Webinar Replay: How Soil Biology Drives Soil and Vineyard Health

When vines stall at ripening and disease pressure creeps in, the real story often starts below ground. Vineyard consultant and microbiologist, Misha Vandal, unpacked what happens when you stop chasing single-strain fixes and instead rebuild a whole soil community tailored to how wine grapes actually perform.

Watch the Webinar Replay

Vineyard Soil Health

Vineyard health starts in the soil, and the story beneath the vines is changing fast. As climate extremes, water limits, and viral pressure reshape viticulture, growers are revisiting the foundation: microbial life.

Wine grapes are a sharp lens for this shift because they’re data-rich, long-lived, and quality-driven rather than yield-maxed. When a block that performed for a decade suddenly stalls at ripening or shows canopy fatigue after 100-degree days, the question isn’t just irrigation or fertilizer—it’s what the microbiome is signaling.

With affordable metagenomic tools now in reach, we can see which organisms dominate, which are missing, and how that balance correlates with resilience, nutrient cycling, and disease pressure. In Napa trials across organic and conventional sites, Misha focused on a whole-community inoculant approach rather than single-strain products, aiming to restore functional diversity, reduce pathogen dominance, and improve ferment-relevant fruit metrics like yeast assimilable nitrogen (YAN). That choice mattered because vineyards need the right biology working in sync with the plant and the season.

Improving the Biology in the Soil

The practical problem with biological products has always been delivery. Compost teas can work, but they struggle at scale due to inconsistency, labor, and tank hygiene. One brew can vary from the next depending on feedstock, timing, and handling, which makes it tough to standardize across 200+ acres when crews are stretched and the window for application is narrow. By contrast, ready-to-apply products, like StrongSoil, reduce the operational burden: agitate, mix, apply in minutes.

In trials, we folded a whole-community product into existing programs, dialing back fertilizers by roughly 8–10 percent to avoid overfeeding and preserve wine quality targets. We weren’t chasing higher yield; we were targeting functional shifts: more phosphorus solubilizers, better iron availability, improved soil aggregation, and measurable boosts to YAN in historically stubborn blocks.

StrongSoil Results in Vineyard Trials

The results point to a pattern. Beneficial bacteria such as Pseudomonas putida increased by roughly 44% and Bacillus species by about 158% post-treatment, two groups with well-documented roles in phosphorus solubilization, siderophore-mediated iron availability, and polysaccharide production that improves soil structure.

At the same time, we saw a marked drop, near 57–58%, in Cladosporium, where it had been comparatively abundant pre-treatment. More importantly, community structure shifted away from single-taxon dominance toward a more even, resilient network that tends to buffer stress when heat spikes or rain events hit.

On the vine side, the signal was clear: a site with a decade of zero YAN finally registered around 80 mg/L, moving into a range that reduces winery additions and better reflects the terroir in the glass. The aim now is to push 150–200 mg/L with adjusted timing, dosage, and paired biostimulants without tipping into excessive vigor or winemaking complications.

Disease and pest pressure intersect with soil health in ways growers can influence. Red blotch remains a heavy economic drag. While vector management is part of the story, plant signaling and overall vitality affect how attractive a canopy becomes to insects like threecornered alfalfa hoppers. The same goes for trunk diseases, an expanding suite of fungi that exploit vines weakened by drought, heat, or waterlogging. You can’t spray your way to resilience if the belowground community is degraded by years of tillage, compaction, and harsh inputs.

Preventative microbiome support outperforms crisis response because it maintains structure and function before stress lands. The operators who succeed will be the ones who make small, consistent changes: manage traffic to reduce compaction, reduce fertilizer rates to avoid canopy excess, deploy community inoculants on time, and use data to verify. The payoffs are fewer replants, steadier ripening, and fewer surprises.

Interested in learning about StrongSoil for your vineyard?