Abstract
In green roofs, the use of plant species that withstand dry arid environmental conditions and have reduced water requirements is recommended. The current study presents the effect of irrigation amount on the growth of four different species of lavender; Lavandula angustifolia, Lavandula dentata var. candicans, Lavandula dentata var. dentata, and Lavandula stoechas established on an extensive green roof system and used in urban agriculture. Two irrigation treatments (high and low) determined by the substrate hydraulic properties were applied. Plant growth studied at regular intervals included measurements of plant height, shoot canopy diameter, plant growth index, shoot dry weight and stomatal conductance. The results were consistent and showed that low irrigation reduced plant growth. With the exception of L. stoechas, the appearance of plants watered with the low irrigation treatment was satisfactory, and their use under low water amount irrigation is supported. Interspecies differences among lavender species were present in both irrigation treatments. Overall, L. dentata var. candicans showed the greatest growth, followed in descending order by L. dentata var. dentata and L. angustifolia. In parallel, for stomatal conductance, L. dentata var. candicans showed the lowest value, similar to L. dentata var. dentata, and L. angustifolia the largest. Differences in plant characteristics and size among the latter three species can be considered in the design of extensive green roof systems. The use of substrate hydraulic properties was shown to be important for irrigation management on extensive green roof systems.
Highlights
There is increasing interest in urban agriculture due to the related economic, social and environmental functions contributing to the sustainability of cities [1]
Though urban agriculture usually highlights food production, it includes the cultivation of other plants such as ornamentals [2], as well as agricultural systems that relate to recreation and leisure [3]
The objective of this study was to investigate the effect of irrigation amount on the growth of 4 lavender species, i.e., Lavandula angustifolia, Lavandula dentata var. candicans, Lavandula dentata var. dentata and Lavandula stoechas on an extensive green roof system under two irrigation treatments in the aforementioned available water range to support the creation of aesthetically-pleasing green roofs for urban agriculture
Summary
There is increasing interest in urban agriculture due to the related economic, social and environmental functions contributing to the sustainability of cities [1]. Cities are characterised by dense buildings, green spaces which are limited in number and size and large impervious paved areas. These characteristics have contributed to creating adverse environmental conditions within the cities such as the heat island effect, restricted air flows, human discomfort and poor health caused by heat stress and poor air. Roof greening (the development of planting on buildings, i.e., green roofs) is one means by which urban agriculture may be realized [1,6]; it has the potential to contribute to mitigating the problems caused by urbanisation on an individual scale, and when applied broadly, could improve the environment of a city [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
