How to keep soil on hills?

Is it possible to keep a goodly amount of soil on hills, for pasture? Most of them aren't too steep, about 20-30 degree angle, some 40, 50, and 60 degree angles. One is too steep to actually walk down. Pretty much crapland. Is it possible to keep a good amount of productive soil on hills?
~Ted

Maybe hedges just off contour (with a swale infiltrating and creeping runoff water back to ridges) with pasture between and light stocking for the lighter slopes.  Distance between hedges maybe driven by soil, with closer spacing on poorly infiltrating soils.

Forest on the rest!

Raindrop impact is a little appreciated factor. People can see gulches and gullies, and these sometimes are a problem. But a slow, invisible movement is usually a bigger factor.  When a raindrop hits bare soil, soil particles fly out equally in all directions. But they travel farther downhill. The net effect is that after a storm, soil has moved downhill.  Shaving off a layer of soil that is about as thin as a dime is invisible, but if that happens several times a year, one is losing much precious soil over time. The answer to this is to protect the surface of the soil with vegetation and mulch.

Another mechanisms is mass movement - from a very visible landslide or mudslide to a slow creep. Again, vegetation is protective. In this case, the roots of grasses and trees and other plants can knit the soil in place. A very steep slope in a humid area is prone to this and land cover is not a 100% cure, but it can often be prevented or reduced.

Good permaculture practices work to reduce erosion on all fronts. Don't till, bring in perennials, include trees and other deep rooted plants. Break up the force of the raindrop impact with live plants, cover the surface of the soil with pieces of organic matter that are much larger than soil particles.

Keep heavy animals away from the steepest slopes -  the very steep areas need more protection from disturbance of the soil, compaction, and grazing.

I don't know about for pasture, but I was just watching some of Sepp Holzer's videos on the use of hillside terracing. They may have an answer for you. Here are some video links to the videos I was watching:
http://www.youtube.com/watch?v=mzRzJRiUylg
http://www.youtube.com/watch?v=EjNGhEzmNdk&feature=related
http://www.youtube.com/watch?v=ADN8bSXSYv8&feature=related

I can't seem to find the fourth video in the series.  When I was watching the first video, I was thinking that this wasn't for me as much of my property is hillside (steep), however as the videos went on.. well it's exactly what I'm needing except that I have to maintain my "forest trees" due to my tax classification.

Anyway, this may be of help to you....

maybe look at vetiver or lemon grass for terracing on contour. have read they work. depending on climate, different trees and bushes should hold well. read someplace that vetiver was used on some islands that had erosion problems. They planted it on contour and continued to farm. Held the soil in place. decades later, the hillsides were terraced and people were starting to take out some of the vetiver because they said they did not have erosion problems. a direct result of them not knowing why they did not have erosion problems.

you can lay rocks, woody debris or other materials in crescent shape "berms" down the hill in contours..one after the other..leave areas of paths between for the grazing animals..you can also take cuttings from trees and shrubs and stick them along these crescents that will give you some growing shrubs or trees that make it easier to hang onto , and these will feed off of the grabbed water and nutrients that the berms hold onto..

pick plants that will withstand grazing by the animals that you keep, or plants that the animals would choose not to graze..or put wire fencing around the plants to keep them from being grazed as they are growing.

these berms will also add a lot of fertility to your soil..if you have very little material you can start out with groups of stones and brushpiles in the main erosion areas and work out from there

HeritageFarm wrote:
Is it possible to keep a goodly amount of soil on hills, for pasture? Most of them aren't too steep, about 20-30 degree angle, some 40, 50, and 60 degree angles. One is too steep to actually walk down. Pretty much crapland. Is it possible to keep a good amount of productive soil on hills?
~Ted

There's no such thing as crapland, just soil waiting to awaken to its potential.

For very steep hillsides, you may need to think about terracing or leaving them relatively untouched since they are at the greatest risk for erosion. Personally I would keep the steepest slopes in native plant cover, and this would mean excluding or limiting livestock. Thick plant or tree cover is important, especially things with deep roots.

When I drive to work going down the hill I live on, I see the effects of grass, brush, and tree clearance that local homeowners and landscapers are doing for businesses on the hill slope or inset into the hill. Every day I watch as sheets of rock and soil tumble and settle and mud slinks down during rain showers. It's bad enough that some businesses at the foot of the hill have been nearly covered in rock/mudslides but yet they keep doing what they do. They prefer bare dirt and keep clearing out all the plants and hope tires and concrete will hold up the hill. Boggles the mind.

Here's some info you may find interesting from one of my old Agronomy textbooks:

the Universal Soil Loss equation

A=RKLSCP

Where A, the predicted soil loss, is the product of:
R=rainfall erosivity
K=soil erodibility
L=slope length
S=slope gradient or steepness
C=cover and management
P=erosion control practices

(they all have corresponding values, which gives you the tons lost/acre)

Without knowing your exact situation, It's difficult to equate exactly how much soil loss can be expected. However, there are certain practices that can limit loss in any situation.

As long as you have the soil covered (cover crop or otherwise), erosion should be controllable. Certain problem areas may become evident, but can be managed with some creativity. The biggest advice I can offer (without seeing pictures) is to not let any erosion problems get away from you.

"an ounce of prevention is worth a pound of cure"

The most important factors (as listed in the equation above) are: soil erosivity (depending on what type of soil you have: alfisols are different from ultisols, from oxisols, etc.), slope length, slope gradient, cover and management, and erosion control practices. As long as you don't have bare soil, rain fall erosivity shouldn't be too bad.  However, if you do have bare soil, you MUST work to remedy that situation.

The effect of barriers is to slow water movement, allowing soil particles to settle out and helping to reduce the effect of "gully-ing" caused by rapid water movement.

Terraces are great, but labor intensive. Buffer strips, grassed waterways (depending on how they are constructed), and plenty of filtering plant life may be your best solution; but it's difficult to say without seeing your situation.

Depending on where you are located, the county soil and water conservation district may be of a huge help. They can tailor plans to your exact needs, and often are able to provide you with federal cost-sharing programs (we paid nothing but labor for extensive dry dam work on our farm). It may not seem like that big of a deal, but soil conservation work can be quite expensive.

Terracing worked for the Incas, it will still work today.

We have steep hills. I make terraces, stone walls, fence lines and tree plantings that follow the contours. This catches the soil. In time I have ended up with lots of terracing. This then also catches the water and slows its rush down the mountains so it soaks into the soil. Studying the land I can see that the past farmers have been doing this for 200 years on our land too. On purpose or not.

Cheers

-Walter
Sugar Mountain Farm
Pastured Pigs, Sheep & Kids
in the mountains of Vermont
Read about our on-farm butcher shop project:
http://SugarMtnFarm.com/butchershop
http://SugarMtnFarm.com/csa

Paul and Kelda continue reviewing (part 4) chapter 1 of Sepp Holzer's Permaculture (the book) in this podcast: http://www.richsoil.com/permaculture/451-podcast-083-sepp-holzer-permaculture-chapter-1-part-4/

They talk about swales and keeping soil on hills.

Plant some good over-wintering grains/grass... I love some winter rye.. Great late-sown cover... I've planted rye on many hills and it's extensive root system really saved the day...Cut it down for great green manure to boot.