岩溶区坡耕地烟水配套工程水肥差异性管理研究：钾素评价

Differentia Management of the Fertilizers and Water Applied in Water-tobacco Project on Slope Lands of Karst Region:Evaluation on Potassium

基于岩溶区水平梯田植烟土壤pH、温度、水分饱和度的原位测量和土壤、烟株钾素的分析,运用烟地土壤钾和优质烟叶钾临界值法,评价了烟水配套工程水肥措施与烟叶品质的关系。结果表明,不同坡位的植烟土壤保水能力不同,表现为坡下>坡中>坡上;土壤中全钾含量差异不显著,但有效钾含量差别较大,坡下表土最高,为188 mg/kg。烟叶中钾含量为7.4～31.9 g/kg,坡下>坡中>坡上,仅坡下烟叶钾高于20 g/kg。可见,岩溶区坡耕地烟水配套工程,宜根据岩溶区坡耕地保熵保肥能力的异质性,实行差异性水肥管理,此可能有助于保证烟叶品质的一致与提高。

Water-tobacco project program was carried out in karst region of Southwest China,at Bijie Prefecture as one of important tobacco production areas of Guizhou province.To evaluate fertilization and watering in water-tobacco project on level terraces of karst region and their effects on quality of tobacco leaves through threshold methods of potassium requested for soil and tobacco,soil pH,soil temperature and water saturation were tested in situ,and potassium elements of soil and tobacco were analyzed.The results showed that the soils on different sections of slope farmlands had differential water storage ability,following the order： lower slopemiddle slopeupper slope.There were not evident differences in total potassium contents of soils among three sections of a slope,but great differences in available potassium contents existed,up to 188 mg/kg in topsoil of lower slope.Potassium contents in tobacco leaves varied from 7.4-31.9 g/kg,more than 20 g/kg only in tobacco leaves from lower slope farmlands,following the order： lower slopemiddle slopeupper slope.So,differential managements of fertilization and watering are proposed to improve quality of tobacco leaves for water-tobacco project conducted on slope farmlands of karst areas due to their heterogeneity in keeping entropy and fertilizers.