Of the many good ideas to come from Germany, one little noticed, but very useful one is hugelkultur, a technique used in Alpine regions of Germany and Austria to enable mountain farmers to make the most of limited space for growing. The word Hugel means mound, and the technique involves making a mound, either a round one or one with a ridge at the top and growing on it. While very useful in mountain regions, it can also be profitably used in desert zones and areas where the soil is waterlogged and therefore so oxygen depleted that it is unsuitable for growing crops.
The basic technique is to dig a trench about 0.3 metres deep and fill it with logs and branches to form the basis of the hugel. This trench can be any length you like, and there is nothing to stop it being long. The logs and branches will over the coming years decay slowly releasing their nutrients for the vegetables. It is better to use wood that is in a state of decay already, for in the initial stages of decay the wood steals nitrogen from the soil at the expense of the vegetables, but in later stages of decay this nitrogen is returned.
Above the trench the soil from the trench is heaped up into a layer, and the grassy turfs laid face down on top of the soil.This is to ensure that the grass does not grow upwards into the vegetable bed, but that it rots down into a source of nutrients. This technique of laying turfs face down is a common one and is used in the making of loam piles and lazy beds. A loam pile is a means of converting turf heaps into soil, and lazy beds used to be common in the West of Ireland and Scotland, and you can find out more about them in my article Growing on the Edge.
Above the upended turfs is laid layer upon layer of organic material: leaves, manure, compost, paper, cardboard and straw. In fact, anything that will rot down is permissible, though there are some woods that you do not want, which I will identify further down.Ideally the materials will be mixed together so as to provide a balanced mix of nitrogenous materials, such as leaves and grass, and carbonaceous materials, such as wood and cardboard. This way you get the best results from the hugel. Planks or logs can be placed along the sides so as to minimize soil slippage.
Hugels decay over time and need replacement, but as they decay they crumble a bit and this allows air to enter the root zone, fostering plant growth. So even the decay is a winning situation.
The books shown below will give you an insight into the world of Sepp Holzer, an expert mountain farmer who has developed hugelkultur greatly.