The Effect Of Biodegradable Membrane On The Growth Of Tobacco Plants And The Quality Of Tobacco Leaves

Long Jiang 911 was taken as the test material in this thesis,and the ground was covered with different materials(including the ordinary plastic film and the biodegradable film)in the field experiment.In order to decrease farmland white pollution,this thesis studies the effects of covering different films on the growth of over ground parts of flue-cured tobacco,the root morphological structure,the rhizosphere microorganism and the product quality.The results can be summarized as follows:1.The biodegradable film can help improve the photosynthetic production capability in flue-cured tobacco leaves,and can increase the net photosynthetic rate and the stomatal conductance to some extent.Being compared with the reference object,qP with the biodegradable film II increased by 9.8%,and the SPAD values in two cases with the biodegradable film increased by 1.08 and 1.53 respectively before lower leaves were harvested.By comparing the growth data of the over ground parts of flue-cured tobacco in four cases,it can be found that the biodegradable film can promote the growth of tobacco stem in the early stage,increase the plant height and stem girth in the rosette and round top stages,and increase the leaf cracks in different parts.Before the middle leaves were harvested,the data about leaf area was collected,and in comparison with the reference object,the leaf areas were increased by 13.2% and 9.4% respectively in two cases with the biodegradable film2.From the perspective of the root morphological structure and rhizosphere microorganism,in comparison with B1(covering the ground with the film and removing the film as usual),the ordinary plastic film and the biodegradable film can increase the amount of rhizosphere bacteria,and decrease the amount of rhizosphere actinomyces.In the quick growth stage,rhizosphere bacteria of tobacco with the biodegradable film grow fastest,and 29.44%-37.44% faster than that in the case of CK;meanwhile,the growth of rhizosphere actinomyces is 29.8%-35.9% faster than that in the case of CK.Being compared with the reference object,the root of tobacco with the biodegradable film is 35.8% and 37.6% longer,the root area is 27.1% and 36.5% greater,the number of lateral roots is 19.8% and 24% more,the root diameter is 5.9% and 11.2% longer,the rood cubage is 15.1% and 42.9% greater.When the dry matter accumulation at the tobacco root in four cases reached the highest point,the weight of dry root in the case with the biodegradable film increased by 1.9%-9.4% in comparison with B1(CK).3.By analyzing the chemical composition of the cured tobacco,it can be known that the biodegradable film can dramatically increase the total nicotine and nitrogen contents in the middle and upper leaves of tobacco.By raising the evaluation values under the criteria about chemical composition,the new coordination of the chemical composition of tobacco increased.The product quality summary indicated that the amount of tobacco in the upper and middle class was increased by 9.7%-13.7%,the amount of tobacco in the upper class increased by 3.2%-16.6%,the amount of orange tobacco increased by 8.3%-14.3%,the average price of tobacco increased by 12.9%-15.9% and the value of output per hectare increased by 2242.5-9951.3.