Protected Crops

Urban vegetable for food security in cities. A review

“…This also includes closed-up or asphalt areas of the city, e.g., in city squares or terraces. This way, there is no risk of plants becoming contaminated by polluted soil (Figure: Gruda, 2013, private collection) which inorganic or organic substrates are used (Gruda 2009;Gruda et al 2007;Gruda and Tanny 2014). In addition, Gruda (2005Gruda ( , 2009 reported that an adaptation of cultural management to the specific cultural system of soilless culture, as well as crop demand, can further result in an improvement of the quality of horticultural products.…”

“…This took place in The Netherlands with the project "de gesloten kas: the closed greenhouse" and in Germany with "ZINEG: the low-energy greenhouse" (Gruda and Tanny 2014). All these systematic tools, together with the use of alternative and renewable energies, without using fossil fuels, can contribute to a reduction of energy consumption by 80-90 % and operate a greenhouse with minimum CO 2 -emissions (Gruda and Tanny 2014).…”

“…The development of light-emitting diode (LED) lamps offers the use of plant-related radiant energy due to optimization of the plant management processes. This is very important for plant growth, plant development, and product quality (Gruda and Tanny 2014). LED lamps have several unique advantages over existing horticultural lighting, such as being small in size and having increased longevity and low heat emission even at very high light intensity levels.…”

“…In addition, LED lamps have the ability to control spectral composition, giving the opportunity to select the most favorable light spectrum for photosynthesis (Fig. 5) (Morrow 2008;Paradiso et al 2011;Gruda and Tanny 2014).…”

“…The increase of blue light (Hogewoning et al 2010) led to an increase of greenhouse cucumbers biomass: Additionally raising lettuce seedlings treated with blue light also promoted the growth of plants after transplanting in terms of high shoot and root biomasses, high content of photosynthetic pigments, and high antioxidant activities in the lettuce seedlings before transplanting (Johkan et al 2010). Gruda and Tanny (2014) state that plant-specific choice of light intensity and spectrum with a combination of far red and blue light rate using LED could contribute to a reduction of fertilizer and chemical use, due to an aimed shortening of the vegetation period and improvement in plant morphology. However, although LED has little energy consumption and produce very little heat, the energy costs are still high.…”