Cultivating Marginal Land

There is much marginal land in the British Isles, much of it in the North and West. This land differs from the rolling green fields of the South and East, which has  tended to give England its image. These lands consists of hill and mountain country, moorland and island and are officially accounted as Disadvantaged and Severely Disadvantaged Areas, where cultivation is very difficult. These areas werestudied by Dr Dorian Speakman, who established the Marginal Lands Project, which provides a database of solutions for those cultivating marginal land, a project reported in Permaculture, issue 92, Summer 2017. 

What makes a piece of land marginal? Take an example.Sarah McBurnie has created a market garden on Unst,Britain's northernmost inhabited island, in the Shetland Isles. She faced the problems of dealing with the harsh winds that scour her exposed isle, which cause crops to be subject to the damaging,often lethal effects of wind chill.Sarah also had to face the problem that the soil of Shetland is in places thin and there is little depth before you hit rock at places, and the bedrock is sandstone, hardly the best for plant nutrients. Yet she wanted fruit and salads, but found that fresh ones were in short supply on her remote isle. The solution! Establish her own market garden. Sarah's technique was to lessen wind chill by using up some of the old fishing nets discarded by the island's fishing industry as a mesh cage to lessen the damaging effects of wind. She also made up her own soil and used  raised beds. The result, a thriving market garden, the most northerly in Britain. 

Lessening wind can be done with a mesh tunnel, which is not a polytunnel, but is designed to slow down wind velocity. The wind blows through it, but is slowed to up to forty percent of its speed.  Shelter belts of trees and bushes can be planted to slow down the winds that come across a site. In Cornwall a richly productive garden has been created on the edge of an estuary using shrubs to shelter the flowers against the salt laden winds, but the shrubs need to be  salt tolerant. 

Marginal land can also be mountainous and/or boggy. In mountain country there can be valleys with rich soil, but as you ascend the slopes soil becomes thinner and often more acid. Peat soils proliferate, and these are quite acid, even down to pH 5 or less, and little grows well in soils like these. Farmers will often find stretches of bog,particularly in depressions, and in certain parts of Britain, such as Dartmoor and Bodmin Moor, the bogs can be very dangerous and have taken people's lives. 

A serious problem, as global warming exacerbates climate change,  is flooding, which can be serious in hill country, as the rainwater runs quickly off steep slopes, sweeping soil and rocks with it. This can destroy property and soil, which is washed away, and lives can be at risk, as can businesses. A few years ago at Plas Cadnant gardens, set in a Welsh valley, flood water swept downhill and  broke into the gardens, destroying a two hundred year old wall! The owner had spent twenty years restoring the gardens. They were not destroyed, but damaged nevertheless. 

There is advantage for nature in leaving wetland as it is in some cases, for doing so protects the environment. About twenty miles from my home is a hill called Kinder Scout. A plateau, it is covered with ancient peat bogs, which the authorities are trying to enhance and preserve. Why? The peat serves a vital purpose as a giant sponge that soaks up the rainwater that deluges the Pennine Range, releasing it slowly. Were it to be released quickly, rainwater would flood down with nothing to slow it and my city would be often flooded. We need to keep the peat safe. 

But farmers need to build up their soil, and this can serve to slow down rainwater drain off, so there can be times when a  wetland needs attention. Chris Dixon at Penrhos Farm, high above the Mawdach Estuary in Wales, had a problem with a small patch of land, a depression, which regularly flooded, and he needed to do something about it. His solution was to experiment with a small drainage ditch, which he filled in with birch poles [fasces] to the brim, then filled the gap with soil excavated from the rest of the farm. The surface was covered  with more birch poles. Water still filled the ditch, but its flow  was greatly diminished, both up and downstream of the one-time channel. Slowly he turned what was once a waterlogged depression in fertile land by adding more birch poles, and in doing so he was assisted by nature, whose plants colonized the causeway and bound the poles and soil  together by the strength of their roots. Slowing the  flow of water is beneficial for the lands downhill of the causeway and also for the farmer who wants to maintain his soil. 

Developing soil on sloping ground can also benefit from key-line ploughing, [plowing] which uses a horse-drawn plough called a kassine which breaks up compacted soil. This helps to  remedy a problem called pan, which is when a hard layer develops below the surface, preventing water from passing down to lower layers. This prevents soil from developing. Unlike a conventional plough [plow] which turns over soil layers, a kassine merely makes a cut, and is considered better for soil health than a conventional plough is, for it ensures that damage to the soil caused by ploughing is minimized. Key-line ploughing also runs long the contours of an area, ensuring that run off does not go downhill  through the plough furrows. 

Some northerly areas are susceptible to frosts even into  May. However, frost can strike in Britain in April, as I discovered to my cost a few nights ago, when my potatoes were slightly damaged by it.I had been delayed in earthing them up due to the pressures of illness in the extended family, and I was caught out.

Obviously, anyone with a heated greenhouse or polytunnel has an advantage, but they can be expensive. There are,however, other, cheaper ways of providing heat for your crops. Many growers in northerly climes use a polytunnel for susceptible vegetables, but polytunnels are not always the perfect answer, as really bad cold can seep through. But heating can be cheap. One answer is to use warm water tanks in the polytunnel. These retain heat quite well and they therefore provide a  thermal store for the protection of the plants. Even as the water tanks cool down, the air retains heat for quite some time, especially if the tunnel is well insulated and protected from drafts. Greenhouses can have extra insulation through a layer of Bubble Wrap on the inside of  their windows, which is taken off in spring. 

Another warming technique is hot beds,which can be used in early Spring. To make a hot bed use a raised bed and place a layer of manure at the bottom. Growing medium, a mixture of soil and compost in equal proportions should be laid above it. The ratio of manure to growing medium should be three to one. The manure will heat up as it decays and this should provide a warm place for plants to grow. The hot bed lasts two months and then the decayed results can be spread on the garden as a soil enhancer. Do  not make the hot bed too deep, though, as this can cause overheating.  

Northerly climes  are susceptible low light levels in Spring because the nearer  you are to the Arctic Circle the longer the nights in Winter and the days in Summer, so in early Spring the days are often short, and this is detrimental to vegetable growing. Artificial lighting can help, but it is expensive, but some growers use a combination of lighting and reflective material to make the most of the light they have.  

If you are growing vegetables in a marginal area one of the key points is do not try to become too large. It is better to keep your operation small and intense, making much use of  limited space rather than less use of  extended space. Enterprising people have been able to grow food in unlikely places, they just need commitment.