Agrobiodiversity and resilience. Research on wheat varietal mixtures proves to be the new frontier of eco-agriculture, under the banner of organic. food security and health for Italy and the Mediterranean, the planet and its inhabitants.
Agrobiodiversity, food security and health
Agrobiodiversity - that is, all the components of biological diversity relevant to agriculture and the agroecosystem - plays a fundamental role for the so-called food security. That is food supply security on the planet.
The food security is severely threatened by climate change, desertification and other anthropogenic factors. Not least, the drastic reduction of cultivated plant species, where only 9 crops today represent 66% of global agricultural production (FAO, 2019).
The reduction of the number of species and cultivated varieties is also directly linked to the increasing spread of a wide range of diseases in the human body. The homogenization of diets – with a reduction in micronutrient and phytocomplex variety – is indeed attributed to several diseases, related primarily to the immune system and inflammations. (1) More frequently in cases of consumption of ultraprocessed HFSS foods (High in Fats, Sugar and Sodium).
Agrobiodiversity, climate change and varietal mixtures
Food systems and agricultural today are not suited to face the impact of climate change, precisely because of the great uniformity that characterizes them. Models predicting variables associated with climate change, moreover, are far from agreeing. And it is virtually impossible to develop reliable breeding programs, whether conventional or molecular.
An effective strategy to allow our crops to evolve and progressively adapt to climate change – ensuring stable yields and appreciated nutritional quality products – is to cultivate varietal mixtures. Breeding thus transfers from research stations to farmers' fields, who are effectively involved in the entire decision-making process by applying the so-called participatory plant breeding (PPB, Participatory Plant Breeding).
Another technique that allows diversity to be brought back into the fields, also relying where necessary on collaboration with institutions, is evolutionary plant breeding (EPB, Evolutionary Plant Breeding). (2) Which consists in the use of mixtures and evolutionary populations:
– mixtures derive from blends of different varieties of the same species. Once planted, they can naturally cross and progressively adapt to pedoclimatic characteristics,
– evolutionary populations intraspecific derive from mixtures that include varieties, crosses, and populations of the same species.
Mixtures and low-input organic farming input
Cereal growing has suffered for decades from a lack of varieties truly suitable for organic cultivation. The versatility and resilience of mixtures – documented by extensive scientific literature – instead allows agricultural activities to be established even in so-called marginal areas or those subject to extreme climatic conditions.
In Italy the first varietal wheat mixtures are thus beginning to be cultivated, adopting sustainable farming practices, finding that their great adaptability allows minimizing the input (or technical means) in agriculture.
The wide genetic base of varietal mixtures allows them to adapt, ensuring a plant presence that tends to be constant under different pedoclimatic conditions. Mixtures therefore guarantee significant stability – even in marginal soils – which surpasses, in terms of yield under equal conditions, that of monocultures. (3)
Wheat mixtures and yield increases. Scientific study
The meta-analysis ‘Unfolding the potential of wheat cultivar mixtures: A meta-analysis perspective and identification of knowledge gaps’ considers about 120 scientific works on wheat mixtures. Under equal conditions, the total yield of wheat mixtures – compared to single varieties – shows an average increase of 3.5% (with peaks of 6.2%, in the presence of significant biotic stresses).
The mixtures are therefore even more effective in crops that do not involve the use of pesticides. Moreover, the uneven height of the plants maximizes photosynthetic efficiency and reduces evaporation. (4) Their competitiveness with weeds is also better. (5)
Wheat mixtures, the great gift of the Mediterranean
ICARDA (International Center for Agricultural Research in the Dry Areas) is a non-profit organization, engaged since 1977 in agricultural research, aiming to improve the livelihoods of communities in the world's arid areas (North Africa, Middle East, Central Asia). Thanks to its large germplasm bank, ICARDA established in Aleppo (Syria) populations of durum wheat (with 700 F2 varieties) and bread wheat (with 2000 varieties among F2, F3 and F4). (6)
The valuable work carried out in Syria has made it possible to create populations capable of providing farmers with the widest possible genetic material, able to adapt to different environments, soils, and agronomic techniques. Including organic farming with low input. Thanks to Prof. Salvatore Ceccarelli, the three evolutionary populations of ICARDA arrived in Italy in 2010. (7) And a small quantity of seed (23 kg) was provided to three farmers in as many regions, within the framework of European SOLIBAM project(8)
From Syria to Sicily, one of the three small lots was assigned to the company Terre Frumentarie located in Aidone (EN). Its owner, Giuseppe Li Rosi, was one of the first farmers to invest in this genetic improvement technique. As well as the first in Sicily to register 3 local wheat varieties in the ‘ sectionConservation varieties' of the National Register of varieties of agrarian species and vegetable species.
Varietal mixtures, the legislative framework
'Heterogeneous material' is the definition given in 2014 by the European Commission to mixtures. Which cannot be qualified as 'varieties', due to the lack of uniformity, distinctness and stability requirements established by European seed legislation. They are in fact populations (Composite Cross Population, CCP) of which Italy – precisely thanks to the work done in the fields in recent years – has been able to declare to Brussels the interest in authorizing the sale. Even if, initially, in a phase of temporary experimentation.
Of the 8 populations of cereals temporarily authorized for sale as seeds, one is precisely the population of wheat ‘SOLIBAM soft Li Rosi’. The MIPAAF and CREA-DC (Defense and Certification) are now defining procedures for field checks, certification of quantities allowed for sale for each population, phytosanitary controls. In view of issuing the label for commercialization and authorization (by derogation) for sale by multipliers farmers. (9)
Wheat mixtures, the Sicilian renaissance of organic cereal growing
In Sicily, several farmers who adhere to the Simenza Association cultivate evolving populations of wheat under organic farming. The wheat is marketed at a price that recognizes the dignity of labor, in a logic of fairness and sustainability of the supply chain.
The flours derived from them are suitable for baking, gastronomy and quality pastry ‘100% Made in Italy’.
‘If you control the oil, you control nations; if you control food, you control the people’ (Henry Kissinger)
From a socio-economic point of view, wheat mixtures can truly express the renaissance of Sicilian cereal cultivation. Offering farmers the significant opportunity to break free from the overpowering control of Corporation that dominate the global market of seeds and agricultural inputs.
#Equality!
Paolo Caruso and Dario Dongo
Notes
(1) Von Hertzen L., Hanski I., Haahtela T. (2011). Natural immunity. Biodiversity loss and inflammatory diseases are two global megatrends that might be related. EMBO Rep. 2011 Oct 28;12(11):1089-93. doi: 10.1038/embor.2011.195. See also previous articles on:
(2) Suneson C.A. (1956). An Evolutionary Plant Breeding Method. Agron. Jour. 48: 188–190
(3) Borg J., Kiær L.P., Lecarpentier C., Goldringer I., Gauffreteau A., Saint-Jean S., Barot S., Enjalbert J. (2018). Unfolding the potential of wheat cultivar mixtures: A meta-analysis perspective and identification of knowledge gaps. Field Crops Research 221 (2018) 298–313
(4) Adu-Gyamfi, P., Mahmood, T., Trethowan, R., 2015. Can wheat varietal mixtures buffer the impacts of water deficit? Crop Pasture Sci. 66, 757
Faraji, J., 2011. Wheat cultivar blends: a step forward to sustainable agriculture. Afr. J. Agric. Res. 6, 6780–6789
(5) AHEE Kaut, HE Mason, A Navabi, JT O’Donovan, D Spaner. (2008). Organic and conventional management of mixtures of wheat and spring cereals. Agronomy for Sustainable Development 28 (3), 363-371, 2008
(6) F2, F3, etc. are the generations that follow after sowing of F1 (first reproduction). In practice, after sowing of F1, part of the harvested seed is reseeded to give rise to the second generation (F2), and so on
(7) Ceccarelli S. (2016). Mix farmers, mix. What it is and how participatory plant breeding is done. Ed. Pentagora 2016, EAN: 9788898187393
(8) The SOLIBEM project was co-financed by the European Commission under the Seventh Framework Programme from 2010 to 2014. V. Bettina Bussi, Riccardo Bocci, Salvatore Ceccarelli, Matteo Petitti, Stefano Benedettelli. The frontier of cereal breeding for organic agriculture: heterogeneous material. Semi rurali,
(9) The European community has extended the temporary authorization for the sale of heterogeneous material, derogating from current legislation, until 2021. The new organic farming regulation allows in any case to cultivate the different populations with this method.
Paolo Caruso, agronomist, collaborates with the Department of Agriculture, Food and Environment of the University of Catania, Section of Agronomy and Herbaceous Crops. Researcher on ancient Sicilian wheat.
