Experts probe with high-tech gadgets to see if farm soil is fertile. They run leaf samples to check if a crop is getting the needed nutrients.
This week, one expert simply shoveled up some dirt and ran his hands through it.
“Earthworms. We have earthworms,” said Jeff Borum, a soil health conservationist, at an almond orchard west of Turlock. Worms help decompose dead plants into nutrients for new growth. They bore tunnels that help with air and water flow.
Tuesday’s demonstration was part of a meeting on how to take advantage of natural processes so farmers do not need to buy so much synthetic fertilizer – mainly nitrogen extracted from petroleum. These and other inputs have greatly boosted yields for a growing world population., but sometimes at the expense of long-term soil structure and fertility.
Borum works for the East Stanislaus Resource Conservation District, which put on the event with the federal Natural Resources Conservation Service.
They urge farmers to keep soil disturbance to a minimum when tilling, planting and harvesting. They want to prevent erosion by wind and rain, and compaction from heavy equipment.
The federal agency promotes grasses and other cover crops between orchard and vineyard rows, rather than the bare ground that still is common in agriculture. These could be clover, beans and other legumes, which have microbes at their roots that help make nitrogen more available.
The NRCS is researching several cover crops at its Plant Material Center near Lockeford, agronomist Valerie Bullard said. Some of them flower around the time of almond pollination, providing extra food for rented bee colonies that have struggled in recent years.
Kamprath Seed Co. of Manteca supplies farmers interested in cover crops. Tom Johnson, an agronomist there, said they can provide benefits even after they are mowed or plowed under to make way for harvest.
“Soil health,” he said, “is all about having critters running around under the ground.”
The demonstration took place at a Taylor Road orchard owned by Edelweiss Nut Co. of Turlock. It uses cover crops, plant residue and other methods to enrich the soil, host Rich Gemperle said.
Gov. Jerry Brown last year launched the Healthy Soils Initiative. He hopes to make this fertile state even more so, and to see if well-managed ground can capture some of the carbon blamed for climate change.
“Soil is really the foundation for the good work and benefits we get out of California agriculture,” said Carolyn Cook, an environmental scientist at the state Department of Food and Agriculture.
John Holland: 209-578-2385