Organic Carbon and Total Nitrogen Status of Soils under the Teak Plantations of Various Ages in Kerala

摘要

In the tropics, the continuous destruction of the forest mostly for timber production accompanied with high rainfall in the region has resulted in die rapid loss of soil nutrient, thereby making most soil infertile. The main objectives of this studywere to examine the status of soil organic carbon, total nitrogen and phosphorus in teak plantation plots of 0-5, 06-10. 11-20, 21-30 and >30 years. Result revealed that the soil organic carbon from all the sites decreased generally with increasing in depth. From the surface down to 100 cm the highest soil organic carbon was in 11 -20 year old teak plantation followed by 0-5 years of 0-20 cm depth. The nitrogen was highest in 0-5 year followed by -06-10 years on the top soil and the available phosphoruscontent was highest in>30 years followed by 0-5 year plantation. Probably microbial activity occurs in the upper soil layers (0-20 cm) as soil at this depth is soil organic carbon and more nutritious and porous. This is so. as mature teak trees have a large biomass which notonly affords the ground adequate cover, but also acts as a huge reservoir of nutrients, thereby, preventing them from being leached away from the plantation.