Soil Fertility


WHEN Shakespeare wrote in Romeo and Juliet “The Earth, that’s nature’s Mother, is her tomb; What is her burying grave, that is her womb”, it is unlikely that he was referring to compost but he at least realised that each new season is dependent on the death and decay of the previous ones. Similarly whilst they lived centuries apart, he would no doubt have agreed with Sir Albert Howard (1940), the grandfather of compost, that:

“The maintenance of soil fertility is the first condition of any sustainable system of agriculture”

Howard further noted as perhaps many an agriculturist before him and since that; ‘In the ordinary process of crop production soil fertility is steadily lost’. This being down in part to the practice of cultivation, which accelerates many erosive, biological and chemical process; and in part to exporting the soil fertility as crop biomass. In a ‘natural’ or undisturbed environment the soil is neither cultivated nor is the biomass exported so the majority of processes occur in situ. Plants generally die where they grew; browsers and grazers defecate where they ate. Whilst nutrients and energy are transformed as they pass between living states, they do not move very far in a spatial context. In agricultural systems, where cultivation and crop export are practised the ‘grave’ and ‘womb’ become disconnected and, unless mechanisms to address this are in place, soil fertility is steadily lost.

“One should be under no illusion that there are exceptions; there are none.
If one is an agriculturist then one is a soil fertility miner; and if close attention is not paid to practices then soil fertility will be depleted.”

However what constitutes soil fertility is a complex and subjective issue that lies somewhere between Shakespeare’s grave and womb: whilst it originates in one and ends up in the other it is never in nor can it be measured by either state but is more akin to the relationship between the two. For whilst we see death and birth as opposites they are in this case at least, joined at the hip; and whilst we can imagine them as two conjoined twins, the reality is more akin to a split personality, for both our twins of death and birth reside in the one body: the soil. If we continue with this analogy then perhaps fertility could be described as the harmonious co-existence, or the rate of exchange between these two different states that reside in the one body, the soil or ‘Earth’.

To add further confusion soil fertility not only lies between but also amongst. For soil fertility is neither a single property, nor is it the sum of the respective properties. Thus it is not the properties themselves, but the way those properties interact that is important in determining the state of soil fertility.

In this respect soil fertility is more of an emergent property than an inherent one. It comes about due to the degree and frequency of interactions between the properties rather than as a consequence of any one. As a consequence of management.

Thus Soil Fertility could be likened to team play as opposed to player talent in football success. Just as a team having a squad of star players but bad management won’t win so a soil rich in properties that are badly managed will not be productive. Football, the language of the masses lends itself well to communicating the language of soil fertility and as a concept it is further explored in phasm’s GSS Project “Fertility Footie“.

In Depth: Soil Quality and Soil Function

external links:

soil quality is an interesting web site that is a collaborative venture to produce a soils advisory site that has similar objectives to this one. It is equally in its infancy and so deserves being linked too. Let’s see if it grows up to stay here?

Free Cultural Works (CC-BY-NC-SA) Malcolm McEwen (2011)

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