Effects Of The Different Duration Of Film-mulching On Physiological Characteristics, Nutrition And Quality Of Flue-cured Tobacco In Liangshan, Sichuan Province

In XiChang tobacco research Institute, Liangshan Sichuan , Field experiments were carried out to study the effects of duration of film—mulching on the conditon of ridge, growth conditiono of plant, physiological characteristics and quality of flue-cured tobacco. Proper time of removing film was put forward. The results were as following:(1) Effects of different duration of film—mulching on the content of water in the ridgeClose correlation was found between the content of water in the ridge and the rainfall. The change of the content of water had the same change trend in layers of all treatment. The content of water in surface layer was acutely effected by the outside, but the content of water in deep layer soil was mildly affected by the outside. Less rainfall, Film-mulching had remarkable effect of water storage and moisture conservation ; More rainfall, The effect of water storage and moisture conservation was'n remarkable. Rainfall couldn't come into the ridge because of film. The content of water in no-removing treatment was fewer than other treatments, especially in surface layer.(2) Effects of different duration of film—mulching on the content of available nutrients and organic matter in the ridgeBecause of film-mulching, nitrogen and potassium moved up and riched in the top of ridge with the water evaporation in deep layer soil .The longer the duration of film—mulching last, the more nutrient moved up and riched in the top of ridge with film—mulching. The content of nitrogen and potassium in no-removing treatment was more than that of other treatments, In no-mulching treatment, the content of nitrogen and potassium of deep layer soil were more than that of other treatments, because more fertilizer was leached to deep layer soil. But the content of phosphorus was affected mildly. In the early removing treatment, the nutrients was efficiently absorbed by the tobacco plants, the use efficience of fertilizer was heightened.In early stage, the content of organic matter have a little change. In the 80th day after transplanting, the content of organic matter declined distinctly, especially in no-removing...