|Eco-restructuring: Implications for sustainable development (UNU, 1998, 417 pages)|
|Part II: Restructuring sectors and the sectoral balance of the economy|
|9. Agro-eco-restructuring: Potential for sustainability|
It should not be necessary to emphasize yet again to the readers of this book that an essential characteristic of sustainable future economic systems must be to minimize the energy and material inputs per service (production) unit, in all sectors. In the realm of food production, organic agriculture is the most appropriate concept. By careful husbanding of soils and landscapes, by relying on site-oriented biodiversity in order to be able to use a maximum of natural synergisms, and by intensive nutrient recycling it minimizes external inputs. Thus, it achieves a maximum net harvest of solar energy in forms usable to humans. In this way it preserves and even improves the soil and achieves the highest possible yields in a way that can be practiced for a virtually unlimited time-horizon. In the remainder of this paper, small-scale mixed agriculture in developing countries will not be addressed specifically. Its merits are widely accepted and documented (e.g. Hiemstra et al. 1992; Radtke 1995). I refer to the experience of institutions such as the Bakara Agricultural College in Molo, Kenya. This started as a conventional training school, but it has evolved into an exemplar of site-oriented small-scale mixed agriculture including agroforestry in order to achieve a maximum of sustainable yield and a diverse diet, unburdened by the residues of agro-chemicals detrimental to human health.
The emphasis hereafter is on the potential of organic agriculture in the present bread-basket countries of the North (i.e. in the industrialized countries). In the following paragraphs, the principal concepts, historical examples, and actual comparisons are presented as evidence that there is a realistic and socially beneficial way out of the "Malthusian food trap" if we are prepared to surmount and challenge the rules of the present game.
The gardening concept
There is evidence that a gardening-like cultivation system with a high input of labour (~0.3 persons per ha), a high turnover of nutrients, and a balanced pattern of mixed cropping is capable of out producing low-labour (mechanized) agricultural production systems by at least three-fold. In times of worldwide structural unemployment it would be a wise strategy to rely on this concept in order to meet future food shortages. But the intelligent intermediate step would be to preserve the skills needed to manage highly productive mixed agricultural systems that later can be more easily intensified towards a gardening like pattern of cultivation. In this light, small-scale mixed agriculture can be seen as the starting block for stepping up agricultural productivity in the future in a sustainable way.
Germany in World War II
I observed an example of (enforced) low-input/maximum-output agriculture in my youth. I was adopted by a farmer family after my father was killed by the Nazis. According to all traditional expectations, Germany - being cut off from all external supplies of food, fertilizers, and agro-chemicals - should have come to starvation point within at least one or two years. But, in spite of massive military destruction, organic agriculture guaranteed the necessary minimum supplies until the end of the war. In fact, invading Allied forces found and captured strategic food reserves in storehouses. Over and above its own population, the German agricultural system had to feed an additional customer in the east because the Red Army could not rely on its own supplies. The dramatic (but temporary) food shortage of 1945 occurred because spring planting was impeded by warfare and seeds were destroyed or consumed for food throughout much of the countryside.
The example of German war agriculture also answers one standard argument against small-scale mixed agriculture, the argument that long-distance supply to towns and cities is not manageable. Even with primitive means (such as horse-drawn wagons and trucks powered by gas from wood pyrolysis), with processing and packaging mainly in small units by hand, an efficient system of collection, storage, and distribution was organized. This task would surely be achieved much more easily by employing advanced technology (microelectronics, informatics, and telecommunications) for networking and designing satisfactory supply systems. Crisis scenarios that were simulated in the 1980s for the Netherlands, Germany, and Finland confirm this past experience (Bakker 1985; Henze 1980; Kettunen 1986).
The potential of organic agriculture in temperate climates
Some preliminary remarks have to be made with respect to the validity of existing comparisons between conventional and organic agriculture.17 First there is a general tendency to underestimate the productivity of organic agriculture for four reasons:
1. Organic agriculture stems from a revolutionary ´'bottom-up" movement. It still has relatively little scientific support, because R&D funding by government and industry is directed to support mainstream activities.
2. In order to achieve full productivity by building up the humus content of soils and optimizing the farmer's skills (including the choice of appropriate crop rotations and intermediate crops), a "learning" period of about 10 years is typically necessary.
3. Organic farmers have always asked for support because of the initial yield-lag during the transformation phase.
4. In many cases shortage of affordable labour is a limiting factor, because the question of labour intensity cannot be addressed within the present system of agricultural support and mainstream economic philosophy. This bottleneck could be overcome by a future ecological tax reform that taxed the consumption of nonrenewable materials and primary energy carriers on the one side and reduced the direct and indirect taxation of labour on the other.
Thus assessment of the productivity potential of organic agriculture has also to take into account these short-term temporary disadvantages. Comparisons between conventional and organic agriculture, assuming similar endowments of labour and machinery, suggest a much higher energy efficiency for organic agriculture. The improvement ranges from 48 per cent to 64 per cent. But there is a corresponding short-term drop in yield of up to 30 per cent (Haas and Köpke 1994; Berardi 1977). One study observed a 10 per cent reduction in natural produce yields when comparing 14 pairs of conventional and organic farms in the eastern central states of the United States (Lockeretz et al. 1976). A 1980 study by the US Department of Agriculture (USDA 1980) in the US Midwest found not only a much higher energy efficiency for organic agriculture but also similar or better average yields per surface area unit. In the case of wheat there was no significant difference between the two. In the case of soybeans, organic methods produced 14 per cent higher average yields.
In Europe a number of similar studies have been made (Granstedt 1990; Rist et al. 1989). They have estimated a 20-30 per cent reduction in yields, based on the average performance of organic farms. Bechmann et al. (1992) propose compensating for the yield reduction by changing the European diet (reducing the present physiologically detrimental over consumption of meat). Meyer (1989), building on a study by Rist, has calculated for the Canton of Zug (in Switzerland) that only 1,430-1,600 m2 (0.14-0.16 ha) of organically farmed land would suffice to feed one adult person. This differs favourably from the 0.5 ha demanded by Pimentel et al. (1994) in order to provide a diverse nutritious diet of plant and animal products. To take an extreme case, a diet based largely on potatoes could feed an adult person from only 110 m2 assuming maximum productivity and from 300-400 m2 assuming average productivity (Walker 1979).
Based on these facts it is possible to make the following rough judgements. The earth is now providing about 4.6 billion ha of land usable for agricultural purposes. About one-third is arable land and two-thirds permanent grassland (ISOE 1995). Divided by a world population of 5.77 billion in 1996, the current world per capita endowment amounts to 0.25 ha of arable land and 0.50 ha of grassland. Thus there is still sufficient (but not ample) room for adjustment towards a global eco-restructuring of the agricultural supply systems without the threat of increased starvation. On the contrary, given appropriate incentives, humanity could save its resource base for future generations and still achieve food security.
In assessing future potentials, the performance of the best farmers should serve as a measuring rod, because they are the spearhead of future development. Personal observation of Austrian organic farms, especially the well-documented model farm of Hermann Pennwieser, shows that within a period of 10 years the humus content of soils increased by one-third (1.5-2 per cent per annum), and that soil life, soil structure, and water storage capacity also increased significantly (Sinabel 1991). One surprising effect is also that the incidence of plant diseases actually decreased, which indicates a strengthening of the plant's immune systems. The average yields of these organic farms are at the same high level as in comparable Austrian conventional farms.
Besides estimating the potential of sustainable organic agriculture, it is also important to assess the resource conservation potential of organic agriculture if it were adopted globally. The energy efficiency of organic agriculture has already been noted. In addition to the examples cited above, a US study by Lampkin (1990) concluded that conventional high-input/high-output agriculture consumes 2.3 times more energy compared with organic farms.
The contribution of organic farming vis-à-vis soil erosion is vitally important. There is clear evidence that soil erosion can be drastically reduced. Reganold et al. (1987) observed a yearly erosion of 8.3 t/ha on organic fields and 32.4 t/ha on conventional ones. Erosion is reduced by three major characteristics of organic agriculture:
- crop rotation, the concept of evergreen agriculture (continuous coverage of the soil by plants), mixed cropping, and underseeding reduce the susceptibility of soil to erosion (Lindenthal et al. 1996);
- augmentation of the humus results in a better soil structure, a higher stability of aggregates, greater penetration by roots, and better water storage capacity (Gehlen 1987; Reganold et al. 1987; Maidl et al. 1988; Beyer et al. 1989; Unger 1989; Diez 1991; Mäder 1993);
- careful (soft) soil cultivation also cuts the risk of erosion.
Higher plant nutrient efficiency
It is usually argued that there are no alternatives to the present high inputs of nitrogen, phosphorus, and potassium (NPK). If all farmers of the world were to follow the high-input model, the minable deposits of phosphorus would be exhausted in about 80 years (Scheller 1991, 1993). The same holds for potassium and for fossil organic resources, which are the base of nitrogen fertilizers (Barney 1980). In addition, the high energy input for the supply of mineral fertilizers has to be taken into account. Nutrient-efficient cultivation techniques are, therefore, a conditio sine qua non for long-term sustainable food supply
Organic agriculture tries to achieve maximum nutrient recycling by integrating plant and animal production and by using all by-products and wastes. Following this concept, nearly balanced nutrient cycles can be achieved (FAT 1994). As far as phosphorus and potassium are concerned, use of the nutrient reserves in the soils and of their geo genous potential, combined with the recycling of organic residuals, can be considered to be a proper intermediate strategy. In the very long term, agriculture must achieve a near closure of nutrient material cycles.
Nitrogen efficiency deserves a separate comment. Conventional agriculture now imports nutrients in nearly unlimited quantities, which have resulted in a nitrogen surplus (N-surplus) in areas where this has been going on for many years. In contrast, organic agriculture limits itself to nutrient recycling and to legumes as sources of nitrogen. In addition, organic farms normally observe the restriction of not more than two large animal units per hectare. Because organic farms are forced to economize on nitrogen inputs, the N-surplus on organic farms is much lower. For the agricultural areas of Germany, for the years 1991 and 1992, Isermann et al. (1994) have calculated a surplus of 145 kg N/ha. In contrast, organic agriculture caused smaller N surpluses of 37-76 kg/ha (Haas and Köpke 1994). This is clearly reflected in the nitrate content of groundwater. Research in Bavaria found that on average the nitrate content was 79 ppm/litre under areas of conventional agriculture with livestock raising and 42 ppm/ litre without livestock (Brandhuber and Hege 1992). Under organically farmed areas the nitrate content of groundwater was, on average, 27 ppm/litre, thus being within safe limits.
Agriculture has always tried to optimize the living conditions of plants and animals and to protect them. Organic agriculture has the same aim. Enlightened organic agriculture therefore does not refuse external aids completely (as some fundamentalists do), but it cuts them to a minimum and tries to rely mainly on the employment of natural synergisms and intensive care. Under these auspices, further increases in the effectiveness and productivity of organic agriculture can be expected. This judgement is underpinned by the fact that political support and public funding of research work in this field are also increasing (USNRC 1989; Lindenthal et al. 1996).
Based on the above evidence, it can be said that pragmatic organic agriculture is a realistic pathway to feed the growing world population and to secure the natural resource base needed for a long term sustainable future. But it has to be complemented by other measures, especially efficiency of food distribution. Most important of all, there must be effective measures to stabilize world population in order to secure a high quality of life for all citizens of the globe in the long term.