The study of soil water conservation practices in rubber cultivation

In rubber plantations, conservation of soil water content leads to reduction of immaturity period of rubber tree. The objective of this study partly was to compare the relative effects of three mulching systems, viz. without mulch (control), with processed oil palm fiber material (Ecomat) and black polyethylene sheet (AA + Mulch) on some soil physical and chemical properties of an area planted with rubber over a period of seven months. This study was conducted at Field 1, RRIES Kota Tinggi, Permatang Division, Johore, Malaysia. Preliminary results showed that higher soil water content was observed in non-mulched area when compared with both mulched area. Lowest soil water content and rainfall were found in February 2008 (within study period from January to June 2008). Soil water content increased with the soil depth in all treatments and was consistently above the field capacity point. This could be due to frequent rainfall received throughout the study period and without a long continuous period of dry weather season. Soil water content in the Ecomat treatments were distributed uniformly throughout the soil profile from 20 to 60 cm and this observation suggested that Ecomat tended to conserve water in the 20-60 cm soil depth. The soil water content at the upper soil layer in black polyethylene sheet plots was generally the lowest among treatments. Significant differences among treatments were found for soil surface temperature, pH, organic carbon, total P, exchangeable Mg and exchangeable Ca. Other variables (total N, exchangeable K, CEC and C:N) were not differed significantly among treatments. Conclusions made from observations in this study and from further incoming data from the same experimental plot will be useful in determining the long term effect of mulching on soil quality and best mulching practices for optimal growth of young rubber trees.