New research demonstrates – again – how deceptive the concepts of productivity and efficiency are in agriculture. Huge increases in labor productivity and modest increases in land productivity are gained by a massive increase of use of external resources, while natural capital is depleted. Is that efficient?

There is a growing body of research measuring resource flows to better understand the impact of developments. It is argued that only if economic growth can become substantially decoupled from material use, waste, and emissions, it can be sustainable. By measuring total use of resources, the total social metabolism, of the economy and not just measuring one parameter, one can avoid being distracted by the fact that usage of one resource has declined, while others have increased.

A sub set of the metabolism of society is the agrarian metabolism which refers to the exchange of energy and materials between a given society and its agrarian environment. In the article The agrarian metabolism as a tool for assessing agrarian sustainability, and its application to Spanish agriculture (1960-2008) in ECOLOGY AND SOCIETY, January 2018, Gloria I. Guzman (Universidad Pablo de Olavide) and colleagues assess how the metabolism of Spanish agriculture has changed through the increased use of mechanization, irrigation, chemical fertilizers and massive use of imported animal feed, to mention the most important drivers.

We are told again and again that modern agriculture and the Green revolution are wonders of efficiency and productivity. But when one look closer into the Spanish figures they give a different picture.

The researchers studied the use of external inputs such as nitrogen (N), phosphorus (P), potassium (K), carbon (C), and energy flows, as well as the “fund elements” that they sustain such as soil, biodiversity, and woodland. The results show that the growing use of external inputs has broken the equilibrium between land and biomass uses required by traditional farming and broken or made redundant internal loops of energy and nutrients. On cropland, the relative fall in unharvested biomass had a negative effect on both biodiversity and the soil, which reduced the replenishment of organic C between 1960 and 1990. A sharp increase in imports of animal feed, and corresponding increase in the use of animal manure, hardly contributed to increasing soil organic carbon between 1990 and 2008. The massive importation of N in feed and mineral fertilizers increased the surplus and the losses of N, which has a negative impact on biodiversity, water, and the atmosphere.

There is also the question of the effect of the production of imported animal feed to consider. That is not included in this research, but one can assume that the large scale export of animal feed, mainly corn and soy, from monocultures in Latin America also leads to depletion of soils there. For those not so well informed about Spanish agriculture, we are talking about a massive increase in the breeding of pigs and poultry.

It is a prerequisite of a sustainable agriculture system that the material basis, the fund elements or the natural and social capital needed, is managed in such a way that it is reproduced and preferably improved. If the farming system leads to the erosion of top soil, depletion of water resources or biodiversity or to the decline of the appeal of farming it is undermining its own foundations. The reduced ability of the system to produce is compensated for with the increased use of inputs of different kinds. In theory, external inputs could be used to improve or replenish the fund elements, e.g. by building fertility in the soil. But the practical experiences is mostly the opposite; increasing use of external inputs and the degradation of the fund elements are often twins in real life.

The research from Spain supports that. Between 1960 and 2008, Spanish agriculture increased the use of external energy more than five times. Meanwhile human labor input decreased to one-fifth, industrial inputs increased five times and the import of biomass, mainly feed from Latin America, rose fifteen times. Despite this massive use of external inputs, the total primary production from the agricultural system increased with only 17% in the period. The total biomass ”socialized” (appropriated, taken, delivered) from the agriculture system increased in the same period with 37%, of which most of the growth was a huge increase in pork meat based on imported feed stuff. It is hard to call such a system “efficient”.

As a result of the intensification and increased importation of animal feed, many different aspects of the production system changed. Big areas of pasturelands and marginal croplands were abandoned, while the remaining lands were used more intensively. A greater share of what grows on the land is taken by humans. Earlier 50% of the biomass remained in the field and provided for soil carbon and biodiversity. This share has now fallen to 38%. This change is a result of the use of herbicides as well as plants and varieties with a higher harvest index (i.e. the share of the total biomass of the plant which is allocated to the parts we harvest, e.g. the kernels in grain). The proportion legumes in the crop rotation as well as the supply of nitrogen from biological nitrogen fixation also fell considerably. The efficiency of the use of supplied nitrogen shrank while emissions and leaching of N20, nitrate and ammonia increased by a factor between two and three.

This research confirms that the current model of farming is not sustainable. The much promoted intensification of farming is a mistake as long as intensification means further specialisation and increased use of inputs.

There is another way to intensify; to increase all the internal linkages and energy loops in a regenerative agriculture system with integration of animals, plants, soils and grassland. And much more human energy, people, and less fossil energy.