Wheat varietal mixtures, agrobiodiversity and resilience

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Agrobiodiversity and resilience. Research on wheat varietal mixtures proves to be the new frontier of ecoagriculture, 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, the set of all components of biological diversity that are relevant to agriculture and the agroecosystem-plays a key role in the so-called
food security
. Namely, the security of food supplies on the planet.

Food security is seriously threatened by climate change, desertification and other anthropogenic factors. Not the least of these is the drastic reduction in the number of plant species grown, where 9 crops alone now account for 66 percent of global agricultural production(FAO, 2019).

Among other things, the reduction in the number of cultivated species and varieties is directly related to the increasing prevalence of a wide range of diseases in the human body. The homogenization of diets-with reduced varieties of micronutrients and phytocomplexes-is indeed attributed to several diseases, primarily related to the immune system and inflammation. (1) With higher occurrence in cases of consumption of ultra-processed HFSS(High in Fats, Sugar and Sodium) foods.

Agrobiodiversity, climate change, and varietal mixtures

Today’s food and agricultural systems do not lend themselves to coping with the impact of climate change precisely because of their great uniformity. Models predicting the variables associated with climate change, after all, are far from in agreement. And it is almost impossible to develop reliable genetic improvement programs, whether conventional or molecular.

Instead, an effective strategy to enable our crops to evolve and gradually adapt to climate change-ensuring stable yields and products of appreciable nutritional quality-is to grow varietal mixtures. Genetic improvement thus moves from research stations to farmers’ fields. Who are effectively involved in the entire decision-making process, applying what is known as Participatory Plant Breeding(PPB).

Another technique to bring diversity back to the fields, also making use where appropriate of collaboration with institutions, is Evolutionary Plant Breeding (EPB). (2) Which consists of the use of mixtures and evolutionary populations:

mixtures result from mixtures of different varieties of the same species. Which, once planted, can cross naturally and gradually adapt to the soil and climate characteristics,

– intraspecific evolutionary populations result from mixtures that include varieties, crosses, and populations of the same species.

Mixtures and low-input organic farming

Cereal farming has suffered from a shortage of varieties actually suitable for organic farming for decades. On the other hand, the versatility and resilience of the mixtures-documented by extensive scientific literature-enables agricultural activities to be established even in so-called marginal areas or otherwise subject to extreme climatic conditions.

Thus, the first wheat varietal mixtures are beginning to be grown in Italy, adopting practices of sustainable agriculture. Realizing how their great adaptive capacity allows minimizing inputs (or technical means) in agriculture.

The broad genetic base of the varietal mixtures allows them to adapt, ensuring a plant presence that tends to be constant under different soil and climate conditions. Thus, mixtures provide significant stability-even in marginal soils-that exceeds that of monocultures in terms of yield under the same conditions. (3)

Wheat mixtures and yield increases. Scientific study

The meta-analysisUnfolding the potential of wheat cultivarmixtures: A meta-analysis perspective and identification of knowledge gaps‘ considers about 120 scientific papers on wheatcultivarmixtures. All other things being equal, the total yield of wheat mixtures–compared with monovarieties–shows an average increase of 3.5 percent (with peaks of 6.2 percent under significant biotic stresses).

Thus, mixtures are even more effective in crops that do not involve pesticides. The uneven plant height, moreover, maximizes photosynthetic efficiency and reduces evaporation. (4) And their competitiveness with weeds is better. (5)

Wheat mixtures, the great gift of the Mediterranean

ICARDA(International Center for Agricultural Research in the Dry Areas) is a nonprofit organization, engaged in agricultural research since 1977, that aspires to improve the livelihoods of communities in the dry areas of the planet (North Africa, Middle East, Central Asia). Through its large germplasm bank, ICARDA had established populations of durum wheat (with 700 F2 varieties) and soft wheat (with 2,000 varieties between F2, F3 and F4) in Aleppo, Syria. (6)

The valuable work conducted in Syria has resulted in populations that can provide farmers with the broadest possible genetic material that can adapt to different environments, soils and agronomic techniques. Including low-input organic farming. Thanks to Prof. Salvatore Ceccarelli, the three evolutionary populations of ICARDA arrived in Italy in 2010. (7) And a small amount of seed (23 kg) was provided to three farmers in as many regions under the European SOLIBAM project. (8)

From Syria to Sicily, one of the three small lots was given to the Terre Frumentarie company 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 varieties of wheat in the ‘Conservation Varieties’ section of the National Register of Varieties of Agricultural and Horticultural 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’ because they do not meet the requirements of uniformity, distinctiveness and stability established by European seed legislation. These are indeed populations(Composite Cross Population, CCP) of which Italy-thanks precisely to its work in the fields in recent years-has been able to declare to Brussels its interest in authorizing the sale. Albeit, initially, in a temporary experimental phase.

Of the 8 grain populations temporarily authorized for sale as seed, one is precisely the ‘SOLIBAM tender Li Rosi’ wheat population. MIPAAF and CREA-DC (Defense and Certification) are now establishing procedures on field checks, certification of quantities allowed for sale for each population, and phytosanitary checks. In view of the issuance of the marketing tag and authorization (as an exception) for sale by multiplier farmers. (9)

Wheat mixes, the Sicilian renaissance of organic cereal farming

In Sicily, several farmers who are members of the Simenza Association grow evolving populations of wheat organically. Wheat is marketed at a price that recognizes the dignity of labor, in a logic of fairness and sustainability of the supply chain.

The resulting flours are suitable for bakery, gastronomy and pastry of ‘100% Made in Italy‘ quality.

‘If you control oil, you control nations; if you control food, you control peoples(Henry Kissinger)

From a socio-economic point of view, wheat mixtures can truly express the renaissance of Sicilian cereal farming. Offering farmers the relevant opportunity to enfranchise themselves from the overwhelming power of the corporations that dominate the global market for seeds and technical means of cultivation.

#Égalité!

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:

Microbiome, gut, and health,

Hepatic steatosis,

(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 each other after F1 seeding (first reproduction). In practice, after F1 is sown, some of the harvested seed is reseeded to give rise to the second generation (F2), and so on

(7) Ceccarelli S. (2016). Stir peasants, stir. What is and how is participatory breeding done. Ed. Pentagora 2016, EAN: 9788898187393

(8) The SOLIBEM project was co-funded by the European Commission, under the Seventh Framework Program, from 2010 to 2014. V. Bettina Bussi, Riccardo Bocci, Salvatore Ceccarelli, Matteo Petitti, Stefano Benedettelli.
The frontier of grain genetic improvement for organic farming: heterogeneous material.
. Rural seeds,

(9) The European community extended the temporary authorization for the sale of heterogeneous material, by way of derogation from existing legislation, until 2021. The new organic farming regulation allows different populations to be cultivated by this method in any case.

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Agronomist, collaborates with the Department of Agriculture, Food and Environment of the University of Catania, Agronomy and Herbaceous Crops section. Researcher on ancient Sicilian grains.