Straw Return with Dolomite Application Increase Flue-Cured Tobacco Leaf Yield and Quality

Straw return and liming are often applied to improve soil fertility and crop yield on acidic soils. Albeit, there are several studies for the effect of these practices on soil physical and chemical characteristics and crop plant growth, it is still unclear whether or how straw return and liming affect tobacco yield and quality. A field experiment was conducted from 2015 to 2018 to study the effect of both tobacco straw return and dolomite application and their interaction on soil pH, yield, quality and chemical elements of flue-cured tobacco leaf. Results showed that compared with the CK, straw return with liming (St + L) or with dolomite (St + D) increased trade yield by 21.4 and 11.7%, and the market value increased by 33.7 and 24.7% in 2018, respectively. The St + L and St + D significantly increased the smoking quality and K concentration of cured leaves compared to the CK, moreover, the reducing sugars in St + D (26.7–27.0%) were significantly higher than other treatments. Since 2016, St + D significantly increased the Mg concentration of leaves compared with all other treatments. The Mg concentration of leaves in St + D increased with the increase of treatment time, while decreased in St + L. Therefore, it is suggested that dolomite should be applied with straw return to enhanced tobacco leaf quality, particularly for Mg concentration and reducing sugars content in tobacco-rice cropping system.