93. There are approximately 930 Mha of salt-affected soils in arid and semi-arid regions of the world. Adoption of reclaimative measures on these soils can lead to increases in above- and below-ground biomass production and to improvements in SOC concentration and pool. The rate of SCS can be as high as 0.5-2 t C/ha/yr. Even if the rate of biomass production, in arid environments with low availability of water and nutrients, is low at 0.5-1 t C/ha/yr, total ecosystem C pool can be enhanced at 1-3 t C/ha/yr. It is estimated that 100 Mha of reclaimed soils can be used for crop production, of which 56 Mha are irrigated and 44 Mha are rainfed. In addition, 280 Mha can be used for perennial land uses. Thus, the potential of C sequestration in 380 Mha of reclaimed salt affected soils is 0.4-1.0 Gt C/yr (Table 28). If economic and realizable potential is 66% of the technical potential, reclamation of salt-affected soils can offset anthropogenic emissions at the rate of 0.25 to 0.66 Gt C/yr for about 50 years.
Table 28. Technical potential of reclaiming salt-affected soils on SOC sequestration (Lal, 2009d).
