文山植烟土壤有效锌含量及其影响因素研究

为探明文山烟区植烟土壤有效锌分布情况及其影响因素,并为烤烟合理施用锌肥提供理论依据,运用GPS定位技术采集了276份土样,测定其有效锌含量,采用经典统计学方法和GIS技术,对其基本特征、空间分布状况及影响因素进行了分析。结果表明:(1)文山烟区植烟土壤有效锌平均含量为1.93 mg/kg,变幅为0.20~8.17 mg/kg,变异系数为70.47%,属于中等变异强度。全烟区有70.12%的区域土壤有效锌在适宜范围内(1.00~5.00 mg/kg)。(2)县域间植烟土壤有效锌平均含量从高到低排序为:麻栗坡西畴县文山县马关县砚山县丘北县广南县。(3)土壤中有效锌含量随着有机质增加而增大,随海拔升高呈抛物线变化;不同海拔组和有机质组间有效锌含量差异均达极显著水平。有效锌含量在土壤p H为6.5~7.5时最低,在偏酸和偏碱的环境中含量较高。(4)文山烟区分布最广的是红壤,其次是黄壤。不同土壤类型有效锌含量差异达极显著水平,含量最高的是水稻土,最低的是紫色土。因此,文山烟区植烟土壤有效锌含量总体满足优质烟叶生产的需求,部分缺锌区域应加强锌肥、有机肥的施用以提高土壤中有效锌含量。

Distribution of Available Zinc in Tobacco-planting Soils in Wenshan and Its Influential Factors

In order to understand the distribution of available zinc in tobacco-planting soils in Wenshan and its influential factors and to provide a basis for the reasonable application of zinc fertilizer, 276 soil samples were collected with the help of GPS. Available zinc contents, spatial distribution and influential factors were analyzed by geostatistics method with geographic information system (GIS) and classical statistical method. The results showed that the average available zinc content ranged from 0.20 to 8.17 mg/kg, with a mean of 1.93 mg/kg and a variation coefficient of 70.47%. 70.12% of the soil samples were in the appropriate level (1.00–5.00 mg/kg), which was very fit for tobacco planting. Available zinc content was in an order of Malipo>Xichou>Wenshan>Maguan>Yanshan>Qiubei>Guangnan. Available zinc content increased with the increase of organic matter content, showed a parabolic trend with the increase of altitude. There were extremely significant differences in available zinc contents among the different altitude and organic matter grades. Available zinc content was lowest in pH of 6.5–7.5, and was higher in the acid and alkali soils. The most of tobacco-planting soil in Wenshan is red soil, followed by yellow soil. Available zinc content in different soil types existed extremely significant differences, zinc content was highest in paddy soil but was lowest in purple soil. So, available zinc content of tobacco-planting soils in Wenshan on the whole meets the requirement of high quality tobacco leaves, but the region with zinc deficiency should strengthen the application of zinc fertilizer and organic fertilizer to improve available zinc content in soils.