Forum home The potting shed

What is it about rainwater?

245

Posts

  • raisingirlraisingirl East Devon, on the Edge of Exmoor.Posts: 4,698
    I expect the microclimate around plants is changed by heavy rain, the wet soil, wet leaves of the plant and its neighbours, create a humid bubble that will alter the transpiration in some way, possibly reducing the physical stress on the plant and allowing it to put on a growth spurt. In the ground, the soil organisms almost certainly become more active, although I doubt that affects potted plants too much
    “There is no military solution
    Doesn't always end up as something worse”
  • FireFire LondonPosts: 10,854
    Yes, certainly the slugs, snails, worms are triggered into new activity. Going out at night at the moment, certain worms are lying all over the earth and retract back into the soil when a torch shines on them. Fungal activity would change.
     - -
    It's good to see that after a week of rain, self-seeded borage seedlings have started to sprout, as if by magic. They need a good deluge in the late spring to get going, and then seem happy to grow on. Last year the rain didn't come and May was parched and no borage showed up at all through the year. I missed them. My hose didn't seem enough to trigger growth over the whole garden. Timing is everything.

    I feel sorry for the bees trying to live out their short life cycles in this deluge. My mason bees have just started to lay in earnest but will have to pause in pollen collecting. They curl up together in the bee boxes and snooze while rain beats on the roof.
  • Chris-P-BaconChris-P-Bacon Posts: 419
    Tap water is relatively low in nitrates and can occasionally contain quantities of various salts. Rainwater is, as rule of thumb, quite high in nitrates. Rainwater also collects CO2 as it falls.
  • ElferElfer Posts: 328
    What an interesting topic to raise @B3 my daughter is a water sommelier (she doesn't know it yet), and she often compares different mineral waters and even has a favourite. I have often had fresh spring water high up in the mountains and it just tastes to different and refreshing in comparison to bottled ones we buy let alone tap water.

    As well as nitrogen which has been pointed out, rainwater contains another vital element, extra oxygen. The slow constant drip drop also helps to wash the salt away from the roots.

    But the benefits far exceed these points, here is a great article on why rain water is so good for our plants.

    https://www.mercurynews.com/2017/02/13/for-plants-rain-has-benefits-that-tap-water-simply-cant-deliver-9/

  • nick615nick615 SW IrelandPosts: 811
    I was never much good at the sciences in school but one fact I do recall is that, as rain falls, it absorbs tiny quantities of nitrogen to become a very dilute form of nitric acid.  Pretty much the sum total of 1950s Biology but .......
  • Hostafan1Hostafan1 Posts: 29,056
    Some say it collects oxygen, some say it collect carbon dioxide and some say it collects nitrogen. 
    Who'd have though rain drops were so busy and so clever. :D
    Devon.
  • B3B3 Posts: 18,677
    Thanks for link @Elfer. It was very interesting.
    In London. Keen but lazy.
  • raisingirlraisingirl East Devon, on the Edge of Exmoor.Posts: 4,698
    Hostafan1 said:
    Some say it collects oxygen, some say it collect carbon dioxide and some say it collects nitrogen. 
    Who'd have though rain drops were so busy and so clever. :D
    It might be easier to just say they are well aerated. Which isn't surprising  :)
    “There is no military solution
    Doesn't always end up as something worse”
  • Chris-P-BaconChris-P-Bacon Posts: 419
    Disovled oxygen in water increases with temperature and is present in higher percentages in unpolluted water. About 100% saturation by the time it hits the ground. Nitrogen is created mostly in the upper atmosphere by electrical activity.
  • raisingirlraisingirl East Devon, on the Edge of Exmoor.Posts: 4,698
    edited 18 May
    Disovled oxygen in water increases with temperature and is present in higher percentages in unpolluted water. About 100% saturation by the time it hits the ground. Nitrogen is created mostly in the upper atmosphere by electrical activity.
    But these, with argon and carbon dioxide, are the main constituents of the air through which the rain passes. And given how raindrops form, it's not surprising that air gets into it
    “There is no military solution
    Doesn't always end up as something worse”
Sign In or Register to comment.