The Significance of Rikuden in the Agricultural Use of Tableland in Kanto Region

Rikuden是台地上的一块稻田，它是用推土机从干燥的田地或树林中挖出来的。陆库登的底板用滚筒硬化。Rikuden不同于洪泛区或冲积谷区的普通水田，前者没有水权。陆空登是通过开采地下水来灌溉的，因此没有灌排渠道。由于日本经济的高速增长，陆库登被积极地创造出来。特别是在关东地区北部和东部地区，那里以洪积台地为主，供水不足，里库登被认为是台地农业利用的一种天赐良机。但是，到了1970年，水稻产量变得过剩，并采取了限制水稻生产的政策。本研究的目的是以茨城县为例，考察陆库登的发展过程，在水稻生产控制时期的用途变化，以及陆库登在台地农业利用发展中的意义。

Rikuden is a rice field on the tableland which is made by bulldozing out of dry fields or woods. The bed of rikuden is hardened by roller. Rikuden is different from an ordinary paddy field in the floodplain or the alluvial valley in the point that the former has no water rights. Rikuden is irrigated by pumping up of undergroundwater, and therefore, has no irrigation and drainage channels.Since the high growth of Japanese economy, rikuden was created actively. Particularly in the northern and eastern parts of Kanto region, where the diluvial tableland dominated and water supply was insufficient, rikuden was considered a kind of a godsend in the agricultural use of tableland. But, by 1970 the rice production had become superflous, and since that time restriction policies of rice production have been taken.The aim of this research is to consider the development process of rikuden, the change of its use at the time of rice production control, and the significance of rikuden in the development of the agricultural use of tableland, taking the case of Ibaraki-ken.