Our current agricultural system is highly flawed with inefficiencies and unsustainable practices. Sustainable agriculture is a journey rather than a destination; it aims to maintain ecosystems, support biodiversity, and endure the challenges of our delicate world. This essay presents three dire issues-loss of soil, depletion of water, and food supply-and examines possible solutions. As of now, there is not a fully sustainable agricultural system in place, but the future shows the possibilities of much improvement.
Soil is the key to life on the land; the right soil is the most important factor for growing crops. Therefore, soil erosion is a major obstacle for farmers worldwide. Soil should be treated like a non-renewable resource; it takes at least 100 years for one inch of soil to be created, according to the USDA, Natural Resources Conservation Service. The amount of soil rendered unusable during our lifetimes will not be replaced for many, many generations. Erosion removes top and surface soil, which often has the highest biological activity and greatest amount of soil organic matter. This causes a loss in nutrients and often creates a less favorable environment for plant growth. Plants need this soil for root growth, to prevent from being blown and washed away by weather, as well as greater root depth for water, air, and nutrients. Once the nutrients are unable to support plant growth on site, the soil can accumulate in water and cause many ecological problems, like algal blooms and lake eutrophication.
This problem is nothing new, and many practices are in place to prevent further erosion. The 1935 Soil Erosion Act, the first national soil conservation program, was a response to the greatest soil erosion crisis ever, the dust bowl. It established the Soil Conservation Service, now the USDA-NRCS, or Natural Resource Conservation Service, to help farmers and ranchers utilize conservation techniques on their lands. These practices include contour plowing, strip-cropping, terracing, no-till agriculture, shelter belts, crop rotation, and legume cover crops or residue.
Because of unsustainable irrigation, grazing, and cultivation practices, surface/rain water is not enough to meet our agricultural needs. A major water resource problem was created in the 1950’s, with the introduction of electric pumps, allowing the use of groundwater for irrigation. A ground-water system prior to development is in long term equilibrium; water removed is balanced by water added, and the volume of water in storage remains relatively constant.
While dependence on irrigation for farming is not likely to go away, smarter methods of irrigation and water conservation do exist. Soil moisture testers can be used to only irrigate fields when the soil is dry, preventing waterlogging and lowering water waste. Times, and morning/evening irrigations methods can be used to reduce water loss to evaporation, and use the least amount of water necessary. Withdrawals from aquifers can be reduced by these methods, as well as choosing better crops (grow less corn, waste less water), reassessing which crops need to be irrigated (corn, and other intensive crops are not used for human consumption, but for animal feed and ethanol), and removing subsides for crops that use more water (higher costs for higher water consumption). Also, these crops are grown in areas that are not naturally conducive to their growth. For example, the majority of all irrigated corn acreage in the U.S. is in four states: Nebraska, Kansas, Texas, and Colorado. These four states have different climates and types of soil. A shift to growing crops in an area where its needs can be better met naturally will drastically reduce irrigation practices.
Flood irrigation is one of the most popular methods of crop irrigation. Water is pumped or brought to the fields and is allowed to flow along the ground among the crops. This method is simple and cheap, and is widely used by societies in less developed parts of the world as well as in the U.S. It is not, however, effective or sustainable; about one-half of the water used ends up not getting to the crops.
Waste water can be minimized by leveling fields; flood irrigation uses gravity to transport water, so the water rushes to areas downhill and does not cover the field evenly. By leveling the field, water will be able to flow evenly throughout the fields. It can also be reduced by surge flooding. It is a less traditional type of flood irrigation; normally, water is just released onto a field, but surge flooding releases water at prearranged intervals, effectively reducing unwanted runoff. Finally, the capture and reuse of runoff will increase efficiency. A large amount of flood-irrigation water is wasted because it runs off the edges and back of the fields. Water runoff can be captured in ponds and pumped back to the field, where it is reused for the next cycle of irrigation.
Trickle irrigation is known as the most water efficient method of irrigation. Water drops right near the root zone of a plant in a dripping motion. This requires extensive tubing to ensure that all of the plants in a garden are reached by the irrigation, but it results in less wastage of water. The system can be programmed to run on a timer, manually operated, or programmed to respond to current conditions. If the system is installed properly, you can steadily reduce the loss of water through evaporation and runoff, as well as reducing the growth of weeds. Trickle irrigation also reduces loss of nutrients in the soil, lowers leaching into the water table and local waterways, and reduces water loss due to evaporation. Soil damage caused by spray and other types of irrigation is also reduced.
These problems are exasperated by our current cultivation system; many crops are grown in non-conducive regions, and require synthetic fertilizer, irrigation, and pesticides. An attempt to grow more efficient and more ecologically sound crops are GMO crops. These genetically modified crops were contested at the class debate and favored by a minority of students. While the current system presents many problems, its future potential cannot be ignored. My fellow classmates ruled against the technology for a multitude of reasons, including the mental and aesthetic preference for organic/natural foods, lack of knowledge about toxicological effects of GMO foods. They also criticized agribusinesses for pursuing profit without concern for potential hazards, and the government for failing to exercise adequate regulatory oversight.
Tolerance to extreme drought, cold, and salinity is perhaps one of the most important modifications for the future of agriculture. As the world population grows and the need for new agricultural lands increases, crops will need to be cultivated in locations previously unsuited for plant cultivation. Creating plants that can withstand long periods of freeze, drought or high salt content in soil and groundwater will help people to grow crops in formerly inhospitable places. For example, GM salmon, infused with genes from other fish species, grows faster than wild salmon and can survive colder water, allowing for the salmon to thrive in new environments. However, it is not currently on the market. Another off-the-market modification is the antifreeze gene. An unexpected frost can destroy sensitive seedlings and ruin an entire harvest. An antifreeze gene from cold water fish has been introduced into plants such as tobacco and potato. With this antifreeze gene, these plants are able to tolerate cold temperatures that normally would kill unmodified seedlings. This technology will allow these plants to grow in colder temperatures in which they would not typically germinate.
Traditionally, American agriculture has been marked by inefficiency and waste. Soil has been massively depleted and fields left sallow, aquifers have been depleted and water wasted or evaporated, and food production is being pressured to meet the demands of a growing global population. Luckily, the situation is not as dire as it seems; many conservation techniques are in place to help revitalize soil, new technology will help protect our finite water resource, and human ingenuity is being applied to food production. Clearly, we are on the way to a more modern, sustainable, and efficient agricultural system.