MarkWhilst we like to quote from scientific sources, they are usually of the pithy variety to illustrate a specific point.
This one from a review by Spanish researchers is stodgy, but it is worth reading in full because it is the best summary of what has happened to the land since humans started their population explosion.
It is 210 words which should take you a minute to read. References were removed to shorten the quote, and C refers to carbon.
Global cropland area expanded about 4-fold since 1700, up to ca. 20% of the vegetated area. In parallel, agroecosystems intensified to meet increases in population density, culminating in a radical socio-metabolic transformation, with the transition from traditional organic, solar-based systems to industrial, fossil fuel-based systems. The former usually operated at the local scale, relying on solar fluxes and internal biomass recycling as sources of energy and fertility. The latter are intensified through imports of fossil fuel-based industrial inputs and international or interregional trade to optimize the conditions for commodity production in a context of a global market economy. These structural characteristics shape the C cycle through effects on the type and quantity of soil C inputs and on the biotic and abiotic factors controlling C losses. Soil C inputs can potentially increase with industrialization due to a higher overall biomass production and a lower use of crop residues for animal feeding. Modern crops, however, usually have higher harvest indices, which reduces the production of residue relative to the main product. In addition, weed biomass is more effectively suppressed in modern cropping systems, and root growth in relation to aerial biomass is usually reduced. SOC mineralization is also affected by the changes in management practices such as tillage, irrigation and fertilization.
Aguilera, E., Guzmán, G. I., Álvaro-Fuentes, J., Infante-Amate, J., García-Ruiz, R., Carranza-Gallego, G., … & de Molina, M. G. (2018). A historical perspective on soil organic carbon in Mediterranean cropland (Spain, 1900–2008). Science of the Total Environment, 621, 634-648.
Let’s try to summarise it into a concise version.
Agriculture went from an energy source to an energy sink.
Organic, solar-based food systems changed to industrial, high-yield, fossil fuel-based systems with an international supply chain driven by a need for efficiency motivated by profit.
And with this change, the soil gets fewer organic inputs and loses SOC over time.
We cannot stress enough the importance of that last sentence.
The loss of soil organic carbon and the potential to recover soil organic carbon is the topic of many posts in the food ecology section of this site, so the point here is the magnitude and consequence of the expansion and the change from organic to industrial food production.
It is as significant a change as a ‘Don’t look up’ asteroid hitting the earth. Not as immediately catastrophic but just as destructive.
However, there is a crucial difference.
Like in the movie, humanity can do nothing about a giant asteroid on a collision course. Deflecting the path is beyond our current technology and skill—no matter what NASA claims about their recent asteroid nudge.
However, we can do something about our over-reliance on fossil fuel-based agriculture and the decline of soil organic carbon.
We can return to a more organic-based system powered only by the sun’s energy and adopt a wide range of production practices that add more organic matter to soil than is lost from land management and mineralisation.
What sustainably FED suggests
Read that quote again. Slowly.
It is a wonderfully concise summary of what has happened to agricultural production over the last 100 years and the critical consequences of those changes.
Then latch onto the hope that such knowledge imparts.
We know what happened to agricultural production and can determine how to reverse some consequences without risking food security.
And that is well worth your attention.
Science source
Aguilera, E., Guzmán, G. I., Álvaro-Fuentes, J., Infante-Amate, J., García-Ruiz, R., Carranza-Gallego, G., … & de Molina, M. G. (2018). A historical perspective on soil organic carbon in Mediterranean cropland (Spain, 1900–2008). Science of the Total Environment, 621, 634-648.
Hero image from photo by Kelly Sikkema on Unsplash
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