Planting for Posterity

As you may have heard, we’ve been having quite the kerfuffle in these parts about trees. The short story: that big corporation that owns a big local winery has been playing fast and loose with our native oak trees.

Freshly harvested olives
Freshly harvested olives

In contrast to that, I thought I’d offer up some good news about trees and agriculture. Some news about Kiler Ridge Olive Farm, a local olive oil producer that’s taking the long view, the sustainable approach.

I wrote about Kiler Ridge for my Local Flavors column in the (San Luis Obispo County) Tribune’s Ticket. That column is based around food, so I only delved briefly into the owners’ sustainable approach to farming.

When Gregg Bone and Audrey Burnham found their 58-acre Paso Robles property in 2004, it was an abandoned almond orchard. Granted, this land was probably home to several hundred oaks at one time, but at this point, the almond trees were either dead or dying. The couple contracted a local company to remove the trees to be repurposed for charcoal and/or firewood. Then they set about planting 2,700 olive trees.

Arguably, olives are as well suited to our climate as oak trees. As Bone explained, once they’re established, olive trees use less water than we get in a typical year of rainfall. Hard to say these days what typical is, given our ongoing drought, but olives are still a low water user in comparison to other crops. Bone estimated that they need about five inches of rainfall/year to stay alive, seven to barely produce fruit, and 12-17 inches to produce a commercially viable crop of fruit. Last season, Paso Robles got an average of 13.33 inches of rain, still within necessary parameters for commercial production.

The Kiler Ridge trees were planted with a drip irrigation line to get them established, but they’re watered only during the hottest of summer days. The drip system delivers water precisely to the trees, so there’s no waste. Any applied fertilizer is in the form of a water soluble solution delivered through the drip – again, no waste.

Another method of fertilizing utilizes the pomace — the solids leftover after the oil is pressed out of the olives. After milling their extra virgin estate olive oils, Bone and Burnham put all the pomace into “Palazzo Vermi.” Yes, that does translate to “Worm Palace.” It’s a dedicated structure on the property where the regal worms can do their thing.

The worms break down the pomace into worm castings. Yes, that is a glorified name for worm poop, but it’s just about the best darn fertilizer you can find. In this case, the worms converted the high tannic acid in the pomace into nitrogen. Better yet, they’ve turned it into nitrites, which is a form of nitrogen that’s easily accessible to plants.

That now broken-down pomace is put onto the ground under the olive trees. Essentially, almost all the nutrients that were removed from the olives are returned back to where the olive trees can reuse them. Full circle, and again, very little waste.

Bone noted the pomace also has the added benefit of acting as a natural herbicide that suppresses weed growth. Fewer weeds mean the olive trees have less competition for water and nutrients.

The real beauty of all this management is that once the trees are established, returning the pomace is really the only thing you would need to do to the soil. Given average rainfall, you’ve created a system of closed inputs – nothing external is being added to the operation. It’s one of the ultimate goals of sustainability.

As I mused in my original column, why would Bone and Burnham go to all this trouble? Sure, in the short term it makes for better tasting olive oil. But they’re also thinking about the long term … the very long term.

“Olive trees can live for 3000 years,” Bone said. “So you better think about that when you’re planting them.”

— By Katy Budge

 

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