Announcements

International Symposium on Organic Farming and Production (ISOP)

The International Symposium on Organic Farming and Production (ISOP) will be held at Can Tho University in Vietnam from the 3^rd of November  to the 6^th of November. The Symposium will be organized by the OrganoRice project with support by ISMC and addresses different disciplines dealing with organic farming in Asia. Contributions to the following topics are welcome:

•    Organic fertilization
•    Organic pest control
•    Irrigation and pollution
•    Variety testing
•    Marketing of organic products
•    Certification process and traceability of the market chain
•    Policies encouraging organic farming
•    Stakeholder involvement
•    Economy of organic production
•    Biodiversity and ecosystem services

For registration visit the OrganoRice homepage

Featured Paper

Do you want your paper featured?

Please share your recent paper if you want to be featured in the ISMC newsletter. With your contributions, we will select one paper to be featured in every newsletter. Submission can be done here. 

Global influence of soil texture on ecosystem water limitation

Low soil moisture and high vapour pressure deficit (VPD) cause plant water stress and lead to a variety of drought responses, including a reduction in transpiration and photosynthesis. When soils dry below critical soil moisture thresholds, ecosystems transition from energy to water limitation as stomata close to alleviate water stress. However, the mechanisms behind these thresholds remain poorly defined at the ecosystem scale. Here, by analysing observations of critical soil moisture thresholds globally, we show the prominent role of soil texture in modulating the onset of ecosystem water limitation through the soil hydraulic conductivity curve, whose steepness increases with sand fraction. This clarifies how ecosystem sensitivity to VPD versus soil moisture is shaped by soil texture, with ecosystems in sandy soils being relatively more sensitive to soil drying, whereas ecosystems in clayey soils are relatively more sensitive to VPD. For the same reason, plants in sandy soils have limited potential to adjust to water limitations, which has an impact on how climate change affects terrestrial ecosystems. In summary, although vegetation–atmosphere exchanges are driven by atmospheric conditions and mediated by plant adjustments, their fate is ultimately dependent on the soil. More information can be found here.

Towards a common vision for the future of hydrological observatories  

The Unsolved Problems in Hydrology (UPH) initiative has emphasized the need to establish networks of multi-decadal hydrological observatories to tackle catchment-scale challenges on a global scale. The already existing monitoring infrastructures have provided an enormous amount of hydrometeorological data, which has helped gain detailed insights into the causality of hydrological processes, test scientific theories and hypotheses, and reveal the physical laws governing catchment behavior. Nevertheless, we are still a long way from being able to fully unravel all the mysteries of hydrological processes to solve practical water-related problems. Hydrological monitoring programs have often produced limited outcomes because of the intermittent availability of financial resources and the substantial efforts required to operate observatories and conduct comparative studies to advance previous findings. Recently, some initiatives have emerged aiming at coordinating data acquisition and hypothesis testing to facilitate an efficient cross-site synthesis of findings. To this end, a common vision and practical data management solutions need to be developed. This opinion paper provocatively discusses two end members of possible future hydrological observatory (HO) networks for a given hypothesized community budget: a comprehensive set of moderately instrumented observatories or, alternatively, a small number of highly instrumented super-sites. 

A network of moderately instrumented, hydrological monitoring sites distributed across the globe would provide broad spatial coverage across the major pedoclimatic regions, help address UPH about the impact of climate and social systems (e.g., land use change and global warming) on water resources, and enhance the potential for knowledge transfer. However, the moderate instrumentation at each site may hamper an in-depth understanding of complex hydrological processes. In contrast, a few extensively instrumented research sites would allow for community-based experiments in an unprecedented manner, thereby providing more fundamental insights into complex, non-linear processes modulated by scale-dependent feedback and multiscale spatio-temporal heterogeneity. Lumping resources has proven to be an effective strategy in other geosciences, e.g. for research vessels in oceanography and drilling programs in geology. On the downside, a few catchments will not be representative of all pedoclimatic regions, necessitating the consideration of generalization issues.

A discussion on the relative merits and limitations of these two visions on HOs is presented with the objective of building consensus on the optimal path for the hydrological community to address the UPH in the coming decades. A final synthesis proposes the potential for combining the two end members into a flexible management strategy. More information can be found here.

Featured Soil Modeler (Sarah Garré)

Understanding and managing soil-plant interactions at various scales

Sarah Garré is a researcher at the Flanders Research Institute for Agriculture, Fisheries and Food (ILVO) in Belgium. In the past years, she has been teaching courses related to agricultural water management, soil-plant interactions and hydrogeophysics as a professor at Gembloux Agro-Bio Tech, ULiège and as a guest professor at KULeuven in Belgium. She finished her PhD research on ‘Non-invasive monitoring of water and solute fluxes in a cropped soil’ at Forschungszentrum Jülich and Bonn University supervised by Jan Vanderborght and Mathieu Javaux in 2010. She is passionate about science communication and author of the children's book ‘The wonderful world of water’.

- Please tell us briefly about yourself and your research interest.

My research career up till now has been about understanding the interactions between water flow in soils and plants on the one hand, and the water system at landscape scale on the other hand, and how these interactions can be optimized to improve agricultural sustainability. Models play a central role in the research in our group. They help us understand the processes behind data we collect in experiments, targeting future research lines and up- and downscaling research results. Working for a governmental research institute, we also produce knowledge to contribute to evidence-informed policy making. In that perspective, models often play a big role, since they help us explore various scenarios, impacts of decisions, etc. A big challenge there is to communicate what those models can and cannot do, what is their uncertainty and where they can be helpful. At the end of the day, policy decisions have to be made taking various types of knowledge and many associated uncertainties into account.   

-  How did you first become interested in soil modelling and learn about ISMC?

That already started before my research career, more specifically during my studies in bio-engineering sciences where we learned about ecological modeling, crop and soil modelling, hydrological models, etc. I was fascinated by the power of models to represent (part of) our world, but also translating it into a context of elegance and clarity. During my PhD in Jülich I started to work with soil models intensively: modelling heat flow in lysimeters to decide on insulation materials, estimating soil hydraulic and root system parameters from soil moisture and matric potential time series and minirhizotron data, … It opened a universe of possibilities and … problems for me. Some of the questions I had back then, I still did not manage to solve entirely yet. 😊 As long as it remains so difficult to obtain an accurate, reproducible and relevant characterization of soil hydraulic properties at field scale using soil physical measurements or sensors, in how far can we rely on results from soil models to predict what will happen in the field and use this to take decisions in agricultural water management? What can we do to reduce this uncertainty? How can we communicate it effectively?

-Can you share with us your current research focus? And, please tell us briefly how your research could contribute to ISMC Science Panel’s activities

Our research group focusses on addressing water-related challenges farmers have or will have in the future: meteorological droughts, limited water availability, changed policies related to drainage and groundwater table management, shifting growing periods, heat stress, …. We investigate different strategies a farmer or a government could adopt to reduce water-related risks to his/her activities and to decrease the environmental impact of agriculture. A crucial aspect coming back in many projects is how to link the effect of small-scale, often spatially-distributed measures, such as weirs, controlled drainage, soil management practices, … with the larger scale processes taking place in the landscape: regional groundwater flow and recharge, land-atmosphere interactions, … Many models exist at their specific scale of interest, but it remains difficult to link those scales in a reliable way and also to validate them. I find it difficult to choose between the Science panel’s activities, but if I must, I think I could probably contribute most in the CROSS-connect panel given the continuous aim of linking soil knowledge and models with needs from other scientific domains, thus finding ways to address complex societal challenges. 

-Please tell us how can ISMC help you advance in your career?

Exchanging with peers on innovative research ideas, identifying knowledge gaps, cross-pollination of ideas, approaches, models from different disciplines, … All these things are present in and promoted by the ISMC activities. Although we, researchers, meet at conferences and meetings and read each other’s publications, structuring those contacts and facilitating collaboration on some key knowledge gaps is needed and ISMC provides that. ISMC can also help take away barriers between scientists from different fields, different careers stages, etc.

- What resources or skills would you recommend that early career members of ISMC should acquire? And how can ISMC help and support early career members in this regard?

In the age of rapid advancements in machine learning and ever-increasing computer power, keeping an overview of all the relevant modelling options and potential combinations with data-driven machine learning tools is not easy, yet crucial. ISMC can help early-career scientists in building up a knowledge base on simulation intelligence for soil-related questions: what are existing approaches, how can they be combined, what are best practices, where are trainings available, …

Given my interest in evidence-informed policy making, I also think that helping young scientists understanding how the science-policy interface works, what our role as soil modelers can be and how results from modelling work can be translated in an impactful  way to policy-makers is one of the big challenges we have in our society. ISMC can help facilitate training in this field, identify needs and give access to a relevant network of experiences people.