As we saw in a recent article, the supply of the main fertiliser elements (commonly called plant nutrition) is driven by soil biology. The micro-life in the soil makes nutrients, the building blocks of plant tissue, available in plant useable form. As the nutrient requirements for plant species above ground changes so does the microbial life underground.
You will remember too that the plants are producing glucose for energy during photosynthesis and all of that energy is used by the plant to grow and live. Our fine perennial grasses release about half of this energy above ground in the stem and leaves and this feeds the above ground food chain like grazers (green mowers!). Below ground they release the remaining 50% of the energy they produce by leaking proteins and carbohydrates as root exudates, building roots and producing thatch. This energy feeds the soil food chain of bacteria, fungi, protozoa, nematodes, arthropods and worms, or the soil food web as we’ve come to know it.