Effects of Rice Straw Returning into Field on Growth and Development and Quality of Flue-cured Tobacco

[Objective] The aim was to study effects of rice straw returning into field on growth and development and quality of flue-cured tobacco,discuss the best amount of rice straw during rice straw returning into field,provide a scientific basis for deeply extending rice straw returning into field,enhancing soil fertility and reducing productive cost of tobacco grower.[Method] Five treatments were designed,which were no covering rice straw and mulching film(T1),covering mulching film(T2) and covering rice straw 4 500,6 000,7 500 kg/hm2,respectively.And T1 was took as control(CK).The investigative flue-cured tobacco indices were earth temperature,soil humidity,growth period of plant,and growth and development,accumulation and distribution of dry matter,economic characters,exterior quality,physical properties,inner chemical compositions,physical inner fragrance and snorting quality and so on.[Result] The results showed that rice straw returning into field had regulatory effects on earth temperature and soil humidity of planting tobacco field.It could also coordinate tobacco leave inner chemical compositions,effectively increase its total sugar,reducing sugar,chlorine and potassium content,decrease its total nitrogen and total plant alkaloid content,and improve its carotenoid and polyphenol content,then effectively improve its physical inner fragrance and snorting quality.[Conclusion] Rice straw mulching can effectively improve the quality of flue-cured tobacco,and 7 500 kg/hm2 is the best amount of coverage.