PurposeTo explore preliminarily the effects of continuous cropping years on the chemical properties and enzyme activities in different types of tobacco-planted soil, the change trend of yield and quality of flue-cured tobacco, and then, the response of different tobacco-planted soil types to continuous cropping was discussed.
MethodThe experiment was conducted in Xundian and Shilin counties, Kunming City, Yunnan Province in 2019. The agronomic traits, economic traits, chemical composition indexes of tobacco leaves, chemical properties and main enzyme activities in red and purple rhizosphere soil were measured and analyzed, including rotation and continuous cropping of 1, 3 and 5 years treatments were studied.
Result1) The effective leaf number, leaf area index, yield and other indicators showed a downward trend under continuous cropping, and the decrease was not obvious within three years, but significantly decreased in five years (P<0.05). 2) The contents of total sugar and reducing sugar in tobacco leaves decreased with the increase of continuous cropping years, but they were almost in the suitable range of high-quality tobacco leaves in Yunnan. 3) With the increase of continuous cropping years, the pH value of two types of soil decreased to different degrees, and the red soil decreased significantly from the first year of continuous cropping (P<0.05), while purple soil decreased significantly in the third year (P<0.05); the contents of organic matter, available potassium and urease activity increased in different degrees, but the response of the treatments in purple soil were lagged behind those in red soil.
ConclusionShort-term continuous cropping did not lead to significant changes in yield and quality of flue-cured tobacco, but it caused changes in soil chemical indexes and enzyme activities to varying degrees, and the response of chemical characteristics in purple soil to continuous cropping years were lagged behind than those in red soil.
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