水稲生育の経年変化と許容塩分濃度

概要

論文の詳細を見る
Rice plant response to salinity in irrigation water was experimentally measured to investigate its salt tolerance. Different three irrigation waters, (1) natural groundwater, (2) diluted sea water with electric conductivity (EC) of 1,400μ S/cm, and (3) the same with 1.8OOμ S/cm, were supplied to the rice plants of the same variety that were growing in different three growth chambers in a greenhouse. The experiments had been conducted for consecutive three years under a scheduled watering and dewatering management. The results show that the waters (1) and (2) produce indistinguishable difference in growth of the rice, while the water (3) delays increasing the number of young shoots and hence, after the panicle formation, reduces the transpiration by about 3mm/d compared with the water (1). The water (3) also causes etiolation of the plants. This salt injury becomes most serious at the end of the panicle formation stage, 7 to 9% of the stems being injured. Use of the water (3), however, causes insignificant yield reduction. This invites us to the conclusion that the maximum allowable salinity level of irrigation water without yield reduction (i. e., rice plant salt tolerance) may be around 1,800μ S/cm in terms of EC.
日本雨水資源化システム学会の論文