Eucalypt Planting on Salt-Affected and Waterlogged Soils in Pakistan

摘要

Eucalypts have become popular in Pakistan in the past two decades. They are grown in small compact blocks, or single or multiple linear rows along the field boundaries or watercourses. Estimates of standing volumes and area of eucalypts vary but include a total volume grown on farm lands of about 0.36 million rn~3 and of 245,000 ha of plantations in 2000. These figures will now have increased. Most wood produced in Pakistan is used as fuel, but 25% of Eucalyptus production is used for industry. Growing eucalypts on salt-affected and waterlogged abandoned lands has not been tested in a scientific and systematic way, but using these wastelands could generate income for farmers. This paper reports results of planting eucalypts on saline and waterlogged land with variables including different plant spacing, timing and planting techniques. The trees were irrigated with brackish groundwater. The unreplicated experiment cum demonstration area covered 29 ha in the Fordwah Eastern Sadqia South region of Punjab. Highest survival (78%) was achieved with September planting, while maximum growth was in trees planted in March. Trees spaced at 2.25 x 2.25 m had the best growth. Planting eucalypts in the middle and bottom of the ridge was quite encouraging under saline and waterlogged land and gave a survival rate of 96%. It was concluded that eucalypts can be fairly successful under degraded soil and water resources with post-monsoon planting superior to spring planting. The trees lowered the water table and served as effective an bio-drainage intervention in waterlogged areas.