Holistic Struggle with Star Thistle

Star Thistle. It’s everywhere this year in the back pasture of the Grange Farm School. We curse it as it pierces our legs and remains unpalatable to livestock once it goes to flower. Even with a crew of 8 digging the plant out, we make slow progress against the vast brambles of thistle. But on Saturday, July 11, Spencer Smith of the Jefferson Hub for Holistic Management held a full day workshop with the Grange Farm School and surrounding community to discuss a decision making framework that takes direction from the four ecosystem processes.  We test our decision to dig out star thistle during the workshop by carefully evaluating the water cycle, mineral cycle, energy cycle, and community dynamics in the pasture.  

First, the water cycle.  The layer of mulch from dead plant material is thick, creating a vapor barrier that traps water in the soil rather than evaporating into the hot, dry summer atmosphere.  Our minimal irrigation seems to be retained under this layer and we find positive results to the cow’s grazing of our winter cover crop.

photo and more info here

Next, the mineral cycle.  Our soil structure has excellent “crumbing,” aggregate held together by glomulin, signifying biological activity that makes minerals available to plants.

Now community dynamics.  The diversity of plant and animal life is more complex than it originally appears- we find bindweed, mustard, wild radish, and a variety of grasses coming up between the star thistle, not to mention the vast diversity of insect life.

Finally- we get to the energy cycle. Are we taking advantage of the most powerful and awesome resource of all: solar?  Is there enough photosynthetic activity to lap up the rays of sun as it pours over the field? By digging out the star thistle, we are removing a large portion of the green material that is doing the work of converting the sun’s energy to sugars, sugars that feed the microbiology within the soil.  The decision to dig out this dominant species does not pass the energy cycle test, as it interrupts the cycle of solar conversion.


In Holistic Management, we are taught to manage for what we DO want, not for what we DON’T want.  Rather than expending an enormous amount of energy digging out star thistle, we need to work towards shifting our soil from a bacterially dominated, low succession level pasture towards a more fungally dominated higher succession ecosystem.  Complexity is the key, and working with existing life and the ecosystem processes will help us to achieve our goal of high quality pasture year round for our livestock.  Our planning has shifted towards cover cropping with species that come to maturity and get grazed down after the star thistle has begun pushing up but before it goes to flower.  In this way we hope to encourage species that we seed, giving them plenty of time to develop and mature, and then graze down all of it with cows, sheep, and chickens in succession. Wish us luck!  Monitoring of our progress is key so stay tuned for updates!

Written by Ruthie King: Co-Director of the Grange Farm School

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s