I sold tractors to farmers who were reclaiming the marsh in the Kings Lynn area from the sea. There, once the sea was held back, fresh water from the rivers soaked into the land and diluted the salt water. Grass was sown on it in some areas, in others crops of barley and wheat were planted in the ploughed land. For the first year or so production was low but it gradually increased. It is now used to grow wheat and potatoes and is some of the most fertile land in Britain. This is the area that our government want to flood because the sea defences are too expensive to maintain!!!
I demonstrated Fords first TW 4WD down there with a Dowdeswll six firrow plough, ploughing through running "creeks". The tractor was shown at a Ransomes Demo some months before it was released to the press. My boss and I grabbed the top man at Ford, David Pearson, and twisted his arm to allow us to show it to a customer who had been pestering us to see if Ford was building such a tractor. It came into my depot and we balasted it up with calcium chloride mix, 90% all round.
We did not use the drainage style ploughs at all. Drains were cut but these were done by excavators. They fed to a main drain which led to the pumping station.
In the early stages the marshes grew a plant called sampher, a sort of salt water marsh plant. This is greatly prized by the locals who cook it and soak it in vinegar or serve it hot. I love it.
When the land dried out it formed flat platelets and would polish a plough body so it looked as if it had been newly chrome plated. It does not wear the plough as bad as the soils of "High Norfolk" do.