Agriculture Changes Deserts From The Ground Up

No doubt New Mexico gardeners will relate better to desert agriculture than to Canadian horticulture (a word that always makes me think of of Dorothy Parker for reasons that have nothing to do with gardening).  Egypt and Hungary may seem too distant to be of interest but the conclusions should not be. For all its challenges, notably water, desert agriculture also presents unique potential for resistant, diverse soil bacteria and carbon capture

Agriculture Changes Deserts From The Ground Up, a Science 2.0  article by Caitlin Knight,  September 9, 2011 (short URL http://tinyurl.com/3ljhvlr)

As human population numbers worldwide continue to increase, we are having to be increasingly clever about finding ways to produce enough food for all consumers. One potential technique is converting deserts into agricultural landscapes. Anyone who knows their history will be aware that this practice is by no means new, but modern technology allows desert farming on much larger scales--not only creating larger agricultural areas, but also producing greater quantities of food.

There have been several studies investigating the feasibility of large-scale desert farming, but one variable that has not received much attention is bacteria--specifically, the type and function of bacteria that are present in desert soils. One thing that is known is that deserts have much more bountiful and diverse bacterial communities than once thought. This is impressive given that these creatures have to tolerate extreme temperatures, the threat of desiccation, high soil salinity, low nutrient levels, high summer UV radiation levels, and physical instability caused by wind. But how will they fare against the introduction of agricultural crops? If they form partnerships with plants (by living in or near plant roots), might they have beneficial effects on crops by buffering them from soil pathogens?

Collaborating scientists from Austria's Graz University of Technology and Egypt's SEKEM and Heliopolis University collected soil samples from in and around desert agricultural fields used to grow German chamomile (Matricaria chamomilla L.), pot marigold (Calendula officinalis L.), and Solanum distichum Schumach&Thonn. (an African herb in the nightshade family). By subjecting the samples to different types of DNA analyses and culturing techniques, they were able to compare bacterial communities between farm and desert soil, identify particular species groups and individual species present at the two types of site, and investigate the potential anti-fungal capabilities of different soil
species.

Desert agriculture has the potential to have many positive effects, including generating more food in poor regions, producing renewable crops for industrial application, and capturing/restoring carbon dioxide in the soil. One of the known drawbacks of this method is the amount of water required for irrigation; for example, approximately 5 billion cubic meters of water is thought to be necessary for the 40% growth of desert farmland forecast for Egypt over the next 6 years. On top of this, the current study indicates that farming will also alter soil bacterial composition; however, while some of the more extreme-habitat-loving bacteria disappeared from agricultural soils, the overall diversity of the bacterial community was actually higher in farm sites. Read the complete article online.

Cited: Kerl, M., Mler, H., Ramadan, E.M., and Berg, G. Desert farming benefits from microbial potential in arid soils and promotes diversity and plant health. 2011. PLoS ONE 6(9):e24452

Additional Desert Agriculture links

• ADASR - exploring, researching and reviving ancient desert agriculture systems
• UC Desert Research and Extension Center