Work on the stabilization of sand dunes started by the Pakistan Government in 1955 is beginning to yield encouraging results, especially with the type classified as "cold region sand dune," illustrated in these photographs, taken by the Central Soil Conservation Organization, Quetta, which is responsible for the conduct of research in this field.
FIGURE 1. - Wind erosion and moving sand dunes are serious problems in many parts of West Pakistan. The dunes not only put land out of cultivation but also affect adjoining productive land by covering it with sterile Band.
FIGURE 2. - Sand dunes encroaching upon a wheat field. In the background is an orchard partly buried under dunes.
FIGURE 3. - Sand dunes encroaching upon tree-cover and habitations.
The valley of Mastung, situated between Quetta and Kalat at an elevation of 6,000 feet (1,800 meters), has been selected for much of this work. The valley is famous for its irrigated crops of potatoes, onions tobacco, spices, melons, vegetables, almonds, apricots, peaches, plums, grapes and apples. Since irrigation water is not adequate for the entire cultivable land, some of it must remain idle for as long as 4 or 5 years, during which time livestock is allowed to graze on the spontaneous weed-growth, and woody shrubs are up-rooted to provide fuel, with the frequent result that the topsoil is exposed to wind erosion during the dry summer season. Over 10 square miles (26 square kilometers) of the valley's productive land has, in this manner, already been turned into unproductive mobile dunes, whose presence threatens roads and neighboring fields, and reduces yields by the abrasive action of the drifting sands. Research on methods of control and stabilization has resulted in an effective technique for raising wind-breaks and for dune fixation in the area without irrigation.
FIGURE 4. - Plantation of Arundo donax, Calligonum ploygonoides and Tamarix gallica, without irrigation, after one growing season.
FIGURE 5. - Reclaimed sand dunes. Two years' growth on right of track, one year's growth on left.
FIGURE 6. - Tamarix two years after planting, without irrigation. Raised from cuttings.
FIGURE 7. - Robinia pseudoacacia one year after unirrigated plantation, from nursery grown seedlings.
FIGURE 8. - Forage grasses are planted once the wind breaks are established. Here, Arundo donax protects a six-month old planting of Agropyron desertorum and Boutelona spp.
FIGURE 9. - Another fodder-grass, Agropyron elongatum, protected by Arundo donax, eighteen months after direct sowing.
Rows of Calligonum polygonoides raised from seed, Arundo donas grown from closely spaced culms, and Tamarix gallica, whose branch-cuttings are set at 5 feet (1.5 meters) in and between rows, rapidly produce an effective, inexpensive wind-break. These are up to 8 rows in depth, and are spaced at a distance equivalent to ten times the height the shelterbelt is expected to attain. The interspaces are then sown with drought-resistant timber and forage trees, shrubs and grasses which thus contribute to the local economy and welfare.