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Analyzing the Spatial Distribution of 4 Crops with a Geographic Information System

For centuries, maps have stirred imaginations and inspired explorations of the unknown. Today, maps are used to help understand relationships across areas and regions. These spatial relationships are analyzed using digital maps within a Geographic Information Systems (GIS) environment.

GIS in Education

For the past 40 years, GIS has quietly transformed everyday decision making in academia, government, nonprofit, and in business through the manipulation of satellite imagery, maps, graphs, databases, and multimedia in a decision-making framework. Agriculture was one of the first fields to embrace GIS, applied to everything from precision agriculture to invasive weed eradication to sustainable practices.

In the classroom, GIS offers a powerful decision-making toolkit that helps students understand content in a variety of disciplines, such as geography, history, mathematics, language arts, environmental studies, chemistry, biology, and civics. GIS is used as an inquiry-driven, problem-solving, standards-based set of tasks that incorporates fieldwork and provides career pathways that are increasingly in demand. It helps students think critically, use real data, and connects them to their own community. It does so in informal, primary, secondary, and university settings and appeals to today’s visual learners. Geotechnologies, along with biotechnologies and nanotechnologies, are the three key skills and job markets identified by the US Department of Labor for the 21st Century (Gewin 2004). The National Academy of Sciences (2005) identified GIS as being essential to K-12 learning because of its ability to foster spatial thinking (Gersmehl and Gersmehl 2006).

What is the relationship between birth rate and life expectancy? How does acid mine drainage in a mountain range affect water quality downstream? How will climate change affect global food production? With GIS, students explore the relationships between people, climate, land use, vegetation, river systems, aquifers, landforms, soils, natural hazards, and much more.

Using GIS provides a way of exploring not only a body of content knowledge, but provides a way of thinking about the world. When epidemiologists study the spread of diseases, scientists study climate change, or businesspersons determine where to locate a new retail establishment, they use spatial thinking and analysis. In each case, GIS provides critical tools for studying these issues and for solving very real problems on a daily basis.

GIS-based questions begin with the “whys of where” – why are cities, ecoregions, and earthquakes located where they are, and how are they affected by their proximity to nearby things and by invisible global interconnections and networks? After asking geographic questions, students acquire geographic resources and collect data online and from their own fieldwork. They analyze geographic data and discover relationships across time and space (Bednarz 2004). Geographic investigations are often value-laden and involve critical thinking skills. The following illustrates just one example of how GIS can be used in education.

Analyzing the Pattern of Four Crops in GIS

What did you have to eat today? Where was your food grown? Where was the cotton in your shirt cultivated? An increasing number of books and research initiatives are aimed at helping students to reconnect with the importance of agriculture. A new resource on the ArcLessons library ( invites investigation of four different crops—soybeans (shown on the map below), wheat, corn (maize), and cotton – in a spatial context using Geographic Information Systems (GIS) technology.

Learners work through the following scenario: The US Department of Agriculture has heard about your extensive skills in GIS and spatial analysis, and has hired you to investigate the patterns of 4 crops as part of its National Crop Assessment Program (NCAP). They would like you to produce a report detailing the results of the following investigation: What are the cultural and physical geographic reasons for the spatial distribution, spatial patterns, and the amount of soybeans, cotton, wheat, and corn grown in the USA?

Learners conduct research on the origin of the four crops, examine the spatial distribution of those crops, and investigate the similarities and differences among them. They discover the most productive counties for each crop, and consider the proximity of major cities and the influence of climate on each. They determine which areas are planted with winter wheat versus spring wheat, based on the evidence. GIS skills developed include investigation of the “G” part of GIS (the maps) and the “I” part of GIS (the tables) through constructing queries, sorting, and creating summary statistics. They also select and identify data, create various thematic maps using different classification methods, including natural breaks, quantile, equal area, and standard deviation. Content emphases include national and global considerations of why different crops are grown, the influence on urban areas on crops, and the social and physical reasons for the spatial concentration or diffusion of the cultivation of those crops.

The resource includes not only the lesson, but the data needed to run the lesson. The data includes agricultural information at the county level from the US Census of Agriculture, climate data from the Natural Resources Conservation Service and the Spatial Climate Analysis Service at Oregon State University, and base layers (states, rivers, roads, lakes) from ESRI. The lesson contains 55 questions, but additional investigation can certainly be done, by students of secondary, university, and informal (such as 4-H) programs.

To find out more about the use of GIS in education, see, and the library of lessons on


-Bednarz, Sarah W. 2004. Geographic information systems: A Tool to support geography and environmental education? GeoJournal 60: 191-199.

-Gersmehl, Phil, & Gersmehl, Carol. 2006. Wanted: A concise list of neurologically defensible and assessable spatial thinking skills. Research in Geographic Education 8.

-Gewin, Virginia. 2004. Mapping opportunities. Nature 427: 376-377.

-National Academy of Sciences. 2006. Learning to Think Spatially—GIS as a Support System in the K-12 Curriculum. Washington DC: The National Academies Press, 313 p.

By Joseph Kerski, posted on September 23rd, 2009 in Agriculture, Articles, Education, Featured Article
By Joseph Kerski, Geographer and Education Manager, Environmental Systems Research Institute (ESRI).