Effect of Soil Texture and Water Content on Growth of Hongda

Some morphological indices,root activity,and nitrate reductase(NR) activity of Hongda(a tobacco variety) leaf under the different soil types and water contents were investigated via the pot test.The result showed that the effects of soil texture and water contents on the plant growth was significant.The effect order was loamy soil sandy soil clay soil.The correlation between some morphological parameter,including plant height,stem perimeter and leaf number,and soil water contents was not significant.A quadratic curve was obtained between root vitality or NR activity and soil water contents.The suitable relative water content of soil was listed as: 60%~63% for stretching root duration in loamy soil,67%~69% in sandy soil,and 60%~61% in clay soil;79%~80% for strong growth duration in loamy soil,83%~85% in sandy soil,and 73%~75% in clay soil;and 74%~76% for mature duration in loamy soil,77%~78% in sandy soil,and 71%~72% in clay soil.