Tall wheatgrass (Thinopyrum ponticum (Podp)) in a real farm context, a sustainable perennial alternative to rye (Secale cereale L.) cultivation in marginal lands

In order to face the expected increasing demand of energy crops without creating conflicts of land occupation sustainability, farmers need to find reliable alternatives in marginal agricultural areas where the production of food hardly ever is economically and environmentally sustainable. The purpose of this work was the study of the viability of the introduction of new non-food crops in marginal areas of real farms. This study compares the profit margin and the energy and environmental performance of growing tall wheatgrass, in the marginal area of a rainfed farm versus rye, the annual crop sowed traditionally in the marginal area of the farm. The cited farm owned 300 ha of which about 13 % was marginal. The methodology was based on the use of the profit margin of the crops as indicator for the economic assessment and Life Cycle Assessment (LCA) as technique for the energy and the environmental evaluations. Results of the economic analysis showed a slight enhancement of the profit margin for tall wheatgrass (156 (sic).ha(-1).y(-1)) compared to rye (145 (sic).ha(-1).y(-1)). Environmental LCA was driven by CO2 fixation due to soil organic matter increase and reduced inputs consumption for tall wheatgrass that produced a Global Warming Potential (GWP) of - 1.9 Mg CO2 eq..ha(-1).y(-1) versus 1.6 Mg CO2 eq..ha(-1).y(-1) obtained for rye. Tall wheatgrass cultivation primary energy consumption was less than 40 % of rye's consumption. According to the results achieved it was concluded that tall wheatgrass is better option than rye from the energy and the environmental point of views and slight better option from the economic view. Considering these results, monetarization of the CO2 eq. reductions of tall wheatgrass compared to rye is essential to improve its profit margin and promote the implantation of this new crop in marginal areas of farms.