For decades, farming has been guided by a chemistry-first mindset. We’ve learned to balance nitrogen, phosphorus, potassium, sulphur, and pH—mostly through calcium—by consulting tables and applying soluble fertilisers to facilitate balance. This system, refined through years of scientific tuning, promises predictable yields. But recent seasons have exposed a troubling truth: inputs don’t always equal the expected output and so there is a very important part of the system that isn’t being managed appropriately. Our current approach treats soil as an inert medium—a passive vessel for nutrients. When something’s missing, we add it. Problem solved… or is it?

I am being a little flippant, but I think we can accept that the soluble solutions had a lot of one-sided science behind them developed over many decades, mostly based on the chemistry and physics of soil. I remember once being told that organic matter could only ever be improved by small amounts in a lifetime by a person of renown because it was a chemical process only. The last thirty years of my involvement have seen huge changes and advances in the science of biology, now coming to the fore. We began to see what is required for soil and farming to function at their most efficient. It is biology that becomes the modulator of nutrient capture, nutrient retention, nutrient recycling and the release of nutrients to the plant, but it always has been, just not been considered with the importance it deserves.

There is no doubt that fertiliser amendments are required when the soil bank is low, however they are often unavailable or locked up or inefficient because the soil isn’t functioning biologically. In compromised soils, chemical inputs become a crutch. This raises a provocative question: have we built a system for fertilisers rather than for soil?

Let’s consider an example using AHDB data headed “Weak association between the amount of inorganic N applied and yield”. This study suggests that our current nitrogen system potentially has some flaws. Under a regenerative system, we are not managing a global approach or a global solution to crops anymore. 

n the example picture below, we see a compromised soil situation, a difficult silt clay, with low organic matter, having very few inputs over many years. So, effectively, poor biology is dominated by physics and chemistry in the soil. This field has been worked into a dry cloddy state with digestate applied into the soil and MAP drilled down and under the maize seed plus additional liquid nitrogen applied after drilling. It effectively has all the nutrients it requires to grow a big maize crop. The poor strip you see is the maize growing in all this nutrient and is actually a spray miss from a £14.00 per hectare foliar application. Just by putting nutrients into the soil does not always ensure success. In this case they are not connected to the soil and the clods are not connected to the developing maize root. We have all the ingredients for a cake but no cake. As Joe Williams aptly said, “Farming soil without biology is just geology.”

Taking this a little further, the field next door has been in a multi-species cover crop for ten months and has come through the worst of the wet winter with the picture being taken in November. The picture below shows what the effect has been on soil crumb structure, porosity and fine rooting. The report alongside shows what the cover crop has managed to extract from the soil in the five months prior to measurement, producing 45 tonnes of above ground biomass and 5.9 tonnes Dry Matter. I think this is impressive, in what is a very compromised and difficult soil situation.