Abstract:

To investigate the optimal ridging height and organic fertilizer application ratio in the Pu'er tobacco area, a field experiment was conducted to examine effects of different ridging heights and organic fertilizer application ratios on soil temperature and humidity, the tobacco root system, and the quality of upper tobacco post-flue-curing. The results showed that, the temperature and humidity of the ridge in the early stage of tobacco growth was mainly affected by the ridge height, with the higher the ridge height, the soil temperature shown rise, the relative water content shown downward trend, and in the later stage of growth, it was mainly affected by the proportion of organic fertilizer, which was positively correlated with soil temperature and humidity. In the resettling stage, with the higher of the ridge height, the little proportion of organic fertilizer, the root activity shown stronger, and the dry matter accumulation of root was increased. 30 cm ridging height and 50% organic fertilizer ratio treatment in boom period were good to enhance root activity and increase dry matter accumulation of root. The level of sugar-alkali ratio and nitrogen-alkali ratio of flue-cured tobacco leaves treated with 30 cm ridging height and 50% organic fertilizer ratio were closer to the required ratio of high-quality tobacco leaves. Comprehensive analysis showed that 30 cm ridge height combined with 50% organic fertilizer + 50% inorganic fertilizer can improve the temperature and humidity of tobacco soil, promote the growth and development of roots and maintain its vitality, and improve the chemical composition coordination and comprehensive quality of flue-cured upper tobacco leaves.

Key words: Ridge height, Organic fertilizer ratio, Soil temperature and humidity, Root system of tobacco, Leaf quality of tobacco