Carbon sequestration in sugarcane plant and soil with different cultivation systems

Abstract

Sugarcane (Saccharum officinarum L.) is a multi-purpose crop, mainly planted in South-western (SW) parts of Iran. However, the capability of sugarcane farms to sequestrate carbon into soil and plant is not well documented. In this research, the carbon sequestration in sugarcane plant and soil in a ratooning traditional cultivation system at the Amirkabir Sugarcane Agro-Industry Complex in Khuzestan Province was evaluated during 2013-2014. The soil samples were randomly collected at 0-30 cm top layer and soil organic carbon (SOC) was analysed in laboratory. Simultaneously, both aboveground and underground parts of sugarcane plants were sampled and the carbon content of each part was measured separately. The carbon stored in the aboveground parts (leaves and shoots) was significantly (p≤0.01) higher (1292 kg ha-1) than that (655 kg ha-1) of underground organs (roots). The total SOC (1987.3 kg ha-1) was not considerably higher than the sequestrated carbon (1947 kg ha-1) in plant parts. Furthermore, a positive and significant correlation was found between SOC and soil clay content. Overall, 3934.5 kg ha-1 sequestrated carbon equal to 14439.6 kg ha-1 atmospheric CO2 was estimated to be in sugarcane farms. In conclusion, the results showed that the Ratoon I has the highest potential of carbon sequestration than other treatments. Current sugarcane farming practices in Khuzestan could act as an important pool for carbon sequestration and consequently enhancing the mitigation of climate change impacts. It seems that changing the current sugarcane traditional harvesting system which is predominantly based on burning the residues towards the suitable management could enhance the capability of carbon sequestration even more.