John DeCarli was born in Ferndale, Humboldt County, California in 1887. He attended high school in Eureka beginning in 1902. In 1908 he attended a three-week course in Veterinary Practices and in Irrigation at the Farm School in Davis.
John and his father, Charles, came to the Delta west of Stockton in 1908 to set up a dairy. Ladino clover seeds from Italy arrived in 1911; John planted them and they grew into the first such field in the country. In June, 1914, an advertisement appeared in the Stockton Record which stated that the DeCarlis were using electric milking machines. He built the first trench silo in 1922. A fully automatic feed grinding and mixing plant was the next invention, in 1933. In the mid-1930's, his cows were getting field fresh chopped alfalfa - a practice considered "new" in the 1950's.
By 1938 John had perfected a parlor milking system where the milker was three feet below the level of the cows and able to reach in and put on the teat cups without bending over. In addition the milk flowed through stainless steel pipes directly to the cooling tank. The following year, 1 man could milk 175 cows. Automatic stalls, now familiar, were called, in 1941, "the most unusual arrangement ever conceived by a dairyman". The dairy wasn't the only place for innovation: John started 8-row cultivation, mechanized his potato harvest, put together a beet digger, mechanized a poultry enterprize, pioneered in chemical control of mustard in barley, was an early user of 2,4-D, and windrowed barley to make way for a second crop. A 16-mm movie film was made of dairy and farm operations from 1938 to 1964 by Dr. George Eby, a professor at Stockton College. A video copy of the film was placed in the UC Davis library by John's nephew Dean DeCarli.
John was active with the California State Farm Bureau, serving on the Board of Directors and as a local representative.
He died in 1969. In recognition of "Personal Contribution to the Agricultural Industry", he was elected to the San Joaquin County Agricultural Hall of Fame on November 16, 1989. In half a century of innovation, he was often too far ahead, but was seldom wrong. History proved the genius of John DeCarli.