Link between biodiversity and agricultural yield
Link between biodiversity and agricultural yield
In recent times, the crisis in the agri-food sector, linked above all to the environmental impact of certain agricultural practices and excessively energy-intensive distribution systems, has led many researchers from various universities to carry out analyzes and research on new production models.
At the center of these researches is the possible link between an increase in natural and agricultural biodiversity and the quality and quantity of the products obtained.
The results were not long in coming and were also confirmed by the declarations, among others, of Giovanni Tamburini, Researcher at the University of Bari and the University of Agricultural Sciences of Uppsala (Sweden) and main author of a study on reflections of biodiversity on agricultural processes, who states that: “The current trend is the simplification of the main cropping systems around the world. We cultivate monocultures on fields that spread over homogenized landscapes. The results of our study indicate that diversification can reverse the negative impacts we observe in simplified forms of cultivation both on the environment and on production itself“ (Tamburini G. et Al. 2020).
To reinforce this and other studies, an English study took care of it, which lasted about 10 years, where it is highlighted how in farms the renaturalization of the surfaces increases the crops.
Contrary to what one might think (according to the assumption of crop specialization) when part of the agricultural areas are reserved for nature, productivity is not reduced. The results indeed indicate, on the contrary, that in some cases it increases it.
This is precisely what emerged from the decennial study of the Center for Ecology and Hydrology of the United Kingdom. The project was conducted on a 1,000-hectare farm in Hillesden, a village in England, belonging to the county of Buckinghamshire.
In this company, since 2005, a renaturalization project of some agricultural areas has been carried out, creating greater biodiversity to support the surrounding habitats.
The data that emerged after several years (remember that a natural cycle needs several years to have statistical significance) is that thanks to the plants inserted in these areas, the presence of insects useful for agricultural production has increased, such as pollinators and predatory insects of parasites.
Therefore, in the work of Tamburini and others, as well as other studies, which we do not mention here in order not to dwell, the increase in yields is connected to a system of flora and fauna biodiversity that is perfectly in agreement with the theory of dissipative systems of Y. Prigogine (Nobel prize for chemistry in 1977), in which the scientist of Russian origin demonstrated that the most complex thermodynamic systems, such as ecosystems rich in biodiversity, make better use of the available energy (mostly solar) leading to a Primary Productivity greater.
In the area covered by the ten-year study, the number of some species of butterflies has also increased, as well as that of small mammals and birds. Among the latter, the presence of the great tit (Parus major Linnaeus, 1758) almost doubled, with an increase of 88%, and of the blue tit (Cyanistes caeruleus Linnaeus, 1758) which benefited from the shelter provided by hedges and grassy margins.
The interesting fact, in agreement, among other things, with the principles and foundations of agroecology, is that thanks to the presence of these insects and animals, despite a portion of the agricultural area having been removed from cultivation, the overall yields of farm have remained unchanged and in some cases improved.
The researchers stated that “it is not convenient to cultivate in areas with little production where instead it is more advantageous to leave room for nature by increasing the average yield. Having more nature on the farm has a positive effect on the crops” And, we probably add, also on their quality, also due to the lower use of synthetic chemicals.
A final note on the study is that of its potential replicability in similar contexts. The project was in fact carried out on a large farm, managed with conventional agricultural practices, in an area with no particularly large natural areas.
This means that in order to be able to replicate it in areas with smaller companies, one could think of a pilot project starting from Rural Districts.
Among other things, precisely in Sicily, the enactment of the L.R. 21 of 2021, on agroecology, would find a normative and regulatory ground, it must be said, particularly fertile.
Guido Bissanti