Charley Mathews and Frank Rehermann are poised for payday as their combines roll through their northern Sacramento Valley, Calif., rice fields following a challenging growing season mired by cool and wet spring weather.

“2010 has probably been the most challenging year for me in the rice business,” said Mathews, 44, owner of C and H Farms in Marysville in Yuba County. “This has been a year for the history books.”

Mathews began harvest the last week of September. Initial yield returns were 8,000 pounds (80, 100-pound sacks) of medium-grain Calrose rice per acre; an average yield in the Valley. About 85 percent of all California rice is the Calrose japonica type.

“I will be happy with an average yield,” said Mathews as he stood on the rice field edge which about 30 years ago was irrigated pasture for an onsite dairy. “The rice looks real good.”

The fifth-generation farmer grew 600 acres of the M206 variety this year.

“I never thought we’d make it this far with the crop. I still have a long way to go.”

Rice quality, Mathews noted later, ranged from average to above-average range.

About 20 good weather days are needed to bring in Mathews’ crop. Custom harvest work on another 600 acres stretches his total harvest period to 35 to 40 days.

Despite the late growing season, Mathews kicked off the harvest a little earlier than he would like, due to inherent rains that usually fall in October and November. The average October rainfall in the area is 3 to 4 inches.

The crop moisture level on early harvested grain was higher than Mathews’ preference of 20 percent to 22 percent.

“Harvesting rice with higher moisture increases costs due to the additional energy needed to dry down the rice,” Mathews said. “It’s sunny outside today so the crop moisture will drop, and I can get more productive days to bring in the rice. It’s a trade-off.”

Mathews farms 600 acres of rented rice ground. He usually kicks off field preparation in mid-March, but the weather abnormalities this spring delayed field work to early May. Many of California’s 2,500 rice farmers struggled to get the crop back on schedule due to cool temperatures and wet fields.

Most California rice is seeded by airplane into fields with 5-inch deep water.