My soil building questions and issues. Am I loving my dirt too much!?

[Nifty]

Yes.... this is YASBT (yet another soil building thread).

I'm a sucker for a nice sifted clean soil. As you can see here:
http://www.nifty-stuff.com/compost-sifter-screen-sieve.php

I've moved my raised bed from the chicken yard to a much safer location. That meant taking out all the soil and using a wheelbarrow to transport it to the new location. I figured since I was doing all this soil moving I may as well take the opportunity to add compost and sift everything.

The original soil in the bed was from two years ago when I mixed some clay soil and lots of compost. I figured the compost had "warn out" so when I moved the raised bed I added a ton more compost.

Boy does the soil look and feel really nice. What an amazing texture and color!

My raised be is at a little bit of a slope. I thought this may actually be good since I've seen people soak one end of their bed and let the water drain to the other end. Well, when I went to drench my soil in preparation for my transplants here is what happened:

1) After dumping a bunch of water on the soil it seeped into the soil nicely. But here's what is odd... digging into the soil about an inch looks like super dry / dusty soil??? I've noticed this before with my compost soil mixes: The water doesn't seem to "mix" with the soil... it's almost like the two are like oil and water.

2) When a lot of water is poured into the bed, faster than it can drain into the soil, the super soft / light compost mix soil just flows like a mudslide down my raised bed!

So, do I have too much compost? Should I not sift my soil? I read that different textures is actually good for plants... but how can they not just LOVE my super manicured soil? My brother saw it the other day and said it looked so perfect and rich he wanted to burrow into it himself!

 

[GwenFarms]

You may want to add some sand in Nifty. It will keep it from being so compacted.

BTW, I want one of those homemade sifters in the worst way. I'm adding it to my hardworking honey do list.

 

[whatnow?]

Was it especially dry? Some soil components like peat are hard to get wet if they are especially dry. Once the moisture level is normal, it should behave. What is the compost made from?

 

[Nifty]

You may want to add some sand in Nifty. It will keep it from being so compacted.

The soil isn't compacted at all... it is actually super light and fluffy... almost too light and fluffy. It flows aways with water and I'm also worried it won't be stiff enough to hold stuff vertical like corn and tall tomato / pepper plants.

Was it especially dry? Some soil components like peat are hard to get wet if they are especially dry. Once the moisture level is normal, it should behave. What is the compost made from?

Hmm... that's interesting. Maybe it was too dry to start with and therefore isn't allowing the water to "mix" with it? I guess in the future I'll need to pre-mix water in thoroughly before adding my plants?

I'm mostly going by the belief that lots of compost is good... I just hope I didn't overdo it.

 

[S0rcy]

When you lift and turn the soil, what happens is that you are tearing apart the pedons, or the way the soil is put together. This affects the way the soil holds water and drains. When it gets tilled, or churned too much it eventually loses most of its structure and it's pretty difficult to get it back. Adding sand will not fix the problem, but adding a generous amount of organic matter and then leaving it alone for awhile will help. The structure of a soil is what allows it to hold nutrients and allow water to flow from one place to another within the soil profile. The rocks and twigs in the compost help these structural elements come together, so getting rid of them ALL may not be a good idea.

Putting some compost on top after adding it to the soil is good and I suggest getting microwaterers to deliver water specifically to each plant until the soil has regained some of that necessary structure. It may take a season or two. Since you have already added compost, you're good to go If you get rain, then a few good rains will really help out the structure.

Adding sand does not help, it may just turn your soil into concrete.

 

[patandchickens]

If it was bone-dry, that may be it -- have you noticed what happens when you get a summer rainfall on a VERY VERY dry pile of dug-up fine dirt? For a while, the raindrops just splash off leaving sort of 'craters', and the water runs of in erosive streams but doesn't really wet things. Takes a little while to start properly wetting the soil; *then* the rain soaks in.

Also, it is possible your soil might benefit from being a bit 'chunkier' with larger organic fragments. They help prevent compaction (which weather can do even if feet don't) and provide routes for surface water to start sinking in. The only reason I'm aware of for screening compost is to produce a fine bed for seeding into... and even if you want that, you only need it in the thin shallow row where you're actually putting the seeds, nto the whole garden. There *are* advantages of having a bunch of bigger compost, uh, particles in the soil.

Finally, how much slope are we talking about here? It *can indeed* be hard to water a sloped bed, you have to either slowly water plants individually or use a drip system. This is especially true if your bed is really *flat* (for instance if you levelled the surface real smooth before trying to water).

Hope something in there was useful to you ,

Pat

 

[digitS']

Hi Nifty,

If the material has completed the early stages of decomposition, I'm not sure if it is really possible for 99.9% of us to have "too much compost." Sufficient minerals, usually found in soil, are needed but that's not likely to be a problem as long as there is some soil in the planting mix. Usually, we scratch in a couple inches - certainly, a 50-50 mix of soil & compost in the top 8" is way beyond the resources of most gardeners.

As others suggest, your problem is likely to simply be the time it will now require for the dry soil mix to absorb water. Dried material, soil or otherwise, doesn't usually become wet quickly. "(D)umping a bunch of water" and "a lot of water . . . poured into the bed" is probably going on too quickly. Look at the erosion of desert landscapes by water. In places where rain occurs very seldom, water erosion is often the most important factor in the topography.

Watering by hand often doesn't work very well because of the speed in which water is applied. Let's say you want to apply 1 inch of water to the soil in a 100 square foot bed - a good soaking. At the usual pressure of an outdoor faucet (see link), you will have finished the job in 12 minutes. So how much water did you put on the soil in 12 minutes of hand watering? Well, if I did my math right you've poured 62 gallons on those 100 square feet.

A rotary lawn sprinkler doesn't apply water anywhere near that quickly. It would take one 2 to 4 hours to put down 1 inch of water. We can measure application rate easily using a couple of tuna fish cans. The impulse sprinklers that I use in my garden are on the high end of the time required and with very porous soil, I still get puddling in the garden paths putting down that much water for a good soaking.

Here's NC State Cooperative Extension information on "Efficient Irrigation" that might be helpful to some folks.

Regarding slope - my father's front lawn has a nearly undetectable slope. The soil is quite porous but water will run across the surface after he's had a rotary sprinkler on for a half an hour or so - not really erosion but "run-off."

Steve

 

[wooden_pony]

have you noticed what happens when you get a summer rainfall on a VERY VERY dry pile of dug-up fine dirt?

Hey Rob,

Summer rain?? What is that?

Just teasing you Pat it is just funny because we do not get rain here in CA during the summer time.

 

[patandchickens]

OK, wooden_pony, you imagine what it would be like to have rain in the summertime, and I will imagine what it would be like to see leaves and, quite frankly, the ground in the middle of January, k?

LOL


Pat, with grass finally growing and 5 kinds of crocus blooming and scilla and daffodils in bud, hooray

 

[Nifty]

Great info and suggestions!

I'll leave the soil composition as is for now and see how it goes. Maybe I'll add more "chunky" soil next year.

As for water absorption: Maybe I'll use my drip irrigation system and/or the mist attachments to slowly soak the soil to get it to the point that it will accept water better.

I'll take pics and keep you all posted!