云南牟定主要植烟区土壤肥力评价

Comprehensive Evaluation of Soil Fertility in Mouding Tobacco-Growing Areas of Yunnan Province

[目的]查明云南省牟定县主植烟区的土壤肥力状况，为土壤改良和烟草平衡施肥提供理论依据。[方法]对该县的3个主植烟区120个土壤样品养分进行检测分析。[结果]牟定植烟土壤平均pH为6．05，处于弱酸性至中性范围；有机质含量为11．10～88．40g/kg，平均为37．67g/kg，含量较丰富；土壤速效氮含量为52．40～282．17mg／kg，基本处于中等偏上水平；速效磷含量为5．26～52．82mg／kg，整体处于中等至丰富水平，但不同地点差异较大；土壤速效钾含量为25．60～228．91mg／kg，基本处于低等水平；土壤交换性镁含量为37．00～868．09mg／kg，95．00％的土壤样品高于50mg／kg的缺镁临界指标；植烟土壤有效硼含量为0．14～1．27mg／kg，20．00％的样品低于缺硼临界值（〈0．50mg／kg）。土壤水溶性氯含量范围为1．30～68．24mg／kg，87．50％的土壤样品水溶性氯含量低于30．00mg／kg，基本处于适宜的范围内。l结论l牟定主要植烟区在平衡施肥时应注重控氮，增施磷肥和钾肥，补施有机肥、镁肥和硼肥。

[ Objective J The soil fertility situations were investigated to provide the theory basis on soil improvement and balanced fertilization in main tobacco-growing areas of Mouding Region, Yunnan Province. [ Method] 120 soil samples from 3 main tobacco-growing areas were an- alyzed. [ Resuh] The average pH was 6.05, which was in an appropriate amount for tobacco growth. The range of organic matter content was 11. 10 - 88.40 g/kg, and was rich in general. The contents of available nitrogen and available phosphorus were in the medium to high levels, reaching 52.40 - 282.17 and 5.26 - 52.82 mg/kg respectively. But the content of available potassium was 25.60 - 228.91 mg/kg, basically in the low level. The content of soil exchangeable magnesium was 37.00 - 868.09 mg/kg, and 95.00% of the samples was higher than the critical index（50 mg/kg）. The range of soil available boron content was 0.14 - 1.27 mg/kg, and 20.00% of samples was below the boron critical index （ 〈 0.50 mg/kg）. The range of water-soluble chloride content was 1.30 - 68.24 mg/kg, and 87.50% of soil samples was lower than the critical index （30.00 mg/kg）. [ Conclusion ] More attention should be paid in balanced fertilization in Mouding tobacco-growing are-as, which was controlling nitrogen fertilizer, supplying phosphorus and potassium fertilizer and increasing organic matter, magnesium, and bo-ron fertilizer.