Posted 8/1/2020 23:50 (#8409949 - in reply to #8408537) Subject: RE: nitrogen mineralization ?
blowsand - 8/1/2020 10:31
IMO both of the above are correct.
Mineralization is basically the same function as residue breakdown, and the subsequent release of the nutrients contained in that residue.
Look at an early harvested cornfields residue in the spring vs. a late harvested. Residue won’t change much over the winter, it takes warm temperatures to get the microbial and insect population working on the residue in a meaningful amount.
And moisture, in a drought year, it seems that lawn clippings accumulate, whereas in a wet year, even though much more are generated, they dissapear. Same reasoning as above, too dry, and the microbe and insect population suffers, and the residue is much slower to break down.
Soil organic matter is basically the same thing as crop residue, it just needs to be converted into a plant available form by microbes and insects. The better conditions for them, the more N mineralized. Clear as mud?
I thought soil organic matter is crop residue (and other organic residue) that is broken down to the point that it can not be broken down any more, can not be converted into plant “food”.