycling rates are low, there is substantial potential to increase the reuse of nutrients in bio-supply. We quantified 2010 crop N, phosphorus (P), and potassium (K) needs along with bio-supply nutrient availability for Pakistani districts, and compared these values to synthetic fertilizer use and costs. We found that synthetic fertilizer use combined with low bio-supply recycling resulted in a substantial gap between nutrient supply and P and K crop needs, which would cost 3 billion USD to fill with synthetic fertilizers. If all bio-supply was recycled, it could eliminate K synthetic fertilizer needs and decrease N synthetic fertilizer needs to 43% of what was purchased in 2010. Under a full recycling scenario, farmers would still require an additional 0.28 million tons of synthetic P fertilizers, costing 2.77 billion USD. However, it may not be prohibitively expensive to correct P deficiencies. Pakistan already spends this amount of money on fertilizers. If funds used for synthetic N were reallocated to synthetic P purchases in a full bio-supply recycling scenario, crop needs could be met. Most recycling could happen within districts, with only 6% of bio-supply requiring between-district transport when optimized to meet national N crop needs. Increased recycling in Pakistan could be a viable way to decrease yield gaps.
|
|
| 4. |
- Brownlie, Will J., et al.
(author)
-
Opportunities to recycle phosphorus-rich organic materials
- 2022. - 1
-
In: Our Phosphorus Future. - Edinburgh : UK Centre for Ecology & Hydrology. ; , s. 219-270
-
Book chapter (other academic/artistic)abstract
- Recycling phosphorus-rich organic wastes and manures is critical for phosphorus sustainability and a transition to a more circular economy for phosphorus. Beyond agronomic benefits, the win-wins are numerous, with benefits to society, environment, economy, and business growth. However, to significantly increase phosphorus recycling, education, awareness-raising, investment in technology and infrastructure, and policy support are urgently needed.
|
|
| 5. |
- Cordell, Dana, et al.
(author)
-
Transforming Cities: Securing food and clean waterways through phosphorus governance
- 2017
-
In: Transdiciplinary Research and Practice for Sustainability Outcomes. - : Routledge. - 9781138625730 - 9781138119703 - 9781315652184 ; , s. 139-154
-
Book chapter (peer-reviewed)abstract
- As an essential input to crop growth via soil reserves or fertilizer, phosphorus underpins global food security. Without phosphorus, food could not be produced, yet phosphorus is mined from fi nite reserves, most of which are controlled by only a few countries1 (UNEP 2011; Jasinski 2015; Cordell and White 2014). Fertilizer prices are likely to increase as fi nite reserves become critically scarce. Globally, a billion farmers and their families cannot access fertilizer markets and many rely on phosphorus-defi cient soils that produce low crop yields (IFPRI 2003). Moreover, mismanagement along the phosphorus supply chain from mine to fi eld to fork has resulted in massive losses and waste, which largely ends up in waterways, causing nutrient pollution and algal blooms (Bennett, Carpenter and Caraco 2001). The global phosphorus challenge is inherently complex; it is as much about international relations as farm soil fertility. It transcends disciplines, sectors, and scales – from geopolitics to ecology to nutrition. In this chapter, we describe and refl ect upon a new project using a novel transdisciplinary approach to address this phosphorus challenge.
|
|
| 6. |
- Feiz, Roozbeh, 1975-, et al.
(author)
-
Key factors for site-selection of biogas plants in Sweden
- 2022
-
In: Journal of Cleaner Production. - Amsterdam, Netherlands : Elsevier. - 0959-6526 .- 1879-1786. ; 354
-
Journal article (peer-reviewed)abstract
- Biogas production through anaerobic digestion is an integral part of the transition toward a biobased and circular economy and its expansion is foreseen in many parts of the world as well as in Europe. In Sweden, a governmental inquiry suggested biogas production to be increased from about 2 TWh today to 7 TWh by 2030. This rapid expansion would require installation of several new biogas plants across the country. However, the location of biogas plants can greatly affect its business performance and there are several geographic and socio-political factors that would limit the choice of location. Through dialogue with existing biogas producing companies and a few other related actors, we identified 12 factors that are commonly considered in the site-selection of biogas plants in Sweden or are considered to be important in the years to come. These factors are grouped into those related to supply and demand (feedstock supply, biogas demand, digestate demand, and carbon dioxide demand), infrastructure and synergies (available infrastructure, adjacent existing industries), land-use and zoning (nearby housing, zoning, and historic preservation sites), and socio-political context (political strategies and goals, organizational capability, and local social acceptance). We discuss how these factors can be used under rapidly transforming conditions in Sweden through different site-selection logics and highlight the importance of spatially explicit analysis for individual or coordinated decision making in future. Our method of enquiry and analysis, and to a certain degree the factors, can be also relevant for other countries, particularly in Europe. This study paves the way for more in-depth investigation of the question of site-selection of biogas plants in Sweden; both in the direction of detailed analysis at the local level, or screening analysis on the regional or national level for improved coordinated actions.
|
|
| 7. |
- Iwaniec, David, et al.
(author)
-
P-FUTURES: Towards urban food & water security through collaborative design and impact
- 2016
-
In: Current Opinion in Environmental Sustainability. - : Elsevier. - 1877-3435 .- 1877-3443. ; 20, s. 1-7
-
Journal article (peer-reviewed)abstract
- Phosphorus is essential to food production, but current management practices fail to ensure equitable access to farmers globally and often results in polluted waterways. There is a lack of local and global governance mechanisms to ensure phosphorus is sustainably managed. The P-FUTURES research initiative aims to address this gap by working with stakeholders to explore visions and pathways of social transformation towards food and water security. In the seed phase of the project, academic, civil, industry, and municipal stakeholders interacted as partners in Blantyre (Malawi), Hanoi (Vietnam), Sydney (Australia), and Phoenix (USA) to collaboratively develop a full proposal and build capacity for transformational change. The article offers guidance on the opportunities and challenges of co-developing a research approach and proposal in a transdisciplinary, international setting.
|
|
| 8. |
- Kingsley, Jonathan, et al.
(author)
-
Pandemic gardening: A narrative review, vignettes and implications for future research
- 2023
-
In: Urban Forestry & Urban Greening. - : ELSEVIER GMBH. - 1618-8667 .- 1610-8167. ; 87
-
Research review (peer-reviewed)abstract
- There is a significant amount of evidence highlighting the health, wellbeing and social benefits of gardening during previous periods of crises. These benefits were also evident during the COVID-19 pandemic. This paper presents a narrative review exploring gardening during the early stages of the COVID-19 pandemic to understand the different forms of gardening that took place during this crisis and key elements of this activity. Research about gardening during the pandemic focused on food (in)security and disrupted food systems, the health and wellbeing benefits of gardening, and the social dimensions of gardening. We offer three vignettes of our own research to highlight key insights from local, national and international perspectives of gardening during the pandemic. The papers conclusion outlines how researchers, policy makers and public health practitioners can harness what has been learned from gardening during the pandemic to ensure these benefits are more widely available and do not exacerbate already entrenched health inequalities in society.
|
|
| 9. |
- Larsson, Madeleine, 1984-, et al.
(author)
-
Towards a more circular biobased economy and nutrient use on Gotland : finding suitable locations for biogas plants
- 2023
-
Reports (other academic/artistic)abstract
- In this study we have investigated the role of biogas solutions to support increased resource efficiency on the island Gotland, including recovery and redistribution of nitrogen (N) and phosphorus (P) within the agricultural sector. First, we analyzed the potential for expanding energy and nutrient recovery from organic residues using biogas solutions. Our findings suggest that the biogas production could expand to 165 GWh, from the current 36 GWh (2020), with manure accounting for a potential 110 GWh biogas annually if all were digested. Comparing the nutrients contained in organic feedstock with the crop nutrient demand on Gotland showed that for N the demand is 2.4 times higher than the supply. In contrast, the calculations showed a 137 tonnes P surplus, with distinct excess areas in the center and southern part of the island.We then compared scenarios with different numbers (3 - 15) of biogas plants with respect to efficient nutrient redistribution and transport costs. Spatial constraints for new plants, e.g. need for roads with a certain capacity and permit issues, were accounted for by adding local information to a national data set. We identified 104 potential locations (1 km$^2$ grid cells) and used an optimization model to identify the most suitable locations for minimized transport costs. Optimal (meeting the crop demand with no excess) redistribution of all nutrients contained in the feedstock, as raw digestate from biogas plants, would result in an export of 127 tonnes of P from the island. The model results indicated that if all potential feedstock would be digested in three additional biogas plants and nutrients redistributed for optimal reuse, the total transport cost would be 2.6 million SEK annually, excluding the costs for nutrient export from the island (3.7 million SEK). If instead 10 or 15 smaller plants would be built, the transport cost would drop to 1.8 million SEK, with the same amount of P being exported. Comparing the scenarios with different number of biogas plants (3 - 15), showed that some locations are more suitable than others in terms of distance to feedstock andto fields with fertilizer demands. Finally, a preliminary analysis of the amount of crop residues indicated that this type of feedstock could add a substantial amount of biogas production, but more extensive analyses are needed to assess the feasibility to realize part of that potential.
|
|
| 10. |
- Liss, Kate N., et al.
(author)
-
Variability in ecosystem service measurement : a pollination service case study
- 2013
-
In: Frontiers in Ecology and the Environment. - : Wiley. - 1540-9295 .- 1540-9309. ; 11:8, s. 414-422
-
Journal article (peer-reviewed)abstract
- Research quantifying ecosystem services (ES) - collectively, the benefits that society obtains from ecosystems -is rapidly increasing. Despite the seemingly straightforward definition, a wide variety of methods are used to measure ES. This methodological variability has largely been ignored, and standard protocols to select measures that capture ES provision have yet to be established. Furthermore, most published papers do not include explicit definitions of individual ES. We surveyed the literature on pollination ES to assess the range of measurement approaches, focusing on three essential steps: (1) definition of the ES, (2) identification of components contributing to ES delivery, and (3) selection of metrics to represent these components. We found considerable variation in how pollination as an ES - a relatively well-defined service - is measured. We discuss potential causes of this variability and provide suggestions to address this issue. Consistency in ES measurement, or a clear explanation of selected definitions and metrics, is critical to facilitate comparisons among studies and inform ecosystem management.
|
|
