2024 Volume 80 Issue 27 Article ID: 24-27040
This study aims to clarify appropriate methods to reduce the impact of phosphate on the coral reef ecosystems, which are in decline due to multiple global environmental impacts, the current phosphorus content of agricultural soil was investigated and analyzed in the Todoroki River watershed, Ishigaki island. In addition, from the standpoint of the precautionary principle, a factorial linkage structure analysis was also conducted on the reduction of point source load to analyze negative factors related to composting and utilization of livestock manure.The results showed that phosphorus is likely to be discharged from soils with high pH, soils with low phosphate absorption coefficients, some soils in sugarcane summer plantings and stubble cultivation, and soils near composting yards. Furthermore, to promote the intra-regional cyclic approaches of phosphorus in agriculture, it was found that various activities are necessary such as increased collection of livestock wastes, increased composting, increased use of compost, increased markets for compost, a shift to environmentally positive agriculture, and others.
