Relationship between Leaf Movement of Trifoliolate Compound Leaf and Environmental Factors in the Soybean Canopy : III. Comparisons of micro-environments between the rice and soybean canopy

Japanese Journal of Crop Science

Ryuzi INAMURA¹  Kuni ISHIHARA¹  Kuniyuki SAITOH¹ 

关键词: Boundary layer resistance;    イネ;    Filter paper evaporation rate;    吸光係数;    Leaf movement;    境界層抵抗;    Light extinction coefficient;    ダイズ;    Micro-environment;    葉の運動;    Rice;    微細環境;    Soybean;    風速;    Wind speed;    ろ紙蒸発速度;   

DOI  :  10.1626/jcs.63.480

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

To clarify the effect of leaf movements on the micro-environments inside the soybean canopy, the vertical distribution of several meteorological factors were compared between the rice and soybean canopy. The upper layer of the soybean canopy had higher leaf area density. In the soybean canopy, wind speed, wet filter paper evaporation rate and CO2 concentration of the air were lower, and dew point temperature of the air was higher, just below the plant cover than the rice canopy. By measuring the wet filter paper evaporation rate and the vapor density difference between the air and the filter paper at each height inside the canopy, boundary layer vapor diffusion resistance (ra) was calculated. ra increased with lowering the height above the ground inside the canopy, and decreased at each height with increase in the open field wind speed. ra was larger in the soybean canopy than the rice canopy due to lower wind speed. The relative wind speed in the upper layer of the soybean canopy became higher late in the morning. It is speculated that wind penetrate into the soybean canopy by the active leaf movement. Diurnal variation of relative light intensity was observed in each height inside the canopy. The light extinction coefficients of the whole canopy decreased as the sun altitude increased, and these changing levels of the soybean canopy were larger all day than the rice canopy. The extinction coefficients in the upper layer of the soybean canopy were smaller during the daytime due to trifoliolate compound Leaf movements. Cleary, sunlight penetrates into the soybean canopy with a decrease in the area of triangle described by the three tips of the trifoliolate compound leaf.

【 授权许可】

Unknown