Water and Agriculture

An example of terraced paddy rice field.  Water plays a key role in agriculture soils due to its manifold interactions in different environmental fields. For instance, water availability within soil regulates plant transpiration, influencing plant growth and sustenance. Moreover, water fluxes transport through the soil nutrients, fertilizers, and pesticides affecting plant nutrient uptake, soil fertility, and groundwater quality. Furthermore, water in the soil is the biological environment where microorganisms catalyse biochemical reactions, which regulate soil nutrient cycles and greenhouse gas emissions, including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Finally, convective heat transport can influence temperature soil profile, which strongly affect physical, chemical, and biological processes.

    Monodimensional model schematization of paddy soil. In this context, the development of mathematical models with a multidisciplinary approach seems necessary in order to obtain new tools able to improve the environmental sustainability of future agriculture productions. More in details, proper modeling of water and heat transport fluxes could allow to evaluate spatio-temporal evolution of nutrients within soils in order to furnish new insights and solutions able to reduce greenhouse gas emissions, limit the fertilizer and pesticide applications, and increase the agriculture productivity.

    The research team in Water and Agriculture have developed a process-based model able to simulate the methane emissions from rice paddy field, focusing principally on the role of water flows (advection, dispersion, and root water uptake) and heat transport in the nutrient cycles. For example, the model is able to simulate the spatio-temporal evolution of nutrients involved in methane emissions within paddy soil, as reported in the picture below [Rizzo et al., 2013], in order to better understand the biogeochemical nutrients cycles during a rice growing season. Currently, the process-based model is applying to study the efficiency of lowering ponding water temperature (LPWT) and microbial fuel cell (MFC) as novel mitigation strategies for methane emissions from paddy fields.
Spatio-temporal variation of nutrient prevalences in paddy soil, expressed in percentages.
  • Rizzo A., Boano F., Revelli R., Ridolfi L. 2013. Decreasing of methanogenic activity in paddy fields via lowering ponding water temperature: A modeling investigation Soil Biology & Biochemistry. 75, 211-222 http://porto.polito.it/2543352/
  • Rizzo A., Boano F., Revelli R., Ridolfi L. 2013. Can microbial fuel cells be an effective mitigation strategy for methane emissions from paddy fields? Ecological Engineering. 60, 167-171 http://porto.polito.it/2512693/
  • Rizzo A., Boano F., Revelli R., Ridolfi L. 2013. Role of water flow in modeling methane emissions from flooded paddy soils. Advances in Water Resources. 52, 261-274  http://porto.polito.it/2505511/

Conference proceedings

  • Rizzo A., Boano F., Revelli R., Ridolfi L. 2013. Effect of water and heat transport processes on methane emissions from paddy soils: a process-based model analysis. EGU General Assembly 2013 http://porto.polito.it/2505087/
  • Rizzo A., Boano F., Revelli R., Ridolfi L. 2013. Microbial fuel cell as mitigation strategy for methane emissions from paddy field. EGU General Assembly 2013 http://porto.polito.it/2505512/
  • Rizzo A., Boano F., Revelli R., Ridolfi L. 2012. Ruolo dei flussi convettivi sulla modellazione delle emissioni di metano da risaia.  XXXIII Convegno nazionale di idraulica e costruzioni idrauliche http://porto.polito.it/2503863/

Thesis proposals