Effect of crop rotation in rubber plantations on some soil properties and carbon content

Abstract

The study aimed to determine the effect of rotation and age of rubber plantation on soil properties and carbon content in Ban Nasan district, Suratthani province. The experimental design was a randomized complete block design (RCBD) with 3 replications conducted with 7 treatments: 1) Forest (F) 2) 1^st rotation at the young stage (R1y) 3) 1^st rotation at the old stage (R1o) 4) 2^nd rotation at the young stage (R2y) 5) 2^nd rotation at the old stage (R2o) 6) 3^rd rotation at the young stage (R3y) and 7) 3^rd rotation at the old stage (R3o). It was observed that at 0-10 cm depth of soil, the forest (F) contributed the highest values in the total nitrogen of 1.79% and available potassium and magnesium of 99.56 and 108.86 mg/kg, respectively. The soil carbon stock was the highest at 17.25 t/ha, with the lowest bulk density value of 1.12 g/cm³ under the forest (F). However, there was no statistically significant difference in soil pH among the treatments. In the 3^rd rotation of rubber plantation (R3), the total nitrogen, available phosphorus, potassium, magnesium and soil carbon stock were resulted in decreasing. Although, the young rubber plantation had better soil fertility, their soil carbon stocks were less than the old rubber plantation. The results also showed a significant difference in soil organic carbon content in the soil depths of 0-5, 5-10 and 10- 30 cm but no significant difference in 30-50 cm depth.