January 17, 2013

Precision agriculture is a farm management concept that focuses on optimizing returns on inputs using imagery, information technology and geospatial tools such as global positioning systems and geographic information systems (GPS and GIS respectively).  Use of these technologies has the potential to detect disease in a rapid manner, improve the ability of plants to absorb nutrients, promote molecular treatment of diseases, and maximize crop yields while minimizing the use of pesticides, fertilizers and herbicides. This efficient monitoring system thereby reduces the monetary input by the farmer.  Precision farming uses remote sensing devices, computers and GPS to analyze various environmental conditions and to “watch” the growth and development of plants, soil conditions and the usage of water, seed and chemicals while controlling environmental pollution and agricultural waste.

Precision farming is not a single method but a network of systems and technologies that work together.  What began in the U.S. in the early 1980’s with the use of yield sensors combined with the advent of GPS receivers has been gaining ground ever since. A few examples illustrate the innovation and application potential of these technologies:

Yield monitors installed on combines can provide real time yield information on a time or distance basis (e.g. every 2 seconds or every 10 feet).  This technology can also report bushels per load and loads per acre.  Then, coordinating the yield monitor’s data with GPS receivers, a farmer can map yields using spatial coordinates creating yield maps of each field.  Once yield maps are in hand, a farmer can customize variable fertilizer applications.   Variable rate controllers are available for granular, liquid and gaseous forms of fertilizers.  Using the information from the yield maps, a farmer can program precision application of fertilizer using controllers that have been programmed with a “prescription map” for each field. 

Weed mapping can also be done while combining, seeding or field scouting by using a keypad connected to a GPS receiver and datalogger.  Weed maps can be created on a computer, those maps can be compared to the yield maps and fertilizer maps, and a spray map can be created.  Once a weed map is made, this information can be used in conjunction with various spraying technologies.  By knowing the exact location, type and concentration of weeds in a field, spot controlling can be implemented.  Controllers are available to electronically turn spray booms on and off while altering the amount and blend of herbicides – greatly reducing the chemical use in areas of a field where it is unnecessary and focusing it where it is. 

Field salinity can also be mapped and measured by a salinity meter towed behind a piece of equipment across a field. Salinity mapping can be useful in combination with yield and weed maps giving the farmer further causal information toward yield declines and enabling preventative measures to be taken.

Further enhancing each of these technologies, manufacturers are currently developing guidance systems using high precision differential global positioning systems (DGPS) that can accurately position a piece of equipment within a foot or less enabling the replacement of conventional equipment markers for spraying, seeding and field scouting.

Beyond the growth of crops, nanotechnologists are hoping that these technologies will transform the entire food industry by changing not only production but the processing, packaging, transportation and consumption of food by using GPS tracking technologies to track your food whether it be a vegetable, grain or livestock from the field to your plate.