"Today, our nitrogen use efficiency can be as high as 85 percent,” said Blake Sanden, UCCE advisor in Kern County, an irrigation expert. He and Patrick Brown, UCCE specialist in the Department of Plant Sciences at UC Davis, have conducted nitrogen trials in almonds with Paramount Farming.

"When you increase the conversion of applied nitrogen fertilizer to higher crop yield, there is significantly less potential for nitrogen to leach below the rootzone and contaminate groundwater,” Sanden said. "But each field is unique and requires site-specific management to achieve these high levels of efficiency.”

Another area where UC research has led to significant crop yield growth is in canopy management and tree spacing. Research by Mario Viveros, UCCE advisor emeritus in Kern County, and other scientists showed that a tendency among growers to over prune was taking a toll at harvest time.

"A lot of farmers who are now growing almonds had experience with fresh fruits, where you do need to prune to get light on the fruit for good color. In almonds more canopy generally means more yield,” Lampinen said. "Today, most almond growers only prune when branches are growing in the way of tractors or other equipment.”

UC research also found that orchards planted with traditional wide spacing between the trees weren't making the most efficient use of sunlight on the farms. Older orchards had 60 to 70 trees per acre. Today, almond orchards are planted at an average density of about 110 trees per acre based on results of UC research.

However, studies have also shown that crowding still more trees into orchards triggers diminishing returns. In almond production, the nuts are shaken from the trees to dry on the ground before they are harvested.

"If the orchard floor becomes too shaded by trees planted too densely, the orchard floor temperature and humidity become optimal for growth of pathogens that could become a food safety problem,” Lampinen said. "You want enough sunlight to hit the orchard floor to reduce potential pathogens, like salmonella.”

MacIlvaine acknowledged the role of UC Cooperative Extension in helping the almond industry achieve the production milestone in 2011.

"The University of California has been a wonderful partner in improving our farming practices,” he said. "The whole system is not only more efficient, but more sustainable at the same time.”