Making Swales/Mounds With A Tractor

[Smithson]

We have a narrow piece of land with a slight slope, it's been used to grow rice, so there is a fair bit of water in the wet season. The dikes for the rice are now gone and I think the land can be used for trees etc.

To improve drainage and prevent erosion, I'd like to create swales/mounds that follow the contour. The properties either side both have mounds that run down hill, which I feel will leads to erosion and washes down fertilizers etc. But the locals, including the tractor driver, all say mounds mounds running with the contour will be destroyed with the rains.

My plan is to make the swales with a slight fall to allow for slow run off. Every 7m or so, there will be holes to trap water and organic matter.

Normally when making swales, dumpy levels are used, however these aren't readily available here. I was thinking of using the 'clear hose' style level and using stakes as markers. This is about as far as the plan has got, so I'd be happy to hear suggestions, especially with making everything simple enough so others working with me can get it right.

Thanks in advance.

[ozzydom]

A single mouldboard chisel plough will do the job ,just run a furrow one way then on the return turn the next furrow onto the first . If there is grass cover on the area,leave about a metre between swales to help prevent erosion .

If you need a wider swale say for planting trees or shrubs then use a twin mouldboard plough.

We were always taught to turn the furrows up the slope when contour ploughing.

[WatersEdge]

I built level retention trenches,

starting with a small flow of water and a hoe,

digging a small ditch as the water filled it on contour level.

No need for a clear vinyl hose level, just run water in the open ditch.

It's very easy, if water runs out the low side at any point then it has to be moved uphill a bit.

When the entire length is full of calm water, it's perfect level.

When the path of the small ditch is established,

then a larger trench can be dug.

I initially built them .60m deep and wide.

These big trenches catch all the water that ever falls.

No water escapes, and therefore zero erosion.

Extreme circumstance =>

it held the runoff from a hurricane with no loss or damage.

I ran the daily waste flow from the hog barn into it,

distributing all the waste the full length of the trench.

I also had a steady supply of coconut husk,

which if used to fill a large trench,

would enable large amounts of water to percolate into the soil

while the land area of the trench still being useful to grow plants.

and a large amount of water remaining available to the plants.

Eventually I expanded to perfect level terrace,

which amounts to a shallow but very wide trench.

It is labor intensive, but once built never changes.

I then cut deep furrows on 1 meter centers,

which distributed the hog waste over the entire field area,

rather than on one trench line.

The idea is to retain all rainfall, and enable flow of dry season pumped water.

Even on tight clay soil, a surprisingly large volume of water will soak in,

if you just prevent it from running away.

Clay has a large holding capacity, it just requires time.

I noticed that the King's Project at Doi Muser built level retention trenches on some rather steep hillsides.

The idea is so effective that I'm surprised everyone doesn't do it.

It is not obvious as it may appear.

There was always a steep learning curve for the laborers,

whose minds were made up that ditches are to drain water away.

Holding water on high ground was most certainly a strange foreign concept.

If I turned my attention away, they would revert to their concept.

We dug some trenches more than once, more than twice, because they refused to understand.

[Smithson]

Thanks for the replies, the block is at the foothills of Khao Yai, so there is a lot of water in the rainy season - too much, so I would like a slight fall of about 1:100 so water could run off without eroding.

As WE said, it's a strange concept for locals. I also don't have any experience farming, so links to pics or other info that would help me get the tractor driver to understand what we want would be helpful.

[Gary A]

This is what land prepared for planting sugar cane looks like. It is done with an opposed two disc plow. I would think that would suit your needs. It can be done on any contour you want.

[Capex]

In another life I was a farmer in Australia and as Ozzdom says, we used a disc plow to make the contour bank on a line that had been laid out using the simple plastic hose (ladarp nam) and wooden pegs to mark the contour with about a 1" drop every 30 feet (25mm every 10 metres.). The distance between contours was determined by the degree of the slope i.e. the steeper the slope the closer the contours. The contour was made by throwing the earth up the slope in 3-4 passes and another final pass down the slope from above the berm previously formed. This ensured that there was a clean flat area above the berm where the water could gather and slowly make its way towards the end of the contour without scouring.

Hope this may help. Happy New Year.

[ozzydom]

In another life I was a farmer in Australia and as Ozzdom says, we used a disc plow to make the contour bank on a line that had been laid out using the simple plastic hose (ladarp nam) and wooden pegs to mark the contour with about a 1" drop every 30 feet (25mm every 10 metres.). The distance between contours was determined by the degree of the slope i.e. the steeper the slope the closer the contours. The contour was made by throwing the earth up the slope in 3-4 passes and another final pass down the slope from above the berm previously formed. This ensured that there was a clean flat area above the berm where the water could gather and slowly make its way towards the end of the contour without scouring.

Hope this may help. Happy New Year.

In my boyhood we only had Clydesdales and the handiest implement on our steep little farm was a "hillside plough" which was a single mouldboard that swung through 180 degrees so you could run back down the same furrow and turn it the same way.