In the GRACE project, the biomass crops miscanthus and hemp are cultivated on marginal lands, currently not used for the production of food or feed crops. In this context, marginal land is defined as land where biophysical (e.g. low soil fertility) or socio-economic constraints hinder the cultivation of food and feed crops. This also includes contaminated land.
Land of low productivity
This is land where biophysical constraints render the yield of food or feed crops either too low, or the cultivation intensity required is too high, to be economically viable. Biophysical constraints include soils of low fertility, high clay or rock content. Economic constraints include awkward field shapes, managment restrictions e.g along water bodies and ppor infrastrucutre. Low-input crops, such as miscanthus and hemp, could be an economically feasible solution for cultivation here. Particularly in comparison to food and feed crops, these crops require considerably less inputs of, for example, fertilizers to produce adequate yields even on such difficult sites. In addition, their management is less intensive. As such, a lot less effort is required to produce the same or even higher output. This increases the farmer’s profit and, in the long run, also adds value through the efficient managing or potential recovering of such soils. The use of these lands is a promising opportunity, not only for increasing the land area available for crop cultivation, but also for strengthening the local economy.
Part of abandoned land used in this project is termed ‘marginal’ mainly due to socio-economic constraints. These constraints lead to a significant part of the population abandoning the area. One example is the area located in the Sisak region in Croatia that will be used in the GRACE project for the cultivation of miscanthus. This area has been abandoned since the war in the nineties and is still suffering from its aftermath. It is characterized by a low population density, an elderly population, a high unemployment rate and the lowest GDP in Croatia. Reclaiming this land for the production of biomass to be delivered to a nearby biorefinery will have a massive social impact, creating new jobs and offering new prospects for younger people in the region. It could also be a first step in the long-term reincorporation of the land into the agricultural production of food and feed crops in this region.
One interesting option for the cultivation of biomass crops without the risk of increasing food insecurity is the use of contaminated sites, where food or feed production is not possible due to health risks. Examples of such sites include brownfields and land contaminated by landfills and sludge through municipal activities. The contamination is often caused by so-called trace elements such as lead (Pb), cadmium (Cd), chromium (Cr) and copper (Cu). Several studies have shown that both miscanthus and hemp can be cultivated on these sites. Miscanthus, for example, sequesters most inorganic contaminants into the root system; the above-ground biomass can be safely used for industrial purposes despite the contamination. A recent study estimates the land area with trace element-contamination in the EU-18 to be over 4 million ha, emphasizing the potential of using such sites.