DD and Mole draining

[mikep]

Please everyone think of why you mole. It's to improve the way water gets away from the surface and is transported away
On some clays it is the main system with few laterals so no matter how long you are in notill then you will have to mole. On others with full underground systems it may be better to subsoil instead of mole.
Now why is it necessary? The main reason used to be cultivation pans so if I am no tilling the need should not arise but many people notill with very heavy equipment in a hurry and cause problems, if you have a wet harvest you have no option to mail things about so the soil can still be damaged even though non notill it will take it better. It can correct itself but a quick pull round with the right equipment can shorten the time.
The one cause of poor drainage notill cannot cure is the percolation of fine silt or clay particles through the soil that on some soils can choke the natural channels and necessitate mechanical intervention
Notill is a tool for looking after the soil just as moling or subsoiling are and you as a farmer must use what you judge to be necessary at the time.

 

[Simon C]

The theory is that without horizontal layers caused by ploughs, subsoilers and any other form of cultivation, rain water can go straight down through the vertical structure that is produced by long term no-till and connect up with the natural water table.

After ten years, I am still waiting for this to happen in my clay soil and I have to agree with @Badshot that moling seems to be more important now. I am continually being caught out by not doing it often enough, I think that cultivations disguise a drainage problem to a certain extent because water can flow sideways whereas in no-till, it can only go down and if there is nowhere for it to go, you get ponding in the top.

I dug this hole in the winter, not having had any rain for three months and the next day water appeared up to the moling depth.

 

[Richard III]

The one cause of poor drainage notill cannot cure is the percolation of fine silt or clay particles through the soil that on some soils can choke the natural channels and necessitate mechanical intervention

I have this problem on my unstable silty soils, a plough pan will form from repeated ploughing even if it is done in dry conditions every year. No Till gets around this completely, as the soil is never loose enough for the silt to wash down, unfortunately though I have replaced this problem with a problem with silt on the surface. Heavy rainfall causes the surface to slump and the silt to wash into every pore, leaving a very thin surface cap. The clods created by tillage prevent this from happening in conventional ag. The problem is much more severe once the surface reaches saturation, so drainage helps. On the worst affected fields I am experimenting with vertical tillage (mole drainer without the plug), the effects were dramatic last winter, but yet to be tested in a wet one. The subsoil is heavy enough to hold a mole here, but silt then washes down and quickly fills it.

 

[Matt L]

If you don't use the expander then the moles will fail due to water ingress resulting in roof collapse and then siltation of the moles leading to wet spots.

 

[damaged]

@Feldspar . 5 yrs no till. 3 yrs red clover then wheat and currently barley. Moores drilled. Straw baled off. Clay loam. Patches of heavier clay sat wet at surface. Moled in autumn. Physically drier in winter and spring. Effect of tillage may also have improved crop development. DAP fert on surface only (not nvz).

 

[yellow belly]

on land drained with porous back fill that holds a mole moling is the one cultivation that is essential

Same land drained in Victorian times at 6 m apart and no backfill requires subsoiling or ploughing as the system was designed for

I mole with twin leg moles and gps at 2.5 m apart so that when remoling
It will be 1.25 m from the last mole
Twin leg takes out the wheel mark out and I now mole post drilling in the spring within a week of drilling when the surface is dry but the mole works in soft clay

Moling at harvest it is often to dry for a proper mole and takes 1/3 more power and fuel the blade and mole also melts away in dry conditions as it gets red hot