Sustainable Stories

Modern agriculture is facing various problems such as explosive growth of the global population, climate change, large-scale natural disasters, and the spread of infectious diseases. Japan has suffered labor shortages due to population aging. Now there is an urgent need to build sustainable food production systems for the future, more productive and environmentally friendly agricultural technologies are required than ever before.

New agricultural materials called biostimulants have been in the spotlight in recent years.
Biostimulants differ from substances such as fertilizers, which supply nourishment to plants, and agrochemicals, which exterminate pests and weeds. They have the potential to bring out the original, natural power of plants, which will lead to steady growth and harvests.
Europe has been an early leader in this field. However, interest in Japan has been growing rapidly and the use of biostimulants as an innovative agricultural technology is expanding under the Green Food System Strategy formulated by the Ministry of Agriculture, Forestry and Fisheries (MAFF) in 2021.

The raw materials for biostimulants are naturally derived substances. They include humic acids produced by the decomposition of plants, polysaccharides extracted from seaweed, amino acids and minerals, and microorganisms that coexist with plants. Some of them have been used in agriculture since ancient times. In a broader sense, the Japanese-originated bokashi compost (a fertilizer made from fermented organic matter) can be considered one form of bio-stimulant.
Deploying these materials effectively in crop cultivation will produce superior effects; for instance, improving the photosynthetic function and increasing root activity in plants, such as increasing the absorption power of water and nutrients. They also increase resistance to stress.

“What I would like to emphasize here is that biostimulants are not a kind of trump card that can be used in all cases. By combining them with complementary existing technologies such as agrochemicals, fertilizers, soil improvers and plant breeding, we aim to achieve better growth while distributing risks,” Mr. Sudo explains.

- Why is there growing global interest in biostimulants now?

“With limited arable land and rapidly increasing populations, the only way to procure sufficient agricultural production worldwide is to increase crop yields per unit area. The key to improving efficiency is in finding ways to combat abiotic stresses, which is still a relatively untouched issue. We believe that by combining conventional solutions such as fertilizers and agrochemicals with new environmentally friendly technologies like biostimulants, we will be able to tackle the food supply problems of the future.”

Mr. Sudo continues.
“In Japan, which has a declining population, the background is somewhat different from the international situation. The advantages of biostimulants in Japan are focused more on improving quality rather than increasing crop yields. High-quality, good-tasting crops can meet the needs of consumers.
If crops grow in a good state, the shape and size of plants in the crop will become more uniform, and the number of plants that are considered substandard (i.e., failing to meet specifications) will decrease. Another advantage is in reducing waste loss. We believe that by reducing the amount of labor required for sorting, we can contribute to improving production efficiency for farmers who are struggling with labor shortages.”

Another factor in the interest in biostimulants is that they are naturally derived. Biostimulants can limit excessive use of agrochemicals and chemical fertilizers by supplementing the roles of these substances without placing a burden on the environment, so they are highly likely to satisfy the needs of agriculture in the future.

Nagase Viita has been conducting research into biostimulants for many years.
“Previous research has shown that our trehalose has the ability to induce the original immunity of plants.
For example, it has been reported that giving trehalose to plants can induce hormones that regulate the opening and closing of pores, causing a phenomenon in which the plants’ ability to withstand dryness is increased. Spraying with trehalose also synthesizes starch, which is disliked by pests such as aphids. Various benefits have been observed, such as in avoiding crop damage from aphids without the use of pesticides.”
Dr. Takanobu Higashiyama, who is involved in bio-stimulant-related research at Nagase Viita, explains.

“Trehalose is originally a component that exists in bacteria and the bodies of insects, so spaying trehalose will trigger a response in plants as if these stressors are present. The plants produce hormones to resist stress. This action makes them less susceptible to disease. Put simply, it’s like vaccination. In addition to abiotic environmental stresses, we also expect to apply this method to increase resistance to biological stresses such as pests and diseases in the future,” explains Dr. Higashiyama.

There are cases of indirect use of trehalose for its cell stabilizing function in biostimulants.
“In South America, microorganisms called rhizobia are used as biostimulants formulations for soybean cultivation. Since the rhizobium preparation is a live fungus, it cannot be stored at room temperature for an extended period as it is. By adding trehalose, we have been able to stabilize the membrane structure of the fungus and greatly improve its shelf life, gaining widespread use among soybean farmers in South America.”

“The widespread adoption of rhizobium preparations has major benefits for local farmers.
The first advantage is cost. If rhizobia cannot be used, then nitrogen must be supplemented using large amounts of expensive chemical fertilizers. Because rhizobia preparations, which efficiently fix nitrogen from the atmosphere, are extremely cheap by comparison, they improve the economic situation of farmers.
Another advantage is safety. Because biostimulants are of natural origin, they can solve problems such as the decline in soil fertility due to the continuous use of chemical fertilizers, and health hazards to farmers.

Dr. Higashiyama continues, “Trehalose is originally made using microorganisms in the soil, so their use in agriculture is essentially returning something that we got from the soil to the soil again. In a sense, we could say that it is the most natural use of trehalose.
We feel that there is great potential in applying trehalose’s excellent quality retention capabilities to the production of crops, upstream of food processing, which will resolve agricultural problems around the world.”

As seen here, there are high expectations for biostimulants. Nonetheless, a broad range of bio-stimulant materials and applications exist, and their effects still have many aspects that have yet to be explained. As Mr. Sudo makes clear, a number of obstacles remain before they achieve widespread use in Japan.
“To put it another way, natural action is gentle action, and the way these effects manifest themselves varies greatly depending on interactions with various other growth conditions. There are many uncertainties, so it is natural for farmers to feel that it is a difficult area to invest money and effort into,” he says.
“If we are to promote the use, we will need quantitative evidence of the usefulness of biostimulants. This will require a concerted effort involving industry, government and academia. At the same time, we will need to encourage understanding of their unique character. As a prerequisite, there is also a pressing need for us to discuss quality standards for biostimulants in the industry and exchange opinions with the government. The association is prioritizing these activities.”

In the future, agriculture will need to reduce its reliance on chemical pesticides and fertilizers, and biostimulants will play a vital role in this.
When farmers can start making effective use of biostimulants with peace of mind, that will represent a major step towards sustainable agriculture. At Nagase Viita, we’ll be stepping up our focus on R&D, aiming to make a significant contribution to this field through products and technologies such as trehalose.