Photosynthetic production is a major determinant of final yield in crop plants. A simulation model was developed for canopy photosynthesis and dry matter accumulation in oilseed rape (Brassica napus L.) based on the e...Photosynthetic production is a major determinant of final yield in crop plants. A simulation model was developed for canopy photosynthesis and dry matter accumulation in oilseed rape (Brassica napus L.) based on the ecophysiological processes and using a three-layer radiation balance scheme for calculating the radiation interception and absorption by the layers of flowers, pods, and leaves within the canopy. Gaussian integration method was used to calculate photosynthesis of the pod and leaf layers, and the daily total canopy photosynthesis was determined by the sum of photosynthesis from the two layers of green organs. The effects of physiological age, temperature, nitrogen, and water deficit on maximum photosynthetic rate were quantified. Maintenance and growth respiration were estimated to determine net photosynthetic production. Partition index of the shoot in relation to physiological development time was used to calculate shoot dry matter from plant biomass and shoot biomass loss because of freezing was quantified by temperature effectiveness. Testing of the model for dynamic dry matter accumulation through field experiments of different genotypes, sowing dates, and nitrogen levels showed good fit between the observed and simulated data, with an average root mean square error of 10.9% for shoot dry matter. Thus, the present model appears to be reliable for the prediction of photosynthetic production in oilseed rape.展开更多
With the super japonica rice Shennong 265 as the tested material, the effects of different nitrogen application amounts and basic tiller fertilizer(BTF)-ear granule fertilizer(EGF) ratios on the yield and nitrogen uti...With the super japonica rice Shennong 265 as the tested material, the effects of different nitrogen application amounts and basic tiller fertilizer(BTF)-ear granule fertilizer(EGF) ratios on the yield and nitrogen utilization characteristics of Shennong265 were investigated. The results showed that when the BTF-EGF ratio was 8:2 or 7:3, the yield of Shennong 265 increased with the increased nitrogen application amount; when the BTF-EGF ratio was 6:4, medium nitrogen level was more conducive to improving the yield of Shennong 265; under the condition of same BTF-EGF ratio, with the increased nitrogen application amount, the total nitrogen uptake increased, and the nitrogen physiological efficiency and harvest index decreased. At low and medium nitrogen levels, the higher the proportion of EGF was, the higher the yield, total nitrogen uptake and nitrogen recovery ratio were; at high nitrogen level, the BTF-EGF ratio of 7:3 was more favorable; at the same nitrogen level, the higher the proportion of EGF was, the lower the nitrogen physiological efficiency and harvest index were. Under conditions of nitrogen application level of 255 kg/hm^2 and BTF-EGF ratio of 7:3, the dry matter accumulation in the leaves, stems and spikes of Shennong265 was higher in the late growth period. Higher effective panicle number and grain number per panicle led to higher yield(9581.5 kg/hm^2, 2.4%-20.1% higher than those in the other treatment groups) and higher nitrogen use efficiency.展开更多
基金Project supported by the National High Technology Research and Development Program (863 Program) of China(No. 2006AA10A303)the Post-Doctoral Program of Jiangsu Province, China (No. 0602027C)
文摘Photosynthetic production is a major determinant of final yield in crop plants. A simulation model was developed for canopy photosynthesis and dry matter accumulation in oilseed rape (Brassica napus L.) based on the ecophysiological processes and using a three-layer radiation balance scheme for calculating the radiation interception and absorption by the layers of flowers, pods, and leaves within the canopy. Gaussian integration method was used to calculate photosynthesis of the pod and leaf layers, and the daily total canopy photosynthesis was determined by the sum of photosynthesis from the two layers of green organs. The effects of physiological age, temperature, nitrogen, and water deficit on maximum photosynthetic rate were quantified. Maintenance and growth respiration were estimated to determine net photosynthetic production. Partition index of the shoot in relation to physiological development time was used to calculate shoot dry matter from plant biomass and shoot biomass loss because of freezing was quantified by temperature effectiveness. Testing of the model for dynamic dry matter accumulation through field experiments of different genotypes, sowing dates, and nitrogen levels showed good fit between the observed and simulated data, with an average root mean square error of 10.9% for shoot dry matter. Thus, the present model appears to be reliable for the prediction of photosynthetic production in oilseed rape.
基金Supported by Earmarked Fund for China Agriculture Research System(CARS-01-37)Liaoning Science and Technology Plan Project(2014201004)Rice Industry Innovation Team Construction Project of Modern Agricultural Industry Technology System of Liaoning Province(LNK[2013]271)
文摘With the super japonica rice Shennong 265 as the tested material, the effects of different nitrogen application amounts and basic tiller fertilizer(BTF)-ear granule fertilizer(EGF) ratios on the yield and nitrogen utilization characteristics of Shennong265 were investigated. The results showed that when the BTF-EGF ratio was 8:2 or 7:3, the yield of Shennong 265 increased with the increased nitrogen application amount; when the BTF-EGF ratio was 6:4, medium nitrogen level was more conducive to improving the yield of Shennong 265; under the condition of same BTF-EGF ratio, with the increased nitrogen application amount, the total nitrogen uptake increased, and the nitrogen physiological efficiency and harvest index decreased. At low and medium nitrogen levels, the higher the proportion of EGF was, the higher the yield, total nitrogen uptake and nitrogen recovery ratio were; at high nitrogen level, the BTF-EGF ratio of 7:3 was more favorable; at the same nitrogen level, the higher the proportion of EGF was, the lower the nitrogen physiological efficiency and harvest index were. Under conditions of nitrogen application level of 255 kg/hm^2 and BTF-EGF ratio of 7:3, the dry matter accumulation in the leaves, stems and spikes of Shennong265 was higher in the late growth period. Higher effective panicle number and grain number per panicle led to higher yield(9581.5 kg/hm^2, 2.4%-20.1% higher than those in the other treatment groups) and higher nitrogen use efficiency.
