AgWIT

AgWIT - Agricultural Water Innovations in the Tropics

Project Website

Coordinator: Mark S. Johnson - University of British Columbia (UBC)

Projects  Partner and Institution:
Susan Trumbore Max Planck Institute for Biogeochemistry BMEL Germany
Paulo Brando Instituto de Pesquisa Ambiental da Amazônia IDRC Brazil
Andrea Suárez Serrano Universidad Nacional de Costa Rica - HIDROCEC - IDRC Costa Rica
Monica García Technical University of Denmark (DTU) IFD Denmark
Steve Lyon Stockholm University - FORMAS Sweden
Chih Hsin Cheng National Taiwan University MOST - Taiwan

Key words:

Abstract:

There is an urgent need to develop methodologies to increase water use efficiencies in both rainfed and irrigated agriculture locally in order to improve food and water security globally. The Agricultural Water Innovations in the Tropics (AgWIT) research consortium evaluated current water use practices in several tropical agriculture systems that supply European markets and assessed alternative soil and water management strategies to improve climate resilience and reduce soil and water pollution in partnership with agricultural producer organizations and other stakeholders. Across our research consortium, we generated measured and modelled information, permitting robust determination of resource use efficiencies and environmental footprints under irrigated and rainfed conditions, with and without biochar additions, for agricultural goods exported to the EU from tropical producer countries. 

The AgWIT consortium used a broad range of methods in the project: detailed assessments of plant water use and soil water dynamics via isotopic sampling and hydrologic modelling; field-based research using eddy flux towers and experimental plots amended with biochar (a charcoal made from organic material added to soil to increase carbon content and improve water retention capabilities); technological development to integrate data obtained using UAVs with ground-truth data from field plots and flux tower footprints. Work performed included (1) detailed measurements of crop light use efficiencies, photosynthesis and canopy stress dynamics; (2) detailed assessments of plant water use and soil water dynamics via isotopic sampling and hydrologic modelling; (3) field-based cropping trials to assess biochar effects on plant, soil and water processes; and (4) detailed assessments of water, carbon and land footprints under rainfed and irrigated conditions.

A central finding from our effort is that biochar additions to the soil can increase plant available water; however, there is much variability in response determined by unique geographical and climatic factors. We found that adding biochar allowed rice plants to access larger stores of water more consistently. This means the plants could grow an extra seven days without irrigation relative to control treatments without biochar. 

Our methodological advances led to the development of low-tech and inexpensive tools to extract water from plants—a necessary step for measuring “where from” plants take their water. These methods can be easily applied at locations with limited access to state-of-the-art resources and ultimately help manage water resources to fulfil agricultural and other competing water needs.

We used drones and satellites to scale up some of the biochar findings regarding soil hydraulic properties, plant water status and physiology. The drones were also used to obtain complementary information to in situ data regarding plant productivity to assess crop responses to biochar. For instance, increases in canopy chlorophyll and biomass estimates were found for rice grown in the biochar amended plots, along with increased crop water use efficiency, with differences depending on biochar type and application.

A large effort in AgWit was done on three aspects of technological development: (i) sensor integration and synergies exploitation (hyperspectral+thermal+RGB consumer grade cameras) on drones; (ii) data correction and calibration (e.g., cloudiness and turbulence effects); and (iii) modelling developments of energy, water and carbon fluxes, first tested on close by pilot sites in Denmark and then in the field in Costa Rica. Applications of the above developments at the eddy covariance sites and biochar experiments are a first step to obtain “everywhere and all the time” estimates of crop water use and productivity, and to connect field and satellite estimates that present disparate scales.

Objectives:

1. Identify improvements in resource use efficiencies and environmental performance of key crops produced via alternative water and soil management strategies under rainfed and irrigated conditions;
2. Determine crop physiological responses of biochar additions to soil using non -destructive optical and thermal sensing at multiple cales throughout > 20 agricultural crop development cycles;
3. Develop/apply crop ecophysiological, hydrological, and biogeochemical models to evaluate innovative soil and water management strategies in relation to the plant - soil -atmosphere system;
4. Evaluate and set priorities among strategies to increase water resilience through structured decision making workshops with local communities, producer groups and water management agencies.

Project structure: 
WP1. Crop responses, water and carbon footprints in relation to biochar additions and water management strategies Annual volumetric water footprints (blue and green) fo r soy, corn, rice, melon, and sugarcane;
WP2. Hydrology, isotopic measurements and modelling at nested scales;
WP3. Structured Decision Making Workshops and Knowledge Transfer;

Implementation:

Outcome/deliverables:
Expected Impact of the Project, Develop and assess strategies to improve agricultural resilience while reducing the water, carbon and other footprints of agricultural practices and improving freshwater security and environmental conditions AgWIT will develop practicable strategies with end users and stakeholders for integrating novel approaches to soil and water management of agricultural systems.

References coordinator and  leaders of  each WP: 

Main outputs:

• Herrera-Ramirez, D., Sierra, C., Römermann, C., Muhr, J., Trumbore, S. E., Silvério, D., Brando, P. M., Hartmann, H. (2021). Starch and lipid storage strategies in tropical trees relate to growth and mortality. New Phytologist, 230(1), 139-154.
• Fisher, J.B. and 58 co-authors including Johnson and Morillas (2020), ECOSTRESS: NASA's Next Generation Mission to Measure Evapotranspiration from the International Space Station, Water Resources Research, 56(4), e2019WR026058,
• Sobejano-Paz, V., T.N. Mikkelsen, A. Baum, X. Mo, S. Liu, C. J. Köppl, M.S. Johnson, L. Gulyas, and M. García (2020). Hyperspectral and Thermal Sensing of Stomatal Conductance, Transpiration, and Photosynthesis for Soybean and Maize under Drought, Remote Sensing, 12(19), 3182.
• Wang, S., García, M., Ibrom, A., & Bauer-Gottwein, P. (2020). Temporal interpolation of land surface fluxes derived from remote sensing – results with an unmanned aerial system. Hydrology and Earth System Sciences, 24(7), 3643–3661.

More results on the project: Data and resources

Contact Point for  Communication/Dissemination activities:

Contact Point for Open Data/Open Access activities: