he day will come when a farmer knows precisely what his or her crops need: a little nitrogen here, a little moisture there, an insecticide to control a particular pest over in that corner of the field.
As for the crop itself, all the plants may look the same and require the same care to grow and prosper, but the plants in this corner of the field may be used to make tires. Those over there may be used in making drugs. And those out in the middle of the field will end up being made into fuel for vehicles. And even within that field of lookalike plants, the farmer will be able to tell where those destined for one use end and those destined for use another begin.
Those are visions of the agricultural future from members of the College of Agriculture and Life Sciences faculty. They foresee a future time in which evolving technologies will tell farmers much more than they now know about their crops and in which the crops themselves may change considerably. It is also a future in which farmers will be more efficient and productive.
Of course, farming, like most human endeavors, is usually in a state of change. It changed considerably in the latter years of the 20th century. Among the changes: two new approaches to agriculture
There are a number of variations on the conservation tillage theme, but all involve leaving a covering of plant residue on at least a portion of a field from one crop through the next. The predominate form of conservation tillage practiced in North Carolina is known as no-till, says Dr. George Naderman, North Carolina Cooperative Extension Service soil specialist. Naderman is starting the fifth year of a long-term study comparing conservation tillage and conventional cropping systems at the Center for Environmental Farming Systems near Goldsboro.
Piedmont growers are particularly fond of no-till, although the practice is common throughout the state. No-till is prevalent among farmers who plant soybeans in fields in which winter wheat was grown. When the wheat is harvested in June, the residue is left in the field, and soybeans are planted directly into the residue, without any cultivation. The soybeans will be harvested in November. Again, the residue is left in the field, and corn or cotton is typically planted the following spring.
The residue left in a field "hastens the rate at which water is captured," Naderman says. "That greatly reduces soil erosion, tends to capture more rainfall in the soil and may reduce summer drought stress on the crop."
greatly reduces soil erosion, tends to capture more rainfall in the soil and may reduce summer drought stress on the crop."
But, Naderman adds, there’s another reason farmers like conservation tillage. They don’t have to make nearly as many trips through fields with tractors and other equipment, which saves money.
Farmers who have tried conservation tillage tend to become converts.
"Many say, ‘If I were not doing conservation tillage today, I wouldn’t be farming,’" says Naderman.
Adoption of conservation tillage by North Carolina farmers has come in waves. Naderman said soybean farmers began to adopt conservation tillage widely in the 1970s and 1980s. Since the mid-1990s, cotton farmers have been turning to a version of conservation tillage known as strip-till.
As new technologies are developed and scientists like Naderman learn more, conservation tillage becomes more refined. It is likely to continue to grow in popularity as farmers adapt it to different crops.
Integrated pest management, perhaps better known as IPM, began to catch on with farmers in the 1970s, says Dr. Mike Linker, the College’s IPM coordinator. Agricultural scientists found it wasn’t necessary to kill every last insect in a field in order to protect a crop. Rather, there was an economic threshold at which the cost of applying insecticide was greater than the damage insects were likely to do. Until this threshold was reached, which was usually determined by counting insects in representative parts of the field, it didn’t make economic sense to apply insecticide.
Since then, IPM techniques have been refined. The threshold concept has been applied to weeds as well as insects. And other indicators, such a weather conditions, have been used to determine when pesticides should be applied. Linker sees IPM continuing to evolve.
"The emphasis will move away from the pest and go to the plant," he explains. "Is the plant under stress? The objective is not to kill insects or weeds. The objective is to keep plants out of stress."
Remote sensing will play a larger role in IPM, Linker says. Multispectral analysis (analyzing light reflected from leaves) is likely to help farmers determine how their plants are doing. The light reflected from plants tends to have characteristic wavelengths depending on the physiological condition of the plant.
"If we understand these wavelengths, then we can understand what’s happening to the plant," says Linker.
Various methods, such as satellite imagery or even small, remote-controlled aircraft, may be used to observe crops. As the ability to measure what’s going on in a plant’s life expands, so will the amount of data produced. As a result, Linker says, computers will become more important.
"Remote sensing produces a large stream of data. It has to be sorted. What does it all mean? Computers will play a huge role," he explains.
Computers — or more accurately, computer software — will help farmers make decisions, for example. That’s something Dr. Gail Wilkerson, professor of crop science, knows about. Wilkerson has been instrumental in creating two software programs — called HERB and HADSS — designed to help farmers decide when they need to use herbicides.
The programs use economic thresholds to help farmers decide whether they need to apply herbicides. They also offer advice on which herbicide or combination of herbicides will do the best job. And the programs provide an economic analysis comparing the likely result of an acceptable herbicide treatment and the likely result if the farmer takes no action.
While the programs are not widely used now, it seems likely they’ll catch on. Wilkerson points out that many farmers are already using budget and record-keeping software.
She believes that as more farmers go on line, they’ll have better access to valuable information.
"We’re thinking about on-line programs that will help farmers rapidly sift through information from many different sources," says Wilkerson. "We will store large amounts of information in searchable on-line databases."
For example, all the years of official crop variety trials may be available on line, along with programs designed to help farmers decide which varieties to plant.
omputers are, of course, an integral part of precision agriculture, a technology introduced late in the 20th century that seems likely to play an increasingly important role in agriculture. Precision agriculture brings the Global Positioning System, which uses satellites to pinpoint locations on the earth, into the service of agriculture. GPS monitors are used to note the exact locations in fields where yields are high or low or where more or less lime or nutrients are needed. With this information, a farmer should be able to maximize yield across a field.
Precision agriculture technology is now being used on 200,000 to 300,000 acres of North Carolina’s roughly 1.4 million acres of cropland, says Dr. John Havlin, head of the Department of Soil Science. It is being used primarily to determine lime and phosphorus requirements.
Over the last two years farmers increasingly have turned to yield monitors to better understand what’s going on in their fields. A yield monitor records yield for each part of a field as a crop is harvested, giving a farmer a picture of yield variation across the field. This information may then be used to vary fertilizer or lime applications from location to location to maximize yield.
Havlin sees considerable potential for precision farming technology on the farm of the future. Very soon, it will be used in applying nitrogen as well as phosphorus, while a little further down the road, farmers will begin using the technology to assess plant stress as well as other yield-reducing conditions in the field.
"We will see precision farming techniques used in pest control to better identify where in a field you’re likely to see nematodes or disease," says Havlin. Farmers may want to plant resistant varieties, which may be more expensive, in these pest-likely locations.
Some of those resistant varieties may be genetically modified. Precision farming technology will allow a farmer to plant a particular genetically modified variety in a specific part of a field and to "remember" where that variety was planted.
The rapidly advancing science of genomics may be the wild card in the future of farming. Genomic tech-nology allows scientists to more easily locate and better understand the interaction of all the genes in an organism’s genome.
Genomic science should greatly assist classical plant breeding efforts by identifying the locations of genes a breeder is interested in, says Dr. Steve Lommel, professor of Plant Pathology and assistant director of the North Carolina Agricultural Research Service. With this information, the breeder will be able to apply classic crossing and breeding techniques more efficiently.
But beyond classical breeding, genomics should greatly enhance the ability of scientists to genetically modify plants and animals. Lommel points out that public attitudes will play a role in the extent to which genetically modified crops are developed and used by farmers. If farmers are to begin growing modified crops, there must first be a market for those crops. While Americans generally seem to accept such crops, Europeans generally seem less comfortable with them.
Until now, perhaps the greatest successes in genetic alteration have been the so-called Bt crops, which incorporate a toxin that kills insects, and the crops that were altered to be herbicide-tolerant, making weed control easier. Lommel points out, however, that both of these alterations involve the placement of single genes into plants.
Genomic science technology also allows scientists to begin to work on multiple gene alterations, improving multiple-gene traits such as yield or drought tolerance.
It should eventually be possible to move entire genetic pathways from one species to another, Lommel says. It might be possible, for example, to insert the nitrogen-fixing capacity of soil bacteria into corn, producing corn plants that fertilize themselves.
It also might be possible to put the genes responsible for producing rubber in rubber trees into cotton plants.
Lommel foresees the possibility that plants, such as corn, cotton or soybeans, which can now be grown relatively easily on large acreages, could be altered to produce any number of substances — oils, antibiotics, rubber. Furthermore, it should be possible to standardize the plants so that large acreages could be grown uniformly.
In other words, a farmer might plant hundreds of acres and would treat all those acres the same in terms of when the crop was planted and harvested and when fertilizer or pesticides were applied. But the plants from different parts of the farm would produce different substances. At the same time, farmers would use the latest remote sensing and IPM advances to better understand exactly what was going on both in their fields and within their plants.
Of course, the best efforts to look into the future are often marred by some unforseen event or technological development, and that may be the case with these visions. But if just a few of these insights hold true, the future of farming will be productive and efficient.