Sustainable crop production is a way of growing or raising food in an ecologically and ethically responsible manner. FThis includes adhering to agricultural and food production practices that do not harm the environment, that provide fair treatment to workers, and that support and sustain local communities. FSustainable crop production is in contrast to industrial crop production, G which generally relies upon monocropping (growing only one crop in a large area of land), intensive application of commercial fertilizers, heavy use of pesticides, and other inputs that are damaging to the environment, to communities, and to farm workers. In addition, sustainable crop production practices can lead to higher yields over time, with less need for expensive and environmentally damaging inputs. F
How Are Sustainable Crops Grown?
Sustainable crops are grown in a different manner from industrial crops. Sustainable crop farmers focus on ensuring that their farming practices can be sustained over time and do not cause undue damage to the environment. FA number of different principles are involved in sustainable crop production, including:
Multicropping is an agricultural method of planting multiple species on one piece of land, either during the same growing season or in successive growing seasons. Multicropping can involve:
- Crop rotation: the practice of changing what is planted in a particular location on a farm from season to season. F
- Intercropping: a method of planting two or more crops of differing characteristics in close proximity to reduce weeds; to encourage plant diversity in order to avoid insect and pest infestation; and to provide shade, nitrogen fixation, or other benefits to the plants being grown. FIntercropping includes companion planting and the use of cover crops.
Multicropping is in direct contrast to monocropping, in which large tracts of land are planted with a single crop. FMulticropping has a number of environmental benefits, including:
- Increased yields. Monocropping has been shown to decrease yields over time, while multiculture practices such as crop rotation and the use of cover crops can increase yields by reducing pests, improving soil health, and increasing water retention. F F
- Decreased pest susceptibility. Multicropping reduces extreme vulnerability to a wide array of pests, including weeds, insects, fungi, and other organisms. The lack of genetic diversity on monocropped farms means that a single pest can decimate large areas of cropland. F
- Increased biodiversity. G Multicropped farms have a number of species that may interact in a meaningful way, such as providing shade for other crops, providing nitrogen fixation for the soil, or repelling pests. F
Minimal to No Pesticide Use
Pesticides are substances that destroy various agricultural pests, including weeds (herbicides), insects (insecticides), bacteria (microbicides), and fungi (fungicides). Industrial crop production relies heavily upon pesticides, in part because the practice of monocropping increases vulnerability to pests. Unfortunately, pesticides can cause health problems in farm workers who apply the chemicals and who harvest the crops, and in consumers who eat foods with pesticide residues. F FVarious pesticides have been linked to certain types of cancer, to neurological problems, and to other health problems. FPesticides also cause environmental damage such as water pollution and soil contamination. FThe use of pesticides can also make pest control more difficult; as in the case of insect control, insecticide use can have the unintended consequence of eliminating insect predators that prey upon pest insects, and can also increase pesticide-resistance in pest insects. FIn addition, pesticides have been shown to cause declines in pollinators and other beneficial insects that are critical to the health of agricultural systems. F
Sustainable crop production greatly reduces pesticide use; in fact, many sustainable farmers do not use commercial pesticides at all. A number of alternatives to commercial pesticides can be used to protect crops from damage by pests such as weeds and insects, including:
- Integrated pest management: Integrated pest management, or IPM, is a pest-management system that integrates several pest-management approaches. Principles of IMP include monitoring and identifying pests before they become a threat; intercropping and crop rotation to reduce buildup of pests; preventing pests before they reach damaging levels; use of plants that are natural insect repellants; and managing pests using a tiered system of control, including manual removal (e.g., weeding or trapping). F FPesticides are generally used sparingly and only when other methods fail. F
- Intercropping and companion planting: Intercropping is a method of planting crops in close proximity in order to reduce weeds, to encourage plant diversity in order to avoid insect and pest infestation, and for other agricultural reasons. Companion planting is a related method that capitalizes on plants that are natural pest repellants (for example, marigolds), plants that are more attractive to pests than the primary crop, or plants that attract beneficial insects. F
- Mulching, groundcover, and manual control: Mulching is the process of spreading organic or mineral (rock) material to manually control the growth of weeds. FGroundcovers (also known as “living mulch”) are generally plants that that are grown close to the ground below the main crop in order to control weeds. Weeds and insects may also be prevented by manual removal, though this is a highly labor-intensive process.
- Release of beneficial insects and organisms: There are a number of beneficial insects and organisms that, when released, destroy harmful pests. Beneficial insects include predators such as ladybugs; beneficial organisms include nemotodes (microscopic worms) that are used to destroy the larvae of pests. F
Focus on Soil Health
Soil health is a critical component of sustainable agriculture and comprises a number of different growing practices and principles. FThere is also some evidence that sustainably grown plants may be higher in vital macro- and micronutrients, resulting from increased soil health as a direct consequence of organic growing methods and sustainable practices. FSome of these practices are outlined below:
Organic Fertilizer Use
Inorganic (commercial) fertilizers are synthetically created (or mined) for the purpose of adding nutrients plants need to grow to the soil. The practice of monocropping and the lack of crop rotation on industrial farms result in the greater need for soil augmentation with synthetic fertilizers. FCommercial fertilizer use can impair soil health over time, resulting in the need for additional application of inorganic fertilizers. It may also cause soil acidification and soil contamination with heavy metals. FIn addition, commercial fertilizers are a primary source of water pollution, causing algal blooms and dead zones in bodies of water throughout the US. FThe production of inorganic fertilizers also requires large quantities of fossil fuels.
Alternatives to synthetic fertilizer use include compost (decomposed organic matter), animal manure, seaweed, and worm castings. Each of these products can help boost soil health through the introduction and maintenance of healthy soil organisms and micronutrients. Organic fertilizers increase soil biodiversity and have been shown to increase the uptake of nutrients by plants. F FThere is also evidence that use of organic fertilizers improves the nutrient value of the plants themselves. F F
Crop Rotation, Intercropping, & Mulching
Intercropping, crop rotation, and mulching are other sustainable crop production methods that help replenish the soil. Intercropping and crop rotation can improve soil health by introducing plants that fix nitrogen (a process that pulls nitrogen from the air and releases it into the soil) or plants that can be turned under after their growing season is complete to add additional nutrients to the soil. FCrop rotation also generally increases yields, while monocropping has been implicated in declines in crop yield and loss of nutrients from the soil. FRotating crops allows soil to “rest,” that is, to replenish its vital micronutrients, microbes, and other important components. FMulching can reduce soil erosion and help retain critical soil moisture. F
Less to No Tilling of Soil and Reduction of Heavy Machinery Use
Industrial agricultural operations use tilling (plowing) to create rows, loosen soil, and to remove weeds. Sustainable farms use no-till methods or minimize tilling in order to protect the soil. FNo-to-minimal till methods can reduce soil erosion and compaction, increase aeration (critical for root growth and function), and reduce loss of water and critical nutrients. F
Large industrial operations also use heavy machinery to till the soil, to plant, and to harvest. Sustainable producers limit (or eliminate) use of heavy machinery, which conserves non-renewable resources (e.g., oil) and can decrease soil compaction and erosion. F
Choosing Sustainable Seeds and Plant Varieties
Seed and plant variety selection is an important component of sustainable crop production. Large industrial operations generally select plant varieties for yield, ease of mechanical harvest, fast growth, and/or ability to be transported over long distances, rather than for flavor or nutritional content. FThe focus on hybridization and monocropping in industrial crop production has resulted in a loss of biodiversity on farms and a decline in nutrients in a number of different staple crops. F F F
Heirloom crop varieties are plants that were grown in the past and generally not used for industrial crop production. FPrior to the widespread introduction of hybrid seeds (in the US starting in the 1950s and accelerating in the 1970s), heirloom varieties were the predominant type of crops grown. FHeirloom varieties are generally chosen for taste and nutritional value and have frequently been bred to be acclimated to a particular environment, thus making them more resistant to local pests and better suited to the local climate. In addition, heirloom seeds can be saved from year-to-year, while most hybrid varieties are sterile. This forces producers to purchase new seed stock every year – and seed stock is generally controlled by a handful of large agribusinesses. FWhile sustainable crop production does not necessarily eschew hybrid varietals, crop varieties are chosen primarily for taste, nutritional content, and adaptability to a particular environment. F
Finally, in industrial crop production operations, genetically engineered (GE G) crop varieties may be grown to control pests, to allow greater application of herbicides, or to conform to perceived consumer demand (e.g., an apple variety that does not brown when cut). F FSustainable agriculture rejects GE varietals due to their potential adverse environmental impacts, the uncertainty of their healthfulness, and the large amount of inputs required for their production (e.g., commercial fertilizers, herbicides, etc.). F
Practicing Water Conservation and Sustainable Irrigation
Sustainable crop production practices include methods of water conservation and sustainable irrigation. Over-irrigation causes the salinization of soil, which can lead to declines in yield. FAdditionally, in many agricultural areas, aquifers used for irrigation are depleting rapidly. FSustainable agriculture water conservation practices include low volume irrigation, rainwater catchment, and the planting of drought-resistant crops or crops that have been bred for a particular environment.
Other Methods of Sustainable Crop Production
In addition to traditional farm planting, there are a number of sustainable agricultural practices that focus on growing food sustainably in ways best suited to a particular location or environment, including:
- Aquaponics: Raising aquatic animals such as fish in a symbiotic environment with hydroponically grown plants.
- Agroforestry: A type of intercropping that involves growing trees and shrubs alongside crops to the mutual benefit of both.
- Permaculture: An agricultural philosophy that combines several agricultural principals, including agroforestry, intercropping, mulching, and rainwater catchment.
- Rooftop farms and other methods of urban agriculture: Bringing food production closer to communities by growing on city rooftops, in small backyard plots, and in vacant lots.
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Socioeconomic Factors in Sustainable Crop Production
Sustainable crop production entails not only environmental responsibility, but also socioeconomic responsibility, which involves ensuring fair treatment of workers, supporting farm communities, and sustaining local food systems.
In many industrial operations, farm workers are subjected to harsh conditions, including toxic exposure to pesticides and other chemical inputs, dismal living conditions, and extremely low pay. FThey also frequently lack legal protections provided to workers in other sectors. FSustainable farm managers strive to treat workers justly, including paying a fair wage for work.
Monoculture farms and their surrounding communities are also economically vulnerable to crop loss (e.g., by drought, flooding, or pest damage) and fluctuations in supply and demand. FDiversifying farms through sustainable multiculture practices can help reduce this economic vulnerability. F
Finally, sustainable crop production aims to support local communities through the protection and maintenance of farmland, by ensuring that money spent for farm inputs is distributed throughout the local community, and by serving as an integral component of local food systems.