关键词: 体系优化, 体系优化

Abstract:

In order to solve the problem that fertilizer loss caused by rain in flue-cured tobacco production and and to improve the nitrogen fertilizer utilization efficiency on flue-cured tobacco, under the high rainfall year, (above 850 mm rainfall in May to September in 2010), no uncover plastic film method was adopted in Xinhuang tobacco growing area in northwestern Hunan Province , to study the effects of different nitrogen application amount (105 kg/hm2, 120 kg/hm2 and 135 kg/hm2) on tobacco photosynthetic physiology, yield and quality. The results showed that: with the increase of nitrogen rate, tobacco plant growth was better, photosynthetic rate, stomatal conductance and transpiration rate were getting higher. Nitrogen rate (135 kg/hm2) treatment was the highest and nitrogen rate (105 kg/hm2) treatment was the minimum. No uncover plastic film can reduce fertilizer loss in high rainfall, but the chlorophyll fluorescence parameters can be reflected the stress caused by the method that no uncover plastic film. Nitrogen fertilizer application amount higher, PSII biggest photochemical efficiency Fv/Fm and Fv/Fo values were higher, photochemical quenching coefficient the qP relevant to leaf absorb the light energy decreased, the non-photochemical quenching coefficient increased, the actual photochemical efficiency (ΦPSII) and the electron transport rate (ETR) decreased. With the increase of nitrogen, leaf maturity, oil and chroma increase, but tobacco leaf organization structure stiffness, identity partial thick. The sugar in all treatments upper leaf content relatively low, but the total alkali content more than the 3%, they were disadvantages of quality. In general, the quality difference between treatments was not significant. Dried leaf production and the average price are the treatment nitrogen rate 135 kg/hm2 highest, nitrogen rate 105 kg/hm2 minimum. Suggestion was to reduce nitrogen application amount under no uncover plastic film method in the future, and to increase organic fertilizer and manure with other agricultural measures to improve the quality of tobacco leaves.