Soil carbon stock in typical grasslands in Japan

• Published in: Grassland science Vol. 55; no. 2; pp. 96 - 103
• Main Authors: Nakagami, Koji, Hojito, Masayuki, Itano, Shiro, Kohyama, Kazunori, Miyaji, Tomoko, Nishiwaki, Aya, Matsuura, Shoji, Tsutsumi, Michio, Kano, Shunpei
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Melbourne, Australia : Blackwell Publishing Asia 01.06.2009; Blackwell Publishing Asia
• Subjects: Carbon sequestration; forest; forests; grassland; grasslands; pasture; pastures; soil carbon; Japan
• ISSN: 1744-6961; 1744-697X
• DOI: 10.1111/j.1744-697X.2009.00145.x

To evaluate the carbon (C) sequestration function of grassland soils in Japan, soil C stocks were measured in 24 grasslands (3-43-year-old pastures) across 14 livestock farms nationwide. Soil C stocks varied among soil types, and the values in the upper 25 and 50 cm were higher in Andosols (mean, 12.4 and 19.3 kg m⁻², respectively) than in Brown Forest soils (7.5 and 13.7 kg m⁻²) and other soil types (5.5 and 7.5 kg m⁻²). At the same time, C stocks varied among pastures within each soil type. Compared to data from the published work on the C content shortly after pasture establishment, aged pastures had decreasing C concentrations as the soil depth increased, suggesting substantial C accumulation in the top soil layers during pasture aging. This C accumulation caused grassland soils to store as much C as adjacent forest soils. Although the C stocks in the grassland soils were not statistically different from those in the adjacent native forest soils, some grassland areas stored greater amounts of C than the forests, indicating a possibility of increasing soil C stocks through improved grassland management.