Historically, populations have clustered around productive farmland, forming cities in close proximity to the harvest. However, as the population increases,  so does the demand for housing and as a result, farmland is converted into residential spaces, and only non-arable land is left (Portnov). The movement of agriculture to places with poor soil quality or water access results in complicated irrigation systems and poor harvests (Portnov).

On a small scale, we suggest using some areas in cities for urban agriculture which would reduce the amount of nationally-protected land that is needed.  Since this would take place in niche areas in the city, regulation would be done by cities themselves.  While there is no immediate economic loss by using empty lots for agriculture, the future economic loss is greater when considering possible developments in that area, and may cause cities to reclaim land from agriculture.  One way to circumvent this would be to require cities to have a certain amount of area dedicated to agriculture.

To address the larger issue of cities taking over agricultural areas, environmental researchers Portnov and Safriel have suggested urbanizing unproductive areas while preserving fertile land for farming (Portnov). Less water is required by the human population than by the agricultural sector, and urbanization is not de facto dependent on the quality of the land. Since formation of cities around a resource is not a conscious decision, simple “mindfulness” will not ameliorate this issue. Instead laws are needed to protect land for farming.

Land can be defined by its innate qualities, its location, and its degree of development. Zoning is a tool that allots land to different purposes based on these qualities. Agriculturally, zoning is meant to ensure that there is enough land to produce food. However, agricultural zoning is mainly done with regard to quantity, that there is enough undeveloped land in one place for a profitable farm, rather than quality of the land itself (Kruft, 2001).

At present, zoning laws remain mainly in the hands of local authorities, and are dealt with on a city or state basis. On a national scale, the only example of zoning is the formation of national parks that are meant to preserve areas and species of interest. On the small scale, regional laws offer little protection and are subject to reversal by the promise of developments that bring more revenue to the community.

To ensure more permanent protection, we should have larger powers take responsibility for preserving farmland. Especially as attempts to reverse desertification take root, part of the land returned to an arable state should be set aside exclusively for farming This can be done explicitly by setting land aside for agricultural means or limiting the number of non-agricultural structures. It can also be done implicitly through creating laws that disallow parcelling of land. As a result, the minimum lot size is so large that the only way to reasonably live there is to farm (Kruft, 2001).

When thinking of a national or international platform to support such an undertaking as this, the UN’s Food and Agricultural Organization (FAO) comes to mind. Although it does not vote on policy directly, the FAO considers itself a key player in “devising agricultural policy, supporting planning, drafting effective legislation and creating national strategies” (How we Work).

Aided by national or international action, farming can take place in areas equipped with proper water resources and soil nutrients. Places with poor natural resources can be used for urbanization, which does not depend directly on the quality of land or even proximity to freshwater; as reservoirs are often removed from urban areas already. With better land and easier access to water, less money will be spent on bringing water to remote locations to irrigate crops (Portnov), and production may increase. Zoning can ensure that there will be a certain amount of farmland available for food production even as the number of densely populated areas increase.

The difficulty with implementing this solution is the of restriction of development. By setting land aside for farmland, developments that bring in higher income are ruled out, with the possibility of hindering financial mobility. For this purpose it is best not to take farmland from areas that have already begun the process of intense development, or places that immediately border urbanized areas.

The United States is a developed country with high numbers of both imports and exports. However, as population rises and as conditions change with the climate, it is necessary to make sure that production of food remains high and that urbanization does not infringe upon that production. Currently the midwest has the most land dedicated to farming as can be seen in the image below.


Figure 1. Amount of land dedicated to farming in the US (United States Census Bureau, 1992)

Clearly there is a lot of farmland that could be set aside for agriculture without disrupting current urban environments. However, as population grows, more land will be needed for people to live on, and so the best of the land must be picked out for zoning to avoid overcrowding of people or creating an entirely static environment.

In choosing land for protection, the soil fertility, precipitation patterns, and vulnerability to natural disasters have to be taken into account to ensure that the land being preserved is the best for farming. The following images show a variety of factors that play into the decision of which areas to zone.

Plants need moisture in the soil to grow. Areas in red, orange, or greenish brown should be avoided as they are too dry.

image00Figure 2. Soil moisture in the United States (National Resources Conservation Service)

Areas in white are less susceptible to droughts and should be considered for conservation.

image02Figure 3. Drought susceptibility in the United States (National Resources Conservation Services, 1994)

One can also look at a range of limiting factors at once. The areas in green show soil that has few limiting factors and is therefore reliable for producing crops.


Figure 4. Number of complications one can expect from soil quality by area (Elvidge et al.)

Another limiting factor is rainfall. The ideal amount of rain depends on the crop being harvested. The particular plant’s tolerance to drought and waterlogging must be considered.

image04Figure 5. Average precipitation per annum in the United States (Oregon Climate Service, 1990.)

Nevertheless, a brief look makes it clear that some land would be more conducive to food production, due to resource availability and a low level of development.  These are the areas that would be most profitable to save for farming purposes.

In terms of area, according to the Indian Institute of Science, the amount of land required to feed a person, including meat is about 0.7 hectares (Myers, 2008). The United States has an estimated population of 322 million as of November 2015 (United States Census Bureau, 2015), and area of 931 million hectares (Lubowski et al, 2006)  The required land would be 225.4 million hectares, or nearly a quarter of the United States’ land at the present.  Not all land necessary must be included in the zoning plan, but this gives a benchmark number.  Below this quantity, the United States would have to resort to importing.  To avoid importation, food has to be used more efficiently.

The process of evaluation holds the same for all countries; finding which land is best suited for farming, and then zoning it for that purpose, while avoiding land that is currently under too much development for the formation of large farming plots to be possible.

To make an informed decision about zones for establishment, data like that seen above is necessary.  While it has been compiled in some countries, it has not in others, and even in places where it is available, it should be updated to make sure that the area’s condition is stable.  The projected effect of climate change on various regions should be taken into consideration, including change in precipitation, temperature, possibilities of flooding, storm systems, and change in flora or fauna.

The aim should be to have this research conducted over five years, after which the land chosen is proposed for protection.

Related Articles

Work Cited

Elvidge, Christopher; Imhoff, Marc L; Lawrence, William T; Stutzer, David. (n.d.). Assessing the Impact of Urban Sprawl on Soil Resources in the United States Using Nighttime “City Lights” Satellite Images and Digital Soil Maps. Retreived 14 Nov. 2015 from <http://landcover.usgs.gov/luhna/chap3.php>

How we Work. (n.d.). Retrieved 8, Nov, 2015, from <http://www.fao.org/about/how-we-work/en/>

Kruft, David. (2001) Agricultural Zoning; Penn State Law School Retrieved 8 Novemberfrom <https://pennstatelaw.psu.edu/_file/aglaw/Agricultural_Zoning.pdf>

Lubowski, Ruben N.; Vesterby, Marlow; Bucholtz, Shawn; Baez, Alba; and Roberts, Michael (2006) Major Uses of Land in the United States, 2002.  Retrieved 23 Nov. 2015 from <http://www.ers.usda.gov/publications/eib-economic-information-bulletin/eib14.aspx>

Myers, Norman. (1998), The Next Green Revolution: Its Environmental Underpinnings. Retrieved 23 Nov. from <http://www.iisc.ernet.in/currsci/feb25/articles16.htm>

National Resources Conservation Service: Soils (n.d) Soil Moisture Regimes of the Contiguous United States. Retrieved 14. Nov from <http://www.nrcs.usda.gov/Internet/FSE_MEDIA/nrcs142p2_050436.jpg>

National Resources Conservation Service Soil Staff (1994) Root Zone Available Water Capacity Less Than or Equal to 6 Inches Retrieved 14. Nov from <http://www.nrcs.usda.gov/Internet/FSE_MEDIA/nrcs142p2_049928.jpg>

Oregon Climate Service, 1990, Annual Average Precipitation: The United States. Retrieved November 14, 2015 fom <http://www.wrcc.dri.edu/pcpn/us_precip.gif>

Portnov, B., & Safriel, U. (n.d.). Combating desertification in the Negev: Dryland agriculture vs. dryland urbanization. Journal of Arid Environments, 659-680.

United States Census Bureau. (1992). Land in Farms as Percent of Land Area. Thematic maps: agriculture. Retrieved 14 Nov. 2015 from <http://www2.census.gov/geo/pdfs/maps-data/maps/thematic/ag064.pdf>

United States Census Bureau (2015), U.S. and World Population Clock.  Retrieved 23 Nov. 2015 from <http://www.census.gov/popclock/>

Various, (n.d.) In Action. The Food and Agriculture Organization, the United Nations. Retreived November 8 from <http://www.fao.org/in-action/en/?page=2&ipp=5&tx_dynalist_pi1[par]=YToxOntzOjE6IkwiO3M6MToiMCI7fQ==>.