By JENNIFER BONNETT
Business Journal Writer
It’s no surprise that San Joaquin Valley growers are digging in the dirt this time of year.
While winter is not really known as a growing or harvest season, valley farmers are planning as it is key to next year’s yield.
Whether it’s moving soil to the top or amending it, they are looking at ways to grow the best crops.
“Our soils are tired, they’ve been farmed a lot,” long-time grower Louie Tallerico said.
“Typically, if you plant a crop in virgin soils, they have a high yield.”
But some of these are getting just as good a yield with new orchards planted on the same site as those ground down.
“A lot of it comes down to the soil; what can you do to it?” said Tallerico who has been growing almonds since 1970.
“If I had it to do all over again, I would have focused on the soil from day one.”
The Valley is home to the world’s largest patch of Class 1 soil — the best there is — and experts agree that the 25-degree average temperature swing from day to night is an ideal growing range for plants.
Here, even in the winter, the sun shines nearly 300 days a year. Still, the season is cool, which offers a whole different growing climate for plants that cannot take the summer heat, and of course, there’s no snow.
This time of year, orchard growers are discing the ground and incorporating old wood back into it. Some are even using organic matter obtained from their former orchards.
It takes years to get the soil amendments to the beneficial level.
“You can put cover crops in, but that takes a lot to bring the organic matter to the levels you want,” Tallerico said, adding that he’s read reports that you’d have to add 63,000 pounds of organic matter per acre to reach optimal levels. “That’s just about a mission impossible.”
So, he was intrigued when he heard about a long-term soil health project headed by Brent Holtz, director and farm advisor for the University of California Cooperative Extension in San Joaquin County. He studies pomology, including deciduous tree fruits and nuts, and plant pathology.
In 2015 when co-generation facilities where plants were burned for electricity began to shut down, farmers were left with a bio-mass issue in orchards. With nowhere to take their old plants and emission regulations curtailing the former practice of burning of the old orchards, Holtz sought a new way.
He has re-planted a new orchard where an old orchard was ground up in 2008 and has been studying the soil where he’s found fertility improvement.
“A lot of growers were worried you’d affect the carbon balance,” he said of the practice known as whole orchard recycling. “But it improved the soil health and ultimately the yield.
“Once growers realize they can keep all that organic matter in their orchard, that makes them happy.”
In Manteca, about a year ago Tallerico did the same with one of almond orchards from the mid-1970s.
“It’s a one-time chance to increase the organic matter. That’s why I went down this path with this experiment,” he said.
But he feels good about it when he reads the reports that tout how much organic matter is needed to amend the soil. Other options include adding magnesium, calcium, ammonia and other nutrients, all of which are done this time of year.
“They recommend all of these chemicals, some of which you put in the ground or spray on the tree. But they always mention this organic matter,” Tallerico said.
“I’m only a year in, but I’m looking forward to the results.”
Up and down California, farmers are in the fields.
Winter forage crops, such as wheat, barley, other cereal grains and forage mixes continued to be planted and seed shipments received. This January, irrigation was still necessary to maintain growth of those plantings that have germinated, according to a report by the United States Department of Agriculture.
Pruning continued in stone fruit orchards, nut orchards and vineyards, although some older, poorly producing orchards and vineyards were removed and prepared for replanting.
Winter dormant sprays were applied to some orchards, and fields were being prepared and planted with winter vegetable crops such as some varieties of carrots.
Weed control was done on organic onions, while conventional onions continued to be irrigated.
Conversely, in this area, orchard floors are kept clear of vegetation allowing the soil to act as a reservoir of sorts for heat from any solar radiation received through sunlight. That heat is stored and released at night.
That process can also be achieved by applying water to the orchard floor.
With more rain and snow due in Northern California later in the month of January, farmers were expected to ease back on wintertime irrigation of developing crops, according to the California Farm Bureau Federation.
The U.S. Department of Agriculture reports that farmers had been irrigating a variety of crops in January, due to dry conditions so far this winter. But rain that fell mid month benefited lettuce, pasture and other crops, but USDA says additional rain will be needed.