Growth Performance, Nutrient Absorption of Tobacco and Soil Fertility after Straw Biochar Application

A Pot experiment was conducted to study the effect of straw biochar application on growth, nutrient absorption of flue-cured tobacco and soil fertility. The tobacco height, productive leaves and leaf area were all promoted by biochar application at appropriate levels (0.2–1.0%), while they were inhibited by high-level (5%) biochar application. Growth of the root system was promoted more extensively by biochar application at all levels tested than the aboveground organs, with 5% biochar addition resulting in the highest root-shoot ratio, which also delayed the senility of tobacco root system including lateral roots. The taproot length, lateral roots and root-shoot ratio of tobacco all increased at early growth stage but decreased at latter growth stage. The biochar had different effect on N, P and K concentrations of tobacco organs. Large amount of biochar addition (5%) decreased N and P contents, but significantly increased K content in tobacco organs. Moreover, the soil bulk density decreased, while an increase was observed in soil pH and soil nutritional indicators including, organic carbon, alkali-hydrolysable N, available P and K, with the soil nutrient level highest in the 5% biochar treatment. Our results induced that 0.2‒1.0% levels of straw biochar application might be appropriate in the tobacco field. © 2016 Friends Science Publishers