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 (Iris ensata 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, the number 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 in shallow soil moisture is larger at the distant point from pond water and a cut-off wall than the near 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 moderate change in soil moisture between drying and wetting is essential for the growth of wild iris and environmental preservation.
