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Project Topic
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The Agricultural Water Innovations in the Tropics (AgWIT) partnership will test key management innovations to reduce impacts of agriculture on water resources, improve climate change resiliency and enhance freshwater security. We will evaluate water and carbon use efficiencies for a range of agricultural production systems under current and alternative management scenarios. We will build on a unique network on tropical agriculture water observatories that integrates eddy covariance towers in Brazil and Costa Rica using infrastructure recently established by two projects funded through the Freshwater Security initiative of the Belmont Forum. Optical and thermal monitoring of ecophysiological indicators of plant water stress at multiple scales will be added to the eddy covariance monitoring systems using field-portable analysers, tower-based sensors, sensors integrated with Unmanned Aerial Vehicles (UAVs), and data obtained via satellite remote sensing. We will also conduct detailed hydrological and isotopic measurements of these soil-plant-water systems in response to soil and water management strategies. We will test the ability of biochar (charcoal derived from waste biomass via pyrolysis) in tropical cropping systems to increase water use efficiencies (from increased soil water storage resulting from biochar additions), increase soil carbon sequestration (through soil application of biochar which has a high carbon content), and improve the water quality of soil leachate (resulting from the filtering effect of biochar, which has very high reactive surface area and exchange capacity). To do this, AgWIT will (i) measure agricultural carbon and water fluxes, crop yields and plant water stress over more than 20 crop cycles in both rainfed and irrigated agricultural systems, (ii) determine using isotopes what portion of water (rainfall and/or irrigation) is used by crops, lost by soil evaporation and percolated beyond the root zone, and (iii) evaluate optimal biochar-based soil treatments to improve crop water use efficiencies. Benchmarking volumetric water, carbon and land footprints under different management strategies will be accompanied by AgWIT social scientist stakeholder group consultations in Brazil and Costa Rica. This will allow evaluation of alternative decision pathways to improve agricultural water management, and reduce vulnerability to climate-change impacts within the hydro-social system. We have strong, on-going relationships with local non-governmental organizations (NGOs), water management agencies and producer groups in both study regions. These relationships will help to structure strategies for specific decisions concerned with freshwater management choices through structured decision-making workshops involving local stakeholders and technical specialists. Scenarios identified by stakeholder groups and water managers will be incorporated into hydrological modelling activities, which will also be used to model biochar impacts at field and landscape scales under realistic management scenarios. In sum, AgWIT will develop a globally unique data set of crop responses to biochar amendments, irrigation practices and rainfall patterns. Volumetric water, carbon, and land fertilizer footprints under alternative management scenarios relative to current crop benchmarks are important to producers to aid in water management decision-making. It is also important for the EU because water, carbon and other resources used in the production of imported agricultural products are indirectly allocated to EU’s consumption. Water and other footprint information will be shared with major life cycle analyses databases in support of the EU’s “single market for green products” initiative.
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