By any account, American agriculture is a tremendous success story. The problem is that this success is precariously balanced on a set of three crumbling ‘pillars’ whose degradation could reverse this course and put us on the path to less, rather than more food production and security.
Much has changed about American agriculture – and enabled vast increases in productivity and profitability – since the Great Dustbowl that inspired the iconic American Gothic painting. In fact, according to Cornell University, in the 25-year period between 1950 and 1975, while “… the acreage in farming dropped by 6 percent and the hours of farm labor decreased by 60 percent, farm production per hour of on-farm labor practically tripled, and total farm output increased by more than half.” New forms of farm mechanization drove less need for labor and greater existing farm hand productivity. The discovery of DDT and other effective pesticides increased the amount of saleable crops per harvest. The use of chemical fertilizers doubled between 1940 and 1944.
Sounds great, so what is the problem? Unfortunately, our impressive agricultural success has been built on three pillars, and those pillars are in trouble.
- Cheap oil – Farmers and our food distribution system use oil in every aspect of modern agriculture, from powering the tillers and seeding machines that plow the earth and plant the seeds, to petroleum based fertilizers and pesticides that feed and protect the crops, to fueling the trucks that transport the harvest over hundreds and thousands of miles to the grocery store. As our oil supplies dwindle and the price of oil increases, these oil-dependent inputs will be increasingly seen as economically impractical.
- Unlimited, pure water – Currently in the United States, 80% of the water we use goes to irrigate our crops, and in some Western states that number reaches 90%. The problem is that this water is becoming dangerously scarcer, as well as more polluted by the very agriculture that it seeks to nurture. In early 2009, then California Governor Arnold Schwarzenegger declared that California, arguably the most productive farming state in the country, was facing an unprecedented water crisis. “No matter what we might want, it is very likely that there will continue to be serious constraints on the volume of water available to all California users, including agriculture.” This is not a problem that is going to go away.Groundwater reserves, such as the massive Ogallala Aquifer, supply 40% of the water we use to irrigate our crops. But according to a recent GeoJournal issue titled “Water and Agriculture” , “The accelerated use of agricultural chemicals over the past 20 to 30 years has profitably increased production but has also had an adverse impact on ground water quality in many of the major agricultural areas. The pollution of ground water, related to nitrogen fertilizers and pesticides, from widespread, routine land application, as well as point sources has become a serious concern… Such widespread pollution is of real concern because of the potential for long-term and widespread exposure to the public of toxic substances through drinking water. While there are many uncertainties, agriculture must move forward toward solutions through better management.”
- Fertile soil – We are simply wearing out the fertility of our soil. Soil compaction from mechanized equipment has caused a loss of as much as 25 – 50% of yield and 74% of the agricultural land in North America has been defined as “degraded. Pesticide use on U.S. farms has risen ten-fold over the past 40 years as agriculture has intensified. These pesticides are killing not only plant-harming insects (although increasingly less effectively) but also critical, living elements of the soil ecology that help it to naturally regenerate, i.e. bacteria, fungi, worms, and beneficial insects.
The good news is that we have a proven agricultural system in use today that provides the solution to all of these issues…and more. It is a called aquaponics.
Aquaponics is a technique that grows freshwater fish and plants in a symbiotic, nearly closed loop system. Aquaponic systems come in many varieties but in all of them, fish live in tanks that are interconnected with beds that house the plants. The fish create waste that is largely comprised of ammonia, which is highly toxic to them and needs to be filtered from their water. The water containing this waste flows to the soil-less plant-growing beds where the ammonia is converted by naturally occurring bacteria into nitrates. The nitrate compounds are excellent plant food and provide nearly all the nutrients the plants require. The mineralized solid waste provides the rest. The extraordinary beauty of this system is that the plant beds with their beneficial bacteria populations become the bio-filters for the fish, transforming the toxic fish waste into plant food which the plants then extract from the water. The cleansed water returns to the fish free of their own waste. It is beautiful. The fish feed the plants and the beneficial bacteria and plants provide clean water to the fish, just like nature does in any healthy pond. The net result is a bountiful source of both plant produce and fish available for harvest.
So, how can aquaponics solve the three problems noted above?
- Cheap oil – Growers can construct Aquaponic systems entirely out of recycled materials. Further, the operating systems require no oil-based inputs. They run entirely on a small amount of electricity which can be generated through currently available renewable energy methods. Further, because there is no need for weeding, watering or fertilizing; aquaponic farms can be run by a single person without the need for gas-powered equipment. Because an aquaponics system does not come in contact with the ground, there are far fewer insect problems and thus far less need for pesticides. As an added incentive, the system must remain free of petroleum based pesticides to avoid harming the fish. Finally, there is obviously no need for petroleum-based fertilizers since the bacteria-converted fish waste feeds the plants with organic, natural plant food.
- Unlimited, pure water – Because aquaponic systems are recirculating, the only water they use is either within the plants themselves, transpires through their leaves, or evaporates from the top of the fish tank. These minimal “loss” points are the reason that aquaponics is generally thought to use less than one tenth of the water of traditional agriculture for the same crop output. Plus, because aquaponic water is never exposed to fertilizers or pesticides, there is no chance of polluting the groundwater systems with chemicals.
- Fertile soil – While aquaponics can’t restore the results of past agricultural practices, it can side-step the problem. Because aquaponic systems use no soil themselves and because they can be built on any surface, they can be erected anywhere there is level ground and a source of sunlight or artificial grow lights. This includes land that is poisoned beyond repair, urban settings like parking lots and warehouses, and home environments like patios, decks, basements, and garages.
- Fish are a healthy, efficient, and safe alternative to meat – It seems that every week we see a news item about an E coli outbreak or a story about the harm that the Concentrated Animal Feeding Operations (CAFOs) are doing to the animals, the environment and the safety of the resulting meat products. By contrast, fish, are cold-blooded animals and therefore cannot harbor E coli (unless, of course, they are contaminated with the pathogen from an external source during processing). In addition, one must remember that an aquaponic system is an eco-system in which all the living inhabitants depend on each other. Thus, aquaponic growers never add antibiotics, growth stimulants, and other medicines because such additives would reach not just the fish but also the plants, bacteria and worms that live in the system (growers add worms to the plant grow beds to help convert solid fish waste into plant food); thereby threatening the health of the entire system. Plus, in the U.S. livestock is responsible for an estimated 55% of erosion and sediment, 33% of pesticide use, and 50% of antibiotic use. Finally, it only takes one and a half pounds of feed to produce one pound of fish, vs. eight to ten pounds of feed to produce one pound of beef. Fish farming is a far more efficient use of our feed crops than growing meat.
In addition to these potent benefits for American food production, I would like to highlight one more …
Aquaponics is not the answer to all of America’s future food supply and environmental issues. Grains and root crops, for example, will probably always be most efficiently grown in the soil. But for above ground, vegetative crops and animal protein, there simply isn’t a better growing technique for our country’s future food security.