Arundo donax (reed)
Description
Arundo donax, giant cane, is a tall perennial cane, native to the Mediterranean Basin and middle east and probably also parts of Africa and southern Arabian Peninsula. It forms dense stands on disturbed sites, sand dunes, in wetlands and riparian habitats.
Characteristics
Arundo donax generally grows to 6m, in ideal conditions it can exceed 10m, with hollow stems 2 to 3cm in diameter. The leaves are alternate, 30 to 60cm long and 2 to 6cm wide with a tapered tip, grey-green, and have a hairy tuft at the base. It flowers in late summer, bearing upright, feathery plumes 40 to 60cm long, that are usually seedless or with seeds that are rarely fertile. Instead, it mostly reproduces vegetatively, by underground rhizomes. The rhizomes are tough and fibrous and form knotty, spreading mats that penetrate deep into the soil up to 1m deep. Stem and rhizome pieces less than 5cm long and containing a single node readily sprouted under a variety of conditions. This vegetative growth appears to be well adapted to floods, which may break up individual A. donax clumps, spreading the pieces, which may sprout and colonise further downstream.
Uses
Carbon sequestration
Research was carried out to evaluate, in the same pedological and climatic conditions, the impact of three long-term (14 years) agricultural systems, continuous giant reed, natural grassland, and cropping sequence, on the organic-matter characteristics and microbial biomass size in soil. The study pointed out that a long term Giant reed cropping system, characterized by low tillage intensity, positively affect the amount and quality of soil organic matter. Arundo donax showed greater values than tilled management system for total soil organic carbon, light fraction carbon, dissolved organic carbon, and microbial biomass carbon. Regarding the humification parameters, there were noticed any statistically differences between giant reed and a cropping sequence (cereals-legumes cultivated conventionally).
Biofuel
Arundo donax is a strong candidate for use as a renewable biofuel source because of its fast growth rate and its ability to grow in different soil types and climatic conditions. A. donax will produce an average of 3kg of biomass per m2 once established. The energy density of the biomass produced is 17 MJ/Kg regardless of fertilizer usage. Outside its native range, this needs to be balanced against its major invasive potential.
Studies in the European Union have identified A. donax as the most productive and lowest impact of all energy biomass crops.
Needs
Establishment is a critical point of cultivation. Stem and rhizome have a great ability to sprout after removal from mother plant and both can be used for clonal propagation. The use of rhizomes were found to be the better propagation method for this species, achieving better survival rate.
A. donax maintains a high productive aptitude without irrigation under semi-arid climate conditions. Several reports underlined that it is more economical to grow giant reed under moderate irrigation.
Fertilizer enhances the productive capacity in the initial years, but as the years go by and as the radical apparatus progressively deepens, the differences due to fertilizer decrease until disappearing. Harvest time and plant density were found to not affect the biomass yields.
Due to its high growth rate and superior resource-capture capacity (light, water and nutrients), A. donax is not affected by weed competition from the second year. An application of post-emergence treatment is usually recommended. Giant reed has few known disease or insect pest, but in intensive cultivation no pesticides are used.
Arundo donax’ s ability to grow for 20 to 25 years without replanting is also significant.
source : https://en.wikipedia.org/wiki/Arundo_donax#cite_ref-14
One of the basic elements of the garden design that is used as a windbreaker and will be used also for carbon sequestration through a hugelkultur-based planting scheme for annuals and more.
