宜章县植烟土壤养分变化趋势分析与适宜性评价

Changing Trend and Applicability of Tobacco-Grown Soil Nutrients in Yizhang

在湖南省宜章县南部烟区采集37个耕层植烟土壤样品,在实验室经自然风干等预处理后,采用凯氏法、钼锑抗比色法、火焰光度法等测定了土壤p H值以及有机质、大量元素、中量元素、微量元素及重金属铅、镉、砷等含量,并采用赵松义等制定的湖南省植烟土壤养分分级标准、国家土壤环境质量二级标准和土壤综合肥力指标值评价了该县植烟土壤适宜性等级。结果表明,宜章县植烟土壤综合肥力较高的占26.47%,中等肥力的占55.88%,肥力较低的占17.65%;该县植烟土壤大部分偏碱性,土壤有机质、交换性钙、有效硫、有效铁、有效铜整体含量水平较高;速效钾、有效硼、有效钼含量普遍较低;而土壤有效磷、交换性镁、有效锰、有效锌、水溶性氯的空间差异较大。建议该区域在烟叶生产过程中,应该根据土壤养分的丰缺状况平衡施肥,合理进行土壤改良。

In this study, 37 samples of the tobacco-grown topsoil in the tobacco253 area south of Yizhang County in Hunan Province were determined on physicochemical properties with Kjeldahl method, Mo-Sb colorimetric method and flame photometry, and evaluated on soil applicability with Hunan tobacco-grown soil nutrient classification standard, the state soil environment quality secondary standard and soil integrated fertility index. The results showed that 26.47% of the tobacco-grown soil samples were at high comprehensive fertility, 55.88% at the medium fertility and 17.65% at the low fertility; most of the soil samples were slight alkaline; the content of organic matter, exchangeable Ca, available S, available Fe and Cu in the soil samples was relatively high; the content of available K, effective B and Mo in the soil samples was generally low; and there were obvious spatial differences in the soil available P, exchangeable Mg, effective Mn and Zn, and water-soluble Cl. So it was suggested that balanced fertilization should be practised based on actual conditions of soil nutrient abundance or deficiency, and soil improvement should be conducted reasonably for tobacco production in the area.