Effect Of Humic Acid Fertilizer On Soil Properties And Growth Development Of Flue Cured Tobacco

In order to study the effect of different humic acid fertilizer application rates on soil physical and chemical properties, flue-cured tobacco photosynthetic physiological characteristics, growth and yield and output of the leaves of Longjiang 911, by pot experiments and field trials manner in 2014-2015. The results showed that: 1. Humic acid fertilizer can reduce soil bulk density and soil pH. 2. 50 g/plant humic acid fertilizer is applied can significantly increase the amount of available nutrients in the soil, In the whole growth period, soil available phosphorus, available potassium and organic matter content increased than control. 3. The administration of 50 g/plant humic acid fertilizer treatment can significantly improve soil enzyme activities, Compared with the control, soil invertase, phosphatase and urease activity were increased by 13.75%~22.48%, 12%~28.24% and 4.6%~21.38%. 4. The administration of 50 g/plant strain humic acid fertilizer treatment can significantly improve the value of flue-cured tobacco SPAD, 5~9 weeks, were increased up 29.95%,37.68% and 8.27%, humic acid fertilizer has increased the photosynthetic performance of flue-cured tobacco leaves wherein the photosynthetic rate of 5~11 weeks showed the highest value, higher than the control increased 10.61%~25.16%. 5. Humic acid fertilizer can effectively increase the nitrate reductase activity and root activity of tobacco plant. 6. The field trial results showed that humic acid fertilizer could significantly promote the growth and development of tobacco plant. In the exuberant period, In terms of plant height and stem diameter, Administration of 1818 kgï¹’hm-2 humic acid fertilizer increased 23.64% and 16.50%. Flue-cured tobacco mature stage, leaf area increased by 26.55%. Humic acid fertilizer treatment of flue-cured tobacco yield and value have improved significantly,the proportion of fine tobacco increase 19.08 percent.In summary, the application of an appropriate amount of humic acid fertilizer not only reduces soil bulk density and soil pH, but also effectively improve soil enzyme activity and soil available nutrients, improve soil fertility, increase photosynthetic characteristics of tobacco, increased root activity, promote flue-cured tobacco growth and development of tobacco plants, increase production output. 50 g/plant was the best.