In my last post, I mentioned something about it maybe being a dry spring... well, apparently I can tell the future because sure enough, it's dry! Now, if that would work when I predict that I'm going to win the STARS lottery... by the way, if you bought a STARS ticket - well done! I always buy a few because I've had a family member go for a live saving ride on that angel in the sky, and our farm here, is directly under their flight path, so STARS is quite often on my mind.
Back to being dry... part of me loves it, because there is no mud in the feedlot. The other part is looking at my empty 3000 gal water storage system and thinking about the plants in my header house that need to be set out as soon as possible. So, today I'm going to drive off to town and come home with a water tank and start hauling water until it rains, from our dugout at the brim of the coulee. Now, I was going to include all this detail in my monthly newsletter, but then I decided that I wasn't going to subject my newsletter readers to my long winded writing - I'll save that for the blog instead!
So, before I start I should give a little description of one technical term E.C. or Electrical Conductivity. I'm going to assume that we all have a relatively good understanding of pH. E.C. is a way for greenhouse growers to ensure that their plants are getting the right amount of feed from the nutrients they're mixing with the water. Okay - Brace Yourself, it's going to get technical and I'm going to dredge up Alllllll those terms you thought you'd forgotten after your last Chemistry exam in high school. Pure water, has poor conductivity because it lacks ions. As you add ions, the conductivity increases (increase in EC reading) because ions carry the current. Got that? It might be easier to remember that low EC when dealing with raw water = good, and high EC = bad.
With that out of the way, I'll outline the issues I face when I have no rain water. I've tested our rain water, and it has a pH of 6.8 with an EC of 0.02mS/cm, and when I add fertilizer, that ends up dropping the pH to 5.8 and increasing the EC to 1.67mS/cm, which is exactly where I want it for growing in the greenhouse at this stage. As the plants grow, I'll increase that EC to between 2.5-3mS/cm. When you are starting out with basically raw 'empty' water, you know that all the nutrients you're adding, are exactly what's behind that EC reading, which is Perfection. Also, the acidic pH reading is where you end up getting optimum nutrient uptake for crops like tomatoes. When you get a higher pH, like 8, you can start to run into issues with nutrient uptake, especially regarding your micronutrients.
I've tried using well water, but it's pH is 7.1, and the EC is 1.5mS/cm... so what are those ions floating around in that water? Sodium most likely. Plant's dislike sodium and generally do not thrive on our well water. We can drink it, but we aren't plants. The end result is, that unless I can split this water with rain water, I can't use it.
My next thought was to use water from the dugout. I tested it, and the EC, while not perfect, is workable at 0.8mS/cm. This issue here is, the pH is 8, and that's likely because we didn't get a good run off, and a good flush through the dugout. However, I think that with the tendency of the fertilizer to drop the pH 1-1.5 points, I should be able to make this work. In order to meet tomatoes voracious demand for Calcium, I apply lime throughout the season to the media. Lime is what farmers will apply to soil that is too acidic, to make it more alkaline, and peat is naturally acidic, so in the past, these two things have balanced each other out. I'll have to make sure that I don't end up applying too much lime and negating the acidifying affect of the fertilizer.