columbia were born to promote urban agricultural practices such as the sharing backyards program. this program exists to help people living in urban areas get connected with others who have extra space in their yards for the purpose of urban farming. organizations also exist to educate people living in the urban parts of vancouver on farming and growing food in an urban setting by running public demonstration gardens. covering the roof of the west building of the vancouver convention centre is the largest green roof in canada and one of the 10 largest green roofs in the world. with around six acres of living space, it is home to more than 400,000 indigenous plants and grasses that provide insulation. it is also home to four western honey bee beehives which pollinate the plants on the roof and provide honey. the living includes other sustainable practices such as recycling and reusing water. the city of kamloops, british columbia, actively promotes urban agricultural practices within their community. they stress the importance of food security and its effect on the economy as well as the ecology. they created the food and urban agriculture plan (fuap), initiated in 2014, which lays out goals and strategies to implement a sustainable food system. the areas which they cover include: food production and land availability, food processing and preparing, food distribution/retail/access, cooking/eating and celebrating food, food waste and resource management, as well as education/governance and capacity building. the fuap greatly emphasizes on urban agriculture. ontario ontario is the second biggest province and is one of the most urbanized in canada. the provincial government of ontario has a website dedicated to providing information to those who are interested in establishing an urban farm or for those who just want to learn more about urban agriculture in ontario. the city of ottawa is home to the largest urban farm in the nation, the central experimental farm (cef). centrally located and surrounded by the city, the 4 square kilometres (1.5 sq mi) farm is an agricultural facility, working farm, and research center of agriculture and agri-food canada. the city of ottawa is also home to numerous urban farms within the 203.5-square-kilometre (78.6 sq mi) greenbelt. along with many other cities in ontario, the city of toronto allows eligible residents in 4 wards across the city to keep a maximum of 4 hens (no roosters) for the purpose of enjoyment or personal consumption of only the eggs. there are other requirements included with rearing these hens under this program such as zoning and guidelines for building the enclosure, waste and disposal. the wards eligible for this program from the urbanhensto site include ward 13 (parkdale-high park), ward 21 (st. paul's), ward 5 (etobicoke-lakeshore), and ward 32 (beaches-east york). workshops are also available to those interested in rearing urban hens. however, failure to abide by these rules and regulations can result in fines. quebec lufa farms greenhouses are constructed on the rooftops of greater montreal. in montreal, about 100 community gardens provide plots where citizens can grow fruits, vegetables, herbs, and flowers. the largest community garden has about 255 allotment plots, while the smallest site has about 25 plots. out of 2 million people living in the urbanized parts of montreal, about 10,000 residents share the garden plots. the program has been in place since 1975 and is managed by the boroughs. some of the boroughs have a gardening instructor who visits the gardens regularly to give gardeners tips. soil, a water supply, a space for tools, sand, fencing, and paint are provided by the city, managed by the department of sports, recreation and social development. canada has a number of companies working on urban farm technology, including in montreal. the most significant is lufa farms, a private company that opened what is reported to be the world's largest rooftop greenhouse at 163,000 sq ft in the montreal borough of saint-laurent. this is lufa's fourth rooftop greenhouse in montreal and is built on the roof of the former sears canada warehouse. lufa's first rooftop greenhouse was built in early 2011, a 2880 sq metre (31,000 sq ft) hydroponic rooftop greenhouse atop a warehouse designated as their headquarters. they built two more large rooftop greenhouses in greater montreal in 2013 (4,000 sq metre / 43,000 sq ft) and 2017 (5,850 sq metre / 63,000 sq ft), spending almost $10 million for the three structures. also in 2017, an iga supermarket in saint-laurent in montreal unveiled a green roof of about 25,000 square feet of green space and products certified by ecocert canada. they state that they can provide over 30 different kinds of rooftop grown organic produce, along with honey produced and harvested from eight bee hives located on the roof. both lufa and iga rely on non-rooftop production for some of their produce. only shallow-rooted plant can grow on roofs, eliminating crops such as potatoes and corn. some local farmers point out that the industrial systems are subsidized and are unfair competition. china china has more than 1.4 billion people and more than 70% of them are going to live in urban areas in 2035. despite the great economic success and other benefits brought by fast urbanization and industrialization development, chinese urbanization has led to various problems such as the diminishing of cultivable land, lack of food security, and environmental destruction because of urban territory construction. beijing's increase in land area from 4,822 square kilometres (1,862 sq mi) in 1956 to 16,808 square kilometres (6,490 sq mi) in 1958 led to the increased adoption of peri-urban agriculture. such "suburban agriculture" led to more than 70% of non-staple food in beijing, mainly consisting of vegetables and milk, to be produced by the city itself in the 1960s and 1970s. recently, with relative food security in china, periurban agriculture has led to improvements in the quality of the food available, as opposed to quantity. one of the more recent experiments in urban agriculture is the modern agricultural science demonstration park in xiaotangshan. traditionally, chinese cities have been known to mix agricultural activities within the urban setting. shenzhen, once a small farming community, is now a fast-growing metropolis due to the chinese government's designation as an open economic zone. due to the large and growing population in china, the government supports urban self-sufficiency in food production. shenzhen's village structure, sustainable methods, and new agricultural advancements initiated by the government have been strategically configured to supply food for this growing city. the city farms are located about 10 kilometres (6.2 mi) from the city center in a two-tier system. the first tier approached from the city center produces perishable items. located just outside these farms, hardier vegetables are grown such as potatoes, carrots, and onions. this system allows producers to be sold in city markets just a few short hours after picking. another impressive method used in chinese agriculture and aquaculture practice is the mulberry-dike fish-pond system, which is a response to waste recycling and soil fertility. this system can be described as: mulberry trees are grown to feed silkworms and the silkworm waste is fed to the fish in ponds. the fish also feed on waste from other animals, such as pigs, poultry, and buffalo. the animals, in turn, are given crops that have been fertilized by mud from the ponds. this is a sophisticated system as a continuous cycle of water, waste, and food... with a man built into the picture. as the population grows and industry advances, the city tries to incorporate potential agricultural growth by experimenting with new agricultural methods. the fong lau chee experimental farm in dongguan, guangdong has worked with new agricultural advancements in lychee production. this farm was established with aspirations of producing large quantities and high-quality lychees, by constantly monitoring sugar content and their seeds. this research, conducted by local agricultural universities allows for new methods to be used with hopes of reaching the needs of city consumers. however, due to increased levels of economic growth and pollution, some urban farms have become threatened. the government has been trying to step in and create new technological advancements within the agricultural field to sustain levels of urban agriculture. "the city plans to invest 8.82 billion yuan in 39 agricultural projects, including a safe agricultural base, an agricultural high-tech park, agricultural processing and distribution, forestry, eco-agricultural tourism, which will form urban agriculture with typical shenzhen characteristics" in conjunction with this program, the city is expected to expand the buji farm produce wholesale market. according to the municipal bureau of agriculture, forestry and fishery the city will invest 600 million yuan on farms located around the city, with hopes of the farms to provide "60 percent of the meat, vegetables, and aquatic products in the shenzhen market". there has also been an emerging trend of going green and organic as a response to pollution and pesticides used in farming practices. vegetable suppliers are required to pass certain inspections held by the city's agriculture bureau before they can be sold as "green". cuba farming enterprise in havana, cuba (2015) after the disintegration of the soviet union and the eastern bloc, cuba faced severe shortages of fuel and agrochemical inputs. these products had previously been imported from the soviet union in exchange for cuban sugar. as a result, cubans experienced an acute food crisis in the early 1990s, which in part was met with a popular movement of urban agriculture. urban farmers employed – and still employ –agroecological techniques, allowing food production to take place largely without petroleum-based inputs. in 2002, 35,000 acres (14,000 ha) of urban gardens produced 3,400,000 short tons (3,100,000 t) of food. in havana, 90% of the city's fresh produce come from local urban farms and gardens. in 2003, more than 200,000 cubans worked in the expanding urban agriculture sector. egypt in egypt, development of rooftop gardens began in the 1990s. in the early 1990s at ain shams university, a group of agriculture professors developed an initiative focused on growing organic vegetables to suit densely populated cities of egypt. the initiative was applied on a small scale; until it was officially adopted in 2001, by the food and agriculture organization (fao). france in 2014, paris mayor anne hidalgo promised to devote 100 hectares (247 acres) of paris to green space, with 30 hectares specializing in urban agriculture. over 60 urban farming organizations emerged in paris in the following five years. reported to open spring 2020 in the 15th arrondissement of paris, the world's largest rooftop farm of 14,000 m² will sit atop the six-story building at expo porte de versailles. the farm paris-based innovative company viparis teamed up with french companies agripolis, who specialize in farms on rooftops or flat surfaces, and research/ecosystem-recreating company cultures en villes to bring this project to reality. agripolis plans to operate the farm while cultures en ville will plan special events. the farm hopes to produce 2000 pounds of fruits and vegetables each day in a season, with over 30 variations of plants. in addition to being the largest urban farm in the world, the rooftop garden will use 10% of the amount of water traditional gardens need. the goal of the farm is to provide food to southern paris businesses and provide educational tours and collaborative exercises for companies. ghana urban agriculture has been present in west african cities for decades. the practice of vegetable cultivation in ghana began under european colonization. during the period between world war i and ii, the colonial government usurped urban vegetable farms in order to feed the allied forces stationed in the country. prior to 1972, government officials were largely hostile to the planting of indigenous crops. however, economic downturn and food shortages during the mid-1970s led to a major policy reversal, and ghanaians across the country were encouraged to grow food of their own choosing. now, there are seven types of urban agriculture systems in accra, and these practices been able to contribute not only to food security, but also sanitation, water management, and public health. irrigated urban vegetable production is the most common agricultural activity within the city, which uses wastewater to irrigate crops. according to one study, this irrigation system necessitates "manual fetching or pumps", which allows plots to benefit from the nutrients remaining in the water, and supports accra's sanitation