Tobacco Growth Responses And Soil Properties To Rice-Straw Biochar Applied On Yellow-Brown Soil In Central China

Pot experiments were conducted to study the effect of straw biochar application on tobacco growth and soil fertility. The growth of ground parts of tobacco was promoted by biochar application at appropriate levels (0.2-1.0%),while it was inhibited by high-level (5%) biochar application. The growth of root system was promoted more extensively by biochar application at all levels tested than was the growth of the aboveground organs, with 5% biochar addition resulting in the highest root-shoot ratio, which also delayed the senility of the root system, including of lateral roots. The taproot length, the first-and second-order lateral roots and the root-shoot ratio of tobacco increased during the early growth stage but decreased at latter growth stage in all treatments. Moreover, with the increasing amount of biochar applied, soil pH and soil nutritional indicators including organic carbon, alkali-hydrolysable N, available P and available K increased with the highest value was observed in the 5% biochar treatment. Our results suggested that straw biochar application at appropriate levels (0.2-1.0%) would lead to an increase in soil fertility and promote tobacco growth. The field experiments are required to test the effect of biochar application on tobacco growth and soil environment with different soil types in tobacco planting area in China.