intercropping in organic agricultural systems

organic farming

Genuine organic agriculture is rooted in four  main principles:

  1. ecology: both ecological systems and cycles should be supported
  2.  health: the well-being of both flora and fauna should be sustained
  3. fairness: providing common and just environment and life opportunities
  4. care: the management of natural resources that is both precautionary and responsible for the benefit of current and future generations, as well as the environment

These four principles are directly applicable to intercropping for many reasons. For instance, intercropping supports healthy ecological systems as it is based inherently on the incorporation of multiple species or varieties into a single system with various motivations for specific pairings or groupings. In this sense, biodiversity is encouraged in two ways. The first being that it prevents one particular variety of pest from aggregating by limiting their food source and ultimately reducing the risk of excessive loss due to one specific pest. The second is that more pollinators and predatory species are present as a result of a more diverse system that provides a habitat for pollinators and predatory species. This is accomplished by the relatively simple act of diversifying the crops grown. Similar benefits can be seen in reductions in total weed biomass. Further, intercropping supports the goal of closed-system production, i.e. nutrient cycling within a system, via the use of nitrogen-fixing legumes as component crops that benefit from their symbiotic relationship with Rhizobia.

640px-nitrogen-fixing_nodules_in_the_roots_of_legumes
nitrogen-fixing nodules from Rhizobia bacteria

The use of these crops also organically increases the soil nitrogen content, which encourages mycorrhizal fungus development, which can also improve phosphorus, copper, zinc, and molybdenum uptake. However, it is worth mentioning that these objectives may be best realized by polyculture farms that incorporate livestock manure as legume fatigue may occur if the soil becomes overly infested with pathogens caused by the over-cultivation of legumes.

When accounting for the above-mentioned factors, it may be supposed that intercropping is best suited for organic production systems because it serves to circumvent the need for synthetic, mineral and chemical inputs, i.e. fertilizers, herbicides and pesticides, that are commonplaces in conventional agriculture and restricted from use in organic agriculture. In a sense, this means that although intercropping is more closely related to historical approaches to agriculture, it is being adapted to modern circumstances that include a rising demand for organic food, increasing environmental stresses, and a growing societal awareness of food and food production processes. Concurrently, conventional agriculture is becoming increasingly cost-inefficient, both economically and environmentally speaking. This has the potential to support an agricultural transition towards organic production methods, especially if evidence substantiating assertions about the efficacy of intercropping continue to emerge. Moreover, the growing body of proof that demonstrates total system improvements in output produced by intercropped systems may help to counter the argument that organic production cannot be as productive as conventional agriculture, especially when comparing it to sole cropping systems. In turn, intercropping may enable organic production to become more competitive with conventional production and ultimately provide an opportunity for further organic market expansion through the establishment of a fairer economic playing field. Ultimately, these factors allow for the creation of more resilient food systems that provide modern day benefits that serve as the groundwork for a more sustainable future. Consequently, this element of foresight has the potential to benefit a wide variety of both human and non-human stakeholders.

sources:

photo credit:

  • geneticliteracyproject.org
  • commons.wikipedia.org

crop quality – when better is better

apple

There is no doubt about it – we like a shiny apple. It just looks so much more appealing than the odd, misshapen apple that has already been sampled by the local fauna. After all, we humans are visual creatures and the appearance of our food is what peaks our initial interest. Besides looking great, we want the apple to taste good and provide us with wholesome nutrition. After all, looks aren’t everything. Sellers also want a product that looks good, but their version of attractiveness comes from uniformity and bright colors that attract customers to their shelves. Just in case the product isn’t purchased right away, the product should also have a long shelf life. Producers, on the other hand, have completely different demands. They need a product that can travel from point A to point B [often thousands of miles] and not be bruised and mushy upon arrival. They want the apple to be dense so that they are paid the most for their wares.

In the end, beauty, i.e. quality, is in the eye of the beholder. In the case of crops, this generally means a favorable mix of appearance, texture, flavor, safety, and nutrition [see the table below]. To produce a crop more likely to please all parties involved, it must be of high quality. To grow a crop of high quality, it must have been produced with care, which means that a number of factors need to be considered during each phase of the production cycle.

Planning Phase

It is first important to understand your growing space. How much sunlight will it get? How much precipitation does your area receive? What are the average temperatures? What is the soil type? How big of an area will you be planting? Will you practice intercropping? How many seasons of the year are suitable for growing? Are you planning to grow annuals or perennials? Once these questions have been answered, a plan for the growing season can be made.

Referencing your plan and a guide for plant spacing, select seed varieties suited to the local climate and growing conditions. If possible, opt for local seed banks or nurseries, cooperatives, or reputable seed catalogs that can provide this information or are already adapted to local conditions. If a particular seed variety is particularly successful, consider saving your own seed for future growing seasons.

bean-varieties

Planting and Growth Phase

When planting the crops, make sure to follow the recommended spacing suggestions. By doing so, the plants are sure to get the appropriate amount of light and there is enough space for air to circulate which reduces the likelihood of disease and pest problems.

As the plants are growing, opt for manual methods of weed management and monitor pest populations to help prevent any major infestations. Having healthy soil helps to reduce the likelihood of pest infestations and provide the plants with the nutrients it needs to remain healthy and bear nutritious fruits.

If possible, protect the plants from extreme temperatures to avoid premature flowering, damage from frost or snow, and leaf scorch.

Harvesting & Post-Harvest Phase

The moment a product picked, it begins to deteriorate in quality. Accordingly, it is important to have a plan and system in place for processing the harvest. The essential parts of this process involve cooling, cleaning, sorting, and packaging. How far a product will travel impacts the approach to packaging. Having a system in place for post-harvest handling also contributes to overall food safety.

General Tips

  • Pay attention to the details and to be consistent.
  • Keep track of the growing process to learn from successes and mistakes

At present, the quality of fresh fruits and vegetables is based on the following factors:

crop quality

For more information about the horticultural production system, click here.

additional resources:

photo credit:

  • sknaturalsadoor.com
  • sciencmag.com

question: what does organic really mean?

The word organic is popping up everywhere. Organic milk, strawberries, and tomatoes. Organic cotton and organic pet food. These items are undoubtedly more expensive than their conventional counterparts and they are often stigmatized as being yuppie products or just another marketing scheme. Organic products have also been recognized as being healthier and more environmentally-friendly. But what is not often discussed is what organic means and what is different about organic agricultural techniques. So, what does organic really mean?

According to the USDA, organic operations are those that protect natural resources, conserve biodiversity, and use only approved substances. 

The EU states that organic agriculture is method of farming and gardening that relies on natural systems and products and is free of virtually all synthetic and toxic chemicals, fertilizers and pesticides.

The International Federation of Organic Agriculture (IFOAM), provides a more comprehensive definition: A production system that sustains the health of soils, ecosystems, and people. It relies on ecological processes, biodiversity, and cycles adapted to local conditions, rather than the use of inputs with adverse effects. It combines traditions, innovations, and science to benefit the shared environment and promote fair relationships and a good quality of life for all involved. 

IFOAM’s definition differs from the others in that it is not only about the practices, rather it denotes the process as a holistic in that it focuses not only on the inputs and outputs but also the complex interworkings between different components of the system. Likewise, it demonstrates that farming practices should fit the environmental system rather than attempting to manipulate ecosystems for agriculture. In doing so, it is expected that organic agriculture is an integrated, sustainable production management system that promotes and enhances biological cycles and soil biological activity.

action-sn-blog-organic-vs-conventional
A comparison of conventional and organic agriculture Image Credit: http://blog.ucsusa.org

In order to achieve these goals, organic production practices are shaped by four supporting principles:

  1. Health: sustain the health of soil, plant, animal, human, and planet as a complex and indivisible system
  2. Ecology: support and promotion of ecological systems and cycles
  3. Fairness: provide common and just environment and life opportunities
  4. Care: management in a precautionary and responsible manner to protect for the benefit of current and future generations as well as the environment

In light of these principles and the impact that they are intended to provide, the term organic can therefore also be considered a part of a lifestyle that promotes a more harmonious relationship with the natural systems that support us.

Criticisms of organic, e.g. the cost, exclusionary nature, and focus on labeling and certification, are being addressed by the organic 3.0 movement, which is focusing on the mainstreaming and normalization of organic in order to better disseminate the benefits it provides.

organic3
Image Credit: food.blog.de

Header Image Credit: http://drivedeschamps.fr

question: what are small farms, how do they contribute to society, and what challenges are they faced with?

Producing a vast amount of the world’s food, small farms are valuable assets that contribute to long-term economic sustainability and food security. What actually constitutes a small farm is hard to specify as there are extreme variations in societal structure, ergo many definitions exist. In the United States, a small farm is defined as any farm earning a minimum of $1,000 and a maximum of $250,000. In Canada, a small farm is considered a farm that doesn’t sell commodities in a market with set prices. The FAO has a much more complicated definition: “small farms are complex interrelationships between animals, crops and farming families, involving small land holdings and minimum resources of labour and capital, from which small farmers may or may not be able to derive a regular and adequate supply of food or an acceptable income and standard of living”, while the European Union has no concrete definition.

Despite a lack of a universal definition, small farms contribute a great deal to society – even beyond food production. It could even be argued that small farmers are some of the most underappreciated members of society even though they add genuine and unselfish value to the world. For example, small farms support rural employment as well as maintain and accommodate social connections in rural areas. This is especially important in an age of widespread urbanization as it contributes to the goal of more balanced development. Likewise, it provides diversity in societal structural. Such diversity is particularly essential to maintaining diversity in ownership in an era when the consolidation of power is a major issue facing society. In this respect, they provide also a basis for community empowerment. In doing so, small farms are a symbol of regional identity.

The benefits provided by these farms are threatened by a variety of factors, with the aforementioned issue of the consolidation of ownership and power being at the forefront of concern. This issue is catalyzed by unfavorable government policies (see Everything I Want to Do Is Illegal by Joel Salatin) that have been developed in favor of large agricultural conglomerates with the financial resources to influence government officials. A lack of societal sympathy and support for small farms due to false perceptions, for example, the belief that small farms are unproductive, further contributes to the problems faced by small farmers.

hoophouses-clay-bottom-farm
This is a picture of Clay Bottom Farm in Indiana that produces 30 varieties of vegetables to feed 200 families on one acre of land. Photo Credit: Clay Bottom Farm

sources:

EU Agricultural Economic Brief

http://www.fao.org/docrep/003/t0757e/T0757E02.htm

http://articles.extension.org/pages/13823/usda-small-farm-definitions#.UsV_8ifCYx4

http://www.sciencedirect.com/science/article/pii/S0305750X15002703

www.foodfirst.org

http://smallfarmcanada.ca/2014/10-years-8-questions/

an introduction to intercropping

Intercropping is a growing method rooted in ecological diversity. In intercropped systems, two or more component crops are grown together for a given growing period. There are currently four types of intercropping systems:

  1. Strip: crops are grown simultaneously in independent rows within the same field
  2. Row: crops are grown together simultaneously and a minimum of one crop is planted in a row
  3. Mixed: there is no specific order to the crops
  4. Relay: the growing system is dependent on the lifecycle stage of the intercropped plants. Typically, the second crop in the intercropping schedule is planted after the first crop reaches the reproductive stage and before it reaches peak maturity

types-of-intercropping
Types of Intercropping, Source: own, Adapted from Mousavi and Eskandari (2011)

Regardless of the intercropping pattern selected, the plants grown together should be complementary in nature in that they have different “rooting abilities, canopy structure, height and nutrient requirements” which produce a yield advantage. This occurs when resources that could not be utilized by a single crop are utilized by an additional crop growing in the same space.  One of the best-known examples of intercropping is the three sisters method developed by Native Americans in the United States, where Maize, pole beans and winter squash are grown together. The Maize provides a form for the beans to climb and shades the squash. The beans stabilize and fix nitrogen for the Maize plants. The squash provides ground cover, effectively maintaining moisture levels and suppressing weeds.

In order to develop an advantageous intercropped system, five fundamental principles must be adhered to:  

  1. A detailed plan must be developed, including an understanding of the characteristics of the component crops
  2. Crops must be timely sown
  3. Adequate fertilizer must be applied at the appropriate time
  4. A weed and pest strategy must be in place
  5. Harvesting must be efficient

If the wrong types of plants are grown together or the spacing is incorrect, the output will decrease.  To determine whether an intercropped system is effective, the land equivalent ratio [LER] is typically used, where:  (INTERCROP 1 / PURE YIELD 1) / (INTERCROP 2 / PURE YIELD 2). Results > 1.0 indicate an advantageous pairing. Results < 1.0 indicate a disadvantageous pairing.

sources:

Lithourgidis, A.; Dordas, C.; Damalas, C. A.;  Vlachostergios, D.N. (2011, April) Annual intercrops: An alternative pathway for sustainable agriculture. Australian Journal of Crop Science, 5(4) Retrieved from https://www.researchgate.net/publication/224934832_Annual_intercrops_An_alternative_pathway_for_sustainable_agriculture
Mousavi, S. R.; Eskandari, H. (2011, January). A General Overview on Intercropping and Its Advantages in Sustainable Agriculture. Applied Environmental Biological Sciences. 1(11). Retrieved from https://www.researchgate.net/publication/220000362_A_General_Overview_on_Intercropping_and_Its_Advantages_in_Sustainable_Agriculture
Sullivan, P. (1998, November). Intercropping Principles and Production Practices. Agronomy Systems Guide.  Retrieved from http://www.iatp.org/files/Intercropping_Principles_and_Production_Practi.htm
Wiley, R.W. and Rao, R.M. (1980, April) A Competitive Ratio for Quantifying Competition Between Intercrops. Experimental Agriculture, 16(02). Retrieved from https://www.researchgate.net/publication/231898671_A_Competitive_Ratio_for_Quantifying_Competition_Between_Intercrops

Zeman, F. (2012) Metropolitan sustainability: understanding and improving the urban environment. Oxford, Cambridge, Philadelphia, Delhi: Woodhead Publishing Limited

zero acreage farming (zfarming): what it is and how it can change the future of (urban) agriculture

It is not uncommon to hear about the challenges that will be faced in feeding the growing population of the world. One of the main concerns is the lack of arable space, an issue that can be attributed to land-use changes, especially urbanization. Subsequently, the rapid growth of cities contributes to a number of issues, with the overwhelming demand for resources, e.g. food, that must be imported from outside systems being among the most relevant. This long-distance between urban-dwellers and agricultural production creates ecological problems in the form of inhibited nutrient cycling, high costs, and emissions problems.

Despite these issues, it is also well-documented that cities are efficient hubs of innovation. Accordingly, cities have birthed the idea of zero acreage farming, or ‘Zfarming’, which is defined as a form of agriculture that does not use farmland or open space, rather it uses otherwise unused spaces. Zfarming can take the form of, for example, rooftop farms/gardens, edible walls, indoor farms, or vertical greenhouses. As the competition between food producers and various interests is alleviated, the conflict related to land-use in urban spaces is resolved. Moreover, urban spaces supportive of Zfarming practices can be considered to have added-value as there is a unique component to said spaces.

Additional potential benefits associated with Zfarming include, for instance, the potential to shift towards new frameworks for food supply systems via input from evolving customer and social demands, and income generation – especially when higher value crops are grown. Furthermore, Zfarming can help address issues related to urbanization by providing economic opportunities which incentivize the transition towards more sustainable, resilient and efficient urban spaces.  

At present, Zfarming is almost exclusive to middle-class spaces with operations often catering to the needs of higher end restaurants or supermarkets with the use of mid- and long-term contracts in order to establish income consistency. This is arguably necessary due to the higher startup and maintenance costs. However, Zfarming is also associated with social/educational centers, efforts to improve the quality of urban life, and supporters of innovation focusing on alternative, i.e. not soil-based, methods for growing. It can, therefore, be assumed that as innovative practices are disseminated, they will gradually become integrated into lower-income spaces.

To encourage and promote Zfarming in more locations and further foster development in existing venues, the following supportive infrastructure is needed:

  • Modern and adaptive policy that is reflective of modern societal demands
  • Financing programs to allow for a shift away from top-down approaches to startups
  • Greater involvement (human capital)
  • Knowledge sharing to address the issue of a lack of practical experience which results in difficulties in the planning and implementation phase, something that can hinder the longevity or establishment of any Zfarming operation

In promoting Zfarming, innovative practices that may contribute to sustainable urban agriculture may be developed and implemented. Supplementary to the practical benefit of growing food, Zfarming also aids in the advancement of new forms of resource efficiencies, farming technologies and the practical application of such innovation, making it a trend worthy of further investigation.


source:

https://www.econ-isr.tu-berlin.de/fileadmin/fg283/Infos/Logos/RAFS_FINAL-1.pdf

sustainable agriculture defined and discussed

Sustainable agriculture has become increasingly supported by citizens and farmers alike. According to the United States’ 1990 Farm Bill, for agriculture to be sustainable agriculture it meets the following requirements:

  • The production must satisfy the human need for food and fibers.
  • The environmental quality and natural resource base that the agricultural economy depends upon must be enhanced.
  • It must improve the quality of life for farmers and society as a whole.
  • The economic viability of farm operations must be sustained.
  • Integrated natural biological cycles and control methods must be employed.
  • Non-renewable and on-farm resources must be efficiently used.

Sustainability is often associated with organic agriculture. An organic agricultural system is designed to maintain the health of the soil, ecosystems, and people. It is structured to mimic ecologic processes in order to preserve biodiversity, limit the input of non-natural resources, and adapt to local conditions. Land must be free of chemical use for three years before it can become organically certified. Organic growing generally produces lower yields, approximately 80% of those using technological inputs, although with good conditions organic crops can compete to within 5%. The discrepancy is attributed to limited nitrogen in a given system. However, productivity typically increases over time due to soil improvement and agricultural management skills. Methods used in traditionally rural settings can include, for example, crop rotation, cover crops, compost and the application of manures as fertilizer.

The employment of organic agriculture practices also requires more space as it is not dependent upon large quantities of outside inputs for its functionality (see what is the difference between intensive and extensive agricultural systems as they relate to livestock production?). Accordingly, there are typically a greater variety of activities practiced, i.e. polyculture, on a given piece of land. When employing low-intensity methods on more diversely populated plots, several benefits have been shown to emerge, including increase in forest cover, larger and fuller hedge-groves, more crop diversity and more vegetation strata. These effects have resulted in an increase in natural vegetation cycles and biodiversity levels.

Sustainability is also a major theme in alternative agriculture systems, particularly in urban spaces, where practices, such as vertical and hydroponic, are driving the competitiveness of food grown in non-traditional spaces.

However, there are obstacles to the transition from 20th-century agriculture to sustainable agriculture. For example, a study surveying sustainability practices of farmers in 12 states it was found that:

  • 84% of farmers were aware of soil testing;
  • 76% knew about crop rotation;
  • 75% were knowledgeable about conservation tilling;
  • 74% were familiar with soil cover;
  • 64% had knowledge of Integrated Pest Management (IPM)
  • 52% were aware of diversification.

However, researchers also noted that awareness does not necessarily transfer to use as only 18% of farmers practiced water management, 13% engaged in nutrient management and 7% employed erosion control. The top three concerns related to issues associated with sustainable agriculture are:

  1. Cost and fear of crop/profit loss during transitional periods;
  2. A lack of education on how to integrate complicated alternative options, coupled with a lack of resources and support necessary to the transition;
  3. Resistance to change.

It has also been noted that there is often an incompatibility between growing conditions and sustainable growing practices, such as when the climate makes growing nitrogen fixing plants difficult, if not impossible. Such fears and obstacles to sustainability have the potential to be overcome via the use of education practices and more equitable public support and financing for food production.

sources:

https://www.nal.usda.gov/afsic/sustainable-agriculture-information-access-tools
Rodriguez, J. M., Molnar, J. J., Fazio, R. A., Sydnor, E., & Lowe, M. J. (2009). Barriers to adoption of sustainable agriculture practices: Change agent perspectives. Renewable Agriculture and Food Systems, 24(1), 60-71.
https://www.researchgate.net/publication/231888132_Barriers_to_adoption_of_sustainable_agriculture_practices_Change_agent_perspectives
Karp, D. S., Rominger, A. J., Zook, J., Ranganathan, J., Ehrlich, P. R., Daily, G. C., & Cornell, H. (2012, September). Intensive agriculture erodes ß-diversity at large scales. Ecology Letters, pp. 693-970.
http://onlinelibrary.wiley.com/doi/10.1111/j.1461-0248.2012.01815.x/abstract;jsessionid=BCD212E8E234B5D0CD57708401BD85E9.f03t01