Drainage question

[Walterp]

Typical that on our upland farm the field with the deepest soil (about 18", which won't sound much to arable farmers, but is about triple the average LFA place) is also in the wettest spot - and the ditches the old guys dug out by hand are now choked with native willow.

We can cure that bit - my son is happy sitting down all day, even if he's doing it on a 360 digger. Trouble is, we can see that the soil, a silty clay loam, sits on a bed of solid yellow clay that used to be dug out to make bricks for Templeton brickworks. Water just sits on the bed, going nowhere fast. Nice flat field, nowhere much for the water to flow; no wonder it's soaking in Winter.

So, any use breaking up that clay once it dries out? If so, what with?

If not, is the only solution an order for some 100mm drainage pipe?

 

[Thick Farmer]

Mole plough or grassland sub soiler might help.

 

[multi power]

is it just not draining away or are there springs rising?

 

[Old Boar]

It is probably more clay under the yellow clay so not much point in breaking it. Mine is the same, but if you can get a gentle decline along the length the clay acts as a pipe, especially if polished with the back of the bucket. The trick is getting the water into the ditch, as no matter how deep the ditch, water will sit within inches of it. Mole plough to the ditch. I also have a lot of springs, and mark them when the ground is hard frozen as you can then see where they are coming up. They move a bit every year, but it gives you an idea of where to mole.

 

[DGC1]

mm... Im sure that you will get many opinions on this post.
- what size is it?
- what do you want to do with it? Cutting, cattle or sheep?

I would avoid subsoiler/mole.. It could make it worse.
Is ph ok? Calcium lime to keep soil structure open and active would be a good starting point- even if it gets ploughed it cant do any harm
Always put 20mm clean gravel layer on pipe if draining

I wonder if drains say every 15m (or wider) and then use a gravel mole across the drains would do a good enough job on upland ground like this- has anyone got gravel mole experience in this situation?

 

[Walterp]

is it just not draining away or are there springs rising?

Water draining into the field from above, just not going anywhere.

 

[multi power]

Water draining into the field from above, just not going anywhere.

you need a ditch/drain to catch the water coming from above

 

[Walterp]

mm... Im sure that you will get many opinions on this post.
- what size is it?
- what do you want to do with it? Cutting, cattle or sheep?

I would avoid subsoiler/mole.. It could make it worse.
Is ph ok? Calcium lime to keep soil structure open and active would be a good starting point- even if it gets ploughed it cant do any harm
Always put 20mm clean gravel layer on pipe if draining

I wonder if drains say every 15m (or wider) and then use a gravel mole across the drains would do a good enough job on upland ground like this- has anyone got gravel mole experience in this situation?

12 acre field, only suitable for cutting a late-heading ryegrass without clover and renewed every 5 years, would be my best guess. Too low-lying for cattle in Spring/Autumn without doing some damage with their 'five mouths', not that running over it with someone's silage-making outfit will do it any good - perhaps a baler, then.

The gravel drain/mole plough combo was popular in the 1970's around here, but these drains nearly all failed in time. Some people say that weed clogged up the 100mm, some that water just won't percolate in heavy clay.

So, is sub-soiling in these circs a good idea? Or a bad one?

 

[Walterp]

you need a ditch/drain to catch the water coming from above

Yep, the 360 has got that bit organised.

None of us are normally very keen on open ditches, but in these circs we've opened a ditch one side of a hedge at the bottom of the slope and I think my son wants to open up a new ditch on the OTHER side, too, 'just to make sure, see, Dad..'.

 

[multi power]

no need for 2 ditches

 

[Walterp]

you need a ditch/drain to catch the water coming from above

Opinions vary - some people reckon that a drain should be run THROUGH a wet spot, whilst others suggest that a drain should be run ABOVE a wet spot in order to catch the source.

Who is correct?

 

[Walterp]

It is probably more clay under the yellow clay so not much point in breaking it.

Recent drilling (for piles for a turbine) suggests 17 metres of clay, mixed with glacial till.

Which is just dandy...


[Walterp scowls, and mutters to himself "Next time I get black-mailed into buying my own farm back, I'll at least try to make sure that it hasn't got 17 metres of crap underneath it.."]

 

[Walterp]

Blimey - the things you can find on the Internet. Uni of WA has research on water-logged soils: if you've got a clay subsoil with a shallow topsoil, the water kills the deep root system - they call this "perched water". Getting rid depends on drains, so we'd better extend the hire on the 360 digger.

Useful note on selecting grasses that tolerate waterlogging, too.

But the best drain may be a stock-proof fence...

 

[Zetor]

Opinions vary - some people reckon that a drain should be run THROUGH a wet spot, whilst others suggest that a drain should be run ABOVE a wet spot in order to catch the source.

Who is correct?

If it is spring water rising you need to be above the wet spot with a pipe to catch the spring however if the spring is already drained and the pipe is blocked then the wet spot will be above the pipe which is your most likely situation, if you land is anything like the land round here the chances of their been a drainage system in are very high and probably just need jetting out, there was a big push on drainage in the 60-80's and also in the 1800's they're all still working, if you have an old system repair it before thinking of installing your own pipe.

If you do some jetting make sure you dig a sump for the silt to run in to (see pic)

 

[Monty]

I managed to drain a spring alright. Found the source of the spring Dropped 2 bits of 4 inch down into the source. Lots of gravel around it for the water to find it's way into the pipes and hey presto been bone dry ever since (except last year of course) Also buried quite a few used left over plastic silage wrap rolls to get rid and help with the drainage. Don't skimp on the pipe or gravel with drains. 6 inch for main drains 4 inch for side drains or short ones. Do the job properly once and you won't have to do it again. I have had to replace the drains a right cowboy left us. 2 and 3 inch pipe used to repair 4 you wouldn't believe the bodge jobs.

Also replaced some clay drains in a peat bog with plastic and gravel. What a difference. You couln't get near it even in the summer. Now it's just so hard and rough where the soil was put back in. Expensive but will pay for itself over the years.

 

[DGC1]

12 acre field, only suitable for cutting a late-heading ryegrass without clover and renewed every 5 years, would be my best guess. Too low-lying for cattle in Spring/Autumn without doing some damage with their 'five mouths', not that running over it with someone's silage-making outfit will do it any good - perhaps a baler, then.

The gravel drain/mole plough combo was popular in the 1970's around here, but these drains nearly all failed in time. Some people say that weed clogged up the 100mm, some that water just won't percolate in heavy clay.

So, is sub-soiling in these circs a good idea? Or a bad one?

12 acre field, only suitable for cutting a late-heading ryegrass without clover and renewed every 5 years, would be my best guess. Too low-lying for cattle in Spring/Autumn without doing some damage with their 'five mouths', not that running over it with someone's silage-making outfit will do it any good - perhaps a baler, then.

The gravel drain/mole plough combo was popular in the 1970's around here, but these drains nearly all failed in time. Some people say that weed clogged up the 100mm, some that water just won't percolate in heavy clay.

So, is sub-soiling in these circs a good idea? Or a bad one?

Maybe i wasnt clear re gravel mole. If you google gravel mole plough you will see various companies building a standard mole but with a gravel hopper above to fill the slot with 10-20mm gravel.
Im not suggesting doing away with pipe & gravel but on marginal ground it may not pay to spend top money on doing a drain every 5m so what im suggesting is to consider only putting one in every 3 or 4 drains in and then cross draining with the gravel mole at a fraction of the cost and it would be alot quicker.
Sportsfield drainage is done on this cross drainage system with gravel bands and then crossing them sand bands and it works well on level ground.
I dont recon gravel drains would work well over longer distances but if drains were spaced at 15m then the water only has to travel 7.5m each way in the gravel mole.
Alot of stone drains up in scotland carry a serious amount of water and have been running for 100 years!
I recon that the gravel mole on heavy ground may just have a place??

 

[Penmoel]

Recent drilling (for piles for a turbine) suggests 17 metres of clay, mixed with glacial till.

Which is just dandy...


[Walterp scowls, and mutters to himself "Next time I get black-mailed into buying my own farm back, I'll at least try to make sure that it hasn't got 17 metres of crap underneath it.."]

Turbine going up now then Walter?

 

[Fuzzy]

The first rule of drainage is to sort the ditch or ditches first, the water has to have somewhere to drain into and if there is an obstruction like roots or 'above ground growth' then that needs moving out of the way too !! Our chainsaw has been very busy this winter pruning near ditches. The digger is also very good at dealing with above ground growth !!
If you can mole drain into clay the mole will last for years.

 

[awkward]

might I say view [ Connaught agri drainage ] on you tube

 

[Old Boar]

Prisoners of War dug most of the ditches round here, and put lovely stone culverts in through banks. Most are still working. Some of the mole drains I had put in 30 years ago are still working - pure blue clay though, nasty stuff. When I bought the farm at an auction, lots of the old men came and told me what a wet farm it was. Then we had the drought (77?), and I had brilliant heavy crops of silage and hay when all around were burning up. Oh, those were the days....