Effects Of Corn And Sweet Potato On Tobacco Growth And Quality As Fore-Rotating Crops

As an effective method of improving production and quality of crops, crop rotation was extensively applied in many croping systems..Significant rotating effect of tobacco with other crops was noticed, but the mechanism was not quite clear.. In this research , effects of two fore-rotating crops, which was noticed to have significantly different effects, were studied from the aspects of nutritional status and characterstic of root exudation. It was hoped that the research could reveal the influencing mechanism of fore-rotating crops on tobacco and provide new and effective methods for tobacco quality improvement. .The results were as following:1. The rhinzospHere soil and non-rhinzospHere soil of sweet potato was higher than maize in N,and Pcontent, but the content of K and CL was lower than that of maize and little difference was noticed in micronutrients. So, maize could absorb more N,and P, but little chlorine, than sweet potato at the same condition, ,Chlorine had adverse effects on obacco quality, So sweet potato would be a favorable fore-roating crop for tobacco in the rotating system.2. added maize and sweet potato flour to the soil could promote the growth of tobacco. maize flour had a better effect in promoting tobacco growth than sweet potato flour in biological characteristics, Plant height ,leaf aera, root,stem, leaves and dry weight of tobacco were notablely different between two flour treated plants. maize flour could promote tobacco growth and budding than sweet potato flour. It was supposed that the high N and P content in maize flour might have played an important role in controlling tabbacco growth.3. maize flour and sweet potato flour could affect the quality indexes of tobacco. maize flour and sweet potato flour all could increase the content of soluble sugar, protein, potassium in tobacco leaves. In suger/protein,K...