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Due to improper discharge of waste water, water sources for the agricultural
irrigation have been polluted. Salinity of the irrigation water will decrease
in crop yield. Furthermore, it will deteriorate the soil quality. In the past,
we have no basis in the correlation about salt concentration of irrigation wa
ter and salinity of soil. Therefore, through this research we hope to establis
h a model for the relationship among the irrigation volume, electrical conduct
ivity of irrigation water and the electrical conductivity of soil, to estimate
the difference of electrical conductivity of soil in reference to irrigation
management. And our study areas include Ping-dung Tai-tuo、Yung-an、Gang-shan
Wan-li、Kaoshiung Lin-yuan and Jang-hua Lan-ya-gou irrigation zones.From the s
tatistical result, it shows that the salt concentration of soil will change as
the salt concentration of irrigated water and its volume changed. The salt co
ncentration will rapidly increase during dry season,which also be harmful for
the crop growth. If there is not enough fall rain during resting period, the s
oil salt concentration will be increased and then the first month after restin
g period, the electrical conductivity of soil will increase to its maximum lev
el caused by decreasing irrigation water. From the data of field samples,the e
lectrical conductivity of soil is not high in such year. This means the salt w
ill accumulate because of the high salt concentration of irrigated water and c
rop evapotranspiration, and leached by rainfull. The result totally fits with
our hypothesis.
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