Desert Arid Energy Type Crops Prove good to be Drought and/or Salinity Tolerant




There are a variety of cultivated crops that could grow well in arid, desert lands and climates that could become bioenergy crops and also serve to make other products such as alternative feed for animals. There are three crops that are worthy of discussion due to their plant growth adaptibility to desert conditions and their possible use as alternative fuel or energy. Salicornia, Sweet Sorghum and Amaranth to some degree are well suited to desert environments in that some of them have special growth characteristics such as low water consumption or drought tolerance and are also well suited to high salinity water and soil conditions. The majority of these plants actually grow better in more favorable ecosystems and climate but have proven to have adapted well to desert soil, water and climate conditions. Growing bioenergy crops on marginal use lands is a hot topic that should be continued to be discussed in future generations. For example, another great bioenergy crop that can grow well in semi-arid tropical like areas is Jatropha which can be converted into biodiesel or jet fuel. The more promising of these three crops is Sweet Sorghum. It is a similar energy crop to sugarcane, in that the sugars that reside in the plant can be squeezed out of the stalk and then further fermented into ethanol. The cultivation of Sweet Sorghum into ethanol is promoted by organizations such as the Sweet Sorghum Ethanol Association. Sweet Sorghum is already being cultivated in Arizona on marginal lands for the purpose of production into ethanol. As far as water requirements, Sweet Sorghum has proven superior in water use efficiency compared to other sugar or ethanol producing crops which include corn, sugarcane and sugarbeets. Sweet Sorghum has been shown to require half of what sugarbeets need for crop production and one fourth of what sugarcane requires for water usage [ 1. Prasad et al 2007 ]. Other advantages of using Sweet Sorghum in desert environments is that it is an ideal crop that can be used on fallow land or in other words it could be used as a rotation crop on farm land that would not be able to support another type of crop due to its soil conditions. Sweet Sorghum also grows much more rapidly (ie has a shorter growth cycle) than both sugarcane or sugarbeets [Same Reference as above mentioned]. It also requires less amount of soil nitrogen for its cultivation.



Salicornia is another salt tolerant or halophyte energy crop that is beginning to gain more interest as an energy crop. Salicornia, like Jatropha previously mentioned, are one of the oilseed crops being considered to produce bio-derived jet fuel. One project called
The Sustainable Bioenergy Research Project accomplishes to produce jet fuel from Salicornia that is grown from seawater based fish farm waste effluent. Salicornia is also known as a very healthy plant due to its high protein and salt content. It contains around 30 % protein content and has a variety of healthy salts that can be sundried and used in foods. Salicornia has been known to have pharmalogical value with special medicinal properties. Other plant properties also make it an ideal candidate for other sustainable materials, alternative animal feed and soil remediation projects. Salicornia is so salt tolerant that it can be directly irrigated with seawater itself, which has been done in past research work [ 2. Glenn et al 1997 ]. It is therefore ideal to use with saline types of irrigation water such as brackish water since it can tolerate salinity levels (NaCl) of around 1 mol per kg of soil. Amaranth is another plant that grows in a variety of climates and conditions. There are many species or varieties of it, but it is known throughout the world to be a very healthy plant. The leaves can be consumed by humans or livestock, the plant contains grains that can be converted into a type of bread or also used in fermentation to produce alcohol. The bread made from amaranth is beneficial to people who require gluten free bread with a lot of other health benefits. The protein content of amaranth is also high for a plant source, being around 15 percent. It also contains amino acids that aren't present in other plant sources. As mentioned before, Amaranth provides grain meal that can be fermented by a variety of microorganisms, one type named Rhizopus oryzae can produce ethanol plus other organic compounds from amaranth [ 3. Bramorski et al 1998 ]. Certain species of Amaranth are known to grow quite well in dry, arid desert lands such as Palmer Amaranth. This type of Amaranth uses water very efficiently and has good drought tolerance. Overall, there are many species of plants that could grow well on marginal desert lands
that could provide both fuel, energy and/or food. These three plants have already been experimented with and have proven good candidates for desert crops due to salinity and drought tolerance.


REFERENCES

1. "Ethanol Production from Sweet Sorghum Syrup for Utilization as Automotive Fuel in India", Energy and Fuels Vol 21 pgs 2415-2420 [2007] by S.Prasad, A.Singh, N.Jain, HC Joshi


2. "Water Requirements for Cultivating Salicornia Bigelovii Torr. with Seawater on Sand in a Coastal Desert Environment", Journal of Arid Environments Vol 36 pgs 711-730 [1997] by E.Glenn, S.Miyamoto, D.Moore, J.Brown, TC Thompson, P.Brown


3. "Production of Volatile Compounds by the Edible Fungus Rhizopus Oryzae during Solid State Cultivation of Tropical Agro-Industrial Substrates", Biotechnology Letters Vol 20 No 4 pgs 359-362 [1998] by A. Bramorski, P.Christen, M.Ramirez, CR Soccol, S. Revah


KEYWORDS: Energy and Food Crops, Desert Marginal Lands, Fallow Land, Palmer Amaranth, Gluten free grains, Salicornia, Brackish Water, Plant drought tolerance, Plant Salinity tolerance, Ethanol Production from Sweet Sorghum, Water Usage from Arid Desert Plants, Healthy Desert Plants, Desert Plants for Animal Feed


Photos taken from US Bureau of Land Management & NASA photo archives









Amaranth Biology Chemistry and Technology