Sustainable crop production is a way of growing or raising food in an ecologically and ethically responsible manner. 1 This 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. 2 Sustainable crop production is in contrast to industrial crop production, 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. 2
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. 4 A 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:
Multicropping is in direct contrast to monocropping, in which large tracts of land are planted with a single crop. 6 Multicropping has a number of environmental benefits, including:
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. 9 10 Various pesticides have been linked to certain types of cancer, to neurological problems, and to other health problems. 11 Pesticides also cause environmental damage such as water pollution and soil contamination. 12 The 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. 13 In addition, pesticides have been shown to cause declines in pollinators and other beneficial insects that are critical to the health of agricultural systems. 14
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:
Soil health is a critical component of sustainable agriculture and comprises a number of different growing practices and principles. 1 There 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. 19 Some of these practices are outlined below:
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. 4 Commercial 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. 20 In addition, commercial fertilizers are a primary source of water pollution, causing algal blooms and dead zones in bodies of water throughout the US. 21 The 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. 19 22 There is also evidence that use of organic fertilizers improves the nutrient value of the plants themselves. 22 23
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. 2 Crop rotation also generally increases yields, while monocropping has been implicated in declines in crop yield and loss of nutrients from the soil. 7 Rotating crops allows soil to “rest,” that is, to replenish its vital micronutrients, microbes, and other important components. 7 Mulching can reduce soil erosion and help retain critical soil moisture. 2
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. 1 No-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. 17
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. 24
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. 25 The 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. 5 26 19
Heirloom crop varieties are plants that were grown in the past and generally not used for industrial crop production. 27 Prior 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. 27 Heirloom 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. 27 While sustainable crop production does not necessarily eschew hybrid varietals, crop varieties are chosen primarily for taste, nutritional content, and adaptability to a particular environment. 19
Finally, in industrial crop production operations, genetically engineered (GE ) 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). 29 12 Sustainable 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.). 4
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. 6 Additionally, in many agricultural areas, aquifers used for irrigation are depleting rapidly. 30 Sustainable 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.
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:
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. 2 They also frequently lack legal protections provided to workers in other sectors. 2 Sustainable 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. 2 Diversifying farms through sustainable multiculture practices can help reduce this economic vulnerability. 2
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.