Swale Wonkyness + Biomass Placement

I like wonky always with a "y", so forgive me.

I recently had 3 swales dug with a trackhoe. Two seem to be fine. The one in the middle has some issues. I'm seeing that one side has good drainage, but the other side isn't draining. If they were connected, I wouldn't notice. But previously we had some test patches dug for cultivation beds, and now they're smack in the middle of the swale (blame the bad designer, me!). It has path issues I'm also working on fixing.

The wonkyness in the middle with the two areas of cultivation are impeding the connectivity of the swale, and I'm working on getting them better connected. Obviously once I can sort this out, things should be swell.

The question is this: I'm working on getting tons of biomass delivered. Mainly grass, leaves, small branches. Where would be the best place to dump them first? On the well-draining side, or on the poor-draining side?

I can think of good arguments for both.

Could it make matters worse in either case?

Thanks,
William

I love your writing style! Scientifically speaking, if you want to increase infiltration - go for the poor drained side. If you want to increase water holding capacity, go for the well-drained side. After all, all problems with soil can be cured with organic matter - lol - but I bet you already knew that.

Thanks!

I think I'm going to start with water retention on the draining side. I've made the mistake before of putting biomass into non-draining ditches and then having to pull it all out again when it became a big soupy mess. Actually, the "drainyness" on the left side I think is responsible for the generally better ecological situation on that side, with more (and more diverse) plants taking root. On the non-draining side there seems to be just patches of grass. Actually all the places where it doesn't drain I'm getting lots of grass. Must be trying to put biomass into the soil.

Anyway, it all does see to even-out in time. Right now I'm just working on getting the bottoms of the swales as flattish as possible, so the water spread is even.

William

Yeah, you can also increase infiltration by planting a cover crop. Daikon radishes make nice holes and when they die earthworms love the carcasses. Only thing is radishes can be invasive in some areas.

Actually I've been thinking about this a lot lately. Maybe too much.

I'm wondering if on my soil it's best to add biomass in small increments. Like 2-4 inches at a time. At least in the first year. It seems that in the first year or so, the soil life just isn't developed enough to really deal with large doses of biomass, and so it just sits doing not much.

In the second year, it seems you can really start piling it on, because then the micro-herds are better developed and the pores are well-developed enough that water does actually drain. In the first year, at least on the last property I did this, zero infiltration with large amounts of biomass.

Another option could be to do patches of low-biological life biomass (grass, leaves) and patches of higher-life biological life (leaves+grass+compost+manure) that already has a higher potential for life going in, which may speed up the process in some places.

The idea of radishes isn't really applicable to my spot, because it is deep, well into the sub soil, and I doubt anything could gain a foothold root-wise. I've worked with daikons and they have mixed results even in the top 4 inches of the soil. Plus the area is going to be covered with a foot or more of biomass when this is all done, so not much going on plant-wise in this spot.

William

Yeah, true that - don't ask me how many times my little Garden of Eden pops into my head.

Three years is what they say for things to really digest on speed (find the balance in life). I guess it doesn't matter if you have tons of biomass sitting on top or not- as long as it's not a fire hazard etc, etc. Adding more life probably does help speed the process, but the balance of life will probably still be off. The higher nitrogen stuff (such as cow manure and cured compost) will help with your C:N ratio, which will help move things along and prevent plant yellowing. I've never heard of a deep soil that has had trouble with radishes. That confuses me. Are you talking really dry deep sandy soil?

@Amit

Sorry for that. What I mean by deep soil is "at the bottom of a swale". It's about 30 cm down and very little can grow on the compacted subsoil that was left after the track hoe left.

Thanks for the advice. That feels like the right approach.
William

The other question is "where?"

I'm thinking that starting with the draining side is best, but on the other hand I think that area is draining pretty well and so maybe I don't want water retention so much. But if I start little-by-little perhaps it won't be too water-logged for the first years.

This will also give me time to work up the calcium in the non-draining side to make it drain better without compost at first, and it will give me time to access the wonkyness in the areas of cultivation which may be preventing the flatness that would help even things out water-wise.

William

It depends a lot on why the non-draining side is non-draining though. If it's because the soil is shallow or because it overlies a shallow aquifer there may be nothing you can do about it. If it's just because the soil is seriously compacted then you might consider adding rock dust or greensand to lighten the heavy clay a bit, and then add some worm food on top to get it going. Normally I wouldn't recommend tilling, but if you've got compacted clay that isn't draining you might want to till in the rock dust and greensand first just to encourage it to drain. Worms can't swim or breathe underwater!

Here's my dilemma: where to put the biomass first? In the end they're both going to get biomass in order to even-out the drainage.

Good design suggests going to the side with the most trouble. So that means put it on the side that has too much water retention. The reason the water is retained in that specific area is that it has a much higher clay content than the other side. The history of the site suggests that someone scraped off about 1 or 2 meters of topsoil and put it further downhill. What was left was the underlying limestone-rich clay. The draining side still has its original topsoil, which might account for its better drainage and overall better 'look' to the wild areas on that side. You can tell that it's just a little more lush. On the non-draining side were only seeing clumping grass and bindweed, which are good indicators that things need to be biomassed and broken up.

Now, going to the side with the most trouble is okay with me. The only doubt I have is that I'll probably have to ease-in the biomass, since I've noticed that heaping on a ton of biomass in one day creates a problem whereby you just create a soggy heap of biomass for about 2 years, until things start to get active (as the above posts confirm). Raising the nitrogen is also a good suggestion, because it will promote soil life, which is what will eventually cause more drainage (and potentially faster).

Starting with the non-draining side is also a good idea because I won't be unnecessarily clogging the good drainage that is going on with the other side and I can ease-in the biomass there too, perhaps concentrating my nitrogen-efforts on the non-draining side.

And yes, most of the tilling I'm doing for a small corn crop I'm concentrating on that side, so that I can break up the soil and add biomass under the blades in the form of compost-leaves-straw. The resulting soil looked promising. It was about 25 square meters and I tilled in 20 wheelbarrows full of compost. Added a wheelbarrow full of calcium sulfate too.

William

I thought people responding might like to see the situation. Here is the swale with all it's wonkyness included.

I successfully connected them and hoping for a rain here to see how things turned out.

William