【作者】 李健；

【导师】 郑有飞；

【作者基本信息】 南京信息工程大学 ， 大气物理学与大气环境， 2012， 硕士

【摘要】 大气层中存在云、水汽、臭氧等气体以及气溶胶粒子等,这些物质的存在会对太阳辐射造成吸收、反射、散射等作用,使到达地表太阳辐射减弱,最终影响作物的生长发育以及产量形成。为了进一步探明太阳辐射减弱对作物生长发育以及产量的影响,本研究在大田试验的基础上设置了3个试验处理：CK,对照组,自然光照；T1,60%太阳辐射；T2,40%太阳辐射,对大豆进行长期的太阳辐射减弱处理,较为系统的研究了太阳辐射减弱对大豆生长发育、光合作用以及产量形成的影响作用,并在大田试验资料的基础上,利用DSSAT模型对大豆产量以及干物质累积进行模拟,为规避太阳辐射减弱对我国农业生产的影响提供科学依据。主要结果如下：(1)太阳辐射减弱延缓了大豆的生育进程。与CK相比,60%辐射组大豆生育全期推迟了1天,40%辐射组推迟了2天。同时随着生育进程的推进,辐射减弱下株高逐渐增高,叶面积变大,并随着太阳辐射减弱程度的增加,这种变化越加明显。(2)大豆叶片的净光合速率,气孔导度,气孔限制值在太阳辐射减弱条件下会出现下降,但胞间C02浓度反而升高,且随着辐射减弱强度的增加这种现象越明显。而光合速率的下降导致大豆叶,茎的干物质累积在结荚前低于自然光照组,结荚后由于对照组干物质快速转移至豆荚而高于对照。(3)太阳辐射减弱下各器官在总干重的比例出现变化,叶重在总干重的比例及根冠比为T2>T1>CK,但茎的比例有降低趋势,根重的比例为CK>T1>T2。同时太阳辐射下降显著降低了大豆的饱和荚数、总荚数、结实粒数、株粒重以及百粒重,最终导致产量下降。与CK相比,T1组下降了29.63%(P<0.01),T2下降了33.80%(P<0.01)。(4)修正后的DSSAT模型对太阳辐射减弱下大豆产量以及总干物质模拟结果较好,相对误差小,决定系数高,对大豆茎、叶干物质的累积模拟效果理想。大豆对太阳辐射的敏感性分析表明：太阳辐射减弱50%时为大豆的敏感点,导致大豆产量严重下降；而太阳辐射增加量在0%-20%间存在一个阈值,使得大豆产量达到最佳。大豆对太阳辐射量和降水量的敏感性分析表明：当太阳辐射减弱,降水量为任意值时,太阳辐射为主要敏感因子；当太阳辐射增加,降水量为任意值时,降水量为主要敏感因子。更多还原

【Abstract】 In the atmosphere, there are clouds, water vapor, ozone and other gases and aerosol particles, which will weaken the surface solar radiation, by absorbing, reflecting, scattering. Also these will adversely affect the growth and physiological properties of crops. In order to elucidate the effects of reduced solar irradiance on growth and productivity of agricultural crops, we conducted a field experiment.In this paper, we conducted a field experiment in Nanjing and the shading treatments is Soybean. In the field experiments, three treatment groups were set, namely CK, T1(60%CK), T2(40%CK), with the total natural solar radiation as the control group (CK), we studied the photosynthesis, growth and yield effects of soybean systematically when the solar radiation was reducing, and simulate the yield and dry matter of soybean with DSSAT model, which can provide a scientific basis of avoiding the effect of solar radiation weaken to the agricultural production in China. The main conclusions of this treatment were as follows:(1) Reduce solar irradiance delay the growth period. Compared with CK, the growth period of T1and T2delay one or two days. With the growth of soybean, there was a significant increase of plant height and leaf area, which would be more obvious if more solar radiation reduced.(2) The more solar irradiance reduced, the net photosynthetic rate, conductance of stomatal and stomatal limitation value will lower, but with a higher intercellular CO2concentration. Before the pod, The dry matter of leaf and stem were lower when growing with lower photosynthesis rate in the less solar radiation, but higher than CK after pod for the dry matter of CK quickly transferred to the husk.(3) The dry matter of each organs were changed. The tendency of ratio on leaf weight to total dry weight and the ratio on root weight to shoot were T2>T1>CK. The tendency of ratio on root weight to total dry weight is CK>T1>T2. But the ratio on stem weight to total dry weight was lower. The solar radiation weakens also significantly reduce saturated pods, total pod number, grain weight, and declined the yield. The yield of T1declined29.63%(P<0.01), and T2declined33.8%.(4) The amended DSSAT model is good at simulating the soybean yield and total dry matter with small relative error and high coefficient of determination, and good at simulating the stem or leaf dry matter accumulation of solar weaken soybean. The sensitivity analysis of soybean to solar radiation showed that: solar radiation weakened by50%was the soybean’s sensitive, which would seriously reduce soybean yield; and there was a threshold, which soybean yield would be the best, in0%-20%solar radiation increment. The sensitivity analysis of soybean to solar radiation and precipitation showed that: when the solar radiation weakened and precipitation was in any value, the solar radiation would be the main sensitive factor; or when solar radiation increased and precipitation was in any value, the precipitation would be the main sensitive factor.更多还原