Module 4: Food and Water
The goal of Module 4, Food and Water, is for students to understand the interconnection between the growing of food crops and our water resources, and in particular to grasp that food cannot be grown without water and that the growing of food has significant impacts on both the quality and quantity of our surface and ground water resources. After completing this module, students will able to:
- Analyze the relationships between climate, availability of water resources, irrigation, and agricultural food production.
- Examine their water footprints and the virtual water embedded in agricultural food products.
- Summarize the major impacts of agriculture on both quality and quantity of water resources.
In this module, students will:
- Explain the relationships between evapotranspiration (ET), climate, and crop consumptive use
- Describe the major impacts of agricultural diversions on the Colorado River
- Relate the spatial distribution of precipitation and ET rates to where food can be grown with and without irrigation
- Relate nutrient loading from fertilizer use to the dead zone in the Gulf of Mexico
- Attribute major water pollutants to appropriate agricultural sources
- Estimate water consumption in the food we eat using the concepts of virtual water and water footprints
Context for Use
Description and Teaching Materials
The Food and Water module introduces students to the interconnections between food production and water resources. The first half of the module considers how and why water is essential for food production. The online text (Student Materials) includes two Knowledge Checks and two Activate Your Learning activities. These online activities are important parts of the module and students should be encouraged to explore them. The formative assessment is included in the first part of the module and requires that students watch a video and visit two other websites. This assessment could be conducted in a classroom setting and could be followed up by small-group or full-class discussions.
The second part of the module introduces the impacts that agriculture has on the quality and quantity of our surface and ground water resources. This is a very brief introduction and focuses on water use and scarcity in the Colorado River basin and the impacts of agriculture in the Mississippi River basin on the dead zone in the Gulf of Mexico. The videos, external reading and Knowledge Check and Activate Your Learning activities in this module are important. The summative assessment could be conducted in class with the students in small groups.
All materials for students are available using the Student Materials link below. These can be implemented entirely in the context of distance learning, or adapted to either a blended or traditional classroom setting. Knowledge Checks and Activate Your Learning online activities are included in the Student Materials. These activities allow students to self-test their understanding and to deepen their exploration of the course material.
Teachers can find documentation of the activities as well as rubrics in the Student Materials. An answer key (instructor access only) and rubrics for the assessments are compiled under Assessment below. Suggestions for teaching and a list of the assessments are found below. In addition, a multiple-choice quiz with solutions is provided under Assessment below. The quiz can be used in an online course management system, or given in person in a traditional class. The answer key (instructor access only) is provided.
Teaching Notes and Tips
What works best for the module?
- Students should be encouraged to explore the extra links and information provided in text and videos, as well as to do all of the Knowledge Checks and Activate Your Learning activities embedded in the online materials. Students who read all of the material, do the activities and follow the extra, external links will develop the most complete understanding of concepts. There are numerous concepts embedded in the links that will foster a richer understanding of assessment topics, and students should be encouraged to investigate these materials.
- Students should be encouraged to read the material in the module before coming to lab.
What students found difficult
- Students who did not thoroughly read the text or look at the accompanying external links had the most problems with the module.
- Some students struggled with the concept of a watershed. If students are not familiar with the concept of a watershed, the instructor may want to spend a little extra time introducing the summative assessment to make sure that students clearly understand that the farm in Kansas is in the Mississippi River watershed and that runoff from the farm eventually flows to the Mississippi River and therefore to the Gulf of Mexico.
- There is a lot of background content to cover in this module, and the topic of water quality impacts from agriculture is vast and beyond the scope of this course. This module only provides a very cursory introduction to some of these topics. The instructor may need to determine what they think is most important given the preparation of their students and to spend some time discussing some of the topics in class or online.
Module 4 includes one formative assessment and one summative assessment.
- Formative assessment, Module 4.1 - Students explore the concepts of virtual water and water footprints.
- Summative assessment Module 4.2 - Students consider water use and irrigation efficiency for different crops as well as water quality impacts from agriculture.
References and Resources
References and Further Reading
Dubrovsky, N.M. and P.A. Hamilton, 2010, Nutrients in the Nation's Streams and Groundwater: National Findings and Implications, USGS Fact Sheet 2010-3078 (http://pubs.usgs.gov/fs/2010/3078/)
FAO, 2011, The State of the World's Land and Water Resources for Food and Agriculture (SOLAW) - Managing systems at risk. Food and Agricultural Organization of the United Nations, Rome and Earthscan, London.
Goolsby, D.A., and Battaglin, W.A., 2000, Nitrogen in the Mississippi Basin--Estimating sources and predicting flux to the Gulf of Mexico: U.S. Geological Survey Fact Sheet 135-00, 6 p.
Hoekstra, A.Y. and M.M. Mekonnen, 2012. The water footprint of humanity, Proceedings of the National Academy of Science, vol. 109, no. 9, pp. 3232-3237 (http://waterfootprint.org/media/downloads/Hoekstra-Mekonnen-2012-WaterFootprint-of-Humanity.pdf).
Jones, J.A.A., 2010, Water Sustainability: A Global Perspective, Hodder Education, 452 pp.
Mississippi River Gulf of Mexico Watershed Nutrient Task Force, 2013, Reassessment 2013: Assessing Progress Made Since 2008, Accessed from: http://www2.epa.gov/sites/production/files/2015-03/documents/hypoxia_reassessment_508.pdf
U.S. Bureau of Reclamation (USBR), 2012, Colorado River Basin Water Supply and Demand Study, http://www.usbr.gov/lc/region/programs/crbstudy/finalreport/index.html
Global annual precipitation map http://www.arcgis.com/home/item.html?id=0698165058384852b23f31b26ae7cace
Good Virtual Water resource from the Water Footprint Network http://waterfootprint.org/en/resources/interactive-tools/product-gallery
- Product gallery with virtual water for different agricultural products and citations for all of their data and maps
Video introducing virtual water, https://youtu.be/j9JywZGtXA4, in liters, used on British news to mark World Water Day 2007
ALL YOU EAT, UN Water, World Water Day, Short graphical video showing the liters of virtual water in a few food products, https://youtu.be/U26Na9Xa5Ug