Assessment of soil carbon accumulation and soil fertility during different growth stages of banana farm (Musa acuminata sp.) after land conversion from a secondary forest at Sg. Rual, Jeli, Kelantan

Soil carbon (C) is a crucial component of the soil ecosystem structure and act as a vital component in climate change mitigation. The banana plantation has capable of restoring lost C pools due to its agronomic management practices that do not encompass devastating activities such as burning biomass and removal of plant residues. The comprehension of C storage and its accumulation in a time series (during the growth of banana), after land conversion from a tropical deciduous secondary forest, is crucial to address climate change mitigation efforts and provide essential information on types of crops, site preference in order to improve the strategies and effective technique responsible for future soil C rehabilitation efforts. Therefore, the objective of this study was 1) carried out to assess the effect of conversion of secondary forest to banana farm on soil C accumulation, 2) to determine the soil C accumulation on the soil during different growth stages of banana cultivation after the land was being converted from a secondary forest and 3) to assess the soil fertility during different growth stages of banana cultivation after the land was being converted from a secondary forest by using Soil Evaluation Factor. Soil samples were successively collected from the five main banana growth stages (sucker growth stage, inflorescence stage, flowering stage, bunch development stage, and maturation and sucker development stage). Ten soil samples were taken at depths of 0-20 and 20-40 cm by using a soil auger to analyze for soil texture, pH, total C, soil organic matter, total N, C/N ratio, Ca, Mg, K, Al and P to calculate the soil evaluation factor. The soil textures in the secondary forest and banana farm were sandy clay loam and sandy loam, respectively. The total N of secondary forest and different growth stages of banana at two different soil depths were insignificant, where the total N of the forest was 0.11%, while the range total N of the banana farm was highest at S5 was 0.13%. The result of the C/N ratio of banana at two different soil depths was significantly decreased compared to the finding of secondary forest that was highest. It was regarding the finding of total N and total C. However, the overall findings of the amount of soil organic matter and soil total C accumulated not show any significant statistical difference in all the five banana growth stages because still in recovering process of the soil C content. The value of soil evaluation factor (SEF) showed that soil fertility was rich at five banana growth stages because the values obtained were 5 and above, regardless of soil depths. This data finding can help to recognize the trend and soil C storage capacity, and C accumulation process of the banana cultivation site after being converted from the secondary forest to plantation land. In addition, this finding also helps the understanding of the role of the agricultural land as a C sink and source. The recommendation of this study is to compare the banana farm with other land uses and existing secondary forest as a control to have a clear view of the changes effect of the C stocks in the soil after land conversion. Banana plants have the potential to be an essential component in agroforestry and mixed farming systems, contributing to rehabilitate and reforest landscapes, reduce C emissions in the atmosphere by biomass and C supplies, and support the economic needs of the local population.