[ Challenge ] in the rice nursery box , to provide root spread of seedling , cost , a layered structure of nursery materials related to water retention , Hokoe in good rice seedlings also to the development of seedlings and reduce the heavy labor work . An A suitable length, width , depth , in no lid , the bottom is provided with a box body 1 that form a plurality of small holes , the bottom surface of the box body 1 , and laid water retention member 2 , on -holding water member 2 , and laying about 1/2 of the bed soil 3 of the volume of the nursery box , on the upper surface of the bed soil 3 , were seeded rice seeds 4 , the seeds 4 seeded , from the top laminated structure of nursery materials related to water retention , Hokoe in rice seedlings which is characterized in that it comprises and covered with a cover soil 5 . When the superabsorbent acrylic polymer constituting the water retention member 2 is in contact with water , it absorbs water it quickly , in less pressure and does not release water , stretched membrane by acrylic polymer in the box bottom , even during watering it has the effect of such greatly suppress the box outside the outflow of water and fertilizer worth . [ Selection Figure ] Figure 1【課題】水稲育苗箱内において、苗の根張り、コスト、重労働作業を軽減させ苗の育成にもよい水稲育苗における保水・保肥に関する育苗資材の積層構造を提供する。【解決手段】適宜な縦・横・深さ寸法を有し、無蓋で、底部には小穴を複数形成した箱本体1を設け、該箱本体1の底面には、保水部材2を敷設し、該保水部材2の上に、育苗箱の容積の1/2程度の床土3を敷設し、該床土3の上面には、種籾4を播種し、播種された種籾4を、その上部から覆土5を被せてなることを特徴とする水稲育苗における保水・保肥に関する育苗資材の積層構造。保水部材2を構成する高吸水性のアクリル重合体が水と接触すると、速やかにこれを吸水し、多少の圧力では水を放出せず、箱底でアクリル系ポリマーによる膜を張り、灌水時においても水及び肥料分の箱外流出を大幅に抑制する等の効果を有する。【選択図】図1
