IMPROVING SOIL CHEMICAL PROPERTIES AND GROWTH PERFORMANCE OF Hevea brasiliensis THROUGH BASALT APPLICATION

Abstract

Rubber tree (Hevea brasiliensis) is the main source of natural rubber in the world. Most of Hevea cultivation area was on problem soil such as Ultisols and Oxisols that were known as infertile soils.  Basalt is quickly weathered rock that consists of few minerals such as of plagioclase, pyroxene, and olivine. This paper will present the effect of different rate of basalt  dust application on Ultisol and response of Hevea brasiliensis grown on that soil. The experiment was carried out with four treatments-`viz. 0 g (control), 179 g, 358 g and 538 g of basalt dust (less than 0.1mm) and six replications of plants of clone RRIM 3001. The experiment was arranged in Complete Randomized Design (CRD). Data were analyzed by Analysis of Variance (ANOVA) and Least Significant Difference (LSD) for comparison of the means. The results showed that the higher rate of basalt application improved the soil chemical properties in the growth of rubber and also enhanced the plant nutrient uptake. High basalt application up to 538g/tree resulted in soil pH increase from 4.28 to 5.15 after 12 months. Similar trends observed for the soil CEC., . Phosphorus, potassium, calcium and magnesium content in soils applied with basalt were significantly higher than non-applied soil after 12 months. During sampling at twelve months, highest rate of basalt application recorded highest plant height, 243.1 cm, followed by rate of 358, 179 and 0 with readings of 210.3, 185.5 and 164.7 cm respectively. Application of basalt at rates of 358 and 538 g/tree gave significantly higher girth with 7.09 and 8.92 cm respectively. During soil sampling after a year, undissolved basalt was visually observed.  Therefore, basalt dust is a good soil amelioration and functions  like a slow release fertilizer facilitating plant nutrient uptake in Ultisol.

Keywords: Soil amendment, fertility, Hevea, basalt, Ultisol