Carbon sequestration potential in coconut-based cropping systems

A field experiment was carried out in a coconut garden having red sandy loam soil at ICAR-CPCRI, Kasaragod, Kerala during May-July 2015 to study the effect of cropping system on above and below ground carbon sequestration in a 50-year-old plantation intercropped with seven-year-old fruit crops. Among the different cropping systems, coconut (Cocos nucifera) + jamun (Syzygium cumini) system sequestered the highest above ground carbon (60.93 t/ha) followed by coconut + mango (Mangifera indica) system with 56.45 C t/ha, coconut + garcinia (Garcinia indica) sequestered 53.02 C t/ha, whereas, coconut alone had sequestered 51.14 C t/ha. The below ground soil carbon stock in the rhizosphere of 0–60 cm depth was the highest in coconut + mango (82.47 t/ha) system followed by coconut + jamun (79.13 t/ha), coconut + garcinia (78.69 t/ha) and it was the lowest in coconut monocrop (47.06 C t/ha). The total carbon sequestration by coconut + jamun (140.06 t/ha) followed by coconut + mango systems (138.91 t/ha), coconut + garcinia (131.72 t/ha), whereas it was only 98.2 C t/ha under coconut monocrop.