Avoiding waste and changes in diet habits may be the way make organic farming a feasible solution, says S.Ananthanarayanan.

While it is the use of chemical fertiliser and insecticides that has helped agriculture meet demands of rising population, the downside is now proving the block to ensuring sufficient food in coming decades. An alternative is to switch to farming without the use of chemicals and relying on natural fertiliser and pest control. Measures like this, however, would call for more land, including land where fodder for livestock is grown, to be brought under cultivation of food grain. And organic farming may still fall short of the quantity of food grain required.

Adrian Muller, Christian Schader, Nadia El-Hage Scialabba, Judith Brüggemann, Anne Isensee, Karl-Heinz Erb, Pete Smith, Peter Klocke, Florian Leiber, Matthias Stolze and Urs Niggli, from institutes of research in agriculture, ecology and environment in Switzerland, Austria, Aberdeen and Potsdam and FOA in Rome report in the journal, Nature Communications a comprehensive study of the economy of implementing rising levels of organic farming. While going organic is the way to escape chemical poisoning that conventional farming involves, the paper proposes a strategy to make the organic route practical.

In 1798, Malthus said the growth of population was so fast that food production would not keep up with the demand for food. The prediction of food scarcity did not come about, however, because synthetic fertilisers, insecticides and irrigation helped multiply agricultural produce. The world’s production of rice and wheat grew ten-fold since 1800 and by a factor of 2.5 since 1950. And the growth of world population, from 1 billion in 1800, to the present 7 .6 billion, has been slower than what Malthus feared. But population is expected to rise to 9.6 billion by 2050, and with consumption of food having risen faster than production, whether there would be enough food in coming decades is still in question.

The problem is that although the land under crops has increased, the real driver of high production has been the greater output possible with synthetic fertiliser. In traditional farming, plants convert the sun’s energy into food, but only with the help of trace, but essential traces, of phosphates, active nitrogen and some others. These agents that enable plants to grow occur naturally in soil through breakdown of organic matter, or from the plentiful, inactive nitrogen in the atmosphere by the action of microbes or of energetic events like lightning.

As agriculture depletes the soil, these nutrients need to be replenished. This can be done by leaving the land fallow, to regenerate, or by alternating crops or by adding manure. Manure, by composting organic matter or the excreta of animals, is rich in active nitrogen and has been the traditional fertiliser. A far richer source of active nitrogen, however, is in the form of chemicals like ammonium phosphate, or urea or superphosphate. The content of plant nutrients in these compounds can be 30% by weight, against only 4% in the case of natural fertilisers.

Manufacture of chemical fertiliser became a major industry in the early 20th century and agricultural production rocketed. With the use of fertilisers rose the large farms of one sole crop. This prevented natural pest control by a mix of species growing together and created the industry of chemical insecticides. It was only later in that the spotlight turned on the damage done by chemicals in the soil, apart from the coal burned to power the factories.

The downside of chemical fertilisers is that they are toxic if not used with plenty of water. And then the run-off water carries excess chemicals to poison ponds, waterways or fresh water sources. The high rate of production also creates imbalance in soil nutrients, calling for a cycle of additives. The Stockholm Resilience Centre has placed biochemical poisoning as one of the nine boundaries of pollution which the earth should not cross, and a boundary that active nitrogen discharge has crossed.

The solutions generally understood are to switch to organic farming, to release land from cultivation of fodder for livestock and to avoid waste or loss of food, which FAO has found to be 30-40%. Each of these have their consequences, the main one being the greater area of land required with organic farming. The studies so far, the Nature communications paper says, have not followed a detailed food systems approach that accounts for the interplay of the three strategies along the way to assuring a certain calorie intake for the world population. Nor, the paper says, have they “captured the main agronomic characteristics of organic agriculture in a systematic way.”

Modelling with software

The current study steps in with a software model which is able to remedy this shortfall by considering the different factors involved in a mix of strategies and evaluating the land use needed to assure sufficient food calories, at different levels of organic farming. The model hence simulates changes in each of the different factors, to picture what happens in different conditions.

A first result is a formal assessment of the land use involved if we were to shift to degrees of organic farming, from 20% to 100%. The first set of bars in the ‘land use’ picture shows the present (2005-2009) land use, at 1.5 billion hectares. The second set is what it would be like in 2050, with no changes in the manner of farming – there would still be three levels of land use, depending on the effect of climate change. The remaining sets are with rising organic farming, rising to 2.75 billion hectares with 100 organic farming and high climate impact.

The simulation then examined how land use was affected by levels of saving land used for livestock fodder for agriculture and by steps to contain waste or loss. The results are displayed in the second figure. Under conditions of 0%, 25% and 50% waste reduction, and then 0%, 50% and 100% reduction of land used for fodder, the percentage change in land required for crops are shown, under different levels of organic farming, according to less and greater impact of climate change.

The boxes with negative figures represent conditions where the land use is less than the reference level. We can see that even 100% organic farming becomes feasible under conditions of medium impact of climate change, 50% reduction of waste and 100% reduction of use for fodder.

As greater organic farming implies improvement first in pollution by active nitrogen and then of the consumption of power and water, this study allows planning for the level of organic farming that is feasible or desirable, while considering the extent of limiting waste or reducing competing demands for use of land. The separate targets, organic yield and production, reducing animal numbers and consumption of animal products and then waste and loss, could hence be implemented in part and in combination, in place of being maximised in isolation, the study says, to help increase the sustainability of the global food system.

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