PhD projects

Farm animals reared under a circular paradigm can play a crucial role in feeding humanity while decreasing the environmental impact. These farm animals would not consume human-edible biomass, such as grains, but mainly convert leftovers from arable land and grass resources into valuable food. The objective of this study is to develop pathways, by means of a ‘proof of principle’, towards regenerative farming in the Netherlands, with a focus on dairy and arable farming by 2050.

The key challenge nowadays is to produce enough safe and nutritious food for a growing and wealthier population within the carrying capacity of the planet. Four of the nine planetary boundaries have been crossed: climate change, loss of biosphere integrity, land-system change, and altered biogeochemical cycles (phosphorus and nitrogen). Farmer’s initiatives focus on the aspect of regenerative farming in which farmers aim to contribute to a circular food system.

Those initiatives, however, are not based on scientific concepts as so far, a sound scientific framework is lacking. To this end, we first need to establish a definition for regenerative farming. Then, we want to assess the environmental sustainability of regenerative farming systems by making use of a food system approach. This will be done by first analysing the environmental impact of case studies on farm level, focusing on dairy-, and arable farming. Then secondly, we want to combine the best performing innovations and asses their scalability to a regional scale. Upscaling of the case studies provides insight in potential competition for resources and markets between regenerative farms and other agricultural activities (e.g. horticulture, pig and poultry production). Finally, to direct us towards regenerative agriculture, transition scenarios will be created for dairy, - and arable farming in the Netherlands, in which agro-environmental and socio-economic aspects will meet.

Thus, the overall objective of this study is to develop pathways, by means of a ‘proof of principle’, towards regenerative farming in the Netherlands, with a focus on dairy and arable farming by 2050.

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Biodiversity plays a crucial role in agroecosystems and the ecosystems services it relies on. Therefore understanding how to make agricultural systems capable of enhancing said biodiversity is key for agricultural sustainability. The aim of this PhD project is to understand how agricultural practices affect biodiversity, in particular under a circular agriculture setting and how such circular systems can be designed to either not harm or enhance biodiversity. In order to design these particular systems, it is imperative that we develop models that account for how integrating circularity to agricultural systems will impact the biodiversity of agroecosystems.

The impacts results from the operation of our current food systems can be felt in multiple different aspects of the planetary boundaries, such as with climate change and depletion of soil, water and ecosystem health. Among such impacts is the increasing reduction in biodiversity observed around the globe. If on one hand agricultural expansion and intensification have been one of the main drivers of such reduction, on the other a growing world population also increases the pressure on food systems. While such a contrast might seem detrimental to finding a solution, it also points out that enhancing biodiversity within agroecosystems might play a major role in global biodiversity reduction while also fortifying our food systems. Circularity has been proposed as a possible solution for how to organize agricultural production in a more sustainable way. Understanding biodiversity remains an essential component of any food systems, the question then becomes under which conditions and settings does a circular agricultural system help achieve biodiversity enhancement.

In order to do that, we first need to establish a framework of how the impacts on biodiversity of potential alternative agricultural practices, found in these different systems, perform when compared to conventional, intensive systems` practices. Then, we want to analyse systematic effects by assessing how the combination of practices change the effects on biodiversity (synchronicity) and the time horizon on which such effects can be seen (chronology). Finally, we compound all studied effects into a dimension of the CiFoS model to analyse the impact on biodiversity of different circular agriculture settings. Thus, the overall aim of this project is to explore potential impacts of different circular settings on biodiversity of agroecosystems and identify the most promising ones for the enhancement of biodiversity.

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Currently, there is a big debate about changing our food habits towards more plant-based diets. There is a wide consent that animal-based diets have negative effects on the environment and human health. The nutrient surpluses from excessive use of animal manure and artificial fertilizer lead to environmental pollution, biodiversity loss, GHG emissions and poor water quality. One obvious solution pathway, is therefore to go more plant-based and cut down the animal numbers. The question is, if it is really most sustainable to go fully plant-based or can a reduction of animal sourced products in our diets lead to more sustainable food system? And if we want to reduce both animal numbers and artificial fertilizers, how are we going to have enough nutrients to fertilize our crops in a plant-based food system without manure from animals?

Hence, during my PhD, I want to identifying trade-offs and synergies between minimizing LU and GHG emissions when transitioning towards a more plant-based food system. My research will be guided by two main research questions:

1. Eat less animals: What is the most sustainable amount of animal-based food that we should eat when considering trade-offs and GHG emissions and Land Use?

2. Bridge the plant-based fertilizer gap: What are the most promising fertilizers in a more plant-based food system with lower amounts of animal manure and artificial fertilizer?

In the first part of my PhD, I will mainly help extend the circular food system model (CiFoS) to a European food system level and add a new more spatial approach to represent the crops in the food system. The plan was to create different zones based on agroecological and soil zones for each of which we determine yields, and land area for each of the ~50 crops.

In the second part of my PhD research, I will then investigate different aspects around the protein transition to answer questions about how much animal sourced protein would be most sustainable, when considering trade-offs and synergies between land use and greenhouse emissions.

Further, I am looking more closely on human excreta and its potential to reduce artificial fertilizer and the nutrient losses from our food system under different levels of innovation and technological assumptions. As another plant-based fertilizer, we will also examine the role of legumes as a promising fertilizer and plant-protein provider when transitioning towards a more plant-based food system.

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While succeeding in producing enormous quantities of food, our current food system does so with substantial environmental and social costs. The high rates of food waste, land degradation, and GHG emissions show that our current way of producing and consuming food is not sustainable. One possible pathway to transition to a more sustainable food system is by incorporating the principles of circularity, where food waste, crop by-products, and grasslands are used to produce animals sourced food. While modeling results of circular food systems have shown their ability to produce healthy diets at a low environmental cost, the economic feasibility of this transition is underexplored. This Ph.D. will play an important role in pushing the current research profile on circular food systems into the frontier of economics and policy.

This Ph.D. will dive into four different research questions. The first question will establish what economic and governance transition pathways are available in transitioning our current food system to a circular one. Research questions two and three will focus on integrating quantitative economic modeling into the Circular Food Systems (CiFoS). In these questions, we will build the economic module for the CiFoS model for New York State in the USA and the European Union. The economic modeling results for the European Union from the CiFoS model will have an additional global food system perspective from collaborator modeling using the MAGNET model from Wageningen Economic Research. Then, in research question four, we will apply the transition pathways established in research question one to economic modeling results from research question two on New York State to build a case study of transition pathways for the New York State food system to adopt circular food system practices.

Through these research questions, we aim to explore several areas that would advance the dialogue on the feasibility of circular food systems. By developing a framework on the economic feasibility of different circular transition pathways, we can broaden the conversation on how food system transitions can occur and what are the tipping points that would positively amplify these changes. Thus. The overall aim of this project will be to merge the economic, governance, and bio-physical conversations on circular food systems to explore the role of circularity in our goal of creating a sustainable global food system.

Additional info

Project start date: September 1, 2021. Porject end date: March 1, 2026.

Partners: Farming Systems Ecology, PE&RC, Cornell University Center for Global Development, AVINA Foundation

Promotor: Hannah van Zanten. Supervisors Mario Herrero, Michiel van Dijk

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Protein sourced foods are responsible for the majority of environmental impact of the food system and transitioning towards more sustainable sources and production methods will be vital for reducing its impact. My research will look into the potential of novel foods and production systems in the protein transition, how these can be translated into local contexts and what the environmental impact will be with an emphasis on biodiversity loss.

Current consumption of protein sourced foods has not only been criticized for its high environmental impact but also for its impact on health. Many health issues are associated with the overconsumption of certain protein sourced foods, particularly animal products. Simultaneously, many populations still lack sufficient sources of protein. The world does not necessarily need to produce more protein instead there is a problem with equity and sharing of the resources we have within the safe operating space of humanity. In order to better supply everyone with protein-rich, healthy and sustainable diets, this will require shifts in consumption and agricultural production. Large scale changes of this nature are complex to navigate. Many foods and methods of production have been suggested to transition towards healthier and more environmentally friendly protein sources from the high tech to low input/traditional. Each of these products and systems with their own unique profile of benefits and drawbacks. Revisiting old and new solutions through exploring novel foods and production systems can help communities find the unique profile of health and environmental benefits that suit their needs. In this way novel foods and production systems offer and opportunity to expand the suite of options available for these transitions.

Before recommendations for sustainable protein rich foods can be made it is important to consider the full suite of sustainability indicators. Biodiversity loss is one indicator typically left out or not fully accounted for in assessments of sustainable diets and foods. Agriculture is the primary driver of biodiversity loss globally with implications for the health and food security of present and future populations. In order to assess the sustainability of novel foods better systems for accounting for biodiversity loss in sustainable diets must be first be developed.

To address these issues my research will examine:

A)Which metrics are best suited for measuring biodiversity in assessments of sustainable diets?

B)What is the potential for novel foods and production systems to improve health and environmental outcomes in the protein transition?

C)Where are the biggest environmental impact hotspots and agricultural production systems in global protein production?

D)How can local protein transitions be realized in hotspot regions?

The global demand for food is expected to drastically increase in the coming decades. Meanwhile, the availability of farmland is reducing and the productivity of land-based agriculture is increasingly jeopardized by environmental changes. To address this complex challenge, innovative and sustainable food systems need to be developed. A promising food system innovation is the rearing of earthworms, known as vermiculture, as an alternative protein source for human nutrition. During vermiculture, nutrients from organic wastes are recycled and bio-transformed to protein-rich earthworm biomass and vermicompost, a high-quality organic fertilizer. Accordingly, vermiculture has the potential to produce nutritious food and contribute to food system circularity. The aim of this PhD project is to optimize vermiculture on spent mushroom substrate as a protein source for human nutrition and assess the sustainability of this process.

Earthworm biomass is highly nutritious and can be a valuable addition to human diets. Earthworms are traditionally appreciated as a food by cultures around the world and recent studies have found a high nutritional value comparable to other animal-based protein sources such as eggs, milk products or chicken. To efficiently produce such nutritious earthworm biomass, the quality of earthworm feed is essential. Several recent studies indicate that spent mushroom substrate, a waste product from edible mushroom production, is a promising earthworm feed. Most of these studies however, focus on waste treatment rather than vermiculture as a source of protein for human nutrition. Accordingly, this PhD project will identify and then optimize key parameters to realize an efficient vermiculture process to produce earthworm biomass for human consumption.

In order to compare the previously optimized vermiculture process with other protein sources, a sustainability assessment will be carried out. During vermiculture, organic wastes decomposed by the joined action of earthworms and associated microbes and greenhouse gases are released. When the remaining vermicompost is returned to the soil, further emissions may occur, while part of the carbon will remain in the soil. Nutrient flows and greenhouse gas emissions will be measured during vermiculture and vermicompost application to the soil. These data will then be used to perform a Life Cycle Assessment in order to compare the sustainability of vermiculture with other protein sources.

The following research objectives will be addressed during the PhD project:

Objective 1 Identify key parameters for efficient vermiculture on spent mushroom substrate in a literature review.

Objective 2 Optimize identified parameters to realize an efficient vermiculture process on spent mushroom substrate.

Objective 3 Quantify environmental impacts of optimized vermiculture and vermicompost application to soil.

Objective 4 Conduct a Life Cycle Assessment of vermiculture on spent mushroom substrate for protein production.

Additional info:

- Project start date: 01.09.2021 - Project end date: 30.08.2025

- Promotor: Hannah van Zanten, Supervisors: Jan-Willem van Groenigen, Alix Vidal, Gerold Rahmann and Alejandro Parodi

- Partners: Thuenen Institute of Organic Farming, Farming Systems Ecology Group (FSE-WUR), Soil Biology Group (SBL-WUR)

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Ethiopia is known for having the largest livestock population in Africa. However, animal source food (ASF) consumption is very low and there is a high prevalence of malnutrition. Studies shows that there is a need to increase animal production yield and ASF consumption. In this study, we aim to assess the potential contribution of farm animals to nutritious diets while minimizing greenhouse gas emissions for the circular food system of Ethiopia. To explore this, a model will be used to study feed-food competition and interrelation of various food system components.

The thesis will be organized in four parts. In the first part, a baseline study to assess the greenhouse gas emission from animal source food production and consumption. Then, we will analyze how to increase nutritious diet while minimizing the environmental impact from ASF to meet the recommended national dietary guidelines. The third part, attempt to explore how we can allocate resources for production of ASF in different agroecological zones and farming systems in Ethiopia. Finally, we will assess the challenges and enhancers towards the a transition to circular food systems in Ethiopia. The outputs of this study may be inputs for policy directions and strategies to meet dietary requirement and towards circular food system of Ethiopia.

The results of this thesis will give insights to questions, such as: ‘how to nourish a growing population healthy and nutritious diet while minimizing the environmental impact on the Ethiopian food system?’, ‘How many animals and which type should we keep in which systems and in which AEZ?’ and ‘Which crops should we cultivate in order to maximize food production and minimizing Environmental Impact?’. Answering these questions informs policymakers on how to improve their governance towards a circular food system.

Additional info:

Project starte datet: October 2021. Project end date: October 2025.

Promotor : Hannah van Zanten. Supervisors: Inge Brouwer, Jeroen Groot and Alejandro Parodi.

Partners : Ethiopian institute of Agricultural research (EIAR) and Ethiopian Public health Institute (EPHI).

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Associated with the ‘Food4future’ project, this research recognizes a transition towards circularity in the food system as a possibility to produce sufficient healthy diets within the planetary boundaries. The transition to a circular food system implies a fundamental shift in infrastructures and technologies, as well as peoples' institutions, competencies, and practices. It can only be induced by peoples' decisions, behaviors, and interactions. Therefore, this project targets the social dimensions of a transition towards circularity.

We will focus on multiple case study countries that differ in socio-economic aspects and agro-ecological conditions, to understand their needs for transformation and related challenges and opportunities. The aim is to develop transition pathways that are targeted to the local socio-economic conditions. After assessing the environmental and dietary impact of different food system scenarios with the Circular Food Systems (CiFoS) model, we aim to understand the societal implications of closing the loop of materials and substances and to compose and model pathways towards circular food systems in the case study countries. This should lead to scalable short-term and long-term strategies that incorporate local targets and circumstances and bring about transformative changes to the current food systems.

In particular, this Ph.D. project focuses on modeling the transition pathways and various key indicators for assessing the related sustainability performance in the case study countries. A main part of the work will consist in further developing and adapting the food system model CiFoS to adequately include the food systems and their envisaged transformations of the case study countries. Further, it aims to enable the analysis of social outcomes as well as local dietary habits and preferences in the model to support stakeholder processes and policy design.

This Ph.D. project is associated to the ‘Food4Future’ project funded by the AVINA Foundation. It is performed together with the Farming Systems Ecology Group, at Wageningen UR, and the Research Institute of Organic Agriculture (FiBL) Switzerland.

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Associated to the ‘Food4future’ project, this research recognizes a transition towards circularity in the food system as a possibility to produce sufficient healthy diets within the planetary boundaries. The transition to a circular food system implies a fundamental shift in infrastructures and technologies, as well as peoples' institutions, competencies, and practices. It can only be induced by peoples' decisions, behaviors, and interactions. Therefore, this project targets the social dimensions of a transition towards circularity.

We will focus on multiple case study countries that differ in socio-economic aspects and agro-ecological conditions, to understand their needs for transformation and related challenges and opportunities. The aim is to develop transition pathways which are targeted to the local socio-economic conditions. After enabling the assessment of the environmental and dietary impact of different food system scenarios with the Circular Food Systems (CiFoS) model, we aim to understand the societal implications of closing the loop of materials and substances and compose and model pathways towards circular food systems in the case study countries. This should lead to scalable short-term and long-term strategies that incorporate local targets and circumstances and bring about transformative changes to current food systems.

In particular, this PhD project focuses on social dimensions and model-supported stakeholder processes related to the development and potential future implementation of transformation pathways. This entails employing a variety of social sciences methods to organise stakeholder processes as well as to collect and analyse the data relevant for understanding the envisaged food system transformations and how to potentially initiate and support them.

This PhD project is funded by the AVINA foundation and is performed together with the Farming Systems Ecology Group,at Wageningen UR, and the Research Institute of Organic Agriculture (FiBL) Switzerland.

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We are in a global context of growing concerns about the environmental sustainability of beef production and consumption -one of Uruguay's main export products- which has led to dietary changes, development of substitute products, environmental certification schemes and potential trade barriers. Livestock production has a large impact on the environment. But there are big differences between beef production systems worldwide -and at country level- that result in different environmental footprints.

The sustainable production of beef on native grasslands can play an important role in food security, by converting grass into animal protein for human consumption. At the same time, it can contribute to preserve ecosystem services provided by native grasslands, including carbon storage and sequestration, habitat for biodiversity, water flow regulation, nutrient cycling, forage production, cultural values, and also provide better living conditions for grazing animals (Tittonell, 2021).

What is the monetary value of these fundamental ecosystem services in different types of beef production systems? Does environmental certification of beef production help to preserve these ecosystem services? What policy instruments are adequate to promote sustainable beef production? What is the role of sustainable beef production in circular food systems at the country level?

This research project is conducted by Carolina Balian under the joint supervision of Dr. Hannah van Zanten (Farming Systems Ecology) and Dr. Milena Holmgren (Wildlife Ecology and Conservation) from WUR and Dr. Francisco Rosas from Universidad ORT, Uruguay.

Additional info:

- Project start date: February 2022. Project end date: January 2026

- Partners: Agencia Nacional de Investigación e Innovación (ANII), Uruguay.