As
reported by Physics.org: Today's agriculture has transformed into a high-tech enterprise that most 20th-century farmers might barely recognize.
After all, it was only around 100 years ago that farming in the US transitioned
from animal power to combustion engines. Over the past 20 years the
global positioning system (GPS),
electronic sensors and other new tools have moved farming even further into a technological wonderland.
Beyond the now de rigeur air conditioning and stereo system, a modern
large tractor's enclosed cabin includes computer displays indicating
machine performance,
field position and operating characteristics of attached machinery like seed planters.
And as amazing as today's technologies are, they're just the
beginning. Self-driving machinery and flying robots able to
automatically survey and treat crops will become commonplace on farms
that practice what's come to be called precision
agriculture.
The ultimate purpose of all this high-tech gadgetry is optimization,
from both an economic and an environmental standpoint. We only want to
apply the optimal amount of any input (water, fertilizer, pesticide,
fuel, labor) when and where it's needed to efficiently produce high crop
yields.
Global positioning gives hyperlocal info
GPS provides accurate location information at any point on or near
the earth's surface by calculating your distance from at least three
orbiting satellites at once. So farming machines with GPS receivers are
able to recognize their position within a farm field and adjust
operation to maximize productivity or efficiency at that location.
Take the example of soil fertility. The farmer uses a GPS receiver to
locate preselected field positions to collect soil samples. Then a lab
analyzes the samples, and creates a fertility map in a geographic
information system. That's essentially a computer database program adept
at dealing with geographic data and mapping. Using the map, a farmer
can then prescribe the amount of fertilizer for each field location that
was sampled. Variable-rate technology (VRT) fertilizer applicators
dispense just exactly the amount required across the field. This process
is an example of what's come to be known as precision agriculture.
Info, analysis, tools
Precision agriculture requires three things to be successful. It
needs site-specific information, which the soil-fertility map satisfies.
It requires the ability to understand and make decisions based on that
site-specific information. Decision-making is often aided by computer
models that mathematically and statistically analyze relationships
between variables like
soil fertility and the yield of the crop.
Finally, the farmer must have the physical tools to apply the
management decisions. In the example, the GPS-enabled VRT fertilizer
applicator serves this purpose by automatically adjusting its rate as
appropriate for each field position. Other examples of precision
agriculture involve varying the rate of planting seeds in the field
according to soil type and using sensors to identify the presence of
weeds, diseases, or insects so that pesticides can be applied only where
needed.
Site-specific information goes far beyond maps of soil conditions and
yield to include even satellite pictures that can indicate crop health
across the field. Such remotely sensed images are also commonly
collected from aircraft.
Now unmanned aerial vehicles (UAVs, or drones) can collect highly
detailed images of crop and field characteristics. These images, whether
analyzed visually or by computer, show differences in the amount of
reflected light that can then be related to plant health or soil type,
for example. Clear crop-health differences in images – diseased areas
appear much darker in this case – have been used to delineate the
presence of cotton root rot, a devastating and persistent soilborne
fungal disease. Once disease extent is identified in a field, future
treatments can be applied only where the disease exists. Advantages of
UAVs include relatively low cost per flight and high image detail, but
the legal framework for their use in agriculture remains under
development.
Let's automate
Automatic guidance, whereby a GPS-based system steers the tractor in a
much more precise pattern
than the driver is capable of is a tremendous success story. Safety
concerns currently limit completely driverless capability to smaller
machines. Fully autonomous or robotic field machines have begun to be
employed in small-scale high profit-margin agriculture such as wine
grapes, nursery plants and some fruits and vegetables.
Autonomous machines can replace people performing tedious tasks, such as hand-harvesting vegetables. They use sensor technologies, including
machine vision
that can detect things like location and size of stalks and leaves to
inform their mechanical processes. Japan is a trend leader in this area.
Typically, agriculture is performed on smaller fields and plots there,
and the country is an innovator in robotics. But autonomous machines are
becoming more evident in the US, particularly in California where much
of the country's specialty crops are grown.
The development of flying robots gives rise to the possibility that
most field-crop scouting currently done by humans could be replaced by
UAVs with machine vision and hand-like grippers. Many scouting tasks,
such as for insect pests, require someone to walk to distant locations
in a field, grasp plant leaves on representative plants and turn them
over to see the presence or absence of insects. Researchers are
developing technologies to
enable such flying robots to do this without human involvement.
Breeding + sensors + robots
High-throughput plant phenotyping
(HTPP) is an up-and-coming precision agriculture technology at the
intersection of genetics, sensors and robotics. It is used to develop
new varieties or "lines" of a crop to improve characteristics such as
nutritive content and drought and pest tolerance. HTPP employs multiple
sensors to measure important physical characteristics of plants, such as
height; leaf number, size, shape, angle, color, wilting; stalk
thickness; number of fruiting positions. These are examples of
phenotypic traits, the physical expression of what a plant's genes code
for. Scientists can compare these measurements to already-known genetic
markers for a particular plant variety.
The sensor combinations can very quickly measure phenotypic traits on
thousands of plants on a regular basis, enabling breeders and
geneticists to decide which varieties to include or exclude in further
testing, tremendously speeding up further research to improve crops.
Agricultural production
has come so far in even the past couple decades that it's hard to
imagine what it will look like in a few more. But the pace of high-tech
innovations in agriculture is only increasing. Don't be surprised if, 10
years from now, you drive down a rural highway and see a very small
helicopter flying over a field, stopping to descend into the crop, use
robotic grippers to manipulate leaves, cameras and machine vision to
look for insects, and then rise back above the crop canopy and head
toward its next scouting location. All with nary a human being in sight.
