Fieldwork

The researchers at Evonik are focusing on three areas of action: They want to find formulations for active ingredients that can be used to treat seeds even before they are sown. In addition, they are looking for biostimulants that boost plants’ resistance and tolerance against abiotic stresses such as heat, drought, or frost, and that promote plant health. Finally, the researchers want to develop substances that can be used to stabilize biologically active ingredients. That’s because the best of nature’s little helpers is of no use if it doesn’t survive long enough or not along the route it has to take to reach the plant.

It’s about providing the plants out in the fields with optimal growing conditions. After all, out there they can be attacked by up to 10,000 different species of insects, 3,000 different nematodes, and 50,000 diseases caused by bacteria, fungi, and viruses. Climate change is another complicating factor. Drought, saline soils, damage caused by increased ultraviolet radiation, as well as flooding limit plant growth and reduce yields.

As a result, it’s all the more important that the seedlings get a good start. “We can ensure this by already treating the seeds,” says Ochrombel. To do this, the seeds are “dressed,” i.e. given a protective coating. This idea isn’t really new either—leek juice was already being used as a material for treating seeds in 450 B.C. Among other things, ancient Egyptians, Greeks, and Romans employed olive pomace, onion brew, and cypress juice to protect their seeds against pathogens.

Today, seed treatment is especially used for wheat, but also for corn, sugar beets, and rapeseed. Germany alone has around 1,800 seed treatment facilities that process around one million tons of grain per year. One of these treatment facilities is located on Esser’s farm in Horrem. This machine would normally not be in use in summer. However, Esser put it into operation in order to demonstrate the treatment process to the two researchers from Evonik. “We can dress about 25 tons of seed in one day,” says Esser. “That’s enough to cover our own needs.”

Seed treatment is one of the gentlest ways to protect and strengthen plants, because the targeted application enables the amounts of active ingredients required to be reduced to a minimum. One of the challenges is to precisely distribute the active ingredients. For example, the Chamber of Agriculture in North Rhine-Westphalia recommends that between 250 and 450 grains of winter wheat are sown per square meter. That translates into around 168 kilograms of seeds per hectare, or about 3.5 million grains of wheat. The seeds themselves have a total surface area of less than 130 square meters. About 40 grams of active ingredient are distributed over this surface, depending on the product in question. That’s only 12 micrograms per grain. “By using the right additives and binders, we can ensure that the coating is effectively and evenly distributed on the grain and that the active ingredients that it contains are released at the right time,” says Ochrombel.

Like most other farmers, Reiner Esser has only used chemical active ingredients until now. These substances protect not only the seed material, but also the growing plants in the field against diseases. However, many farmers have recognized that it’s not enough to simply protect plants against diseases and to supply them with fertilizer. They need products that also increase the plants’ resilience and promote their health. Biostimulants are used for this purpose. “These products mostly contain amino acids, algae extracts, or microbes,” explains Ochrombel. “Microbes can, for example, adhere to the roots after a plant has sprouted. There, the microbes promote the plant’s growth, foster the uptake of nutrients, and supplant other germs that could potentially be pathogenic.”

Biostimulants expand the toolkit of today’s farmers. They improve fertilizer exploitation and soil fertility, mobilize nutrients in the soil, and fixate nitrogen from the surrounding air. In addition, they strengthen a plant’s resistance to environmental stress.

Although these substances won’t completely replace traditional plant protection products and fertilizers, they are cause for great hope. “That’s why it’s important that we obtain scientific insights into how each one works and that the formulations are reliably effective out in the field,” says Ochrombel.

The use of microbes can be complex because they often unfold their effect in several stages. Suppliers are already using a wide variety of bacterial strains for seed treatment as well as in the fields. Some of the coatings contain various species of Bacillus, while biostimulants for use out in the fields are strains of Pseudomonas or Penicillium. “We systematically study the potential of individual microbes in the laboratory. That way we can find precisely the organism that is best suited for a certain seed material and a specific task,” says Ochrombel.

Esser has also been won over by Evonik’s concept of providing tailored solutions instead of standard products. “I can well imagine that I’ll use more biological products in the future,” he says.

Many farmers still put their trust in conventional products, because they often think that biological solutions, and, in particular, those containing microbes, are insufficiently effective compared to chemicals. The researchers therefore have to develop a product that remains stable in storage and which is evenly distributed during use and works consistently in the field.

As a result, the first step that the researchers at Evonik took even before the Advanced Agro Solutions program was launched was to develop biocompatible additives and carrier materials that improve the performance and durability of microbial active substances in agricultural use. In the fall of 2019, the products were first presented in Europe and in the USA. They are now also available in the Asia-Pacific region.

“Our additives, for example, contain bio-based and biodegradable polyglycerol esters that are also approved for organic farming,” says Daniela Kruse, who managed the development program for the Interface & Performance business line. The product range also includes biodegradable substances based on polyether siloxanes. An accelerated storage test showed just how effective the products are. For this test, the solutions containing the microorganisms are stored in a heat cabinet at 40 degrees Celsius, which is comparable to a long summer heat wave. In unstabilized solutions, only one to two percent of the microbial spores survive this torture. However, if the solution is stabilized with polyglycerol esters, the survival rate rises to as high as 12 percent, and even to 30 to 40 percent if polyether siloxanes are added.

The additives that are marketed under the name BREAK-THRU® can do even more. Depending on their type, they also ensure good wetting, adhesion, and retention of bio-based plant protection products on leaves or an even penetration and distribution of active ingredients into upper soil layers without any leaching. “This makes Evonik one of the world’s pioneers in this field. I know of no other company that offers such a comprehensive range of additives and carrier fluids for microbial agricultural solutions,” says Kruse. It makes a small but important contribution to boosting the production of healthy, sustainable food.

Producing enough food to live from and later pass on the farm to the next generation while preserving nature—this sustainability principle has always been an important rule for farmers. That also applies to Reiner Esser: “Farmers like me have always lived off of and with the land.” Farmers have been using integrated plant protection, flower strips, and expanded crop rotation for a long time. In the future, the research work at Evonik will also enable them to rely on the help of millions of microscopic allies.