|I took my garden soil's temperature the other day - 94°F (34°C)!|
What can grow in that! No wonder my harvest has been so poor.
By the time we'd emptied the last of our rainwater tanks, I couldn't help but think of all the water we're wasting as it goes down the drain to the septic tank.
Now, before anyone rushes to hit the comments to tell me I can't put greywater on my garden, please read the rest of the post. Dan and I have Art Ludwig's book and I highly recommend both his book and web page on greywater errors. Actually, I'm thinking more along the lines of modifying one of our original ideas for greywater use.
|Sketch from "Homestead Master Plan, 2012 Revision."|
That is, to use the water from the wetland filtration bed for some areas of the garden, and save the rainwater for root veggies and things we eat fresh.
I did my initial research on greywater while I was working on chapter nine of 5 Acres & A Dream The Book - "Water Self-Sufficiency." From that I still had unanswered questions; not so much the how and why, but the what. What products could I use in a greywater system that would be safe for plants?
Some things make sense to avoid and are fairly easy to do so by reading labels: chlorine bleach, anti-bacterials, synthetic colors and fragrances, whiteners, softeners, enzymes, and artificial preservatives. Other ingredients are pretty ubiquitous in cleaning products and more difficult to avoid, especially borax (boron) and sodium. My other concern is pH, because soaps and detergents make greywater alkaline.
Boron. In cleaning products, borax is the source of boron. Found on the laundry aisle at the grocery store, borax (sodium borate) is 11% boron. As a laundry cleaning booster, it cleans and whitens by converting some of the water molecules to hydrogen peroxide. Borax is also used as a boron supplement for boron deficient soil. Boron is an essential nutrient for plants, however, it can be toxic to them if allowed to accumulate. My soil is boron deficient, and it shows up as a clicking sound in my goats' knees. So in some ways, borax is not a major concern. This link to the Agronomic Library can give you details on boron if you're interested.
Sodium. Look at any ingredient list for soap, detergent. and cleaning products, and you'll find many a sodium something or other. Excessive soil sodium interferes with plants' ability to take up water so that they dry up. Plants can also experience toxic effects by accumulating too much sodium. Some of my soil tests have indicated high levels of sodium. What's the answer? According to Neil Kinsey, "An open soil with plenty of calcium and plenty of water will not permit sodium to accumulate." [Hands-On Agronomy, page 23. He has an entire chapter on soil sodium which is informative reading.] So even though there's somewhat of an answer for sodium, it's still something I would rather avoid.
pH. Almost all the products we tend to use as cleaners: washing soda, baking soda, soap, borax, etc. are alkaline. This can kill acid loving plants. My soil is actually quite acidic, so slightly alkaline water would offer some benefit and is probably the least of my concerns.
Ways to manage these problems in greywater systems include periodic flushing. Even better is to use pH neutral products that are not high in boron and sodium. This was the motivation behind this round of research.
I had two research goals. The first was how greywater friendly my current products actually are. I believe that we humans are intended to be stewards of the earth, which means we are responsible for what we do and how it impacts the earth's health. Consequently, I try to make conscientious choices in the things I use, but since I hadn't aimed for products that are specifically greywater safe, I wanted to know if I needed to make changes. This points to my second goal, which was to research what I could buy locally that would fit the bill. Putting everything I learned into one post made it too long, I thought, so I divided my results into two posts. Next I'll share what I've learned about the products I currently use.
Happily, it started raining again so my garden is back in production mode. Unfortunately so are the weeds, but that's another story.
Of Soap, Detergent, & Greywater © July 2016