Is Organic Farming the Solution?
by Mark Edwards
n spite of the numerous advantages associated with organic food production, less than 1% of the world’s croplands are farmed organically. About 4% of European Union’s farms, where farmers receive subsidies to use organic methods, practice organic farming. The US has only 0.8% of cropland and 0.5% of pasture certified for organic production. Organic farms are smaller than industrial farms. Nearly all the research on organic production has been conducted on small farms.
Animal manure creates several problems: nutrient pollution, pharmaceutical disposal and inefficiency as a fertilizer. Over 70% of pharmaceuticals sold in the US go into animals, and 80% of antibiotics. Both flow out in the animal waste.
While the actions taken by organic farmers are commendable and less pollutive, most industrial farms in the US are unlikely to convert to organic production any time soon. The US would need at least 10 times more farmland than currently exists to create enough organic compost to transition all farms to organic production.
Organic famers run the risk of animal pharmaceuticals re-emerging in their produce. The USDA and FDA organic regulations limit raw manure use to no more than 120 days before harvest, to limit the possibility of foodborne illness being present on the crops. Many crops have less than a 120-growth cycle, which makes organic farming difficult. Manure animals are often raised thousands of miles from field crops – which makes transporting heavy manure impractical. Even if meat and dairy animals were raised close to grain fields, there are far too few animals to supply sufficient manure for the vast Corn Belt croplands.
Organic fertilizers are highly variable in nutrient composition. Synchronizing nutrient availability with plant growth and development needs represents a major challenge for organic farmers. For most large farms, organic fertilizers simply may not be available or affordable, or the transportation costs are prohibitive.
Organic and industrial farming are equally consumptive of fossil resources, including fertile cropland, fresh water and fossil fuels. Organic compost and manure as fertilizer consume huge amounts of fuel, time and physical labor. Organics must be collected, loaded, stored for a year or two, transported, and then applied to fields. Compost must be plowed into soils in order to avoid N volitazation. Organic farming saves on agricultural chemicals, but organic farmers must invest more time and labor in compost and often experience lower crop productivity.
Land plants made a major compromise when they evolved from algae 500 million years ago – the development of roots. Roots were necessary to hold land plants in place, as well as to create a plumbing system to extract water and nutrients from the soil. Unfortunately, roots created a heavy production drag for plants because growing and maintaining root structures consumes about 30% of a plant’s energy. Roots anchor the plant in place, creating a dependence on the soil moisture and bioavailable nutrients present in the plant’s root zone or rhizosphere. The rhizosphere constitutes the narrow region directly influenced by soil microorganisms where roots can absorb them.
Communities of nano-sized algae have lived symbiotically with plants for millennia. As land plants moved inland from ancient shorelines, they needed a foundation and food, but they had no roots. Algae formed soil crusts that provided the foundation that enabled plants to withstand wind and weather. Algae also supplied food energy in bioavailable nutrients before plants had roots. Thus, algae provided the bridge that enabled water-based plants to adapt to terrestrial ecosystems. Today, terrestrial algae continue to live symbiotically with land plants. Algae, and the microflora they attract, provide plants with a full set of macro- and micronutrients, while they continuously improve soil structure.
Roots significantly limit plant growth because these delicate appendages can take up nutrients when they are in a bioavailable form, usually after they have been broken down by soil microbes in a process called mineralization. Therefore, even though a nutrient such as P may be present in rhizosphere, a plant cannot use that nutrient until it has been processed and mineralized by microorganisms into a digestible form, called reactive or bioavailable P. When a plant experiences a growth phase without a needed macro- or micronutrients in bioavailable form, growth may continue, but with a dilution of nutrient density.