Soil respiration in rubber tree plantation applied with biochar

Abstract

Soil respiration (Rs) is a key component of the terrestrial ecosystem carbon cycle. It is linked directly with the dynamic of soil carbon and its possible feedbacks to global warming. In Thailand, rubbeer tree plantation (Hevea brasiliensis Muell. Arg.) has increased substantially especially in the eastern and northeastern parts in Thailand. On the other hand, application of biochar to soil has been suggested as a potential way of enhancing soil carbon sequetration and plant productivity. However, we know little about its effects on soil carbon dynamics, espeically soil respiration. In this study, the effect of biochar on soil respiration in rubber tree plantation was assessed. Rs between wet season [April to October] and dry season [November to March] was significantly different (p-value ≤ 0.05). The results show that soil moisture is a main driver of soil respiration at seasonal scales. The correlation between soil respiration and soil temperature was negative when temperature increases but positive when soil moisture increases (pvalue ≤ 0.05). The results also show that biomass of rubber tree did not differ significantly among treatments (T3=2,212 > T2=2,187 > T4=2,072 > T1=2,027 kg dry matter ha-1). Thus, plant growth and soil respiration did not stimulate by biochar application but benefits through soil carbon sequestration can be recognized.