Water quality of farm-use water at main irrigation spots in Hyogo prefecture [Japan] from 1996 through 1998

• Published in: Bulletin of the Hyogo Prefectural Agricultural Institute. Agriculture (Japan) no. 49
• Main Authors: Matsuyama, M. (Hyogo-ken. Agricultural Inst., Kasai (Japan)), Oshio, T, Kuwana, T, Kishigami, M
• Format: Journal Article
• Language: Japanese
• Published: 01.03.2001
• Subjects: IRRIGATION WATER; ORYZA SATIVA; ULTRAVIOLET SPECTROPHOTOMETRY; WATER QUALITY
• ISSN: 1341-0326

Water quality of farm-use water at 45 main irrigation spots in Hyogo prefecture was investigated from 1996 through 1998. Samples of water were collected 5 times for the irrigation period of rice plants and 2 times for the non-irrigation period. (1) Generally, water quality is getting better than that of ten years ago, except for the east Harima area. But T-N has increased in all areas. In the Kakogawa river system, water quality is bad during the irrigation period, especially at transplanting time. In east Harima, water quality of farm ponds is bad in the non-irrigation period. (2) In the Kakogawa river system, the stream length of the river from the sampling point to the upper stream and the population in the catchment area are correlative with SO4, EC, Na, Cl, T-N, which are very much affected by human activities. (3) The biological decision index of water quality has a negative correlation with T-N and Cl. (4) In spectrophotometry, absorbance of 260nm had a correlation with COD and absorbance of 210nm had a correlation with NO3-N. So we can use these relationships for rapid water analysis.