Tiled fields

[Fetch33]

I looked at a homestead property that has a 20 acre tiled hayfield. What affect does tiling have on trying to develop land with permaculture methods?

[Nicodemus]

Tilling breaks up and often kills off the natural layers of life within the soil such as fungal nets.

If you discontinue the practice, the layers will eventually establish themselves once more depending on other practices that were used on the land such as the spraying of pesticides or weed control chemicals.

[Fetch33]

So by discontinuing the practice you mean dig up the drains?

[Jack Crabb]

Unless it is a typo, you may be talking about two different things.

I believe tiling, with one 'L,' is installing drainage pipes in the ground to move the water out.

Tilling, with two 'L's,' is turning over the soil by any of several methods. The usual share plow can create a hard pan about 12 inches below the surface so your field ends up with some loose soil on top but the hard pan prevents deep roots and water absorption.

There are no-till crops and planting that save planting time/cost and reduce the soil compaction/hard pan concerns.

There is also the chisel plow that has prongs that penetrate into the soil to break it up, but does not turn the soil or create the hard pan as a share plow does.

If the property Fetch33 is looking at is tiled, it is probably because the someone found the field too wet. If you dig up the drains, you might restore the land to its former swampy existence. What you lose in alfalfa production you get back in cattail yield.

[Nicodemus]

I completely misread that. I did indeed think the OP was talking about tilling. Sorry.

If the land is tiled, it has been done so for drainage. I don't think it's necessarily against permaculture principles to change the landscape into something other than it was initially. That is as long as it doesn't destroy the only area habitat for plants and animals and in turn provides for others with as little external input as possible.

Having said that, holding and using water in the landscape is an important permaculture principle.

Really it depends on what you're intentions are with the land and what is currently happening due to the tiling.

Is too much water drained off of the land so that an alternate means of irrigation is necessary?
Are the drains taking away important nutrients away from the land?

[Cedar]

Unless it is a typo, you may be talking about two different things.
I believe tiling, with one 'L,' is installing drainage pipes in the ground to move the water out.
Tilling, with two 'L's,' is turning over the soil by any of several methods.
[/quote

This....

Cedar

[cheryl1]

Tiling is done to prevent standing water after heavy rains. The tile doesn't come into play until all the soil above it is fully saturated.

[RationalHusker]

I looked at a homestead property that has a 20 acre tiled hayfield. What affect does tiling have on trying to develop land with permaculture methods?

I'm an agricultural engineer and am currently doing some research simulating the effect that subsurface tile drainage has on the loss/transport of water (and nutrients).  You're property is likely in the Upper Midwest, and was tiled to allow row crop production (i.e., corn and soybeans).  Somewhat counter-intuitively, most of the water "exported" from the soil by tile drains actually enters the tiles from below due to a rising groundwater table.  Yes, the tiles intercept some water as it infiltrates the soil column, but the vast majority of the water flowing through tiles (on an annual basis) is from groundwater fluctuations.  If the property you're looking at has significant pothole depressions with surface intakes, then this would add to the amount of water that enters tiles from above. 

The ramifications of having tiles on your land could be both positive and negative, depending on your desired uses of the land.  Also, tile drainage systems have several components, and if I were you, I'd want to know more about the system.   Here are some questions you should obtain answers to:

1.  Are there any pothole depressions in the landscape (i.e., very shallow pond/wetland/marsh areas) that are usually dry, but can hold water seasonally or for short periods during wet weather periods?  If present, do they have surface intakes?

2.  Are there any drainage district tile mains that run through this property.  Tile "mains" are somewhat publicly owned and were installed by drainage districts to convey water from sevearal adjacent tile "laterals."  Tile "mains" eventually enter a drainage ditch, stream, or river.  This is important, because if you wanted to, you could fairly cheaply "plug" your drainage system if you know the location where your laterals enter the "main."  You could just excavate at the downstream end of the tile and block your lateral from entering the main.  However, it would be unlawful to alter or impact the function of the tile main in any way, because you'd be affecting other peoples' drainage.

3.  Personally, I would not shy away from land with tile drainage, especially if I could obtain more information about the system.  If you have potholes, you could do some pretty interesting things with them related to unconventional crops, water "recycling", etc., etc.  They are also great habitat if the hydrology is restored (i.e., block or slow the drainage).  You could even "manage" the drainage by building a control structure that allows you to manage the water table levels.

Maybe the biggest thing to think about is that tile drainage indicates intensive agriculture has occured on this land.  The soil has been worked hard, and tile drains are a known pathway for nutrient loss.  But lots of new tiles have been put in recently, so it's also possible (but unlikely) that this land hasn't been farmed that long.  But if this property meets your needs otherwise, I think you can work with this.  No, it's not a great and sustainable practice in the big picture, but if you learn more about the system you could actually (potentially) make it work for good.

I'd be happy to answer more questions about this.  I'll follow this thread, or you can PM me.  If you happen to be in Iowa, I could probably help you track down some more info.

--RH

[RationalHusker]

Here is a photo of tile drain installation that occured this fall, taken by one of my colleagues:


Here is a very small pothole/depression with a surface intake  This isn't a true depression, most are natural and larger.  This is actually just a puddle:


Here is a view of several potholes after a rainfall event, courtesy of USDA-NRCS.  A modern farmer would look at this picture and say it needs more/larger tile drains:


Here is a diagram I developed that illustrates how water and nutrients move through tile-drained land.  You're looking at a cross-section of the soil profile (imagine somebody cut the earth straight down from the ground like a piece of cake.  You're looking at the side of the piece of cake...the frosting is the soil surface.  This diagram is an over-simplification, as it neglects some of the interactions between pathways.  For example, groundwater can enter the tile drains as groundwater levels rise.  It then becomes tile flow.  That is not shown here. 

Now you know more than you ever cared to about tile drainage.  But I actually enjoy talking about this with somebody that may use this info in an unconventional, permaculture way.  Hope this was helpful.

--RH