Abstract:
Objective This study analyzed the content of soil chlorine (Cl) and the leaf Cl risk in order to provide a scientific basis for fertilization in the tobacco area.
Method Based on 2059 soil sampling points in the tobacco growing area of Bijie, the spatial distribution characteristics of soil Cl− content and tobacco chloride risk were studied by classical statistics and geo-statistics methods.
Results The results showed that the average content of soil Cl− was 29.4 mg kg−1. The area without Cl risk of leaf (20 ~ 30 mg kg−1) accounted for less than 12.2%, that with the 2nd level of low Cl risk (< 10 mg kg−1) accounted for 40%, and the total proportion of the area with low Cl risk level (10 ~ 20 mg kg−1) was more than 60%. The area with high Cl risk accounted for 26.3% of total area. Among the counties, the content of soil Cl− in Zhijin was low, while that in Qixingguan district was the highest. Among all soil types, Purple soil and Lime soil had large areas of low Cl risk, while Yellow Brown soil and Coarse Bone soil had had large areas of high Cl risk. The soil derived from shale and carbonate had higher risk of lower Cl of tobacco leaves, while the soil derived from basalt and sandstone had higher risk of high Cl of tobacco leaves. The area with low Cl risk was mainly distributed in the southern and eastern regions, while that with high Cl risk was mainly distributed in the western and northern regions of Bijie.
Conclusion There is a strong spatial variability of soil chloride ion in the tobacco growing area of Bijie, and the risks of low Cl and high Cl in tobacco leaves exists together. The Cl fertilizer application scheme at regional level should be scientifically formulated according to the Cl risk level of tobacco leaves.