Friday, March 26, 2010

Why you need enough Nitrogen in your compost

This bird bath needs compost.
A major source of locally derived soluble nitrogen (N) for your plants is...the bacteria that eat your compost!   They live at a certain ratio of C:N (carbon to nitrogen).  Since there is usully enough C in the environment, these guys are usually hunting for N.  And if they can't find enough N in the environment around them (say, your compost bin), then they can't grow. So if your compost does not have enough N (too much C) , it won't break down very quickly.  But here is where your garden comes in- if you put fresh compost onto your soil that hasn't completely broken down, and there is not enough N in the compost for the bacteria to grow, then the bacteria will compete with your plants for the N in the soil water solution- no bueno!

Sources of nitrogen for your compost:
  • coffee grounds (just like manure, don't add directly to plants before composting!)
  • animal manure (make sure this cures, there could be disease)  
  • any more ideas?
This looks like a good place to add some Nitrogen!
If you don't have coffee grounds or animal manure, don't worry.  Most mature household compost has plenty of nitrogen (a ratio of 15:1 versus the maximum 25:1 ratio).  Just make sure you don't input too much "dry" stuff to your compost, such as dried up grass or leaves.  For example, sawdust, straw, and newspaper has WAY too much carbon to compost on its own.

1 comment:

  1. Amanda! We came home from the cookout and I searched for your blog to no avail. I am so glad you commented. I will read all your posts tomorrow and you guys are always welcome for a visit. I want your soil wisdom:)