Changes of Selected Soil Properties in a Floodwater-Irrigated Eucalyptus Plantation in the Gareh Bygone Plain, Iran

Abstract

In Iran, current plans aim to rehabilitate 1.5 M ha of severely degraded land (mostly moving sands) by means of planting drought-resistant tree species. Therefore, a study was initiated to monitor the measurable changes in some selected soil properties by the floodwater-irrigated Eucalyptus camaldulensis; E. microtheca; E. gillii; and E. oleosa in the windswept Gareh Bygone Plain in Fars province. Composite soil samples were taken to a depth of 80 cm from beneath (under canopy) and between (intercanopy) the trees rows. Organic matter, total N, available K, DTPA-extractable Fe and Mn, soluble Mg²⁺, and increased, whereas, soluble Na⁺, pH, and electrical conductivity decreased under the canopy compared to those of between the rows. Effects of the tree species on calcium carbonate equivalent; available P, Zn, and Cu; and soluble Ca²⁺, Cl⁻, and were not significant. E. camaldulensis and E. oleosa were more efficient in macronutrient accumulation than E. microtheca and E. gillii. Although the artificial recharge of ground water with floodwater transferred water soluble nutrients and some fine fractions to depths inaccessible to shallow rooted plants, the trees were highly efficient in restoring nutrient levels in surface soil layers.

Keywords:

• canopy
• desertification control
• eucalyptus
• sandy soils
• soil quality

This work was part of the M.Sc. dissertation of the lead author in soil science at the Shiraz University, I.R. Iran. He would like to thank the Soil Science Department technical staff for their invaluable help and advice throughout this study. All authors thank the Kowsar Floodwater Spreading & Aquifer Management Research, Training & Experiment Station staff for their sincere cooperation in this research project.

Notes

*Means followed by the same letters with lowercase letters (species) and capital letters (species bulked) are not significantly different at the 0.05 level.

Note: Means within a column followed by the same letter are not significantly different at the 0.05 level.

*Means followed by the same letters with lowercase letters (species) and capital letters (species bulked) are not significantly different at the 0.05 level.

*Means followed by the same letters with lowercase letters (species) and capital letters (species bulked) are not significantly different at the 0.05 level.

^a*^,**^,***stand for significance at 0.05, 0.01, and 0.001, respectively; ns stands for not significant.