Back in my graduate school days, I had an astronomy professor who on the first day of a course asked each of us in class to define “dirt.” Not surprising, everyone in class had their own definition of dirt. Although, most thought dirt was slang for soil. If that was the case, then we next needed to define “soil.”
While there was a group consensus that soil had something to do with the material in the top layer of the earth’s surface, its composition was up for debate. Some defined it as unconsolidated debris above bedrock. Others defined soil as a mixture of minerals and organic matter above the regolith. Of course, either definition assumes everyone can define “bedrock” and “regolith.” If our common understanding of soil includes the “biological” weathering of material at the top of the earth’s surface in addition to its organic composition, then what is a “soil” on Mars?
Clearly, any reference to a Martian soil assumes the absence of biological material of any kind in our neighboring planet’s surface layer. We would conclude in the case of Mars that the definition of soil would be somewhat restricted, as compared to earth, due to the different parent materials and weathering processes.
This conclusion about a Martian soil was exactly the point of the exercise in defining dirt and soil in the astronomy class. The professor was trying to bring to light the perspectives in our understanding of what constituted a soil. All our knowledge and experience about soils at the time of the course was earthbound. Today, a handful of landers and robots have begun to explore a miniscule fraction of the Martian surface and we are beginning to think of soil on an extraplanetary scale.
Deepening The Definition
OK, so what does all this dirt and soil talk have to do with precision agriculture? Analogous to soils, our definition of precision agriculture is based on our knowledge of the embedded technologies and our experience in applying those technologies to agricultural production.
Precision agriculture began to become popular twenty years ago with the introduction of affordable geographic information systems (GIS) and global positioning systems (GPS), which could “precisely” locate you on the earth’s surface with geographic coordinates. The early GIS/GPS definition of precision agriculture suited us well because everyone had so little knowledge and experience with any competing previous technologies. But with its current evolution over the ensuing years, our understanding and, hence, definition of what is precision agriculture has become more diversified and complex.
This evolving complexity of precision agriculture was very evident at the recent InfoAg 2009 conference and is exemplified by the technologies highlighted in this issue. Today, innovations in precision agriculture can be seen in the number of wireless sensors and equipment for vehicle tracking and for removing the necessity of hand-carrying media for software installation and data collection. They are evident in guidance systems, automatic steering, and in seed and spray precision applications. Innovations are also apparent in the abundance of desktop and web-based information technology (IT) solutions to support on-farm decision making.
In the recent period of economic turbulence and rising production costs, another word has been sneaking into the definition of precision agriculture — “efficiency.” Growers are increasingly seeking technologies and practices that save time, material, and labor, while sustaining yields and net profits. These savings represent efficiency — getting the same or more output with less input. This new emphasis on efficiency in precision agriculture can be seen in the International Plant Nutrition Institute’s (IPNI’s) 4Rs for fertilizing forages: Right source, Right rate, Right time, and Right place. Precision technologies may be in one or more of the “Rs,” but collectively they represent efficiency in fertilizer management. Adding efficiency to precision agriculture technologies helps keep a grower competitive and economically viable in a changing world.
If efficiency is the watchword of precision agriculture today, then how does a grower choose among all the ever-increasing offerings? A grower must know precision technologies much like he or she knows soils in agricultural production. He or she must know the limits and practices of precision technologies in his or her operation just like knowing the limits and practices appropriate for a soil in a field. A grower should have evidence, either through research or a neighbor’s testimonial, that the adoption of a particular precision agriculture technology will be beneficial. Assuming a sustained production output, the efficiency of a particular adopted technology can be calculated in terms of savings, be it materials, labor, or time.
Over the years, as growers learned more about soils, the better managers they became. The same is true for precision agriculture. As growers learn more about precision technologies such as those featured in this issue, they will become more efficient managers. And like soils, precision agriculture will continue to redefine itself as we work with it over time.