The 63-year-old said he could remember telling himself "this ain't good, this is not good at all" as he tried and failed to pull his leg out.
Mr Kaser said he had removed a safety covering at the end of the auger in the winter to make the equipment fit under a grain bin, and told ABC News he was "kind of disappointed in myself that I didn't think of fixing that thing".
"It just sucked my leg in and I was tryin' to pull it out, and it kept pullin'", he told the local ABC affiliate in Omaha, KETV. "I said, 'The only way I'm getting out of here is to cut it off, ' so I just started sawing at it".
Kaser said he was afraid he'd pass out but he made it. "I knew I was done cutting because I felt a amusing feeling, maybe it was a tendon I cut".
A lifelong farmer is on the mend after amputating his own leg. "When I was cutting it, the nerve endings, I could feel, like, the ping every time I sawed around that pipe, and all at once it went and it let me go and I got the heck out of there".
Once free, the farmer said he crawled about 200 feet to his house. After treatment, Kaser began physical therapy.
"He pretty much told me his goal was, 'I need to get home and get back to what I was doing before, ' and his main goal was farming", she recalled to KETV. "I am just glad he's here with us".
The farmer spent weeks in hospital and rehabilitation before returning home to Pender near the Iowa border on Friday.
Although most people would be devastated at losing the bottom half of their leg, Kaser is staying positive, saying: 'I guess I'm stubborn.
His wife said they are now adjusting to the new lifestyle and within time they know everything will be back to normal.