Nature’s fertilizer: how tiny soil bacteria are helping produce our food

Nathan Froese, global seed treatment research and development, BASF

Like children need their calcium, crops such as peas, soybeans and chickpeas need nitrogen for healthy growth and repair.

To keep their crops healthy, farmers rely on a range of supplementary products, including organic and mineral fertilizers, to grow strong plants that can withstand disease, droughts or floods.

One exciting area with enormous potential for optimising plant nutrition and health is the use of a natural bacteria that convert nitrogen from the air into a form that legume plants can use.

This is one of the most impressive examples of circular agriculture, and has a long history of being exploited by farmers going back centuries. And thanks to new developments, it is also an emerging example of precision agriculture.

It starts with a naturally-occurring bacteria called “rhizobia” that can be found in soil. These bacteria attach and penetrate root hairs of compatible legume crops such as peas, and converts atmospheric nitrogen for the host plant, providing it with a nutrient essential to healthy growth.

In recent years, crop scientists have been getting better and better at identifying which of these bacteria are best for which crops and in which soils.

With new technologies, we can then reproduce them at high concentrations, which are then either used in coatings for seeds or applied during planting, to be even more effective.

This ensures the crops benefit from the right bacteria in the right amount to receive valuable nutrients to aid in productivity.

This innovation is just one example of how crop scientists are harnessing what nature provides to help farmers achieve more with fewer and better quality inputs.

One benefit of using nature’s fertilizer, known as inoculants, is the efficiency savings.

Just 300g of modern, high-quality inoculant contains as many rhizobia as a four-tonne truckload of soil taken from the field.

This allows farmers to minimise the inputs needed per hectare for a healthy harvest, helping to reduce costs and labour.

Another benefit is that this product can help farmers in developing and developed countries.

In Ghana, for example, farmers have seen their peanut plants grow 50cm taller after applying an inoculant.

Finally, their natural beginnings mean organic and conventional farmers alike can use them.

Unlike with mineral fertilizers, there is no risk of runoffs into waterways and inoculants do not generate greenhouse gas emissions, making them a valuable contribution to “climate-smart agriculture”.

Many crop science innovations rely on improving natural processes to maximise food production, but industry is also working hard to ensure they also meet farmers’ needs, by carefully designing packages of inoculants in different sizes.

By combining nature and science in increasingly creative ways, crop science can help farmers feed the world within planetary boundaries.