Cotton Farming

Imagine what a farmer at the turn of the last century would have thought about the technology we use today. Now think about what producers 50 years from now will be using on their farms. Hard to imagine, right? Not if you are an agricultural researcher, and it is your job to imagine the unimaginable.

Usually, it all starts with a problem that needs solving. The most critical problem facing cotton production today is the increasing demand for water from urban areas and the need for efficient water-use by producers.

To that end, the University of Georgia (UGA) has pioneered much of the technology aimed at improving irrigation efficiency, including variable rate technology, irrigation scheduling models and studies of the effects of drought stress at various stages of plant growth.

Currently, a study by Glen Ritchie, research coordinator with UGA’s Department of Crop and Soil Sciences, involves using innovative aerial imagery as a method to detect when cotton needs water.

“By looking at pictures taken from overhead, you can identify plants approaching water stress by changes in crop growth and color,” Ritchie says.

Not So Odd

What is so unique about Ritchie’s study is the means for taking the overhead pictures.

“When we began looking for some way to schedule irrigation in cotton by using remote sensing, we started thinking of all the possible places cameras or sensors could actually be mounted,” he says.

“We first looked at mounting sensors on the center pivot. But with the pivot, it takes a long time to get around the field. Plus, you have costs and wear and tear on the pivot from running it dry just to see if you need to water.”

Next they looked at airplanes, but instead sought a less expensive alternative – something that would be easier to schedule.

“We were looking for a way to take the pictures ourselves,” Ritchie says.

Model airplanes and/or helicopters were considered, but also ruled out because one crash could destroy the airplane and camera equipment.

That’s when the idea of a blimp came about.

“The blimp is tethered, filled with helium, and it can get up to a couple of hundred feet high,” Ritchie says. “It will just stay there, and you get nice clear pictures.”

The blimp is about 15 feet long and mounted on it are two cameras: one visual and the other infrared. A smaller blimp could be used if lighter cameras are available. Plus, Ritchie says, it’s quick to get out to the field.

“From taking the blimp out to the field, taking pictures and then moving it back to the shop, it takes 30 to 45 minutes,” he adds.

But what do the data indicate?

“In 2004, by scheduling irrigation based on information obtained from images taken using the blimp, we saved from between .6 inches and 1.2 inches of water,” Ritchie says. “That’s about two passes of the center pivot, and we still made three bales.”

Ritchie says the system would not be much of a factor during a wet year, but in a year with less rainfall and limited irrigation water, it could be.

“We were definitely able to use less water,” he says.

Finding Efficiency

Ritchie’s project is just one of the many research activities funded by the Georgia Cotton Commission (GCC) that is aimed at enhancing the efficiency of producers.

“Georgia cotton producers have many unanswered questions related to irrigation,” says Richey Seaton, GCC executive director. “The commission chose to fund this research for reasons that will directly affect the producer’s bottom line.”

Seaton hopes this research will lead to a better understanding of the cotton plant’s response to water stress and the identification of when it occurs.

“The primary goal of the project is the verification of efficient irrigation techniques that will result in high cotton yields which allow cotton producers to maximize their yields and profit potential,” he says.

Seaton says the findings so far indicate that this remote sensing method can produce yields and quality comparable to those obtained with conventional soil moisture monitoring at a fraction of the cost.

Similar Studies Elsewhere

Remote sensing is also being investigated by USDA-ARS Southeast Watershed Lab and USDA-ARS National Peanut Research Laboratory for improved crop management and irrigation scheduling, says Dana Sullivan, soil scientist at the Southeast Watershed Lab.

“We are looking at a range of characteristics from the small-plot scale to a farm-scale operation,” she says. “Studies utilize visible, near-infrared and thermal infrared regions of the light spectrum to investigate crop response to tillage and irrigation.”

Sullivan says researchers are looking for early plant signals of crop water demand, which may be useful to help trigger an irrigation event prior to seeing visual signs of stress.

“Preliminary analyses indicate that the thermal infrared is sensitive to crop water demand and may be useful for scheduling irrigation events and preventing potential yield losses,” Sullivan says.

Another partnership involves scientists at the NASA Goddard Space Flight Center. Together they are evaluating an unmanned aerial vehicle (UAV) equipped with a thermal infrared sensor.

“We will use the UAV specifically to evaluate field-scale variability in crop water demand,” she says. “The UAV is still being used experimentally at this point, and we hope to have protocol in place for data collection in 2006.”

As for Ritchie’s project, it has one more year in the study from which he hopes to gain good research numbers.

“This recent research is still relatively new, but it has the potential to give producers another viable tool for irrigation scheduling.”

Contact Amanda Huber at (352) 486-7006 or ahuber@svic.net.

Remote Sensing Becomes More Accessible
By Amanda Huber Southeast Editor
Imagine what a farmer at the turn of the last century would have thought about the technology we use today. Now think about what producers 50 years from now will be using on their farms. Hard to imagine, right? Not if you are an agricultural researcher, and it is your job to imagine the unimaginable. Usually, it all starts with a problem that needs solving. The most critical problem facing cotton production today is the increasing demand for water from urban areas and the need for efficient water-use by producers. To that end, the University of Georgia (UGA) has pioneered much of the technology aimed at improving irrigation efficiency, including variable rate technology, irrigation scheduling models and studies of the effects of drought stress at various stages of plant growth. Currently, a study by Glen Ritchie, research coordinator with UGA’s Department of Crop and Soil Sciences, involves using innovative aerial imagery as a method to detect when cotton needs water. “By looking at pictures taken from overhead, you can identify plants approaching water stress by changes in crop growth and color,” Ritchie says. Not So Odd What is so unique about Ritchie’s study is the means for taking the overhead pictures. “When we began looking for some way to schedule irrigation in cotton by using remote sensing, we started thinking of all the possible places cameras or sensors could actually be mounted,” he says. “We first looked at mounting sensors on the center pivot. But with the pivot, it takes a long time to get around the field. Plus, you have costs and wear and tear on the pivot from running it dry just to see if you need to water.” Next they looked at airplanes, but instead sought a less expensive alternative – something that would be easier to schedule. “We were looking for a way to take the pictures ourselves,” Ritchie says. Model airplanes and/or helicopters were considered, but also ruled out because one crash could destroy the airplane and camera equipment. That’s when the idea of a blimp came about. “The blimp is tethered, filled with helium, and it can get up to a couple of hundred feet high,” Ritchie says. “It will just stay there, and you get nice clear pictures.” The blimp is about 15 feet long and mounted on it are two cameras: one visual and the other infrared. A smaller blimp could be used if lighter cameras are available. Plus, Ritchie says, it’s quick to get out to the field. “From taking the blimp out to the field, taking pictures and then moving it back to the shop, it takes 30 to 45 minutes,” he adds. But what do the data indicate? “In 2004, by scheduling irrigation based on information obtained from images taken using the blimp, we saved from between .6 inches and 1.2 inches of water,” Ritchie says. “That’s about two passes of the center pivot, and we still made three bales.” Ritchie says the system would not be much of a factor during a wet year, but in a year with less rainfall and limited irrigation water, it could be. “We were definitely able to use less water,” he says. Finding Efficiency Ritchie’s project is just one of the many research activities funded by the Georgia Cotton Commission (GCC) that is aimed at enhancing the efficiency of producers. “Georgia cotton producers have many unanswered questions related to irrigation,” says Richey Seaton, GCC executive director. “The commission chose to fund this research for reasons that will directly affect the producer’s bottom line.” Seaton hopes this research will lead to a better understanding of the cotton plant’s response to water stress and the identification of when it occurs. “The primary goal of the project is the verification of efficient irrigation techniques that will result in high cotton yields which allow cotton producers to maximize their yields and profit potential,” he says. Seaton says the findings so far indicate that this remote sensing method can produce yields and quality comparable to those obtained with conventional soil moisture monitoring at a fraction of the cost. Similar Studies Elsewhere Remote sensing is also being investigated by USDA-ARS Southeast Watershed Lab and USDA-ARS National Peanut Research Laboratory for improved crop management and irrigation scheduling, says Dana Sullivan, soil scientist at the Southeast Watershed Lab. “We are looking at a range of characteristics from the small-plot scale to a farm-scale operation,” she says. “Studies utilize visible, near-infrared and thermal infrared regions of the light spectrum to investigate crop response to tillage and irrigation.” Sullivan says researchers are looking for early plant signals of crop water demand, which may be useful to help trigger an irrigation event prior to seeing visual signs of stress. “Preliminary analyses indicate that the thermal infrared is sensitive to crop water demand and may be useful for scheduling irrigation events and preventing potential yield losses,” Sullivan says. Another partnership involves scientists at the NASA Goddard Space Flight Center. Together they are evaluating an unmanned aerial vehicle (UAV) equipped with a thermal infrared sensor. “We will use the UAV specifically to evaluate field-scale variability in crop water demand,” she says. “The UAV is still being used experimentally at this point, and we hope to have protocol in place for data collection in 2006.” As for Ritchie’s project, it has one more year in the study from which he hopes to gain good research numbers. “This recent research is still relatively new, but it has the potential to give producers another viable tool for irrigation scheduling.” Contact Amanda Huber at (352) 486-7006 or ahuber@svic.net.

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