More than One Kind of Mole

We all hate moles in our nicely manicured lawn, lifting great mounds of earth up into mole hills and digging tunnels along the surface so they can move about under the cover of soil and darkness. They can be a pain but down on the farm, we have a very large and loud ‘mole’ that is currently ripping through the grass crop land that will shortly be cultivated and put into winter wheat.

It’s a mole drainer out doing its job. So what is a mole drainer? This is a special piece of equipment that is used on heavy land farms to help drainage. You have to have a certain type of soil to use it correctly and you also need the right soil conditions to benefit from it.  It is the deepest-working, pulled cultivator found on the farm and it takes the most amount of power to pull it. Remember the general rule: the deeper you move the soil, the more horsepower is required; well, this is a prime example.

It looks small but it does stick it's heels in to make it hard to pull

The implement is relatively small and is dwarfed by the large ‘New’ Caterpillar tractor boasting 320hp but the mole’s unique design and depth it makes it the hardest implement to pull in our clay soils. The machine has wheels to turn and move it on the road but in the working position, the wheels are not in contact with the ground so the whole machine slides on the surface. Mounted on the back is a blade which is a long, thick, very strong piece of metal that is held low, below the frame. At the end of the blade, you have a bullet which pulls a ceramic expander. Those are the correct terms but I describe them as a leg and foot pulling a ball and chain!

The idea is to create a mole: a round tunnel formed in the clay subsoil just above the field drains. The field drains are permanently placed pipes and gravel that remove water from the field, working with the slope. The temporary mole is formed just above these, so not to break or damage the pipes and they are formed at ninety degrees to them. Therefore, over all our fields we have a lattice work of pipes to allow the water free movement out of the topsoil, making our fields easier to work and better for the plants to grow in. 

The leg sets the depth and then the foot starts to move the tightly compacted clay ready for the clay to be pushed back by the hard ceramic expander that creates a smeared clay channel. This smeared clay channel then hopefully dries out to create a natural clay pipe. This is repeated every four metres over the whole field and they normally last about 6-7 years before they collapse or fill with sediment, so it is a on-going rotation around the fields with clay soils. The conditions are very favourable this year to make the moles as the wet spring (and summer) means the clay is very receptive to being formed into the mole, as deep down it is very moist. It also means that the blade does not wear away very quickly as the top soil is not baked solid. The pressure on the foot, expander and blade is huge. The friction is massive and you can see flakes of metal peeling off them and they become very hot. The ceramic expander can get so hot that if you hold it with your bare hand your skin will burn!

The foot and expander hang under the frame.

The new tractor has had its first run out and the noise it makes sends goose bumps up my neck, that really deep throaty roar of the exhaust belting out power! We are looking forward to working it hard this autumn but first we need to clear the harvest, which is proving challenging with these showers and thunderstorms. I hope I am not making a mountain out of a mole hill! But if the sun does not come out soon we will be in a right muddle with crops being spoilt and ruined wheat sitting ripe on ear!

Sun would be most welcome to help with harvest and bake the newly formed moles deep in my clay! BWB