A mong other beneficial effects, biostimulants can increase nutrient use efficiency so that farmers receive a better return on their investment in fertilisers. This includes making use of nutrients in the soil that might not otherwise be available to plants, for example by solubilizing phosphorus into plant-available forms. These nutrient use improvements reduce nutrient losses and the related environmental impacts (and thus the cost of clean-up). The link between good nutrition and high yields is well established.

Biostimulants also help plants to tolerate abiotic stresses such as drought, extreme temperatures, salinity, and flooding better. Such harsh growing conditions can reduce yields as crops divert energy into stress responses. In the absence of biostimulants, stress may even kill the plant. By helping plants to cope better in the face of stress, biostimulants help ensure that yields are higher than they would be without this “biological insurance”. Although it is not their primary reason for use, making plants more vigorous in the face of abiotic stresses is likely to make them less vulnerable to disease in the same way that you are less likely to fall ill if you eat a healthy, balanced diet.

Both the improved use of nutrients and stress tolerance enhance quality of output. Improved yield and quality both influence farmer profitability.

Biostimulants that foster robust root development also improve water use efficiency, which will often help improve yield as well.

All of these benefits have been widely tested and documented in field trials.

It is difficult to generalise the exact level of the impacts because it depends on the crop in question, the specific biostimulant product, the original state of the soil, how well managed crops already are and several other factors. However, minimum yield increases related to biostimulant use are reported at 5-10%.

When viewed in the light of the overproduction that occurred in Europe in the not-too-distant past, the need for increased productivity may not seem obvious. But the global agricultural situation changed radically in 2008, when markets entered a period of high volatility. The OECD-FAO Agricultural Outlook: 2001-2020 stresses the need to rebuild stocks to reduce volatility, but also points out that high prices “are a positive signal to a sector that has been experiencing declines in prices expressed in real terms for many decades and are likely to stimulate the investments in improved productivity and increased output needed to meet the rising demands for food” (p.14, emphasis added). There is an increasingly strong consensus that improving agricultural sustainability depends on optimising output on the best arable land and reducing pressure on land that would be better used for other things, including conservation. In the same report, OECD/FAO say that “Land available for agriculture is increasingly constrained...Substantial further investments into productivity enhancements are needed to ensure the sector can meet the rising demands of the future” (p.14, emphasis added). This sustainable intensification is dependent on efficient use of inputs such as nutrients, water and plant protection products, which are fostered by biostimulants use.