Harnessing the power of beneficial microbes for resilient crop growth

In the traditional view, growing media served as an inert conduit for nutrients and water to nourish plant roots. Soil biology, on the other hand, was often perceived negatively by growers, associated with the presence of harmful pathogens like phytophthora and pythium.

However, a shift has taken place in recent years as a newfound fascination with the soil microbiome emerged. This interest stems from the realisation of its immense potential to benefit growers. By cultivating a robust and healthy soil microbiome grower can harness an array of beneficial microbes to elevate the quality, vitality and resilience of their crops.

Remarkably, this transformative approach also facilitates a reduction in fertiliser inputs and is paving the way for a more sustainable and eco-friendly horticultural practices.

Nature’s hidden heroes – exploring the remarkable benefits of soil microbes

Find out how the world of soil microbes holds the key to a myriad of benefits that together weave an intricate tapestry and pave the way for a resilient crop.

Enhanced nutrient availability: 

Microbes break down, or ‘mineralise’ complex organic matter, such as dead plant materials and organic fertilisers, into essential nutrients that plant roots can readily absorb. Microbial activity and plant metabolism are both regulated by temperature – meaning that a steady and balanced supply of nutrients are supplied at a rate that matches the plants needs.

Improved soil structure:

The presence of microbes improves soil's physical structure. Fungal threads, called mycelium, acts like an extended "root system". These hyphae bind soil particles together, improving soil aeration, water retention, and drainage. As a result, the soil has a more favourable environment for root growth and is less likely to become waterlogged.

Disease suppression:

A healthy microbial community acts as the first line of defence against plant diseases. Certain beneficial bacteria and fungi form symbiotic relationships with plants, helping to suppress harmful pathogens. This is done either by physically shielding the roots to excluding pathogens, stimulating the plants’ natural pathogen resistance, or by directly attacking the pathogens. A general rule is that the more diverse the microbiome, the lower the risk of pathogen attacks.

Environmental stress tolerance:

Microbes play an essential role in environmental stress tolerance, such as extreme temperatures, drought, and salinity. Some microbes produce stress-resistant compounds, while others trigger the plant’s natural stress tolerance mechanisms, making plants more adept at handling adverse conditions.

Nutrient recycling:

Microbes contribute to a sustainable gardening practice by recycling nutrients within the soil. Dead plant matter and peat-free ingredients such as coir, bark and wood fibres are broken down by microbes to release nutrients into the soil for the plant use. This recycling process reduces the amount of fertilisation required and minimises nutrient runoff.

Root growth and development:

Fungi, such as mycorrhiza and trichoderma, form a mutualistic relationship with plant roots, stimulating their growth and extending their reach into the soil. This partnership results in a larger root surface area, enabling plants to absorb more water and nutrients. Some root dwelling bacteria will also trigger the production of plant growth hormones, further stimulating root development.

How to improve soil biology

To improve your soil microbiome, you have to create the conditions for beneficial microbes to flourish. However, many growing medias are inert and so the introduction of products that contain these microbes will ensure you get the benefit. It’s important to understand what you want to get from your soil microbiome and how your plant will interact with it – as some microbes will not form relationships with some plants.

1. Create a good environment for soil life:

• Growing media selection: Select a mix that has good physical properties to deliver oxygen to the root zone and contains a good amount of organic matter to feed the microbes – something that is easier in peat-free mixes than peat-based ones.
• Avoid overwatering: Overwatering leads to waterlogged soil, creating an anaerobic environment unsuitable for beneficial microbes.
• Use organic fertilisers: Organic fertilisers release nutrients slowly in the form required to support microbial activity, before they are mineralised for plant uptake.

2. Introduce soil life to environment:

• Use green compost in your mix: Compost contains a diverse range of beneficial microbes and is available to be premixed by most growing media manufacturers.
• Use beneficial microbe products: You can purchase beneficial microbes, like mycorrhizal fungi (Rootgrow), Trichoderma (T34) and beneficial bacteria (Vivisol).
• Ensure correct chemical pesticide and herbicide use: Chemical pesticides and herbicides can harm beneficial microbes in the soil. Ensure that their use only covers the plant, and you limit the amount that reaches the growing media.