Column: Healthier soils the solution to some invasive species

I am not an expert on the topic on which I write this week: “weeds” or invasives.

I am not an expert on the topic on which I write this week: “weeds” or invasives.

What I believe is that they are indicators or deeper lying issues or conditions that need to be addressed.

Quick technical fixes seldom are long lasting and may bring about other problems.

We need more trials and demonstrations of alternatives to herbicides.

Healthier soils are, I believe, the solution to some of the invasions of certain of the species, which concern us.

We have had experience with three species: burdock, orange hawkweed, and oxeye daisy.   I will not say we have permanent solutions yet.

What we know at this point is that by intensively grazing the area affected by hawkweed and daisy, we can reduce the invasion by something like 90 per cent.

I have been observing the areas treated by grazing on our pastures and comparing it to the areas of lands immediately beyond our treatment (high stocking and short duration grazing).

What I have observed is the same as what others have demonstrated on their pastures treated in the same way.

Why would grazing appropriately help? Because we leave sufficient grass so it can rebound quickly and because there is a concentration of fertilizer (manure and urine). And the offending plants are grazed which sets them back.

Incidentally, I have heard from a producer that grazing rattlebox early in the spring by intensive management then letting it regrow for hay significantly reduces the volume of this “weed.”

Weeds indicate soil deficiencies and when addressed can virtually eliminate the offending plants. Each weed brings up the deficient minerals. That is their role.

Some soil amendments (natural if you want to be “organic”) can change the soil health in order to deal with the problems or encourage more desirable plants.

Our soils have a lot of necessary calcium, but it is often tied up by the high magnesium levels, so is not available. Adding the right kind of calcium can address this.

Low levels of phosphorous are also a common condition of soils.  The young soils of our geographic region usually mean low organic content, insufficient for healthy soils.

Most of these conditions can be treated by getting more animal manure and leaf litter on the ground and allowing for significant regrowth which will crowd out the undesirable plants.

What others and I have observed is that the orange hawkweed and oxeye daisy can be hugely reduced to where it may not be a problem if proper management of grazing is continued.

Cows will eat burdock when it is young. In more extensive pastures, it may be harder to control. For us, this is a work in progress. So far, we have had to resort to mechanical control (cutting) as well as the grazing.

What we need is replicable demonstrations, which are designed to test the effectiveness of the alternative treatments.  Try soil amendments and fertilization on a small scale. Encourage others.

Speaking of alternatives, if you want to see goats at work on weeds at the TRU campus in Williams Lake next week, a demonstration will be held July 18th, Monday. Call TRU for specific times.

David Zirnhelt is a member of the Cariboo Cattlemen’s Association and chair of the advisory committee for the Applied Sustainable Ranching program which started at Thompson Rivers University in Williams Lake this January.