Forest soil fertility in Okinawa Island, subtropical region in Japan
Access this Article
Search this Article
This study investigated the influence of soil types on the forest soil fertility in the subtropical region. Three sampling points were established for each soil type (limestone, marlstone and silicate). Samples were taken from surface and subsurface soils in each site and analysed for total C, total N, total P, organic P and soil pH. The main objectives were; (1) quantification and comparison of nutrients distribution and cycling in forests under different soil types. (2) Evaluation of impact of acidic soils on the forest soil fertility.The soil pH showed that limestone and marlstone soils were neutral to alkaline with pH range (5.84-7.81), while that from silicate rock was strongly acidic with pH range (3.41-4.99). The quantities of nutrients availability are different within these three geological sites of soil formation. Limestone soils shows to have much more nutrients availability followed by marlstone and silicate soils. In comparison to soil layers, surface soils (0-10 cm) also have much nutrients availability than subsurface soils (10-20 cm) in all sampling stations. All three types of soils show to be more favourable with C/N ratio than C/P ratio. The C/N ratio in this study varied between 10 to 70; while C/P ratio varied between 150 to 2070.
- Bulletin of the Faculty of Science, University of the Ryukyus
Bulletin of the Faculty of Science, University of the Ryukyus (78), 267-284, 2004-09