Gradual Terracing

It is a standard belief that the great terraces of the world (Indonesia, Phillipines, etc) were all built from scratch using very labor intensive methods - the walls were built to full height, soil was moved or hauled in using baskets and back-breaking effort, etc.   But how true is that belief?  What if there was a low-labor way of building terraces?

I've noticed that grazing animals tend to walk back and forth on the contour lines, and large animals like cows can leave noticeable flat areas.  I also believe that instead of building large walls and doing lots of work, one could build a very small wall and let gravity/erosion gradually move the soil.  These walls might only grow by a few inches each year, as part of a process of moving the rocks out of fields.  Or it could a 3 inch bundle of sticks or bamboo laid along the contour and staked into the ground.  With just a little work each year, the soil can be held in place, and terraces will form themselves - rather slowly if the slope is under permanent vegetation, but much faster if the hillside is cultivated and the soil is broken up and exposed to wind and water.

Is there anything in the permaculture literature about this?

I have no answers as I know little of permaculture but if I were to terrace my place it would be a little at a time as you suggest.  All my projects are little grow as we go if possable.

Absolutely, yes.

The Permaculture Designer's Manual has a series of illustrations showing each of the processes you've outlined, plus another showing vetiver grass.  One of the forum topics has a link to a .pdf of this book.

Vetiver grass (I had to look it up...) is long-lived and doesn't spread, to the point it's sometimes used to mark property lines.  But it's tremendously deep-rooted, and good at catching passing silt.

when i terraced my garden, it was not the hardest work, it was just a lot of work. you just start at the bottom and work your way up. i imagine if there was a few dozen or hundred people all doing something it would go by much faster than one would think.

well i didn't do terracing per se but did do raised beds..and originally before our fire we had dozens of double dug beds for our french intensive gardens..a lot of very difficult work

after our fire..when we lost those beds to the construction of the new homes..i decided to do it an easier way here..by choosing to pile up material where i wanted the beds..rather than digging..so i sheet mulched a lot of organics on top of the soil and planted in the midst of them.

i honestly think the latter beds are better than the former..

kinda hard to tell though as they are fairly new yet..but they seem to be better quality soils now then the old beds

A few years ago, Joel Salatin wrote about the value of putting in permanent fences along countour lines.    It helps to build a sort of poor man's swale.

paul wheaton wrote:
A few years ago, Joel Salatin wrote about the value of putting in permanent fences along countour lines.    It helps to build a sort of poor man's swale.

I noticed that with a chain link fence we put at the bottom of a hill - it only took a few years to build an inch of debris and soil.

edges, yes, permaculture teaching was the first place i heard about edges..every place you add an edge gives you an opportunity to build on it.

i try to create edges wherever possible

      I have a path running form top right to bottom left of the slope and it was very thin, and every so often i have dug a out a bit more of the slope to widen the path and it was not too hard, less hard than digging a hole that means you have to pull up the earth. i usually dig with a mattock which is much easier for some things.
      If i lived there and was doing a bit every day it would not be too hard. The hardest bit might be to get going and mark out the contour. i hate doing things i don't know how to do.  Digging is quite nice it is a bit of exercise and in these age of knowing more about whats good for your health it is great to do a bit of exercise, it makes you feel happier about your health. In madrid I can only think, "lor, i don't do hardly anything for my poor body except fattening it, sadly. agri rose macaskie.

I also believe that instead of building large walls and doing lots of work, one could build a very small wall and let gravity/erosion gradually move the soil.  These walls might only grow by a few inches each year, as part of a process of moving the rocks out of fields. 

I'm thinking of terracing a SE facing slope, and I could see how this might work....the disadvantage is that the terraces wouldn't be very useful until they are flat and wide enough.
Also the soil has to come from somewhere - either infill brought in, or from up hill (which could undermine terrace walls above).

Nancy Reading wrote:...Also the soil has to come from somewhere - either infill brought in, or from up hill (which could undermine terrace walls above).

My concern exactly. The only way I can see it working well, would be very slowly: build the lowest retaining wall, fill it partially or more with woody debris coupled with dirt from above on the slope, let it settle for several years, then start the next level up, making sure that the next level is on solid ground that will support it long term.I  have heard that dry stack rock walls need to start several feet below the original ground level, particularly in places with freezing temperatures or heavy rains. Sepp Holzer was careful about slopes so that mud slides wouldn't result.

I have an area where I want to do this. At the base of the slope, there's a bit of a depression that I'd like deeper so that it will hold the winter rains longer, but digging that dirt out and moving it up the slope behind big rocks would be a huge job, so I'm not sure it will ever happen without heavy machinery.

I think our long dead ancestors were much tougher than us modern folks who spent much of their early childhood sitting behind a school desk instead of outdoors working hard!

Really worth digging (lol) into the central Mexican traditional "lama bordo" incremental terracing system, which is raised in the latter half of this relevant thread here (& might be where I first encountered the idea as well!):

https://permies.com/t/119683/small-rocks-bad-building-steep

Jordan Lowery used chickens to gradually terrace his slope (accidentally!) from: https://permies.com/t/4726/Terraced-Gardens-Hillside#41061

Jordan Lowery wrote:the chickens will scratch downhill as they ALWAYS do. over time of adding material they will fill up the terraces with there scratched scraps, weeds and waste, a little bit of soil and of course there manure. let sit for a month or two or over winter. come spring you have leveled terraces, rich in organic matter, full of nutrients.

I think the key is probably not to set the terraces too close together (or do one at a time) and make sure the terraces are porous so that they don't act as a dam and hold back too much water as well as soil.

Seems to me that straw bales and wood chips might be the solution here.

Fall leaves added to that equations, too.

After all that maybe mushrooms ...

Flipping this round... why do gradual?

Most of the major permaculture designers would be advocating for earth moving in the early stages of a project as part of improving water retention in the landscape, building fertility, and creating microclimates. Terracing, building swales and ponds are all excellent investments in the land.

How much could you get done if you hired a skilled bulldozer driver and machine for a day? I think it would be a lot.

Michael Cox wrote:Flipping this round... why do gradual?

Several reasons i can think of:
resources: time, money, skills
access : mountainous/sloped areas not always accessible by machinery
personal ethics: use of fossil fuel

I think it's good to have a choice.

My way of terracing is sort of like swaling but the reverse. I dig the trench downhill and deposit the soil a bit uphill, and throw the rocks on the steep side. If they slide around then that is what they do, I just rearrange them when needed, and hopefully some “weeds” (medicinal flowering perennials and compost crops) come in and stabilize things over time. I read that in Nepal they regularly scrape the bottoms of the terraces and take the sod upslope as fertilizer which keeps them from sliding and eroding, maintains their shape. I do the same thing—tidy up terraces every fall.

I also do a trench-composting sort of thing upslope. Imagine the upper swale that forms when the soil is deposited upward of the trench (between original grade and deposited soil). I fill that with compost materials, then dig a pit a little upslope and cover those compost materials with soil. Then I gradually fill the pit with yet more organic matter.

On our farm we just fell trees that are fairly straight and dont have a ton of clbranches(and cut off any that obstruct movrnent) and just lay them along the hillsides to create slow terraces. The grade was anywhere from 15 to 60 degrees and we saw soil accumulation in every one after one year. It helps to also lay in grass or small sticks to prevent erosion under the log.

To elaborate, we would leave at leave a vehicles width between each terrace except on steep slopes where we knew we wouldn't drive. Always enough space for a walking path. And leaving staggered spaces open to drive at an angle along the hill.

This is the ideal situation for me in western NY but I'm not sure if i'm going to be able to do it this spring. Here it's sixty five degrees and unseasonably warm. -Marta

How steep does a slope have to be to realize benefits of terracing? If my field drops six feet of elevation over 100 linear feet, does that merit intervention for any reason? It seems fine undisturbed, but I could be missing something. I've even been trying to decide if I should create a flat terrace for a high tunnel or just let be slightly sloped.

Christopher Weeks wrote:How steep does a slope have to be to realize benefits of terracing?

I think that unless you are creating terraces for water retention, and you don't have an erosion problem why bother? On a slight slope you can work on it either on foot or machines without a stability issue. Terraces have the problem of retaining walls which you can trip over and may need maintenance. There is enough work to do generally without creating more!

rose macaskie wrote:      I have a path running form top right to bottom left of the slope and it was very thin, and every so often i have dug a out a bit more of the slope to widen the path and it was not too hard, less hard than digging a hole that means you have to pull up the earth. i usually dig with a mattock which is much easier for some things.
      If i lived there and was doing a bit every day it would not be too hard. The hardest bit might be to get going and mark out the contour. i hate doing things i don't know how to do.  Digging is quite nice it is a bit of exercise and in these age of knowing more about whats good for your health it is great to do a bit of exercise, it makes you feel happier about your health. In madrid I can only think, "lor, i don't do hardly anything for my poor body except fattening it, sadly. agri rose macaskie.

I see that you are not digging, but what do you put on top of your mound of logs?

Christopher Weeks wrote:How steep does a slope have to be to realize benefits of terracing? If my field drops six feet of elevation over 100 linear feet, does that merit intervention for any reason? It seems fine undisturbed, but I could be missing something. I've even been trying to decide if I should create a flat terrace for a high tunnel or just let be slightly sloped.

If it's shallow just do swales.  The terrace occupies less space on a steep slope. I wish I could do swales instead of building check terraces, it would be a lot easier

ross. mckay wrote:If it's shallow just do swales.

That is a great suggestion for sinking and slowing the water - welcome to permies ross!

Would you start at the top or the bottom ?

Carol Sloanes wrote:Would you start at the top or the bottom ?

I suspect that would be incredibly location specific.

When I was trying to keep heavy rain from damaging our sloped, gravel farm road, it was important to start at the top where the rainwater hadn't yet picked up speed. Then it took only a little effort to redirect that high-up water off the road into an infiltration area.

Then the next section of road, also only needed a little work because I wasn't dealing with rain hitting as many feet of roadway.

However, slope, average rain vs heavy rain events, soil type and the specific purpose one is terracing, would all be factors I'd be thinking about when I made my decision.

Nancy Reading wrote:

ross. mckay wrote:If it's shallow just do swales.

That is a great suggestion for sinking and slowing the water - welcome to permies ross!

Thank you Nancy. Looking forward to being part of the community instead of just an observer