Effect of Spacing on Soil Properties of Eucalypts Planted on Paddy Bund in Chachoengsao Province

Abstract

The effect of spacing on the soil properties of eucalypts planted on a paddy bund in Chachoengsao province was investigated at a spacing trial in Phanom Sarakham district. The trial plots were established using a complete randomized block design (CRBD). Trees from clone K51 were planted in a single row with spacing between trees of 0.5, 1.0, 1.5, 2.0 and 2.5 m. Soil samples were collected before planting and after three years for analysis of the physical and chemical soil properties.

The soil texture varied and included sandy loam, loamy sand and sandy clay loam. The bulk density increased over the three-year period, for all spacing distances, while porosity decreased, due to increasing bulk density. Soil pH increased, but soil organic matter decreased for all spacing distances. The level of total nitrogen tended to increase constantly. Available phosphorus increased for the 1.0 and 2.0 m spacing, but decreased with the 0.5, 1.5 and 2.5 m spacing. Exchangeable potassium and magnesium and the cation exchange capacity decreased for all spacing distances. Exchangeable calcium increased with the 0.5, 2.0 and 2.5 m spacing, in contrast to spacing at 1.0 and 1.5 m, which decreased. The base saturation percentage increased for all spacing distances.

Keywords: spacing, eucalypts, paddy bund, soil properties, Chachoengsao province