Simulation Research On Effect Of Different Underground Water Level On The Growth And Development,Yield Of Barley

Crop growth simulation is a newly established research area, and useful for understanding, predicting, and regulating growth and development of crop plants in response to environment.Based on crop growth model MACROS developed by Penning de Vries and field experiment, a barley simulation model was established. Some parameters were adapted and model modified according to the field experiment.This paper studied the dynamic developments of leaf area index, dry weight of above ground vegetative organ and stored organ, total bio-mass and yield of barley plants under different underground water level. By means of the barley growth simulation model , total bio-mass , yield of barley plants , and soil water content were simulated . The correlation between the observed and the simulated results was analyzed.The results are shown as follows:1 There existed significantly positive correlation between different underground water level and LAI, dry weights of ground organs. During vegetative growth stage, the death rate of green leaves was not significantly,, while the dry weights of green leaves, stems and total bio-mass increased dramatically. At reproductive growth stage, the dry weights of yellow leaves and stored organs increased significantly, while those of green leaves and stems decreased.2 At a certain underground water level ( 60cm), there existed positive correlation between barley yield and differentunderground water level(r=0. 9705**, n=24). 60cm was optical in terms of the dry weight of green leaves, stems, leaf area index and yield. And 30cm was next. At underground water level^60cm(CK), the yield decreased correspondingly. This indicated that the amount of yield increase would decrease at a certain low underground water level. In view of the components of yield, the barley number per ear and effective panicles among treatments are significantly different, but the weight of one thousand grains is not significantly different.3 Analysis concerning nutrition content(N > Solvable) of barley plants indicated that yield of the plots that water was excessive or deficient was low accordingly, while their nutrition content was high. Nutrition content of barley ear was on the contrary.4 Simulation results showed that there existed positive correlation between the simulated and the observed value of 10-20 cm soil water content(r=0.8805, n=40), while these of 0-10 cm soil water content were not so consistent(r=0.7642, n=40).5, Actual LAI fluctuation was simulated better by the model, there existed positive correlation between the simulated and the observed value of LAI(r=0.9645 , n=44). Despite the simulated value was less than the observed value, their tendency was consistent. Simulation results showed that correlation between the simulated and the observed value of dry weight of root was less (r=0.9095,n=44) .6 Simulation results showed that there existed positive linear correlation between the simulated and the observed value of yield> total bio-mass. Their correlation coefficients were rB=0.9809"(n=48), rY=0.9409* ( n=24 ) respectively. Simulation results also showed there was very consistent between the simulated and the observed value of growth and development stage by only one-day disparity. Results showed that the model could accurately simulate the dynamic growth and development of barley plants.7 The bio-mass of several years(1980-1987) under different underground water level was simulated by the barley model respectively. The results are shown as follows: (1) There existed significantly negative linear correlation between the total bio-mass of the same year(different underground water level) and precipitation (r=0.9305*,n=14) . (2) There existed positive linear correlation between the total bio-mass of the same plot(different years) and different underground water level (r=0.9553*,n=12) . (3) There existed significantly negative linear correlation between the bio-mass of different...