| In this experiment, in order to analyze the apricot-wheat & apricot-cotton Intercropping Systems light environment, space-time windows change and the factors that effect light environment, WinSCANOPY For Canopy Analysis made in Regent Instruments company(CANADA), SunScan For Canopy Analysis made in Delta company(UK) were adopted to analyse the rules in daily and seasonal variation of light environment, relationships between intercropping system crop light response curve and intercropping system space-time window size and the influence of intercropping trend, the height of the tree, crown width, the shape of the tree. It had revealed the competition relation of light in apricot-wheat & apricot-cotton Intercropping Systems. Get the following main research results:The influence of shade almond trees line by intercropping system, apricot and cotton photosynthetic available radiation(PAR) has obvious the spatial and temporal variation characteristics. Among the highest, from intercropping systems to both sides gradually diminishing among; East west intercropping system than photosynthetic available radiation to reach peak. From May to August, the PAR seasonal changes in a lower from low to high trend. Transmittance in the intercropping system, different spacing of leaf area index (LAI) are expressed as with the apricot phenology (flowering to fruit maturity) goes upward trend, to fruit maturity, decreased slightly. Sky opening (DIFN) decreased with phenology, to fruit maturity, increased slightly. Natural fun-shaped, Y-shaped, and the evacuation of three hierarchical tree-shaped leaf stage to harvest from the development of the leaf area index of the trend of change gradually increases to fruit maturity, decreases, decreases the sky opening to fruit ripening Period increased.Along with the increase of the PAR winter wheat photosynthetic rate increase gradually, to 1000-1200μmol·m-2·s-1 reached light saturation point, and cotton in 1400μmol·m-2·s-1, higher than winter wheat. With the decrease of the apricot planting spacing, tree height increase and crown width expansion, apricot-wheat & apricot-cotton intercrops of intercropping systems "PAR space-time Windows" reduce gradually until vanishing. Planting spacing 1.5mx4m, tree height 5.1 m, crown width 3.0 m, and planting spacing2mx4m, tree high 5.4 m, crown widths 3.4 m doesn't appear PAR space-time Windows in cotton. Shows that lighting conditions of their cannot give full play to the photosynthetic carbon assimilation capacity to meet the light demand of cotton.The effect of apricot and cotton in intercropping system, the analysis of the factors that light distribution of each index changes with cotton decision in intercropping system apricot distribution of light. Along with increase of the tree height, expansion of canopy widths, decreases of transmittance, and apricot shading is serious; the larger planting spacing, the stronger PAR; As the sun moves from west to east east-west direction of caused by light intercropping is far less than that of north and south; In planting spacing and tree height under the condition of the same, three tree forms the greater canopy width, the larger spreading angle. The biggest of all is the open centre model, then the Y shape, and the smallest is the evacuation layered form, transmittance in descending order the max is open centre model, the second is Y shape, the minimum is evacuation layered form. |
