What are the impacts of various vineyard practices on soil health, water retention, soil temperature and yields? Agrology, a soil health monitoring vendor, provided data and insights in a year’s-end online webinar showcasing data from more than a half dozen vineyard clients it works with in California.
Agrology’s Arbiter soil monitoring system measures soil microbial biomass and continuous metabolic activity in the soil, which provide advantages compared to more static measurement systems disadvantaged by lag time from sending samples to a lab and waiting for a result. Static sampling does not provide real-time data on fluctuations.
“The Arbiter system looks at CO2 concentration in three different ways,” said Charlie Dubbe, head of regenerative partnerships for the Sonoma-based company. “It looks at it through a soil chamber, looking at what’s called soil respiration.
“We’re telling you what the actual activity is based on the real-world conditions of soil moisture and the climate that you’re in and the practices that you’re doing. So, it’s this really interesting continuous measurement of the amount of life in your soil.
“The larger and more robust that dialog is between soil microbiome and plant roots, the better a plant can produce these biochemicals that are called secondary plant metabolites,” he said. In wine, those are polyphenol compounds and tannins.
Dubbe said up to 50% of the energy that plants gather from the sun is released into the soil microbiome then slowly processed by the soil microbiome and humified (turned into humus). “That stable carbon form is what we’re really looking forward for,” he said, both for fighting climate change and increasing crop production.
“So, long story short, Agrology monitors that amount of microbial activity through soil respiration,” Dubbe said.
The trio of presenters then went on to provide a cornucopia of data from various clients and vineyard sites, ranging from Napa and Sonoma to the Central Coast, looking at no-till practices. Data showed no till preserved soil structure, enhanced microbial life and water retention and reduced the need for irrigation. It also improved overall soil health.
“No-till methods, while potentially more labor-intensive and difficult to implement to transition, offer longer-term benefits like improved water retention, reduced evaporation and better microbial health,” said Dana Revallo, Agrology’s head of customer success.
“We know consistent tillage does very bad things for the soil microbiome,” added Dubbe. “No. 1, by just disrupting all their homes and kind of slicing up the structure and destroying that pore space, you’re creating this massive feast, you’re chopping up all the soil organic matter, and then you are adding all this oxygen, so there’s this massive kind of burst of activity. But all that food is gone later in the season.”
“The Goldilocks Zone”: No Till’s Benefits in Soil Temperature and Moisture
Jay Adocchia, head of agribusiness development at Agrology, pointed out soil temperature plays a critical role in determining the rate of evaporation and microbial activity in the soil.
“When the top 6 to 8 inches of soil goes above 100 degrees [F], we lose 85% of that moisture just through evaporation,” he said. “The full-till blocks experience soil temperatures over 100 degrees [F] for extended periods. By contrast, the no-till practices buffered soil temperature fluctuations, keeping temperatures lower and stable. The data from the trial showed the full till resulted in 69 days, or exceeded 85 degrees [F], while the no till above 85 was only 29 days.”
Water Retention
The team also reported no-till practices yielded the highest water retention levels, allowing the soil moisture to be more effectively held, rather than full till or the every-other-row till. The ability to reduce irrigation while maintaining healthy soil is a significant advantage, they noted.
The full webinar with several case studies, including some from Donum Estate, Joseph Phelps and a very large grower, provides graphs and insights into a variety of practices, including using rye as a cover crop, ROI analyses and more. It can be seen online at https://www.youtube.com/watch?v=yvfUipcXJzQ.
