Abstract
One of the writers, SATO has already reported on the temperature-lowering phenomena by prevention of pnetration of solar-radiation into the water of the paddy field, and recognized the favorable effects of that technique upon the rice-plants in Late-Cultivation (transplanting on Aug. 4, 1955).
In 1956, the technique above mentioned was adopted in Common-Cultivation of Rice (transplanting on July 2).
The experimental plots are;
(A) Clear Water, (B) Carbon Black Powdering, and (C) Carbon Black Suspension.
In (B)-and (C)-Plots, the daily maximum temperatures at every vertical positions of water- and soil-strata are lowered than those in (A)-Plot. The temp.-lowering are remarkable in late July and in early August. The phenomena continue for some days after the stop of these techniques. See Figuers 1, 2 and Table 2.
The growth and yields of rice in the three plots will be stated in the 2nd report.
