Nature reflects our nature
pollution , water shortages or increased seasonal flooding , reduced numbers of pollinators , and degradation of soils . It will be tempting to convert even more natural areas for food production resulting in a reduction in natural biodiversity and critical ecosystem functions .
In a recent review , Simkhada ( 2019 . Acta Scientific Agriculture . 3:77-78 ) indicated Nepal is importing an increasing percentage of its food . Also , the recent supply chain disruptions from the earthquake , border blockade , and Corvid-19 lockdown all point out the value of growing food close to where it is consumed .
In Nepal , urbanization is occurring at a high rate . In the Kathmandu Valley , for example , there are rapid declines in the amount of agriculture land , riparian habitats along rivers and streams , other non-developed habitats , and open vegetated spaces of any kind as more buildings , roads , and other infrastructures are needed to accommodate the growing population . However , one potential area for growing food that is increasing is flat rooftops .
Some people already are growing plants on their roofs in Nepal , and this is beginning to happen commonly in some other countries such as Singapore , Australia , United Kingdom , and Denmark . Many benefits are being recorded such as a reduction in air pollution ( absorbing carbon dioxide and emitting oxygen ). Also , growing food locally can add to food security , reduce the costs and use of fossil fuels needed to transport food great distances , and in many cases provide fresher and sometimes healthier food . Many people also report growing their own food adds to their sense of well-being . The use of rooftops can help to reduce the pressure for using the last remaining natural areas near cities for agriculture .
For rooftop and other small space areas to produce significant amounts of food for a family , produce must be grown in high densities . One method for doing this is called aquaponics . It is a combination of hydroponics ( growing plants in water or watersoaked media ) and aquaculture ( growing fish in confinement ). Fish food is the primary input to the system , and beneficial free-living bacteria convert the uneaten food and other fish waste to plant food while the plant roots help maintain
k | ltlaDa good water quality for the fish . Nutrient-rich water is recirculated through the system , so the plant roots are constantly being watered and fertilized , therefore more plants can be grown in a small space than would be possible is soil . Aquaponics systems also use far less water ( the main loss is in evaporation ) than irrigation of soil-based growing .
Aquaponics is relatively new , and it has become popular , particularly in western and middle eastern countries , within the last 15-20 years . Aquaponics research has expanded tremendously in the past 10 years , and the approach to growing food is being seen now as having great potential to contribute to food security in locations with water scarcity ( at least seasonally ), lack of access to fertile soils , and in protected growing environments such as greenhouses to provide “ off-season ” fresh produce . It is also considered an environmentally friendly method .
In Kathmandu , there has been recent encouragement by the Municipal government for people to begin rooftop gardens . As more people decide to use their rooftops to grow some of the food for their families , aquaponics could be considered as a technique to provide both fish and vegetables . More information on the costs and benefits of family-sized aquaponics units in Nepal will become available in the next few years because of research now underway at Kathmandu University .
G . Vernon Byrd PhD candidate
DESE
Nature and Social Concern Society 99