S. Brown

Steve,
You can use Bentonite, especially if you've sandy soil. It mixes best with sand, rather than other clay or dirt.

A trick to keeping it clean looking is to mix in the clay with the sand, compacting it aggressively. Then simply lay out stone on the shelves, a nice layer of clean sand/feet friendly gravel in the bottom and make sure you have a bog filter area to handle the general filtering. Use the stone, sand, gravel in several inches to feet as part of the filtering and you won't end up with the cloudy mess.

It'll take a while for the bog/plant filter to get stabilized, but once it does you'll have clear, clean, no chemicals water.

You can also build up your sides with anchored, untreated lumber.

Eric Hanson wrote:Todd,

So from what you are saying, it sounds like it really comes down to N after all.  This is the reason I am trying my comfrey cover crop idea in the first place.  I am hoping to charge up the soil with nitrogen for eventual release.  Perhaps the comfrey will crowd out the clover, but by that point, the clover will have done its job and by dying it should give up a last batch of N for the comfrey to feed upon.  You say use urine.  I am totally OK with this and I have already give my comfrey plants a good helping of diluted urine and plan to continue.  This plus the clover in addition to any soil-borne nitrogen already in place will hopefully provide plenty of nitrogen for comfrey plants.

Eric

Eric,
Comfrey doesn't make a good "cover crop" for larger areas, but does for under trees and along paths. Your better off with a fast growing annual, such as Kodiak spinach, to start with, then progressively expand your other perennials. Just chop the spinach before it goes to seed and you'll have a great mulch starter.

With regards to the nitrogen issue, but a cheap bag of beans or peas and scatter them about, let them grow, then chop and drop them. Your Comfrey isn't a nitrogen fixer, but it doesn't strip it out like a lot of other plants. Most of it's resources are pulled from well below the depth of other plants. So, once the Comfrey takes hold and gets it's roots down deep, you'll find that chopping and dropping it will help with nitrogen depletion.

Another nitrogen fix is to run wood chips through a 1/4" screen, mix that 2 to 1 with aged manure and spread a few inches around your plants for a fast breakdown and release of nitrogen. Then just take the remaining wood chips and spread in thick layers to keep the process going.

You can also add a little chicken manure for a quick nitrogen fix.

Within a few months you'll have a few inches of beautiful, healthy, active soil.

Hope this helps.

Mike,
Bryant RedHawk is right about not removing anything until the saplings you want get a good start. Also, they'll help protect the other plants you're putting in, along with minimize potential erosion from their removal. Once the other trees have their start, erosion will be less of a concern.
Keep in mind that the older trees create the canopy layer of the forest. Be selective on what you remove and only when you absolutely must. Instead look at pruning to increase the light to a particular area.
By adding, rather than removing, you'll end up with a healthier, happier, more productive piece of happiness (property).
Hope this helps.

Mike,
I was stationed at Camp Stanley and up in the DMZ. Great country. Sad to see the conditions it's facing now.
Onto the farming...
Don't make your hugelkultur or swales in a straight line. Follow the natural curves of the landscape. Go around trees, up or down slope from them, and use the erosion zones to your advantage.
Look for natural ridges that you can use as the ramps, or at least start of the ramps.
You'll find that the natural look feel will make the extra walk well worth it. It'll also will increase the productivity of the entire property.
Side note: I woke to my cranberry hibiscus peeking out of the trays. 3 days from seed to sprout!
Hope this helps.

Mike,
I was stationed in S. Korea myself... 27+years ago. Great country.
With regards to your slope issue, using swales with slopped ramps to the next  level and feeding back into the tiers is the easiest answer.
Think of it as the curve of a race track. Each level is graded to the back edge, to keep as much water available as long as possible. A swale, possibly edged by a hugelkultur (which is what I've expanded into doing), with the ends sloping upwards at their edges.
By doing this the water will transfer from one level to the other, on the inner edge, without degrading, while still giving you a dry path all the way to the top.
You can also split the swales so you're not walking the entire length of each level. Putting in a piece of pipe under the ramped area will allow water to flow to each side without interfering with the viability of the entire system.
To maintain the grade and increase water retention, simply grade the back edge slope out with wood chips.
I've 4 tiers on my property with a rise of around 30 feet over 250 feet. This method has solved my issue, increased my water reserves greatly and made the trip with the gorilla cart from the bottom to the top of the property a lot less exhausting.
Hope it helps.

Eric,
An issue with integrating clover, or other secondary cover crops to the comfrey is the distinct potential of chocking out one or the other. Try integrating peas, beans and/or possibly a small legume tree to the mix. They'll grow taller and die out. Even if you've no interest in harvesting the byproducts, they'll increase the nitrogen upon their demise and will often self-seed.
Just rip off a few comfrey leaves to give access to the soil, drop in the seeds and before the comfrey can choke it out the beans will be well on their way.
Personally, I put comfrey throughout my food forest. This makes it easily accessible, without having to drag a bunch of it from one spot to the other. It's great under fruit trees, especially if you have a dog that likes to dig and play under them. It helps to increase the amount of individual comfrey plants and continually releases minerals with a natural chop & drop process.
I also randomly toss old beans and legume around to do what they will. Later, I might harvest some, or just chop and drop them.
On a side note, comfrey makes a great weed barrier & border to paths and around beds. Kneeling on it to work in an area only increases the productivity of the soil. Comfrey is hard to hurt in the long run, so crushing a few leaves isn't a negative.
Hope this helps.