Rooftops of buildings are usually large areas overcrowded with junk and useless objects. With a little effort and money, these rooftops can be transformed to mini-gardens that produce vegetables and fruits, free from hormones and pesticides.
Many countries have embarked on projects to increase the amount of greenery on rooftops. This provides a good opportunity for housewives and youth to use their time fruitfully and increase oxygen production.
We suffer from rapid expansion of the human populations and building on cultivated land. These lead to limited resources for many families living in the metropolises.
This situation has a negative impact on the general well-being of the families living in poor urban or suburban neighborhoods. A solution for this problem is providing these families with a source of income and healthy nutrition.
Increasing awareness of this problem has encouraged some communities to increase the availability of fresh and high-quality vegetables.
They encourage a more efficient use of water and possibly create a source of income for housewives. It depends principally on planting fruits and vegetables without wasting excess water or using soil.
This technique aims at using water efficiently in a “closed-system” using simple substrates. A “closed-system” as opposed to traditional open field production and conventional irrigation, collects the water for irrigation in plastic buckets where it can later be reused.
As for the substrates, they are easy to find and readily available. Examples include rice husks, sand and peat moss. More importantly, there is no use of pesticides, ensuring the production of healthier vegetables.
Another advantage is that the produce is closer to the consumer (on rooftops) thus saving transportation, packaging and storage costs.
Two alternative types of soil are peat moss (a form of algae) or perlite, a type of volcanic eruption that manufacturers treat at a temperature of 1,000 degrees Celsius to form granules suitable for use in agriculture.
Peat moss, perlite, sand and rice husks have the advantage that they don’t get infections that plague normal soil; thus, there is no need for pesticides.
Green Food from Green Roofs
This easy-to-do project can be done by anyone. The area should have sunlight for at least four to five hours daily to allow enough exposure for the fruits and vegetables to flourish.
Expenses vary depending on the system used. The manual system consists of wooden containers (barrels) with plastic sheets filled with peat moss or perlite used as substrates.
The drainage goes through small plastic hoses to a bucket. This system is suitable for leafy crops such as parsley, radish, and carrots.
The manual system isn’t suitable to generate a source of income. It is mainly for domestic consumption of produce. The main element here is exposure to sunlight; it doesn’t need extra care.
If the project is established for the purpose of business, then wall gardens are a good choice. Wall gardens consist of plastic tubes or bags hung on the roof’s walls to hold the plants; irrigation and drainage are automatic. This way a larger area of the roof is used in contrast to the wooden containers used in the manual system.
The beauty of this project is that it is easy to maintain, it is inexpensive, and requires only enough hours of sunlight to get the project underway.
Usually the produce from these crops grow earlier than under normal conditions. Another advantage to this method of agriculture is that it allows diversity; meaning you can grow vegetables, fruits and other types of plants in the same area.
Egyptian researchers at Ain Shams University found that the plants grown on the rooftops contain from three – seven times the amount of active ingredients (natural chemical components found in plants and have nutritional value) than those grown the traditional way.
A logical reason behind this would be that gardeners use no pesticides in the closed-system method, thus no decrease occurs in its nutritional content.
A field study revealed that the temperature on the planted rooftops was seven degrees Celsius lower than that of rooftops that weren’t planted. The objective of the project became more environmentally-oriented. Thus, all levels of the community were considered.
All in all, this could be an important environmental step. If given the attention it deserves, it could mean a cleaner environment, as well as an opportunity for students, graduates and even housewives to be interactive with the community around them and make some money on the side.
This article is from Science’s archive and we’ve originally published it on an earlier date.