衡阳市烟田土壤养分丰缺指标研究及应用

Application of Soil Nutrient Plentiful-Lack Indexes in Tobacco Fields in Hengyang

采集了衡阳市737个烟田土样进行检测,分析表明:衡阳市主要烟区土壤速效养分比双季稻田土壤均有较大幅度的增加,其中速效钾增加了61.9%、有效磷增加了57.6%、碱解氮增加了6.4%,说明在烤烟栽培过程中磷肥、钾肥施用量较大,烤烟吸收利用较少,富集在土壤之中;依据烟田土壤养分平均值划定了6个丰缺指标,其中达到中、高等肥力水平的面积为4 707 hm2,占总面积的67.9%,说明衡阳市烟田的肥力水平较高,有利于发展烤烟生产,但是还要加强对32.1%的较低肥力水平以下的烟田的地力培肥;依据土壤丰缺分级指标制定了在不同的目标产量下的推荐施肥量检索表,同时制定了衡阳市主要烟区氮磷钾配方施肥量;该指标的制定反应了衡阳市烟田土壤养分的实际供给能力,为正确评价烟田肥力水平,指导大面积烤烟生产的科学施肥提供了参考依据。

737 soil samples from tobacco fields in Hengyang city were collected and analyzed in this study. The results showed that soil available nutrients in main tobacco field zones in Hengyang city were increased significantly compared with double-cropping paddy soil.Available K, available P and alkaline hydrolytic N increased by 61.9%, 57.6% and 6.4% respectively, which indicated that P, K fertilizers were applied in relatively large quantities, but only a little of them were absorbed by tobacco while most of them accumulated in the soil.Based on the average score of soil nutrients, six plentiful-lack indexes were identified. The area of the medium and high fertility level was 4707 hm^2, accounting for 67.9% of the total area, which showed that the fertility level of Hengyang tobacco fields was high and favored the development of tobacco production, but still we should enhance the soil fertility of the rest 32.1% tobacco fields of relatively low fertility level. According to plentiful-lack indexes, we made the identification key of recommended fertilizer rates under different target yields, and at the same time, worked out prescriptive fertilizer volumes of N, P, K fertilizers in Hengyang main tobacco zones. These indexes could reflect the actual supply capability of soil nutrients in Hengyang tobacco fields, and provide reference for evaluating the fertility level of tobacco fields correctly and guiding the scientific fertilization of flue-cured tobacco production in large scales.