The Helpful Gardener
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Ch. 17 Mulch

I have done a lot of mulching over tha past few days, so this one hits me where I live...

I personally don't do much green mulching; I use compost to mulch where I want some bacterial power (veggies mostly) I alternate compost and bark mulches around perennials and use wood chips in more shrubby beds, and Jeff covers the C:N ratio thing again to explain why that's so. The protozoa tea at the end was a neat tip, and it set's us up nicely for our next chapter...

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rainbowgardener
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This is the chapter that made the biggest impact on my actual practice. I've always just mulched everything with wood chips or fall leaves, because that's what I have around. I have an endless supply of homemade wood chips for the trouble of running the cut brush through the shredder and I can bring home as many bags of fall leaves as I want.

Authors point out that maybe this is not the best for annuals that like more bacterial soils. Actually on a close reading, I wasn't doing so badly. They do say once you bury the mulch in the soil, you are moving it toward more bacterial. What I did was lay down the bark or leaves in fall; in spring turn it under and bury it. Later in the spring once soil warmed up, add more. So it wasn't totally fungal, there was some balance.

This year I did green mulches on my tomato bed and green pepper /basil bed-- hay, pulled grass (not clippings, pulling grass from where I didn't want it to be), pulled weeds. Those beds have done very well, definitely better than last year. Is that due to the green mulch? I don't know; this is a very different year than last year, which was cold and wet all summer. No control groups. But everything is doing well enough that I will keep doing this and see if I get consistently good results over years.

They also mention drowned weeds, soaking straw or weeds for a few days to culture a bunch of protazoans for the food loop. But needs a bubbler, pump and air stone, so not something I'm likely to try.

garden5
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This was really interesting learning that not only do the types of mulch encourage certain microbes, but so does the form they are in and how they are applied. So, I suppose if you are going to apply a bacterial mulch, grind it up and work it into the soil.

I'm glad to finally have the low-down on nutrient lock-up. Since this is caused by primarily bacteria, then we shouldn't have much trouble with it if we are applying a bacterial mulch, like grass clippings or hay, anyway. These have a lower carbon:nitrogen ratio. I'll suspect that if we are planning on using straw, it wouldn't be a bad idea to mix in some alfalfa pellets to supply some extra N.

Also, that protozoal tea sounds like a pretty good idea, as well. I would suspect that it would be best to apply it after the mulch starts to break down, this is when it will actually be harboring bacterial/fungal colonies.

Although, if we spray protozoa on the soil's surface, won't they just eat the bacteria and fungi that are in the mulch, thus releasing nutrients where there are no roots? Maybe it would be best to wait until most of the mulch is decomposed since maybe then most of the microbes would have gone back into the soil, nearer to the plants rhizoshpere?

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The amount of cilliates already found on straw and hay is staggering, so too late. The protozoa are already there. Mix hay or straw into water and look under a microscope. The big zoomy guys? Cilliates. Straw or hay IS spraying protozoa everytime you water...

Don't forget the medium all biology travels in is moisture. Only the stuff that stays moist gets the action. Stuff that dries out survives. And watering moves everything DOWN. Don't worry about roots, etc. Everything is moving down at a rate that works out very nicely for everything involved...

HG

garden5
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So, keep it moist and don't worry about it. Sounds good :D. That kind of the gist of the book (or one of them): in and organic environment, things tend to all work out.

One thing this chapter makes me think of is when someone posts a picture of their wood-chip mulched plant that isn't growing well, and we tell them is is because the wood chips. However, according to the book, whatever nutrient lock-up there is, occurs at a thin layer of soil at the surface and should have no bearing on the growth of plants such as tomatoes, peppers, etc. that have deeper root systems. I'm going to have to start changing my advice.



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