摘要
A field investigation was conducted to determine the survival and growth rate of eucalyptus (Eucalyptus camaldulensis Dehn.) and guava (Psidium guajava L.) saplings planted in salt-affected soils. The field used was highly saline-sodic in nature with a wide variation in electrical conductivity of the saturated soil extract (ECe), pHs, sodium adsorption ratio (SAR) and gypsum requirement (GR). A randomized complete block design was utilized with three treatments, i.e. T1 = plastic container bags totally removed, T2 = only the plastic container bag's base removed and T3 = plastic container bags un-removed. There were 34 and 8 plants in each block for eucalyptus and guava, correspondingly. The survival rates of eucalyptus and guava saplings were greater than 90%. In addition, gain in eucalyptus height was significantly higher in the T1 treatment where the bags were totally removed while for guava height the treatments were not significant.The gain in girth was not significant for both eucalyptus and guava saplings. With eucalyptus the taproot length was greater than the lateral roots while for guava the lateral roots were longer than the taproots.There was a decrease in the salinity-sodicity of the soils for the upper 30 cm depth under both types of vegetation, indicating that the salts had leached down to the B-horizon.
A field investigation was conducted to determine the survival and growth rateof eucalyptus (Eucalyptus camaldulensis Dehn.) and guava (Psidium guajava L.) saplings planted insalt-affected soils. The field used was highly saline-sodic in nature with a wide variation inelectrical conductivity of the saturated soil extract (ECe), pH_s, sodium adsorption ratio (SAR) andgypsum requirement (GR). A randomized complete block design was utilized with three treatments,i.e. T1 = plastic container bags totally removed, T2 = only the plastic container bag's baseremoved and T3 = plastic container bags un-removed. There were 34 and 8 plants in each block foreucalyptus and guava, correspondingly. The survival rates of eucalyptus and guava saplings weregreater than 90%. In addition, gain in eucalyptus height was significantly higher in the T1treatment where the bags were totally removed while for guava height the treatments were notsignificant. The gain in girth was not significant for both eucalyptus and guava saplings. Witheucalyptus the taproot length was greater than the lateral roots while for guava the lateral rootswere longer than the taproots. There was a decrease in the salinity-sodicity of the soils for theupper 30 cm depth under both types of vegetation, indicating that the salts had leached down to theB-horizon.
基金
Project jointly supported by United Nations Development Programme (UNDP) and Australian Agency for International Development (AusAID) (No. PAK/97/024).
