土壤pH与烤烟钾素营养关系的研究

RELATION BETWEEN SOIL pH AND POTASSIUM NUTRITION OF FLUE-CURED TOBACCO

选择代表性的贵州植烟土壤，施石灰提高pH，施硫酸亚铁和硫磺粉降低pH，通过两年烤烟盆栽试验，研究了土壤pH对烤烟钾营养状况的影响。结果表明：土壤pH平均为5．33和6．1时烟叶产量较高。超出此pH范围，产量有下降趋势。pH低于5．0产量急剧下降。烟叶吸钾状况及施钾效果均以土壤平均pH5．33的最高；pH低于5．0及高于6．1对烟株的钾素营养都有不同程度的影响，以低pH对钾吸收的抑制作用最大。初步提出土壤pH5．0是烟株遭受Al3+毒害的临界值。

Pot experiment for studying the status of K nutrition of tobacco plants was carried out in 1995 and 1996 by liming or adding FeSO4 or sulfur powder to regulate the pH value of soils. The main results obtained are as follows:The average yield of tobacco leaves is higher in the soils with pH 5.33 or 6.1,but that is lower in the soils with pH above 6.1 or below 5.0.The absorbing capacity of potassium by tobacco plants and the efficiency of potassium fertilizer are highest in the soils with average pH 5.33, below or above this pH value the two indexes are lower.According to the study it is shown that the desirable yield of tobacco leaves with K content about 3.3% can be expected if tobacco is planted in soils with pH 5.33～6.1 range and N, P and K fertilizers is fully supplied. It is pointed out tentatively that soil pH 5.0 is a critical value that tobacco plants were injured by active Al.