Troubleshooting Keyline Swale approach

Hey all.

I was just wondering if there was a reason anyone could tell me why we don't use trenchers to dig trench swales on-contour, and then fill with woodchips, or slash, and biochar, with the fill piled downslope. It seems to me to be a great way to combine principles of hugelkultur, keylining, and swales, to provide water harvesting soil sponge filter strips that act as soil biome nurseries and fungal highways through largely bacterial or even largely inhospitable soil.

-CK

I was just considering this for prairie restoration using the BCS and a Caravaggi Mini-Trencher.  It seems like it could also be a good tool for no till farming.  I wonder if compacts/seals the soil as it runs.  I just asked a question on Earthtool's YouTube Page for thr trencher: https://youtu.be/jD7HBK4_KxY

Chris Kott wrote:Hey all.

I was just wondering if there was a reason anyone could tell me why we don't use trenchers to dig trench swales on-contour, and then fill with woodchips, or slash, and biochar, with the fill piled downslope. It seems to me to be a great way to combine principles of hugelkultur, keylining, and swales, to provide water harvesting soil sponge filter strips that act as soil biome nurseries and fungal highways through largely bacterial or even largely inhospitable soil.

-CK

Yeah, this seems doable and I've thought of variations of this same thing.....for a desert/arid setting.

I had rather thought it would fit well anywhere you don't have to use chinampas to grow.

I would be very careful of specific geology and soil types, as I am aware that cutting a trench of any depth in some cases might have immediate destabilizing consequences. Even just increasing water retention capacity in some soils and situations runs the risk of consequences as severe as landslides or mudslides. Hydrology is a tricky, fickle thing.

I developed the idea digging one manually for a hugelbeet. I excavated my trench, piled up a couple of dismembered invasive trees, manures, and my compost heaps, and piled the subsoil up, backfilled with wood chips, and put the topsoil atop the pile, planted as a veggie patch.

What impressed me about this whole thing that I hadn't expected was the wood chip path. It was three feet deep, and it drank all the rain the spring and summer could throw, where before there was ankle-deep mud.

In late july through September, that half of my garden was the greenest patch of land not directly under a leaky tap or regular sprinkler. I never had to water.

I think that, rather than being arid climate specialised, that this technique has benefits in a range of circumstances.

-CK