Original Articles: 2014 Vol: 6 Issue: 3
The effects of soil pH on tobacco growth
A pot experiment was carried out to study the effects of different soil pH values (7.0-9.0) on the nutrient absorption, agronomic traits, and chemical component levels of tobacco leaves. The results showed the following information. (1) The pH of the tobacco field soil affected its fertility. Increasing pH values caused small increases in the level of alkaline hydrolyzable N (Ah-N) and significant increases in the amount of available P (AP), available K (AK), available Fe (AFe), available Zn (AZn), and available Mn (AMn) in the soil. Higher soil pH also caused small increases in the levels of N and P, small decreases in the levels of Ca, Mg, Zn and significant decreases in the levels of Fe and Mn in the tobacco leaves. (2) Soil pH values affected the growth of the tobacco plants in the soil; excessively high pH values significantly decreased the single-leaf dry weight. (3) Soil pH also affected the quality of the tobacco leaves. The Cl-, nicotine, and the difference between the amount of total sugar and that of reducing sugar (DBTR) levels all increased with increasing pH values. When the soil pH reached 8.6, the Cl- content exceeded the optimum range (0.3%-0.8%). When the soil pH reached 9.0, DBTR level exceeded 5%.