Sustainable Soil Management

Short summary

The nutrient cycle in the Netherlands remains largely open, with limited recovery and reuse of nutrients from waste streams. Circular agriculture focuses on optimizing nutrient recovery from sources like animal manure, municipal and industrial wastewater, and organic residues. Implementing circular agriculture can reduce waste, lower reliance on external raw inputs, and minimize emissions through the processing of manure and other waste materials. 

Why this theme?

This work aligns with policies aimed at increasing nutrient reuse from manure and organic residues. The goal is to process these materials to reduce nitrogen losses, prevent nutrient leaching, and lower emissions. By reducing methane and nitrogen emissions, circular agriculture supports environmental sustainability and helps meet agricultural emission reduction targets. 

Highlighted projects (3-5 projects) 

• FERTIMANURE
• KNAP
• BIOVALOR
• SYSTEMIC
• NITRINURE

Highlighted methods

Evaluation of nutrient recovery installations: we monitor (pilot)installations were digestate, manure or waste streams are being converted into organic or mineral fertilising products. We evaluate recovery processes in terms of   mass- and energy balances and economic performance. Examples are the evaluation of installations for treatment of pig manure and for recovery of nitrogen from dairy manure. 

Agronomic performance: we are experienced in testing fertilising products in pot- and field trials. This gives insight into the agronomic and environmental performance of fertilising products. Examples include field trials with ammonium-sulphate, mineral concentrates, struvite and organic fertilisers.

Short summary

Sequestering carbon in the soil plays a role in climate change mitigation and adaptation by capturing CO2 from the atmosphere. At the same time, soil carbon influences other ecosystem services such as soil fertility and acts as a food source for a wide array of soil organisms. Our team assesses the effect of management practices on soil carbon stocks using dynamic soil carbon models and monitoring data. We do this at various scales, from individual farm level up to European scale. Our approach is characterized by an integral view of soil carbon management practices in relation to soil functions, soil biodiversity, the emission of nitrous oxide (N2O) and the practical implementation of these practices. 

Why this theme?

Carbon removals are required to achieve the climate goals as determined in the Paris agreement which is ratified by the European Union and further elaborated in the Dutch Klimaatakkoord. Worldwide, soil is the second largest active carbon pool (behind oceans), storing more carbon than the atmosphere and vegetation combined. The yearly carbon flux from the atmosphere to the soil is roughly ten times as large as the CO2 emissions related to fossil fuels. Therefore, a relatively small increase in the carbon uptake by soils could potentially lead to the sequestration of a substantial amount of CO2. With our research we want to contribute to these climate goals by providing knowledge to stakeholders and policymakers that can incentivize the required changes in soil management.  

Highlighted projects

• Slim landgebruik

• Monitoring emissieregistratie
• MARVIC
• Nutribudget
• EO4CSM

Highlighted methods

In order to monitor and predict soil carbon dynamics, we work with several models. These models and the input data they require are constantly being updated so they include the latest scientific insights. The models we use: 

• RothC model, which predicts the turnover of organic carbon in non-waterlogged topsoils. The tool is integrated in MITERRA-Europe and the Praktijktool BodemCoolstof and the algorithms are based on Coleman and Jenkinson (2014).
• MITERRA-Europe model, which can assess carbon (C) and nutrient flows important for plant growth at regional level for the whole of Europe. The tool provides insights in the effect of policies and can therefore help policy makers in their decisions regarding sustainable land management practices.
• Praktijktool BodemCoolstof, a hands-on tool based on RothC calculation rules that is freely available through the platform FarmMaps. The tool can calculate the change in soil carbon over time and the effect of different management practices on this soil carbon change, and is therefore recommended to use for assessing carbon farming schemes.

If you are a student and would like to be involved in projects about soils and carbon, please do not hesitate to contact us. 

Short summary

Water quality is determined by the physical, chemical, and biological properties of water, which, in combination with and depending on water quantity, influence its suitability for food production, drinking water supply, and the health of freshwater ecosystems, including rivers, lakes, groundwater, wetlands, estuaries, and deltas. It is influenced by natural factors like geology and climate, as well as human activities such as land use, pollution from point and diffuse sources, dewatering, dam and channel regulation, and (over)abstraction. Our team’s core mission is to promote sustainable water quality through dedicated research, focusing on maintaining balanced nutrient levels and reducing water pollution to protect aquatic ecosystems, support sustainable food production, and safeguard water resources.

Why this theme?

Water quality research serves as the scientific basis for the protection and management of water resources, which are crucial for both environmental sustainability and human health. A thorough understanding of the factors influencing water quality allows for the identification of pollution sources, the assessment of their impacts, and the development of effective strategies to mitigate contamination. The significance of water quality research is underscored by key regulations in Europe and the Netherlands, primarily governed by the EU's Water Framework Directive (WFD), alongside supporting directives such as the Groundwater Directive (GWD), Drinking Water Directive, Urban Wastewater Treatment Directive, and Nitrates Directive. In the Netherlands, the implementation of these EU regulations is ensured through national legislation, including the Water Act and the Environmental Management Act.

Highlighted projects

• New Harmonica
• Evaluation of the fertilizer policy
• Fairway
• Analysis of current and future load reduction targets to achieve good ecological status of fresh surface water bodies in Dutch river basins.
• Measures in groundwater protection areas to comply with the nitrate standard

Highlighted methods

Our team has developed several widely recognized models, including the nutrient runoff and leaching model ANIMO, the national water quality model LWKM, and the pollution source apportionment model ECHO. These water quality models are vital for the effective understanding and management of water resources, providing essential insights into the factors influencing water quality. They not only support regulatory compliance but also aid in creating management strategies designed to reduce pollution and protect aquatic ecosystems.Our field experiments primarily concentrate on nutrient loading studies and pollution source tracking, assessing the impact of agricultural practices on water quality. These investigations yield critical insights into the dynamics of aquatic systems and the effectiveness of various management strategies. The data collected enhances our understanding of aquatic ecosystems, informs policy decisions, optimizes water resource management, and promotes sustainable practices to address specific water quality challenges.

Short summary

Soil health is defined as the continued capacity of soil to function as a living ecosystem that supports plants, animals, and humans. Understanding soil health requires an interdisciplinary approach, covering topics such as soil contamination, biodiversity, and soil processes. This theme brings together our diverse team to address the complex challenges that underpin the sustainable functioning of soils.

Why this theme?

Awareness is growing that soils must be protected to safeguard their vital contributions to society, including essential ecosystem services. Soils form the baseline for addressing current societal challenges such as achieving a circular economy and ensuring food safety. This urgency is reflected in recent developments like the Global Sustainable Development Goals and the EU Soil Monitoring Directive, which highlight the importance of sustainable soil management and protection.

Highlighted projects

• MINOTAURBokashi
• BO Bodembiodiversiteit
• Law for healthy soils (OBN Herstel rijkere Eikenbossen, EcoCertified)

Highlighted methods

Experiments and observational field studies combined with statistical and machine learning approaches to identify suitable indicators for soil health and soil functioning, and evaluate the influence of management practices and contamination on soil health…A range of established and novel assessment methods for soil health, biodiversity and processes (incubation studies, stable isotope tracing, microbial community profiling using fatty acid markers and eDNA)Transfer models for contaminants.

If you are a student interested in assessing soil health or being involved in related projects, do not hesitate to contact Laura Riggi or Anna Edlinger.

Short summary

Complex environmental problems, and scientific research and policy decisions to address these problems often rely on modelling studies that integrate multiple environmental themes. Within our team, various integrated models have been developed that are used to monitor losses to the environment and to evaluate the effect of policy options on agricultural practices and related impacts on nutrients, metals and carbon fluxes and balances in the agro-environmental system.

Why this theme?

Partly policy driven changes in land cover/land use, atmospheric deposition and climate affect nutrient, carbon and metal cycling in agriculture, impacting their losses to the environment altogether. For example, multiple nitrogen compounds (e.g. NH3, NO3 and N2O) are emitted by multiple sources (e.g. livestock housing, manure and fertilizer application), interact with each other in various compartments (plant, soil, water and air), and can have multiple effects (e.g. acidification, eutrophication, human health) at various spatial scales (local, regional, national, global). By developing and using integrated models, our team strives at capturing these multifaceted effects for various compounds, compartments and across various scales.

Highlighted projects

• Integrated studies to support national and regional policies for improving environmental quality (e.g. an integrated modelling study in view of the National Rural Area Programme);
• Evaluation/scenario study in the view of the Manure Act (EMW);
• Monitoring and evaluation of the Nitrogen Reduction and Nature Improvement Act (MESN);
• Redesign and further development of a spatially explicit national model on gaseous emission from agriculture.

Highlighted methods

Our integral models combine cross-disciplinary knowledge on processes describing nutrient, carbon and trace metal flows in the agro-environmental system. This involves the integration of GIS databases, containing spatially explicit information on agricultural census, with emission factors that are determined through experimental work and literature studies. Scenarios are coupled to the models to evaluate how policy driven adjustments in the agricultural system affect the losses of nutrients, carbon and trace metals.

Short summary

Management of agricultural soils can lead to emissions of greenhouse gases like nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4), and air pollutants, such as ammonia (NH3) and nitrogen oxides (NOX). Reducing these emissions is crucial to mitigate global warming and reduce environmental pressure on nature areas. Within our team, we conduct experimental research to investigate the effect of a wide range of management practices such as fertilization, soil tillage, water table management, and species composition on the emissions of these gases, and by doing so design or advice on mitigation strategies that may relieve the environmental pressure of agriculture.

Why this theme?

Agriculture in the Netherlands, as in other places, is under increasing scrutiny and is expected to reduce its carbon footprint and emission of polluting substances. There is a lot of interest from governmental institutions, the farming community, and the agricultural industry in finding ways to reduce environmental pressure.Our work on gaseous emissions is also driven by goals and agreements to reduce emissions of greenhouse gases and air pollution on global, European, and national levels. Examples hereof are the Paris climate agreement, national emission ceiling (NEC) directive, Goteborg protocol, and associated national legislation like the manure and nitrogen policies. Our research feeds into models that calculate emissions from agriculture on a national (NEMA) and regional (INITIATOR) scale and that are used to report emissions to international directives, run scenario analyses, or assess the impact of mitigation measures on different spatial levels.

Highlighted projects

• Improving emission factors for N2O and NOX: in this project we assess the N2O and NOX emissions from various mineral fertilisers and from grazing cattle (urine and dung patches) under Dutch conditions. The goal is to specify N2O and NOX emission factors for fertilisation and improving model estimates of these emissions at the national and regional levels.
• NOBV: in the national research programme for greenhouse gas emissions from peatland areas, we measure N2O emissions from managed peatlands. In this research we look at the effects of different nitrogen sources (fertilisers and animal manure) and water management regimes (ditch level and drain type).
• PPS Reducing N2O emissions: in this project, which is partly funded by the Ministry of Agriculture and partly by the dairy sector (ZuivelNL and FrieslandCampina), we look at various mitigation options for N2O emissions, such as timing of fertilisation, liming of agricultural soils, and selection of grassland species.
• NKS improving emission factors NH3 from fertilisers: for the national nitrogen knowledge programme (NKS), we are investigating the NH3 emissions from different mineral fertilisers. We are looking at the effects of factors such as fertiliser nitrogen form, fertiliser coating, soil type and texture, pH, and soil moisture. Here too, the goal is to improve emission factors and model predictions.

Highlighted methods

We use a combination of literature studies, lab incubations, greenhouse experiments, and field trials in our research of agricultural emissions and their driving factors. Typically, field trials are set up for the determination of yearly emissions and emission factors, as well as the effect of agricultural practices. These emission factors can be used in emission models. We use greenhouse and incubation studies used to increase our understanding of underlying soil processes.For the gas measurements in our experiments, we typically use a static chamber design combined with a gas analyzer to detect concentration increases of greenhouse gases (N2O, CO2, CH4). For emissions of NH3 and NOX, we use a ventilated or dynamic chamber design in combination with an acid trap or a gas analyzer. Additionally, we employ automatic chambers in combination with a sensitive analyzer to study temporal emission patterns in high resolution under controlled measurements.