1.Survey of Content of Nitrate in Well Water of Rural Areas
Shinji Asanuma ; Akira Suzuki ; Kazuo Kurosawa ; Kiichiro Sasaki ; Eishiro Abe ; Masahiko Sakurai ; Hidesato Ide ; Shosui Matsushima
Journal of the Japanese Association of Rural Medicine 1984;33(2):173-182
We investigated the content of NO3-N in the well water of the eastern, middle and nothern districts of Nagano Prefecture. The NO3-N content seasonally changes and takes on the pattern of a high in summer and a low in winter.
Rain is considered to dilute the contaminated well water, but it lets NO3-N flow from the soil into the.well water, when the rain is poured by a typhoon. As a result, a high content of NO3-N is measured in the well water.
The water sample of 25 out of 85 wells in Matsukawa Town exceeded the tolerance level of NO3-N (10 ppm, but 44.3 ppm in terms of NO3-).
By crop area, the amount of NO3-N was highest in the fruitgrowing area, which was followed in order of the vegetable-growing area, the flower-growing and the rice planting area.
We consider that the contamination of well water is caused both by chemical fertilizers and the less absorbility of the soil.
Result Analysis
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