Original Articles: 2014 Vol: 6 Issue: 3
Improvement of alkaline tobacco field soil by humic acid
In order to control the alkalization trend of tobacco field soil of Chenzhou city in Hunan province and provide good soil environment for tobacco growth, humic acid was applied to a slightly alkaline soil in Wutong country to research its effects on tobacco soil and plants. The experiment results showed that: (1) Applying humic acid to slightly alkaline soil could reduce the pH value of tobacco field soil, but only when the addition amount was higher than 5 g/kg, the humic acid reduced the soil pH value significantly. However, it was not enough to apply humic acid only once to make the soil pH drop to the theoretically appropriate range (5.5-6.5). (2) Applying humic acid to slightly alkaline soil could improve soil fertility. Compared with untreated soil, application of humic acid at 10 g/kg increased the contents of available P, Mn, Cu, Zn and Fe by 87.7%, 52.0%, 88.3%, 45.2% and 74.0%, respectively, and the contents of Cu, Fe in tobacco leaves increased by 17.6%, 32.5%, respectively. (3) Compared with control, tobacco plant height, maximum leaf length, maximum leaf width and number of productive leaves had no significant difference after humic acid treatments. It indicated that applying humic acid to slightly alkaline soil did not have a negative impact on tobacco growth.