If you stumble across unfamiliar track markings spiraling across the Syrian Steppe, don't worry. It isn't a landing zone for some strange, tracked space vehicle, and the tracks will soon disappear under a thriving layer of range vegetation. It's a sign that the latest machine to emerge from the ICARDA Range Project for keeping regeneration costs to a minimum has been going through its paces.

hy has ICARDA built the world's biggest garden roller? And why isn't it perfectly round, anyway?
The answer lies in a link between the effect of sheep or cattle hoof imprints and an improvement in plant growth on the degraded rangelands of arid zones. Simple field observations have highlighted that in arid zones, grasses and other plants grew much better in the imprints left after rain by passing sheep and cattle than they did in the surrounding, unmarked flat soil.
          Since the same stronger growth can also be seen in the wheelmarks of cars or the deeper imprints of bulldozers that have passed across the steppe, here was an effect that might be used to restore degraded rangeland in the 150-250 mm winter-rainfall zones. In many of these areas the vegetation cover has been destroyed by overgrazing or by uprooting when shrubs are collected for use as fuel wood. Continuous cropping with barley also exhausts the soil seed stock and destroys the native vegetation cover.
          The classic approach to rangeland regeneration in many countries is expensive. Sites are fenced off or enclosed with a ditch to keep out trespassing flocks. Forestry techniques are then used if there is an abundant and cheap rural labor force. Nursery-reared seedlings are transplanted during the winter into soil that has been opened with a deep 80cm ripper. The young shrub seedlings, which may be native or imported species, have to be watered two or three times with 10 liters each for their first two summers. They have to be protected from grazing for at least two seasons.
           Where hoof prints or car tracks have been imprinted, the thin 2 mm soil crust which is typically found on these baked arid rangelands is effectively punched through and a depression created. Within this area, rain or runoff water is collected and focused on the imprint which is nurturing and providing a stable rooting environment for its fragile seedling plants. This water running off the surrounding fairly impervious crust also washes in tiny particles of soil and organic matter that provide a friendly environment for a newly emerged seedling. It adds up to water harvesting in micro-format.
         Keeping large flocks of sheep continually moving across the steppe to increase hoof printing is neither very practical nor desirable. Alternatives which are both considerably cheaper and more efficient than forestry-type transplantation are being sought.
         Building low-cost, low-input range regeneration machinery is one of the targets set for the Range Project of the ICARDA Natural Resource Management Project (NRMP) in collaboration with the Syrian Steppe Directorate. The first machine tested with reasonable success by the team is a simple and light 'pitting' machine--modeled on the Camel Pitter from Kimseed Ltd in Australia (See Caravan No. 3). Capable of being towed by a two-wheel-drive car, it has been tried out on 200 ha of difficult range reseeding with native Artemisia and Salsola species on the Obeisan, Adame and Delboah Range Stations, and on the Tallila FAO project near Palmyra, Syria.

Fabrication Workshop with technical support from Dr Jòrgen Diekmann and Abdulwahab Kabbani, is designed for use in the region.
         The two machines tested by ICARDA are very different in that the pitting machine scoops a pit in the soil which removes the top layer of soil, with any vegetation. This means it is best suited for use on medium (10-30cm) depth loamy soils with a homogenous soil profile. Because soils on the Syrian steppe are frequently gypsiferous, the bottom of the pits being created can be quite sterile and inhospitable to emerging seedlings.
          There may be sufficient water collected in the pits but the fertility of pure gypsum is not ideal. Nevertheless, these large gypsiferous areas of the Syrian steppe have an important role in supporting livestock. They are usually covered with a shallow--no more than 2 cm--top organic horizon which is biologically quite active and carpeted in spring with Carex stenophylla and the nutritive, but short-lived plant, Poa bulbosa. This ephemeroid short grass is a valuable spring feed for sheep.
         The range project team wants both to improve the productivity of this grass and also to encourage the establishment of palatable shrubs such as Artemisia and Salsola to create a denser and more diversified, vegetation mat cover and most importantly, more feed resources for the agro-pastoral communities.
          It is hoped the shallow grooves of the Land-Imprinter will avoid destroying the existing vegetation while at the same time making easier the introduction to

the range of mother plants of white Artemisia and Salsola vermiculata which don't need to be seeded on all of the range area.
          Treating just 10-20%, or even less, of the range using the imprints could be enough to re-establish a starter-vegetation with these valuable, self-reseeding native plants.
          Particular care is being taken in the species chosen for range reseeding since they must be acceptable to the pastoral community. Salsola vermiculata, locally known as "Queen of the Steppe" is favored by the Bedouin communities, along with Artemisia herba-alba.
         In a good year, the seed is easily collected en-masse and then cleaned. During reseeding the seeds are mechanically dispersed in the pit from seed boxes mounted on the pitting machine or broadcast in the imprinted grooves mixed with finely ground sheep manure. Just 100 g of the very fine clean seeds of Artemisia are sufficient to re-stimulate one hectare of degraded steppe. Both it and Salsola have established successfully in the pits on several Syrian range sites.
          The Land-Imprinter is now being evaluated to confirm whether the initial success can be repeated, and that the cost of this type of re-seeding remains minimal and therefore acceptable to the Syrian Steppe Directorate and other development agencies in the region. The robust simplicity of the design keeps maintenance to a minimum.
          It is planned to mount seed dispersal boxes on the Imprinter in front of the roller for dry soils. Using the same arrangement in wet soils would result in the freshly dispersed seed being picked up by the damp following roller so the seed boxes will be shifted to the rear. A small harrow comb can be fitted to run behind the Imprinter to scratch some light soil cover for the seeds.
         The current version of the ICARDA Imprinter leaves only lateral, parallel imprints and doesn't yet have an offset or right-angled imprinting edge. Incorporating this will close off the lateral imprints and reduce the risk of erosion from having the imprints running in the same direction. In their existing versions, both the Imprinter and the pitting machine are drawn across the steppe in spirals to minimize the risk of water erosion.
          However, there is more to be done. Direct seeding may prove useless if not supported by appropriate range management measures carried out by the agro-pastoral communities and supported by government authorities. The plants being used are resilient to overgrazing but it may still take at least 10 years to reestablish a proper and valuable range cover. Controlled spring grazing would allow collection of the biomass from the annuals and not touch the perennials. Let's be careful when we deal with this arid environment !

Dr Gustave Gintzburger was formerly Range Specialist at ICARDA  from 1992-1999, and has now joined the Institut National de la Recherche Agronomique (INRA), Montpellier, France. The regeneration equipment was developed and tested with the technical support of Nabil Bathika, Fahim Ghassali, Elias Khoudari and Ali Rajab (Range Group - ICARDA).

         The second, simple machine--a rather bizarre roller--was tested recently on an utterly degraded range site on the Obeisan station. With the knowledge that imprints encourage plant growth, the research team modified a heavy 2.3t roller-compactor, filled with a further tonne of water, so it punches 100 cm long grooves in the soil. Towed by a small 45hp tractor, it leaves imprints--

7-8cm wide and 1-6 cm deep depending on soil moisture--to harvest rain and runoff water.
          It is believed this machine will have an advantage over the pitting machine in that it will not destroy the remaining native vegetation and the very valuable carpet of Poa bulbosa grass, a precious feed highly palatable to the flocks of the agro-pastoral community. 
          Safe in its imprint, the young seedling is also protected from the seasonal blast of cold or hot winds that can lay bare the root structure of vulnerable plants. Wind erosion and exposure are frequent causes for the loss of rangeland species in degraded areas.
          The imprinting concept itself is not entirely new since a prototype was first built in the 1970s in the USA and named Land-Imprinter by its inventor (Dixon, 1977). However, the range group's version, built in ICARDA's

.