Les bio-intrants et micro-organismes, des alternatives aux pesticides en Amérique du Sud ?

South America supplies 15 billion 300 million tonnes of the world's agricultural products. Sugarcane, corn, and soybeans account for 80 billion 300 million tonnes of local production and are primarily exported to Europe, Asia, and North America. Chemical pesticides are widely used on large farms, at some of the highest levels in the world. The FARM Foundation interviewed two researchers with expertise on the subject to understand the pathways being considered to reduce pesticide use in these countries. 

• Decio Karam is a researcher at EMBRAPA (Brazilian Federal Institute of Agricultural Research, attached to the Ministry of Agriculture), a specialist in weed control in corn and sorghum crops. He is in charge of EMBRAPA's project portfolio entitled "Integrated Management of Agrochemicals," which aims to rationalize the use and minimize the impacts of these products in the various Brazilian agro-ecosystems.

• Frédéric Goulet is a researcher at CIRAD (Centre for International Cooperation in Agricultural Research for Development, France), he is based in Mexico, after several years spent in Brazil. His research focuses on the emergence of bio-input technologies in agriculture, the transformations of agricultural research in response to societal challenges, as well as the production and sharing of knowledge among farmers.[1]. 

South America has the highest concentration of chemical pesticide use. What explains this trend?

Decio Karam (EMBRAPA) : In Brazil, very different agricultural systems coexist, between large-scale crops (soybeans, corn, cotton, etc.) that are produced over large areas and other agricultural production. Our climate allows for a great diversity of crops and even several crops in the same year. This is also the case for weeds: they can undergo several reproductive cycles in the same year, germinating and re-infesting the cultivated field very quickly.

The same is true for insects and microorganisms. Temperature and humidity conditions allow them to have multiple development cycles in the same year. This leads farmers to frequently use treatment products in their fields. The growth in pesticide use goes hand in hand with the expansion of the agricultural system based on soy and corn which has grown significantly since the 1990s. It is also very difficult to imagine producing corn or soybeans today without pesticides.

Intensification, in my opinion, explains the growth in pesticide use. Farmers almost systematically harvest two crops on the same area in the same year: a first harvest of soybeans or corn, then a second harvest of corn. The quantity of inputs per unit of area increases accordingly.

But things are changing, particularly in the fight against insect pests, as farmers are increasingly using biocontrol products.

Frédéric Goulet (CIRAD) : Across South America, there are differences between countries and cultures. Not all share the same agricultural model. A distinction must be made between the Andean countries and the countries of what I will call the soy basin (Brazil, Argentina, Uruguay, Paraguay). The crops that consume the most pesticides are indeed large-scale crops (corn, soybeans), but also arboriculture. The soy boom since the mid-1990s has increased pesticide use: the aim was—and still is—to produce soybeans for export at low cost, on very large areas. It is a highly technical agricultural model, which consumes a lot of chemical inputs. The desire to reduce the use of inputs was almost non-existent until recently; the challenge was, on the contrary, to improve the logistical conditions for accessing them.

More recently, there has been a reversal, driven by rising fertilizer costs and chemical residue standards imposed by import customers in the European Union and the United States. Trade policies are an effective driver of transformation on the ground, much more so than mobilization or social pressure for the reduction of chemical pesticides who ultimately have very relative power compared to agro-industrial lobbies, particularly in Brazil.

What alternative strategies to pesticides seem most relevant to you?

Decio Karam : Within EMBRAPA, we have developed a program " Rational Pesticides Management ", which studies the consequences of using chemical pesticides. We propose alternatives to reduce their use.

To do this, we identify three areas of work. The first is the use of methods of biological insect controlThese products, commonly called biocontrol, are increasingly used as a substitute for chemical insecticides. This is the case, for example, in the vast majority of sugar cane plantations.[2].

The second is the use of plant cover between each successive crop. They are mainly used to protect soils and retain moisture. We find that they also have a positive benefit on crop health (plants are more resistant) while regulating the presence of pests. For example, in the Cerrado region (Brazil), farmers grow Brachiaria (a herbaceous plant that provides interesting pasture) before sowing soybeans.

Finally, there is genetic innovation and seedsWe invest in these biotechnologies, in collaboration with private players.

Frédéric Goulet : Brazil and Argentina have in fact implemented agricultural policies in recent years which explicitly aim to promote “bio-inputs” as alternatives to chemical products. This family of products includes biocontrol products and biofertilizers. A large majority of countries in the region have also implemented national programs, legislative projects, research support, or support for industry to develop this sector. This is a real, very promising turning point that took place about ten years ago towards the use of microorganisms (bacteria, fungi, and no longer just insects) as bio-inputs. This is a far cry from the image of insect farming that we might have in Europe because we are talking about biotechnologies.

The use of biologically derived inputs is an ancestral practice. The dissemination of these technologies to farmers has grown considerably in recent years, notably thanks to private entrepreneurs who have invested in innovations resulting from public research. Moreover, what's interesting about microorganisms is that, unlike synthetic products, farmers can produce them themselves on the farm. It's not uncommon to see large farms that have installed units for the production and multiplication of microorganismsA service economy has been created: supply of turnkey installations, strains of bacteria, growing media, advice, etc. A network of producers has also been structured at the federal level, the GAAS (Associated Group for Sustainable Agriculture). Farmers are taking advantage of it and sharing their experience; it is a sector in full swing.

The bacteria used work on both fertilization and plant protection functions. Corn producers in Brazil report having halved their use of chemical insecticides. Technically, it works, and economically, it's very attractive. Therefore, it's a way for producers to resolve the equation between reducing plant protection products and improving economic performance.

The economic argument for on-farm production of microorganisms—less expensive than purchasing ready-to-use products—is gaining traction among producers. They consider bio-inputs as less expensive alternatives to chemical fertilizers and pesticides, without necessarily calling their production system into question. But at the same time, educated by specialized advisors or organic input companies, they understand that agronomic reasoning must be different, that it is in their interest to extend crop rotation cycles and diversify the varieties they use. The use of a new family of technologies, bio-inputs, is a gateway to broader thinking at the level of the production system. But bio-inputs are not a complete substitute for pesticides; chemistry remains a pillar of an agro-export model, which is therefore not being challenged for the moment.

What are the obstacles and levers to activate to more widely disseminate agricultural practices that use less chemical pesticides?

Decio Karam : Firstly, there is a real lack of information, training and advice to small producers on the subject of pesticides, particularly in the fruit and vegetable food sectors. These farmers, whose farms are very modest in size, are the poor relations of agricultural policy, its support, and its regulations. They do not benefit from the subsidies allocated to major sectors such as large-scale crops (corn and soybeans). They also do not have access to protective equipment or training on the proper use of chemicals. The risks of contamination are high.

Next, it is important to know that in Brazil, the approval process for new products is changing. Previously, approval decisions were shared between the Ministries of Agriculture, Health, and Environment, and the process lasted 10 to 20 years. new law will accelerate the approval process for new pesticides with a maximum period of 2 years. The links between Parliament and large farmers are now closer.

Frédéric Goulet : Regarding major crops, let's be clear: economic profitability always prevails, before the question of environmental sustainability. In Brazil, Argentina, and more recently Mexico, however, the context is favorable for innovation in major export crops. The agricultural world there is extremely innovative, highly technological, and geared to international competition. In this context, bio-inputs benefit from a favorable alignment between the scientific innovation ecosystem, the economic and political sectors. This makes them a way forward for reducing dependence on chemical inputs, fertilizers, and pesticides.

Soybeans, cereals, citrus fruits and coffee are sectors that are evolving, driven by pesticide residue standards imposed by import customers. For small producers and family farmers, the picture is a little different. They have sometimes long been convinced of the use of natural inputs and microorganisms. In Brazil, the Lula government is also considering a support program to facilitate the installation of small bio-input manufacturing units on small family farms, as is already the case in Mexico and other countries.

It's still a success to see that the technical solutions proposed by research are being adopted in the field and supported at the political level. But such enthusiasm for on-farm microorganism production is not without risks. Scientists highlight the biological risk linked to the multiplication of undesirable microorganisms and the spread of resistant bacteria. How can we regulate and control them on the scale of a country like Brazil? First and foremost, farmers, technicians and advisors must be trained on the use of microorganisms. Public policies are also necessary to support their development and use.

*****

Through the Pretag initiative (Pesticide Reduction for Tropical Agricultures), the FARM Foundation is working alongside Agropolis Foundation to support the production of knowledge and solutions for the reduction of pesticides in agriculture in the Global South.

Coordinated by CIRAD, This initiative aims to build, with various private and public actors, trajectories for effectively reducing the use of chemical pesticides, relying in particular on multi-actor platforms in the sectors:

• market gardening in West Africa,
• rice in Asia (Cambodia),
• coffee in Central America,
• cocoa in West and Central Africa
• banana “export” to the Antilles, Africa and Central America.

[1] Goulet F., 2021. Biological inputs and agricultural policies in South America: between ruptures and continuities. Montpellier, CIRAD, Perspective 55. https://doi.org/10.19182/perspective/36381

[2] Postali Parra, J.R., & Coelho, A. (2019). Applied Biological Control in Brazil: From Laboratory Assays to Field Application. Journal of insect science (Online), 19(2), 5. https://doi.org/10.1093/jisesa/iey112