Characteristics and Afforestation Problems of Saline Alkali Soils

In view of their vast expanse, the saline-alkali soils are perhaps the most problematic of the waste lands in the country, The various factors responsible for their formation and infertility have been elucidated, Analytical data on the physico-chemical characteristics of the more important soil profiles examined in the semi-arid and arid tracts of the various States have been reported which reveal that these soils differ widely from place to place and carry different natural flora. It has been suggested that these soils offer one of the best possibilities for extending the area under forests. A brief account has been given of the measures required for the reclamation of different types of saline-alkali soils. For a permanent amelioration of alkali soils it is, however, necessary to replace exchangeable sodium with calcium ions. Since reclamation of alkali soils is a costly operation, attention is focussed on growing appropriate alkali resistant species and using suitable planting techniques, the choice of which will vary accordingly to the nature and intensity of salinity and alkali. A comprehensive review has been presented of the field experiments conducted so far and the results obtained on afforestation of these lands employing different species and planting techniques. The different methods of soli working under various planting practices have been explained in brief. In conclusion, an urgent necessity for well-planned field and laboratory investigations including soli analysis to evolve sound techniques and to select exacting species for afforestation of saline-alkali soils has been suggested.