Liquid Clay Product Shows up Big in Romaine Lettuce Field Trials

Two commercial romaine lettuce field comparisons conducted with a large specialty crop grower in California’s Salinas Valley produced substantial harvested yield increases and notable per-acre profit gains following applications of Liquid Natural Clay (LNC) product, according to Desert Control, a provider in liquid clay soil amendment technology.

An initial trial earlier this spring was conducted on a historically underperforming sandy loam field in the Salinas Valley, where growers often face rapid water drainage, low organic matter, and limited nutrient retention. One acre treated with Liquid Natural Clay was compared to one acre of untreated romaine lettuce under identical irrigation practices. Results were verified by the customer, a large grower in the Salinas Valley.

Results showed the Liquid Natural Clay-treated plot produced 427 boxes per acre, compared with 329 boxes per acre in the untreated control — a 29.8% increase in yield. Average box weights remained nearly identical between the two plots, indicating that the increase was driven by a greater number of harvestable lettuce heads rather than increased plant size.

The study also demonstrated a substantial improvement in water-use efficiency, according to Desert Control. The LNC-treated field achieved 5.7 tons per acre-foot of water, compared with 4.3 tons per acre-foot in the control plot, representing a 33% improvement in water-use efficiency.

By increasing the soil’s reactive surface area, the product helps retain water and nutrients within the root zone, slowing water percolation through sandy soils and improving crop access to essential resources. This aspect of Liquid Natural Clay was especially crucial during the first trial as crop performance was maintained during a delayed harvest period after irrigation had been stopped.

“These results demonstrate the practical value of improving the soil’s ability to hold water and nutrients where crops need them most,” says James Thomas, Chief Executive Officer, Desert Control. “In these trials, Liquid Natural Clay demonstrates yield increases of approximately 30% and higher, while meaningfully improving water-use efficiency, all without requiring additional water or changes to standard farming practices. We were pleased to see this degree of improvement in soil with 64% sand content; a type of soil which has not been the focus of our marketing efforts.”

For more information, the whitepaper from the first trial is available at desertcontrol.com/results.