Holistic Growing (2)

What is Holistic Growing?

At Fargro we call our agronomic approach ‘Holistic Growing’. This approach is built around harnessing and enhancing natural plant processes to grow healthy and productive crops.

What is Holistic Growing?

In the natural world, it’s a very rare sight to see a plant that is riddled with disease or covered by pests – why is that?

It’s rare because plants are robust organisms. Being sessile, and so unable to move, means that when there’s a threat, they have to handle it or die. Because of this, they are exceptionally well adapted to handle a huge variety of different pressures – both from the environment and from other living organisms. Like lions in the savannah, pest and disease prey on the weak and old, but struggle to overcome the defences of a strong and healthy plant.

Understanding plant resilience and crop vulnerability

So why is it the case that crops, unlike their wild counterparts, are so susceptible to severe outbreaks of pest and disease?

This is due to our style of crop production. We focus on providing the plant with the tools to grow big and fast, but not the tools to undertake the countless defensive mechanisms they’ve evolved over millions of years.

A new approach to crop production

There is a wide assumption that there’s a trade-off between these two, with the protective properties of plants sacrificed in the race for yields,  and chemical pesticides used to bridge the gap. 

But, this style of production is no longer sustainable. Heavy applications of mineral fertilisers have led to huge pollution on land and in waterways - and the widespread use of broad-spectrum pesticides has caused ecological devastation. It can have significant impacts on human health. 

As such, both are under extreme pressure from governments worldwide and restrictions on use or outright bans are now commonplace. 

So, how can we continue to deliver the yields required without the armoury of tools that have driven our ability to attain them?

The answer lies in shifting our understanding of plant biology.

The traditional approach understands plants as a collection of connected but independent parts – roots, leaves, stem, flowers – that exist broadly separate from the wider ecosystem. The resulting agronomic approach breaks the needs of plants down into simplistic requirements of certain amounts of each key nutrient and water, and a substrate that allows them to be taken up – along with sufficient light and appropriate temperatures and humidities for growing. 

The aim is then to produce a sterile atmosphere, both in the substrate as well as on the foliage, to avoid disease. Ideally, also, the site is free from insects – except for when pollinators are required.

Parallels between human health and plant health

This approach mirrors very closely the conventional view of human health. For the past few decades, dietary advice has been provided in a similar way. Calculations are made for how much carbohydrate, protein, fat and other macro and micronutrients are required, with little importance ascribed to their source and what form they come in. 

But in recent years the understanding of how the human body interacts with nutrition has shifted dramatically, particularly in the understanding of the gut microbiome – the community of microbes that reside in the digestive system. 

Our view of the gut microbiomes has shifted from it being labelled as pseudoscience, to acknowledging its existence but assuming microbes are inert and insignificant, to now understanding they perform a crucial role in human health. 

Interestingly, this role is not limited to digestion, but has wide ranging effects across the body – including controlling our immune response and regulating our mood.

By using a holistic understanding of the human body, we betterunderstand the whole system as well as the function of its individual parts. This has inevitably led researchers to look at what a good or bad microbiome looks like and what we can do to make sure we have a good one.

Research has discovered that human dietary demands are much less simplistic than was assumed. Simply providing the appropriate quantities of nutrients, no matter their form, is not sufficient to support a healthy microbiome and so is unable to properly nourish a person. 

Instead, the nutrients must largely come in the form of whole foods – which allows microbes in the gut to consume the organic molecules that they’ve evolved to eat, before releasing the nutrition to our cells. Without this process, the microbes starvewe’re unable to properly uptake the nutrients – and there’s a wide ranging impact on our health.

The same story is true for plants. In a natural system, a complex and diverse community of microbes exists around the roots. This community operates similarly to the gut microbiome. It degrades organic matter into plant available nutrients, but also protects from pathogens, stimulates the plant immune system and helps to mediate strong and steady growth.

The conventional approach, of feeding exclusively with mineral nutrients, bypasses this microbiome – creating the same situation as in the gut, where it’s starved of food. This means the plant is improperly fed and is unable to exploit the wide-ranging benefits of these microbes to its health.

Plants fed in this manner may grow quickly but the requirement of total fertiliser is much higher and they’re unable to undergo important processes correctly and protect themselves from environmental and biological stresses.

In taking a holistic approach to agronomy, you actively encourage the presence of these microbes and use organic materials for fertilisation to nourish and support them – emulating a natural system. This allows us to harness and enhance these natural processes, all whilst keeping fertiliser inputs to a minimum. So crops are grown that are more robust and able to handle the rigours of their environment.

The role of bio-based crop protection products

But it is important to understand the crop production isn’t a natural system. Large area monocrops, which are grown at a fast pace, are always at risk of providing pests and diseases an opportune environment to proliferate. 

Correct fertilisation and a thriving root zone microbiome provides some protection but this is likely not enough. We need plant protection products – but rather than chemical controls, we can employ a holistic understanding of the plants biology to deploy biological ones effectively.

Chemical pesticides mostly act like antibiotics, they contain an active ingredient that is toxic to the target, but it is often also toxic to beneficials. This leaves a vacuum that pests or pathogens can exploit when the effect wears off.

Biological pesticides work differently – they are derived from naturally occurring protective bacteria and fungi, or non-toxic natural extracts and harness and enhance natural processes.

Microbial biopesticides can form mutualistic relationships with the plant, colonising foliage or root surfaces, protecting from pests and pathogens and feeding on metabolites released by the plant that are designed to recruit and sustain them. 

Natural extracts, such as from yeasts, insect skins or tree barks, prime the immune response of plants – making them less accessible by pathogens and less palatable to pests. These products marry with the introduction of predatory or parasitic invertebrates to target pest species directly.

These biopesticides strengthen the plant, and, along with the beneficial invertebrates, provide sufficient protection for a holistically fed crop to overcome any pest and disease problems it faces.

Conveniently too, the rhizosphere supports improved nutrient use efficiency and the biopesticide applications support strong and fast growth, meaning this protection can be achieved with similar yields to a conventionally managed system. And even more conveniently, most of the organic fertilisers and biopesticides are produced from industrial byproducts – making them cheaper than their conventional counterparts.

Benefits of Holistic Growing

So, by understanding the nature of the interactions between different parts of the plant and with their microbial and invertebrate colonisers, we are able to produce crops in a way that is friendly to the environment, lower cost than conventional systems, and equally as productive.

By Jack Haslam, Fargro's Technical Development Manager.