| On the basis of observation to Photosynthetically Active Radiation(PAR) , soil temperature and crop evapotranspiration under inter-planted winter wheat and spring maize , the results are as follows:(1) the diurnal change of the percent of PAR intercepted (IPAR) by wheat canopy was bimodal curve, and the curve was symmetrical. There was a good relationship between IPAR and leaf area index (LAI). The results also showed that there was the bimodal curve in the diurnal change of the percent of shading ( LI) , and a good relationship between LI and height) of the crop;(2) The instantaneous PAR had severely effect on the IPAR of intercropped maize. There was a good relationship between IPAR of intercropped maize and LAI and height of the crop;(3) The trend of diurnal change of soil temperature was: decreasing since emergence stage, reaching the lowest at winterovering, begin increasing after revivng,comparatively steady after heading,rising after the wheat harvest.There was better linear relationship between air temperature and the diurnal and seasonal change of soil temperature.(4) The results showed that compared with the sole cropped wheat, during the winter wheat growing period in the first experiment period, the evaporation of intercropping increased 34.63mm, transpiration decreased 65.81mm, evapotranspiration decreased 31.18mm,The ratio of E/ET of the monoculture was 20.42%,the intercropping was 29.72%. During the winter wheat growing period in the second experiment period,, the evaporation of intercropping increased 26.00mm, transpiration decreased 64.81mm, evapotranspiration decreased 40.81mm.The ratio of E/ET of the monoculture was 17.65%,the intercropping was 25.13%.The results also showed that compared with the sole cropped maize, the evaporation of intercropping decreased 40.94mm, transpiration increased 147.73mm, evapotranspiration increased 106.79 mm.The ratio of E/ET of the intercropping was 19.76%,the monoculture was 32.14%.
|
PDF Full Text Request