Salinity status of soil under eucalyptus plantation at Latif Farm [Pakistan]

In order to evaluate the salinity status of soil under eucalyptus plantation at Latif Farm, 81 soil Spots were sampled for each depth i.e., 0-15 and 15-30 cm. Therefore total number of composite soil samples were 162. After processing the samples were analyzed for physico-chemical characteristics. All the samples were clay in texture under both the plantations. The soils under plantation showed high amount of calcium carbonate which ranged front 14.0 to 17.9%. The soils under new plantation had minimum and maximum of 14.3 to 18.0% CaCO3. The soils were alkaline in reaction under both the plantations. The pH values under old plantation ranged from 7.38 to 8.68 while under new plantation ranged from 7.40 to 8.89. The EC values of soils under old plantations were varied from 0.40 to 12.6 ds/m and under new plantation were observed greater than old plantation which ranged from 1.05 to 16.7 dS/m. Exchangeable calcium was found to be dominant followed by magnesium, sodium and potassium under both the plantations and similar trend were observed in soluble cations. The chlorides were found to be dominant anion followed by sulfates and bicarbonates under both the plantations, while the carbonates were absent in all the soil samples. The ESP values of soils under old plantation ranged from 9.74 to 33.19% while under new plantation were observed greater than old one, which varied from 9,50 to 42.18%, SAR value for old plantation was ranged 0.49 to 4.80 and under new plantation was also ranged from 0.5 to 4.48. Osmotic pressure values of soils under old plantations varied from 0.21 to 3.47 atm and 0.43 to 5.22 atm for new plantation. The soils in both old and new plantations were heavy in texture. Under old plantation 8% soils were non-saline 53% saline, 26% saline- sodic and 13% sodic respectively, while under new plantation 3% non-saline, 48% saline, 43% saline-sodic and 6% were sodic soils respectively. The salinity was more in surface soils than sub-surface soils under both the plantations. It is also concluded from analytical results that soil salinity has no injurious effects on the growth of new and old eucalyptus plantations. Because the research literature has also suggested that eucalyptus plants can tolerate wide range of salinity and alkalinity levels of soil. However, the adverse effect may be due to the planting of over age nursery plants, high dose of irrigation water and improper drainage conditions. It is suggested that eucalyptus nursery plants may be planted at the height of 6 to 8 inches.