Contouring the Land

I attended your talk at Permaculture Voices II and was very impressed with what you are doing at Versaland. I am thinking about buying land next to mind that is hilly and would make a great place to plant fruit trees on terraces. ANy idea what is the best way to work with an elevation map of your property and design such a system?

Pavel Mikoloski

Pavel Mikoloski wrote:I attended your talk at Permaculture Voices II and was very impressed with what you are doing at Versaland. I am thinking about buying land next to mind that is hilly and would make a great place to plant fruit trees on terraces. ANy idea what is the best way to work with an elevation map of your property and design such a system?

Pavel Mikoloski

FIRST THING: read Darren Doherty's Regrarians Handbook specifically, Chapter 2 on Geography

Keyline(AU-tm) or keyline-ish(my preference) methodology for terracing is likely the way to go. The "Keyline" concept has a lot of verbage-based pedantry flinging about these days, but it is a very sound science for most applications.

My work with the "challenge of landscape" has specifically been using RTK GPS technology to speed the design and implementation of these systems using CAD modeling and GPS-guided equipment (bulldozers and tractors) - and LOWER COST. We go in-depth on that here: http://www.versaland.com/workshops/gps-keyline-design/

This is perfect! Using GPS along with keyline is brilliant. I'll definitely take this course when I buy the property.

Thanks, Grant

Pavel Mikoloski wrote:work with an elevation map of your property and design such a system?

Google Earth + Google Sketchup allows you to create contour lines quickly and easily (and free). They are not perfect, but a great place to start a design.

sketchup tutorial

If you prefer, there are also several youtube videos on how to do this.

Thanks Ed. Did not know this existed. It is very helpful for what I intend to do.

Ed Colmar wrote:

Pavel Mikoloski wrote:work with an elevation map of your property and design such a system?

Google Earth + Google Sketchup allows you to create contour lines quickly and easily (and free). They are not perfect, but a great place to start a design.

sketchup tutorial

If you prefer, there are also several youtube videos on how to do this.

the google maps hack for generating contour maps (e.g. 2 ft contours from a 20 ft contour map) is notoriously inaccurate, though a good visualization tool.

Grant,

Do you have a specific thought process you go through to decide whether to terrace, swale or do nothing? I am in central Missouri and have a very similar climate to you in Iowa and I am having a hard time deciding which approach to take.

Todd McDonald wrote:Grant,

Do you have a specific thought process you go through to decide whether to terrace, swale or do nothing? I am in central Missouri and have a very similar climate to you in Iowa and I am having a hard time deciding which approach to take.

There's a multitude of factors, so rather than say the overused phrase "it depends" - I'll throw a few visuals out there.

The main factor: What are you DOING with the land? What is it producing?

TERRACING

YES if annualized tillage e.g. annual vegetables. Keep slope under 2% in both directions in an annual vegetable bed. It is worth the energy expenditure to build a true terrace to keep soil onsite.

NO if perennial cover and no existing erosion issues



TWO WAYS TO INCREASE SOIL MOISTURE

1) Increase infiltration rate e.g. subsoil rip on contour to SINK water into soil profile fast.
2) Increase retention time e.g. build swales and berms on contour that will hold water on a site letting it soak in over hours or days instead of shunting off the surface and downslope.



SWALES

Do you see large swings in precipitation volume throughout the course of the year? Is drought an issue? Then YES.


Is the water table so high that root rot is an issue? Perhaps you need raised beds instead and drainage is a good thing.

Thank you for such a clear and concise answer.