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**Change of Soil Moisture in Clustered Field of Wild Iris
Toru HOSHI*, Katsumi FUJII** and Eiichi KURASHIMA*** United Graduate School of Agriculture, Iwate University, -ῌ+2ῌ2 Ueda, Morioka,
Iwate *,*ῌ2//*, Japan** Faculty of Agriculture, Iwate University, -ῌ+2ῌ2 Ueda, Morioka, Iwate *,*ῌ2//*, Japan
Abstract
The main aim of farm-land consolidation projects is to preserve the environment, while keeping
high agricultural productivity. In this research, soil moisture of a clustered ﬁeld of wild iris (Irisensata var. spontanea) in Hanamaki, Iwate, was measured to grasp its temporal change, and to
consider their relationships with meteorological and hydrological conditions. In this area, thenumber of ﬂower stalks has decreased remarkably since the farm land consolidation project.
The results revealed that the soil at the test site is almost saturated, and the temporal change inshallow soil moisture is larger at the distant point from pond water and a cut-o# wall than thenear point. Although change of the volumetric water content by precipitation was not signiﬁcant, its reduction by fall of pond water level was clear.

Thus, it was suggested that a moderatechange in soil moisture between drying and wetting is essential for the growth of wild iris andenvironmental preservation.
Key words : Farm land consolidation project, Measure against environmental preservation, Clustered ﬁeld of wild iris, Soil moisturez{|z}~4D B pB;

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Boobie, M. and Robert, J.L. (,**-) : Laboratory evaluation of a commercial dielectric soil water sensor. Vadose Zone Journal, , : 0/*ῌ0/..
Decagon Devices, Inc (,**-) : http : //www.ech,o.com/
probes.html.

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