According to the provisions contained in the working document of the European Commission “Adapting to climate change: the challenge for European agriculture and rural areas”, attached to the White Paper “Adaptation to Climate Change: Towards a European framework action”, it is expected that in the coming decades the agriculture sector suffers the negatives influences of climate change both globally and in the EU itself.
Mainly due to the variability of weather conditions associated with crops, some facts as the increase in the concentration of CO2 in the atmosphere, the higher temperatures, changes in the annual and seasonal patterns of rainfall as well as the frequency of extreme events will affect the volume, quality and stability of food production and natural environment where agriculture is practiced, with a clear impact on the availability of water resources, on the prevalence of pests and diseases and on the status of the soils.
These effects are expected to get worse as climate change accelerates, which certainly is forcing farms to adapt to new conditions through technological and management solutions (new production schedules, new crop varieties, valorization of by-products, optimization of the use of resources such as water, sustainable criteria in the use of chemicals, etc.). However, over the time it will be increasingly necessary to apply policies and measures in a full-sector scale and responding to national needs in climate change adaptation.
Despite the negative effects of climate change in the agriculture, it also has a negative influence on climate change primarily for its direct contribution to the production of greenhouse gases (GHG as CH4 from livestock digestion processes and NO associated to nitrogen fertilization), and indirectly by the emissions related to the use of different machinery and equipment in farming practices that require fuel and energy consumption, the effects of organic matter decomposition in soils, etc. Nonetheless, there has been a decrease of 20% in the emissions associated with agriculture in recent years (between 1990 and 2006).
Despite these positive data, the European Commission has defined within its policy established for issues related to agriculture and the environment and in the strategy defined for the Common Agricultural Policy (CAP) facing the new Horizon 2020, as one of the key challenges for the agricultural sector, to continue releasing the potential in mitigating climate change and adapting to its consequences for agriculture, as well as to the need to continue progressing in reducing the GHG associated with the growth phase and in the implementation of measures related to production efficiency and to the improvement of the energy efficiency, the biomass production and the renewable energy from it, the carbon uptake and the retention of the carbon stored in soils.
SOSTRICE project aligns perfectly with the strategy shown above, especially because of its application in a crop like rice, which in Spanish production areas has a high degree of integration with the environment, both environmental and economically. Given this, project actions are being implemented in two of the areas where rice cultivation has reached considerable importance in Spain: Las Marismas del Guadalquivir (Andalusia), with around 35.000 ha, and L’Albufera (Valencia), with 15.000 ha. In both cases there is an interaction between agricultural activity and the proximity to areas of high environmental protection, such as Doñana Natural Park in Andalusia and L’Albufera Natural Park in Valencia. These wetlands have a high biological value because of the large number and diversity of environments and animal and plant species they contain.
However, rice farms in both areas are facing severe environmental problems associated with the management of the vegetable waste from crop harvesting, the so-called “rice straw“, which can be removed from the field through two different operations with a clearly negative environmental effect: the burning of this rice straw or its grinding and incorporation into the soil, a practice commonly known as “fangueado”.
Among other negative environmental impacts associated to these traditional practices, stubble-burning releases large amounts of CO2 into the atmosphere while causing negative effects on biodiversity and human health, apart from the possible security problems associated with adjacent areas to rice plots with high environmental value. Concerning the “fangueado”, it causes uncontrolled fermentations of rice straw, which is degraded by anaerobic pathways due to the existence of high levels of moisture in the ground, emitting methane (a GHG with an effect 21 times more intense than CO2) and H2S, which causes certain diseases (physiopathies) in the crop itself.
SOSTRICE project aims to reverse the environmental effects of current rice straw management model through its energy valorization by applying two innovative technological processes, the anaerobic digestion and the combustion. In this sense, it is foreseen the design and construction of an anaerobic digestion prototype and a combustion prototype in which a series of tests will be performed throughout the project.
This new model is intended to have, on the one hand, a direct and positive environmental impact in terms of reducing GHG emissions by the disappearance of stubble-burning and the decrease in rice straw fermentation in the soil and, on the other hand, indirect and positive environmental effects associated with the use of the by-products generated in the combustion prototype (i.e., heat generation) and in the anaerobic digester (i.e., biogas/energy, bio-fuel and bio-fertilizer). In addition, SOSTRICE project is intended to both assess the Carbon Footprint of the rice cultivation through the identification of good environmental practices and reduce it after the application of the SOSTRICE model in the rice straw management.