Revegetation of a remediated brine-contaminated soil

Field and growth chamber studies were conducted to monitor and assess changes in soil physico-chemical properties and the survival and growth of planted loblolly pine (Pinus taeda L.) seedlings on a remediated brine-contaminated soil in Springhill, Louisiana. The site was remediated using a subsurface leachate system and a fresh water irrigation system, gypsum, fertilizer, and woody organic amendments. Bermuda grass (Cynodon dactylon L.) and annual ryegrass (Lolium multiflorum Lam.) were planted to stabilize the soil.; During the current phase of the study, bulk density increased significantly, but still remained below levels found before the addition of soil amendments. Sodium adsorption ratio and electrical conductivity measurements during this phase of the study showed significant increases in both parameters at depths below 40 cm.; A survival rate of 84% was determined for planted loblolly pine seedlings during the first year. An increase of 37% in height and 24% in ground line diameter (GLD) occurred during the first year of growth. A survival rate of 63% was determined for the seedlings, and an increase of 43% in height and 61% in GLD during the second year.; A companion growth chamber study was conducted to compare the dry down response of loblolly pine seedlings between a remediation brine-contaminated soil and a commercial potting soil mixture. There was a significant difference in the water potential between loblolly pine seedlings planted in the two soil types. The results of the companion field and growth chamber studies together suggest that physico-chemical properties of the brine-contaminated soil are able to support the growth of loblolly pine. However, the long-term prospects for pine tree survival are unclear due to remaining brine-contamination below the depth of 40 cm. (Abstract shortened by UMI.)...