Compost Magazine

Composting tips, advice and science.

Carrots lying on a small mound of compost.

Compost Is Secret To Growing More Nutritious Veg Says New Study

5th April 2023

In a groundbreaking new study, researchers have discovered that using compost can significantly improve both the growth and nutritional quality of vegetables, specifically carrots.

The scientists behind the study were experimenting with a compost that had been made at high temperatures. 

The compost used in the study contained the bacteria Baccillus, a common microorganism found in compost made at higher temperatures. 

The study results suggested that exposure to the compost led to increased levels of antioxidants, amino acids, flavonoids and/or carotenoids. 

The carrots initially fell behind the control. 

However, after one month carrots grown with the compost containing Baccillus not only caught up with the control group, but surpassed them in both size and color; the carrots were larger, had a deeper red hue, and tasted significantly better.

This was in stark contrast to previous research, which found carrot colour and flavour is primarily determined by genetics. 

This study’s findings suggest that using compost could also lead to crops that are more nutritious and better for human health. 

For example, the carrots grown with compost containing Bacillaceae contained higher levels of antioxidants, which are thought to prevent heart disease, cancer and other chronic diseases.

In addition to the potential health benefits for vegetable lovers, the use of compost has broader implications for global food security. 

What’s the problem with artificial fertilisers?

Robot sprays plants in a huge greenhouse.
The majority of modern agriculture relies on artificial fertilisers made with scarce resources in often unstable countries.

Some scientists believe we could run out of one key resource, phosphate, in just a few years. 

The production and transport of artificial fertilisers also uses huge amounts of energy. 

 This contributes to global emissions, even as excessive use can devastate local ecosystems and pollute our rivers and seas.

See How Humanure Can Change The World for more information on issues with artificial fertilizers.

With a growing world population, and deaths attributed to malnutrition and global warming, it’s increasingly important to produce crops that are both sustainable and nutritious. 

The use of compost containing Bacillaceae could be a step towards achieving these goals, which could help provide a more secure food supply for the future.

This is a particularly exciting study, as most research focuses on how compost can improve soil structure and growing conditions, not on the impact on nutrition.

However, it’s worth noting that this study was limited to one type of crop and one specific type of compost.

The study did not compare the effects of compost containing Bacillaceae with other types of composts and natural fertilizers, so it’s unclear how it compares to other sustainable farming practices.

At a time when the world is grappling with both global warming and food insecurity, more research is urgently needed to fully understand the effects of different types of compost on different crops and in different settings, as well as to corroborate the results. 

So while the study’s findings are promising, it’s important to approach them with caution until more research has been done. 

Still, it’s clear that the potential benefits of using compost in sustainable agriculture are potentially huge. 

What’s more, one other study – as well as case studies from the 1940’s – suggest that compost can improve the health benefits of vegetables.

The practice could help produce crops that are both nutritious and environmentally-friendly, providing a more secure food supply for the future.

Source: Miyamoto, H., Shigeta, K., Suda, W. et al. An agroecological structure model of compost—soil—plant interactions for sustainable organic farming. ISME COMMUN. 3, 28 (2023).

Before you go…

Compost thermometer showing hot compost.

Many composters find hot composting hard – but if you follow a few simple rules, it’s not that hard! To learn how see: The Five Rules to Successful Hot Composting (or How Anyone Can Hot Compost)

Hand holds sawdust.

Is there a secret to making hot compost? These researchers believe there is – and believe that by using it home composters can make compost in 21 days. See Researchers Unveil Secrets to Effective Home Composting for details.