A new scientific discipline — the computer-driven “geospatial technologies” — is helping agricultural researchers and farmers get a whole new look at cropland, pest interactions and disease movement.
People have sought to better understand their world with drawings since primitive humans began scratching pictures on cave walls. These drawings evolved steadily in artwork, maps and photographs, but now computers have taken them to a whole new level as “spatial data,” which are computer maps and geography-referenced imagery. With geospatial technology, humans are no longer limited to what the eye can see. Geographic information systems (GIS) software allows technicians to process spatial data to reveal a wealth of information ready to be turned on or off with the click of a mouse.
Geospatial technologies include GIS, Global Positioning Systems (GPS), remote sensing and spatial statistics. These systems let growers and scientists “step back” and take a broad view of a landscape and what's happening there in a way that wasn't possible before GIS software was developed to draw maps into the digital domain and attach attribute data to map features. The full effect of the technology is the overlay of computer maps onto aerial photos and satellite images. With GIS and image processing, the viewer can see trends and patterns that aren't visible from the ground. Growers can see their farms' soil types, cropping patterns, hydrology and other features over high-resolution imagery.
Recognizing the enormous potential of geospatial technologies, universities and companies are hiring experts in the field to work with scientists and farm managers to take advantage of this new science. One such expert is Kris Lynn-Patterson, an academic coordinator for geospatial technologies based at the UC Kearney Research and Extension Center near Parlier. Lynn-Patterson supports the 25 UC Berkeley, UC Davis and UC Riverside scientists based at the center. A number of projects have already yielded useful results.
For example, Lynn-Patterson worked with UC IPM Advisor Pete Goodell to understand the migration of lygus bugs through the San Joaquin Valley's mosaic of diverse crops. In the spring, lygus can reproduce in the lush vegetation on foothills surrounding the San Joaquin Valley. As the plants dry when the weather warms and rain stops, the lygus begin looking for a new home in Valley agriculture. Lygus move into various crops and weeds, and when these become unsuitable, they move into cotton, where lygus costs farmers nearly $19 million in yield loss each year.
By combining observations made on the ground — Where is cotton growing? How far away is alfalfa? How many lygus are in the fields and when? — with GIS mapping technology, Goodell was able to determine the areas in the San Joaquin Valley where cotton is most likely to have lygus problems in mid-summer. Where alfalfa is scarce, cotton fields absorb the migrating bugs. But where alfalfa is close to cotton fields, the alfalfa acts as a lygus sponge and spares cotton most of the damage. (Lygus bugs love alfalfa, but don't damage it.)
Lynn-Patterson and UC Riverside citrus entomology specialist Beth Grafton-Cardwell are collaborating on a program to track the incidence of citrus peel-miner in the San Joaquin Valley. Grafton-Cardwell trained citrus farmers to monitor pheromone traps and orchards. They then go online and fill out a simple form, specifying the location of the orchard, the type of citrus being grown, the extent of fruit damage, the number of moths flying into the traps and what crop is growing adjacent to the orchard. The data is connected to a map of the area, revealing citrus peel-miner's distinct pattern of infestation.
“We've concluded that certain neighboring crops promote the peel-miner. In the fall, when crops like cotton, beans and grapes are harvested and the plants dry out, peel-miner moves into citrus and causes a lot of damage,” Grafton-Cardwell said.
In the private sector, large family and corporate farms are beginning to hire specialists in GIS or train staff on its possibilities. Bowles Farm, a family operation that cultivates 12,000 acres in Merced County, is using geospatial technologies for regulatory compliance, tracking yield, mapping soil, creating variable-rate prescriptions for amendments, planning irrigation systems and other operations.
“It's been tremendous,” said Canon Michaels, Bowles' Farm vice president of business operations and a member of the sixth-generation to work on the farm. “Our focus is to put resources in the right places. GIS allows you to do that and GPS allows you to go to an exact area, figure out what the soil needs and put down the exact amount.”
In a project designed to support the UC Cooperative Extension farm advisors in the Central Valley, Lynn-Patterson is working closely with Colusa County Farm Advisor Jerry Schmeier to put soil maps for each county in the region, spanning from Tehama County in the north down to Kern County, onto compact discs and the Web. The data being used was collected by the United States Geological Survey decades ago. The federal Natural Resources Conservation Service recently digitized the files. Lynn-Patterson and Schmeier processed the data and created a system that will allow farm advisors, even with little computer know-how, to get a picture of the soil type anywhere in their counties. They will be able to show a farmer, for example, where a fan of sandy loam crosses a farm of predominantly clay soils.
“We are providing soil data that's good to go,” Lynn-Patterson said. “We hope this will inspire people to get to know geospatial technologies and look into its many other applications.”