Bangalore: A study led by Indian origin professor Shrini Upadhyaya at University of California says that farmers could save up to 20 percent fuel by properly inflating their tractor tires. "Field experiments have shown that using a low or correct inflation pressure for radial ply tires required 6 percent to 20 percent less diesel fuel and improved productivity 5 percent to 7.5 percent," said Upadhyaya, a UC professor of agricultural and biological engineering.

According to him, farmers generally over-inflate their tractor tires, with 20 to 24 psi (pounds per square inch). Depending on the tire and axle load, tire pressure could go down as low as 9 psi to 6 psi for fieldwork, Upadhyaya added.

The lower pressure minimizes soil compaction and allows for better tractor efficiency. In the spring, under moist soil conditions, fuel savings could be 18 percent to 20 percent, while dry summer conditions lend savings from 6 percent, Upadhyaya was quoted as saying by cfbf.com.

Farmers could also save time by properly adjusting tires' inflation pressure because they are able to develop better traction in the field, allowing them to work faster, Upadhyaya said. "The tire doesn't slip that much in the field, so it actually makes the job quicker," he said.

The practice is especially hard to implement for those who switch from operating in the field to hard pavement, which requires higher inflation pressure. Leaving tractor tires at a low psi while on the road will burn more fuel and wear out tires more quickly, he added.

Upadhyaya said he is currently working on a study to look at the practicality of designing tractors with the ability to not only read the condition of the ground they are on but also automatically adjust to the right tire pressure to fit the condition. Some military vehicles are already equipped with so-called central inflation pressure systems that can change inflation pressure depending on where they are.

In another study that's under way, Upadhyaya said he and other UC researchers have developed a compaction profile sensor that would allow farmers to do more precision farming and thus reduce fuel usage. Attached to the sensor is a tine or chisel that drags across the field sensing the compaction level of the soil to let the farmer know whether an area needs to be tilled or not.

"This is basically a prescription map, what we call site-specific tillage," Upadhyaya said. "The sensor senses not just the compaction; it senses the compaction by depth. If the soil is not compact, you may not need to till it. So that would be a considerable savings if you don't have to deep-till the soil," he added.