Agrobiodiversity and resilience. Research on varietal mixtures of wheat proves to be the new frontier of eco-agriculture, in the name 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 components of biological diversity relevant to agriculture and the agroecosystem - plays a fundamental role for the so-called food security. That is to say, the security of food supply 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 9 crops alone today represent 66% of global agricultural production (FAO, 2019).
The reduction in the number of cultivated species and varieties is also directly correlated to the increasing spread of a wide range of diseases in the human body. The homogenization of diets – with reduction in micronutrient and phytocomplex varieties – is indeed attributed to several diseases, linked primarily to the immune system and inflammations. (1) More frequently in cases of consumption of ultra-processed 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. The models predicting the variables associated with climate change, moreover, are far from being in agreement. And it is virtually impossible to develop reliable genetic improvement programs, both conventional and molecular.
An effective strategy to allow our crops to evolve and progressively adapt to climate change – ensuring stable yields and products with appreciable nutritional quality – is instead to cultivate varietal mixtures. Genetic improvement thus transfers from research stations to farmers' fields. They are effectively involved in the entire decision-making process, applying the so-called participatory plant breeding (PPB, Participatory Plant Breeding).
Another technique that allows diversity to be brought back to the fields, also relying, where appropriate, on collaboration with institutions, is evolutionary plant breeding (EPB, Evolutionary Plant Breeding). (2) Which consists of using mixtures and evolving populations:
– mixtures derive from mixes of different varieties of the same species. Once sown, they can naturally crossbreed and progressively adapt to pedoclimatic characteristics,
– evolving populations intraspecific derive from mixtures that include varieties, crosses, and populations of the same species.
Mixtures and low input
Cereal farming has suffered for decades from a lack of varieties truly suitable for cultivation with the organic method. The versatility and resilience of mixtures – documented by extensive scientific literature – instead allows the establishment of agricultural activities even in so-called marginal areas or those subject to extreme climatic conditions.
In Italy the first wheat varietal mixtures are thus beginning to be cultivated, adopting practices of sustainable agriculture. Noting how their great adaptive capacity 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 – that 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 monocultures – records an average increase of 3.5% (with peaks of 6.2%, in the presence of significant biotic stress).
The mixtures are therefore even more effective in crops that do not involve the use of pesticides. The uneven height of the plants, moreover, 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 livelihood of communities in the arid areas of the planet (North Africa, Middle East, Central Asia). Thanks to its large germplasm bank, ICARDA had established in Aleppo (Syria) populations of durum wheat (with 700 F2 varieties) and soft wheat (with 2000 varieties among F2, F3, and F4). (6)
The valuable work carried out in Syria has allowed the creation of populations capable of providing farmers with the widest possible genetic material, able to adapt to different environments, soils, and agronomic techniques. Including organic farming under 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 supplied to three farmers in as many regions, as part of the European SOLIBAM project. (8)
From Syria to Sicily, one of the three small plots was entrusted 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. Additionally, he was the first in Sicily to register 3 local wheat varieties in the section ‘Conservation 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. They cannot be qualified as 'varieties', lacking the requirements of uniformity, distinctness and stability established by European seed legislation. They are in fact populations (Composite Cross Population, CCP) of which Italy – precisely thanks to the work carried out in the fields over these years – was able to declare in 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 soft wheat ‘SOLIBAM Li Rosi’. MIPAAF and CREA-DC (Defense and Certification) are now defining procedures on field inspections, 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 multiplying farmers. (9)
Wheat mixtures, the Sicilian renaissance of organic cereal farming
In Sicily, several farmers who are members of the Simenza Association cultivate evolutionary wheat populations under organic farming. The wheat is marketed at a price that recognizes the dignity of work, 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 represent the renaissance of Sicilian cereal cultivation. Offering farmers the significant opportunity to free themselves from the overpowering control of Corporation that dominate the global seed market and cultivation technical means.
#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 the 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 the F1 (first reproduction). In practice, after sowing 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 participatory plant breeding is and how it 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 genetic improvement for organic farming: 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 in any case allows the cultivation of diverse populations by 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 grains.
