What are you using to support the beds? What kind of soil are you working with? How high will the beds be?

Can you post a photo? (Hi Maro)

the soil is frighteningly pure clay. therefore raised beds.

we are going to copy something from the book Tropical Bamboo by Villegas where the support comes from bamboo runners & risers. do these beds need to follow the contour lines or can they simply go across the slope dictated by eye?? we have at times intense steady rainfall.

these beds are for general veggie production, so soil height ontop of the clay I am thinking of keeping @18 -24 inches.

with a few of the beds I am going to turn the clay & add humus from local horse & chicken farms along with compost just to get started. the rest I would like to try green cover cropping & then mulching & then planting into the mulch which reads like it is better for tropical soils.

still on dial up here, have yet to find boadband which reaches so a photo is out as of yet....

Do a search for "terrace gardening + rice". You should find some helpful ideas/pictures there. Also, I called our son who was an agricutural consultant around the Pacific Rim for a number of years. He said that terraced gardens follow the land contours.

rubrifolia,

When I read your posts, a vision comes to mind of a blind man walking toward a cliff. If things are as you say, you are headed to disaster.

Steep is a term that can be many things to different people. I would suggest you quantify the slope by the following method.

Measure a 40 ft length of string and attach it to the top of a 10 ft pole. Stand the pole at the bottom of the project area as shown in the graphic below. Use a string or spirit level to determine if the string is downhill to the pole as in the top half of the graphic, or uphill as shown in the bottom.

Do not consider doing this project on any of the area like the top half of the graphic.

{{gwi:51632}}

In my opinion, using bamboo in a multi-tiered system for a steep slope would be a mistake.

And the planned amendment is wrong for a pure clay.

The first thing to know about terraces is that they are best avoided whenever possible. If the area involved is not so small and steep that interrupting it with walls is demanded then better to work with the natural contour. Otherwise it should simply be a matter of using walls that will remain intact, and filling behind them with soil that seems to have desired properties - if obtainable locally. Digging organic amendments or sand into existing soil results in an amended version of existing soil, rather than a completely different soil. Organic amendments will decompose over time and return the soil to its original condition, unless periodically replaced - possible with frequently rotated, short-term plantings like vegetables but not with long-term plantings. Incorporation of sand can affect a permanent change in soil texture but may require clumsily huge amounts to achieve this unless there is a fairly high sand percentage present in the soil to be treated already. And some soils may tend to assume a concrete-like consistency when sand is incorporated, actually making them harder to use rather than more mellow.