Utilization Of Salt-Affected Soils By Growing Some Acacia Species

Abstract

In Pakistan most of the salt affected areas are located in the heart of its agriculturally important tract of the Indus plain. Growing conventional crops in these problem lands is not economical but these could be utilized gainfully by growing salt tolerant trees or shrubs. However, there is a need to identify suitable species for such conditions. The present study was, therefore, undertaken to evaluate the performance of some local and exotic trees, belonging to Acacia species, in salt affected soils of Pakistan. Five species of Acacia, i.e., Acacia ampliceps, A. stenophylla, A. machonochieana, A.sclerosperma, and A.nilotica were grown along with an Australian halophytic shrub Atriplex lentiformis in a field where salinity ranged from 4-25 dS m-1. After three years of growth, A. ampliceps and A. nilotica showed markedly higher growth as compared with the other species examined. Although A. ampliceps grew well under saline environment, its maximum growth was observed under-1 (12-1 medium to high salinity levels (8-16 dS m-1), while Acacia sclerosperma and A. machanochieana were only populated on low salinity patches (4-8 dS m-1). Analysis of plant leaves, for nutrient contents, showed that the concentrations of Na + and K + ions in the Acacia species were comparatively less than those in Atriplex lentiformis. However, Acacia nilotica had comparatively higher nitrogen and phosphorus than the other Acacia species examined. On the other hand, the concentrations of Na + and K + were higher in Atriplex lentformis while the concentrations of Ca 2+ were higher in Acacia sclerosperma as compared to the other Acacia species and Atriplex. At the end of the experiment, complete soil analysis was carried out which showed that the soils on which Acacia species were grown, N, P, and K contents increased to some extent.