Photosynthetic Diurnal Changes of Bothriochloa ischaemum Mixed Sowing with Lespedeza davurica in Loess Hilly-gully Region
Field experiments were conducted using a replacement series design in which Bothriochloa isch-aemum(B) and Lespedeza davurica (D) were sowed at row ratios of 0 :10,2:8,4:6,5:5,6:4,8:2 and 10 : 0 in the same plot. The photosynthetic diurnal change characteristics of B. ischaemum in different mixed sowing ratios were investigated and compared. Results indicated that the diurnal changes of net photosynthetic rate of B. ischaemum presented a double-peak pattern cure under different mixed sowing ratios, showing obvious photosynthesis midday depression phenomenon. Peak values appeared at 10: 00 and 16:00, respectively, while the lowest value appeared at 12:00. Except at B4D6 ratio, in which the transpiration rate diurnal changes of B. ischaemum presented a double-peak pattern cure, the curves had only one peak at the other mixed sowing ratios. Diurnal change of leaf instantaneous water use efficiency presented a double-peak pattern cure at all mixed sowing ratios, and the peak and lowest values appeared at the same time as photosynthetic rate. Compared with other ratios, B. ischaemum had higher daily average photo-synthetic rate, higher daily average leaf water use efficiency and lower daily average transpiration rate at B8D2 and B6D4 ratios, which indicated that these two mixed sowing rations are beneficial to improve the photosynthesis and leaf water use efficiency of B. ischaemum.
Bothriochloa ischaemumLespedeza davuricaMixed sowing ratiosPhotosynthetic physiologyReplacement series
NETL
NSTL
万方数据
维普
