Our approach to Plant Fertilisation
🌿 As promised in a previous post, I am going to discuss how we use liquid inputs.
First of all, please have a look at my previous post to see what I think about the limitations of fertilising plants (rather than soil) as a regenerative approach.
🥗 I like to compare the foliar or root fertilisation of plants (especially via liquid inputs) to food supplementation in humans. In both cases, one of the aims is to address any imbalance that can cause disorders, diseases or parasitic attacks, by identifying an underlying nutritional deficiency, and fixing it. Obviously, in the case of plants, we also want to improve flavour and yield - but both of these should come as a by-product of our regeneration efforts.
👩🌾 The similarity of this predicament in the human and plant case is one of the reasons why many regenerative practitioners are motivated to address health holistically. This is usually addressed by attuning their lifestyle and agricultural practices to achieve the health of the ecosystem they manage, and consequently their own.
⁉ When we use fertilisation or food supplementation as approaches to nutrition, we are (implicitly or explicitly) recognising that there is an imbalance and we decide to address its nutritional basis. The cause of the imbalance is not the nutritional deficiency, but the underlying problem that induces it. A truly radical, systemic, regenerative approach should aim to identify the root cause of the deficiency itself. In the case of humans, the root cause is often linked to lifestyle, as well as food and environmental policies which characterise our civilised society. In the case of plants, the issue is nearly always linked to agricultural practices, but sometimes it might also be related to climate or geological reasons.
🌳 Moreover, those who have read my previous post on ecosystemic approaches to plant nutrition you will recognise that the supplementation approach is typically subjective/reductionist, because it does not address the ecosystem as a whole, and instead it focuses on one of its components (human or vegetal).
🏭 Another limit of using food supplements and plant fertilisers is that it relies on the availability of mineral and synthetic resources, imported and processed by large industry - and thus it is hardly sustainable.
Having said this, there is nothing wrong with adopting such an approach as a tool, without forgetting that true regeneration will need more holistic solutions, and therefore any supplementation will be a limited solution.
🌟 So, let’s discuss the framework that we adopt at Living Soil Garden for plant nutrition, and in the comments I will draw a parallel with human nutrition.
We can describe the approach as comprising 4 steps of increased sustainability: (1) action, (2) investigative supplementation, (3) identification and (4) systemic adjustment.
(1) 🚿 Action. In case of infestations or outbreaks that put at risk an important crop, one may “act” by using a biological pest deterrent. These can be neem oil, diatomaceous earth, garlic and chilli spray, JADAM Herbal Solution or Sulfur, and other sustainable alternatives. Note that none of these is of synthetic origin. However, although organic, they are used as a pesticide and we consider it a last resort.
We have used Jadam Sulfur only twice to trial its effect in preventing Downy Mildew in Basil (in the tunnel), which had heavily impacted our yields in 2020 and was extremely effective in 2021. I am personally not a fan of any of the others listed above, and have never used any of them.
(2) 🧪 Investigative supplementation. If we see a recurring disorder or disease hit one or more crops, we may try to see what is the effect of providing better nutrition. The first step is to identify the problem, then do a bit of research (the book Mineral Nutrition and Plant Disease can be very helpful), and finally come up with a solution in the form of a product to apply. This product, in our case, is always going to be of organic origin, and in 80% of the cases homemade or locally sourced. Examples include Water Soluble Calcium made from eggshells, Horsetail, Nettle and Comfrey liquid feeds (made from plants in the garden), SeaWeed extract, Fermented Plant Juice (made from weeds around the garden), a Garlic ferment, and others. In most cases, nutrition is improved by providing good conditions for diverse microbial life, so we may use inoculants such as IMO (Indigenous micro-organisms, harvested from local woods), homemade Vermicompost extract, homemade compost extract or JMS (Jadam Microbial Solution, made from potatoes and local leaf mould).
The idea for (2) is that we are trying to give the plant all it needs but somehow is not able to find in our horticultural system. Although this type of applications will always find a place in a commercial garden, especially if we are prone to experimentation and varying crop plans, it should not be seen as a definitive or routine solution.
(3) 📖 Identification. If our feeding regime has worked in suppressing or reducing a problem, we can reduce the inputs until we find the minimum combination needed to fix the issue at hand. This tells us which nutrient was critical. By knowing how that nutrient is linked to specific plant functions and environmental conditions, we can identify some alternative solutions that don't require regular feeding.
For example, if we had Downy Mildew and we fixed it with Jadam Sulfur, it can either mean that the plants immune response wasn’t working properly because of stress or because of poor drainage. Or it could mean that we need to improve ventilation in the tunnel.
A more straightforward example might be the case of Blossom End Rot, which can be solved by applying WCa or FPJ, and which points at inhibited uptake of Calcium from the soil. Perhaps there aren’t enough fungi (responsible for Calcium storage and enhanced availability) or we have applied too much compost or too acidic.
(4) ♻ Systemic adjustment. Once we have identify the root cause of the issue, now it’s time to replace that input with a more sustainable practice. We might need to amend our soil with rock dust, or apply less compost, or change the way we make our own compost, or water less, or water more, or solve drainage issues, etc. In a lot of cases, the answer might be to increase biodiversity, either by creating habitat for pest predators or by planting perennial systems alongside our annual vegetable beds. These solutions are all integral to our design, and will provide a stable source of stability to our system. Once we have implemented this step (4), we want to monitor the original problem and see whether we need to do anything else. We may need to resort o (2) again, but hopefully not (1).
If you like acronyms, you might have noticed that this approach may be referred to as ASIA (I never do that though).
In a perfect system, one would only do (4) and nothing else would be needed. In a young and imbalanced system, (2) may be used often, (1) should be uncommon in a regenerative system, but it can be necessary if things get out of control.
🔬 Some of you will argue that Sap analysis can take away the need for step 2 and 3 altogether. True, but it’s expensive and as some growers have experienced directly, it is very difficult to find benchmark/target values for each crop, variety, etc. So we can get a very expensive sap reading, and still not know whether those values are critically low or not. At the end of the day, our observation skills, knowledge of the individual variety and data gathering for yields, etc. are going to be more important.
🍽 If you are interested in a parallel with human nutrition, check out the comment section below.
In a future post I may discuss some of the specific inputs mentioned in the above - just drop a comment if there’s anything in particular you would like to know about!