“GPS tractor guidance is one of the most important uses and the benefits are easily understood and quantified,” said Michael. “I am sure this is the most widely adopted form of GPS use in agriculture. Being able to pull wide implements without any overlap is a huge savings in time and diesel.” Michael also pointed out that there is less dust and emissions because of this greater efficiency. There is also less fatigue for the tractor driver “since concentrating on driving straight is very taxing.”

Bowles has been using GPS yield monitoring technology in cotton for many years. “It helps us find locations in fields that are under performing. We can then go to these areas using GPS and determine what the problem is.”

Using GPS, GIS, imagery and yield monitoring, Michael can also identify areas of variability within fields. “GPS allows me to sample soil and tissue in areas of interest in my fields and come up with prescriptions on what each area needs.”

Variable rate technology (VRT) was quickly coupled with GPS mapping when it was introduced a decade ago for more precision in applying chemicals and fertilizers.

At Bowles Farming in Merced County, an application file can be emailed to an aerial applicator that he can then insert in the rate controller of his plane. ”He sees the field I want applied on his controller and flies to it using GPS,” explained Michael.

The file also contains data that tells the controller where Michael wants to spray and how much volume to be applied at those locations.

“The pilot just flies the plane over the field and the controller opens valves at the locations I want sprayed. This would not be possible without GPS,” he said.

Bowles gets back a file showing the aerial applicator’s flight pattern showing where he sprayed and how much he put out at each location.

“This record is valuable and could be used to solve disputes or for claims if there was a report of damage from one of our applications. This technique puts the material exactly where it should go and results in less chemicals being used. We use variable rate by air for many PIX applications in cotton every year,” Michael explained.

Bowles uses GPS with ground applications in much the same way. “We can generate files that tell the sprayer when to turn on and off in the field.  We also apply a lot of soil amendments (sulfur, potash, zinc, gypsum) by ground with large spreader trucks equipped with rate controllers and GPS. The gate on the back of the truck opens and closes at locations determined by the file I give him and the location to put the right amount of material at the locations I specify. This saves considerable material and also targets the areas of the fields to meet specific needs. No more ‘broad brush’ spreading of the entire field,” Michael said.