Test plot growth at Maui Gold Pineapple ‘better than anticipated,’ sources say

For every 1% organic matter, one acre of soil can hold 20,000 gallons of water, according to the Natural Resources Defense Council. If agricultural spaces in Hawaiʻi can increase organic matter in soil by 5%, water-holding capacity will improve to 100,000 gallons per acre.

That’s according to SoilThrive Hawaiʻi LLC, a Maui-based business that has pilot programs to sequester carbon at various Maui County parks, hotels and for the past seven months, on one acre of Maui’s only large-scale pineapple farm.

The spiky crowns of tens of thousands of variety 7350, or “Maui Gold,” pineapples had been fed SoilThrive’s microbe juice since May. According to Maui Gold’s hands-on president, Darren Strand, the soil amendment is now being delivered to the pineapple’s root instead of its crown. They’ve integrated the liquid compost into Maui Gold’s irrigation “fertigation” system on the test plot. The change has reduced labor hours from a full day’s work to just 15 or 20 minutes start to finish, once every couple weeks.

“I think think the next step is scaling this up,” said Strand, who joined SoilThrive Hawaiʻi LLC Co-Founder Charlotte O’Brien for an edition of Maui Nui Marine Resource Council’s “Know Your Oceans Speaker Series” on Thursday. The group discussed progress since Maui Gold began testing the soil amendment on about 27,000 pineapples this summer.

In collaboration with MNMRC, the farm has taken tissue samples from the plant each quarter to analyze nutrient data. “We’re seeing some nutrient levels that are different from our other plants, but generally the plant growth is very similar,” said Strand. “Specific to this project, we’ve seen better growth than anticipated.”

Traditionally, going back over 100 years, its predecessor, once the largest grower of Hawaiian pineapples in the United States, Maui Land & Pineapple Co, used an assortment of fumigants and chemicals to fend off parasitic nematodes and soil fungal diseases on 8,000 acres of its golden fruit territory.

About a year and a half ago, the new ownership of Maui Gold Pineapple Company committed to completely eliminate fumigants from its practice and focus more on regenerative farming. Stand says they haven’t yet reported negative effects or a decline in plant growth as a result, although it’s too early to make definitive conclusions.

“It’s unusual for larger farms to embrace a project like this,” said Strand. “A lot of times it just doesn’t line up with the Initiative’s of a lot of commercial and conventional farms. I think our management group, and our ownership group is really open minded.”

Their hope is that about 80-90% of its trial crops produce fruit that’s good enough to harvest. Strand expects the 18-20 month crop cycle to end before November 2025.

In the public webinar, O’Brien discussed regenerative farming’s potential, such as its impact on China’s Loess Plateau, where centuries of poor land management had left an area the size of France unable to retain moisture, drying it out for hundreds of years. Over the last two decades, global efforts to boost biomass and organic matter have increased vegetation coverage across two-thirds of the area.

O’Brien says her goals for Maui’s dry agricultural lands are similar. She wants to reduce runoff by improving soil health, but there also needs to be an emphasis on reef-safe technology. Sediment deposits on reefs have been shown to smother corals and interfere with their ability to feed and repopulate, and some pesticides also interfere with coral reproduction and growth.

Her business helps transition resorts and homeowners transition to regenerative, non-toxic agricultural techniques by replacing traditional pesticides. She also creates and uses locally-grown, full-spectrum microbial treatments that support plant health through a natural communication processes.

For Maui Gold, SoilThrive drops off 100 gallons of its locally-brewed microbial treatment about twice per month to feed the acre of pineapples.

Despite the test plot success, Strand says scaling it to 757 acres of Maui Gold pineapple will be a challenge because SoilThrive is not a large-scale compost producer.

“I think if we have the capacity to expand it today, we certainly could,” Strand said. “It’s becoming easier and easier to incorporate into our operation, so those roadblocks really aren’t there.”

He says it could come down to the supply of local compost creators.

“We can’t, or really we shouldn’t be shipping compost between the islands with the invasive species issues,” Strand said. “So I think we really need to start a conversation about regional composting systems and how we’re going to fund those.”

View the full recording of November’s “Know Your Oceans Speaker Series” on MNMRC’s Facebook page.