A free accessible individual-based simulator enabling virtual experiments on soil organic matter processes in classroom
Journal of Technology and Science Education
This work addresses and aims to fulfil a very clear need in teaching biosystem engineering. When introducing students to the complexity of soil processes, one of the frustrations that teachers ofen experience is the impossibility to demonstrate practically, in the lab, some of the concepts and processes discussed in class. Either the experiments take far longer than a typical laboratory session or they require access to specific equipment. To deal with this situation, it would be ideal for
... nts to be able to do virtual experiments. The purpose of this work is to display the individual-based simulation model INDISIM-SOM, available free from a website, and to show how it can be used in experiments or as a teaching-learning instrument in the classroom. The computational model has been designed specifically for the study of soil organic matter and is based mainly on the activity conducted by two diferent prototypes of microorganisms. One option of using INDISIM-SOM is as a way to introduce the individual-based model as a methodology to improve understanding of the agents involved in soil microbial system and their processes. Another option is to develop the ability to work with simulators by connecting concepts and helping students in the development of modelling competence. Virtual experiments were carried out as an example of what may be expected from using the INDISIM-SOM web simulator. Temporal evolutions of five virtual soils with diferent organic C content and proportional content in organic N, easily hidrolyzable N, nitrate and ammonia were generated and discussed. Keywords -biosystems engineering educaton, computatonal model, individual-based simulatons, virtual experiment, soil organic matter processes ----------In the nineties, a new approach to modelling complex systems, referred to as individual-based modelling (IBM), began to emerge, characterized by both a philosophy and perspective that were diferent from the continuous models predominantly used until then. This approach is also known as biological agent-based models. In IBM models, the individuals that make up the system are treated as autonomous and discrete entities (Grimm & Railsback, 2005; Grimm, Berger, Bastiansen, Eliassen, Ginot, Giske, et al., 2006; Grimm, Berger, DeAngelis, Polhill, Giske & Railsback, 2010) . The models focus on the characterization of these entities by means of rules of behavior, which allow the elements to interact with one another and with the environment in which they are evolving. These computational models require distinct simplifications from those assumed by continuous models, and they are a good modelling alternative to deal with specific aspects related to biosystems (Grimm & Railsback, 2005) . Multidisciplinary courses are being developed at a number of colleges and universities that highlight the use of soils in agriculture and the sustainable or unsustainable uses of natural resources. The content of the courses is usually complex, as it includes concepts from such varied disciplines as soil science, geology, chemistry, physics and microbiology. The learning goals for these courses include developing skills in the critical analysis of complex soil systems. In an attempt to address these issues, activities that focus on the connections existing between the diferent elements that make up the soil system and the intricate processes evolving in it are especially beneficial (Jacobson, Militello & Baveye, 2009) . One way to deal with all of these items is by using modelling and simulation as tools for teaching and learning.