Carbon sequestration in kiwifruit soils of New Zealand
M Hasinur Rahman*, Allister W Holmes, Alan G McCurran and Steven J Saunders
Soil is a major component which sequesters huge amounts of carbon. With space and time soil may exhibit a complex degree of variability in organic carbon content. Changes in soil organic carbon (SOC) levels have not been monitored for kiwifruit grown under different management practices. To evaluate the sequestration of organic carbon in Andisol soils used for kiwifruit production we analysed three management systems from three growing regions in the Bay of Plenty of New Zealand. Replicated soil samples were collected from three kiwifruit orchards per region. Within each orchard samples were taken from the grass alleyways, the wheel tracks and plant rows in three depths for two consecutive years. For comparison soil samples were also collected from nearby pastoral and arable land as paired samples. In kiwifruit orchards of two regions, soil under organic management sequestered more carbon than under conventional management while the opposite was the case in the third region. We recorded higher SOC concentrations in the wheel tracks followed by the alleyway and the plant row. In the top 0.15 m SOC significantly decreased over 5 cm increments. Kiwifruit orchards in the Katikati region sequestered more SOC than pastoral land and the reverse was true for the Te Puke orchard region. SOC stocks in kiwifruit orchards were significantly higher than under arable land use in all three regions. Our results indicated that soils of kiwifruit orchard can be a good carbon sink.” Download full article.