Dan Sheng

Myron Platte wrote:The three sisters garden has been used as an early succession soil building plan on the way to a food forest. Annuals slowly give way to bushes, then understory trees, then canopy trees.

I will look into the Three Sisters Gardening as part of the plan, thank you, Myron :)

Thank you, Eliot for your advice.

From what I could see on New Zealand soil map (https://soils-maps.landcareresearch.co.nz) that the soil on the property is likely to be Perch-Gley Pallic, which is said to be "susceptible to erosion because of high potential for slaking and dispersion".

Since the arrival of European settlers 200 years ago, much of New Zealand native forest has been cleared for conventional farmland and I am guessing that this property has also endured similar fate. Not sure if the most recent large-scale effect on the land had been for pine forestry or not. However, gorse is one of the most efficient first-colonizers of open land, thanks to the British for bringing them in for hedge planting.

I would say that the deep-rooted nitrogen-fixing gorse which feature significantly on the slopes are the current ones holding the ground.

If I were to create terraces, they would be between strips of gorse to be left standing, also as nursery shelter strips. My plan is still to re-generate native forest and incorporate it with an edible forest as well. I am not sure how it will turn out but am open to ideas.

It is very tempting to dive right into it upon arrival, eager to get on the excavator to shape the land but I know it is good to observe for a while, like you suggest. I will definitely do smaller-scale trenching and see how it goes.

I would still like to hear more inputs about terracing on such a gradient from others, thanks.

Given that my hill slope gets over 70% steep at places, I am considering terracing.

Any suggestions for how to get going? Anyone has experience working with excavators on slopes 70% or more for terracing? I tried looking at earthworks for terracing but haven't found many that I could use to understand better. I am totally new to this.

Would a 5-tonne excavator do?

Any input would be appreciated.

Cheers.

Nick Kitchener wrote:Personally I would not be using swales at all. I would be creating terraces for growing annuals and for access, and growing trees between the terraces to hold the hillside in place.

Sepp Holzer also puts in a series of drainage pipes and cisterns along the base of each terrace cut, and connects them with a pipe which he runs to the bottom of the hill which can be tapped for pressurized irrigation water.

I am also concerned as the soil type on my property is known to be Perch-gley Pallic. which is of weak structure and may not hold too well when saturated with water.

Where can I find out more info on terrace building and specifics in dimensions pertaining to slope and soil attributes?

Hello all, my first post on this forum.

I am glad that someone is talking about steep slopes. Have been researching on swales but have not yet seen convincing results from working on very steep slopes.

I have just acquired 18 hectares (45 acres) of land with 35 acres on slopes between 20% and 70% above the house. Much of those 35 acres is covered in gorse and I intend to mulch strips in between the gorse (allowing the rest to continue to hold ground and act as nursing shelter) to create some form of swales and/or terraces to retain water and to plant native trees and incorporating an edible forest.

Elevation from the house to the top of the boundary is about 395m (1304 ft) and 660m (2178 ft). Beyond my property boundary, the elevation goes up to the hill top at 835m (2755 ft).


[See attached photo of the slope behind the house]

Location: Oxford, New Zealand (South Island, temperate climate)

Rainfall: around 800mm average annually

Main fresh water source: stream and creek on land.

Sunlight: north-facing all-day sun (Southern Hemisphere)

Has anyone any experience in working on such steep slopes? I intend to get a mini excavator (maybe 5-tonne) to get it going. I'm trying to get as much experienced advice as I can before starting the project, if it is feasible in anyway at all.

Any help in any direction would be appreciated. Thanks.