The Role of Fallows in Sustainable Development

Abandonment of crop production on agricultural lands for several or more years is a widespread practice not only in Europe but also around the world. Economic and political considerations lead to the abandonment of crop production on the poorest lands, although sometimes agriculturally valuable lands are also excluded from farming. Fallow land can be afforested, designated as a dedicated protection area, exposed to natural succession, or used to grow biomass for energy purposes. However, the most important role of agricultural land should be to ensure food safety. The set-aside land with high production potential should be treated in a special way. While lying fallow, the soil can have its fertility sustained or even improved considerably. To this aim, uncultivated land should be properly protected by growing a permanent cover of plant species which will have a positive influence on the soil's physical, chemical, and biological characteristics. Depending on the geographical location, different plant species will have a beneficial effect on set-aside soil. Given economic and environmental considerations, the best solution is to sow a mixture of grasses and legumes, which can improve substantially the biodiversity on fallow fields, raise the soil's fertility, ensure high CO2 sequestration ratios, and influence beneficially the soil's nutritional status and nutrient management. Soil protection can be provided for many years with little effort. The most recent reports implicate that it is possible to achieve several economic and environmental aims simultaneously in the course of the management of land excluded from agricultural production. These aims include the improvement of biodiversity, control of greenhouse gas emissions, generation of energy, and readiness to resume production of commodity plants. Proper management of fallows corresponds well with the challenges defined in the Green Deal for Europe or the US Green New Deal.