摘要： 采用田间小区试验方法,研究了不同钾肥施用量对露地秋季大白菜产量和硝酸盐积累及钾肥利用的影响。结果表明,大白菜施K2O 450 kg/hm²以下时显著增产,增产幅度达7.7%～10.3%,施K2O量在225 kg/hm²左右时大白菜产量最高;大白菜施钾总体上能降低可食部分硝酸盐含量,降低幅度在5.7%～21.9%;施用钾肥能显著增加大白菜外部莲座叶、内部黄白球叶(可食部分)及整个植株(莲座叶+黄白球叶)的干物质积累,施K2O量在150～300kg/hm²时大白菜干物质积累达到最高或较高水平;施用钾肥能显著增加大白菜外部莲座叶、内部黄白球叶及整个植株的钾素吸收,施K2O量在300 kg/hm²左右时大白菜钾素积累达到最高或较高水平;施K2O 300 kg/hm²以下时钾肥利用率较高(31.5%～61.2%),施K2O 225 kg/hm²以下时钾肥农学效率较高(42.8～105.5 kg/kg)。在本试验条件下,基于产量、干物质积累与分配、钾素吸收与分配、钾肥利用效率等的露地秋季大白菜适宜钾素(K2O)用量范围为225～300 kg/hm²。

关键词: 大白菜, 钾营养, 产量, 钾素利用

Abstract: This study was conducted to determine the effects of potassium levels on yield,nitrate and nitrogen utilization of Chinese cabbage under open vegetable field with relatively low soil potassium fertility level by the field experiment in He village,Zhonghan town,Gaoyi county in Hebei province.The results showed that significant increases in yield of Chinese cabbage at K2O rates below 450 kg/ha were found,and potassium application averagely increased yield of Chinese cabbage by 8.7%,with the highest yield at K2O rates of about 225 kg/ha applied.Potassium application averagely decreased contents of nitrate in Chinese cabbage edible parts by 12.9%.Distinct increases in biomass accumulation of rosette leaves,heading leaves and total plants(rosette leaves+heading leaves)by potassium application were observed,with respective average increases being 40.9%,21.2% and 28.9%,and the highest or relatively high biomass accumulation at K2O rates ranging from 150 to 300 kg/ha applied.Obvious increases in potassium uptake of rosette leaves,heading leaves and total plants by potassium application were found,with respective average increases being 49.7%,18.2 and 30.8%,and the highest or relatively high potassium uptake at K2O rates of about 300 kg/ha applied.Relatively high recovery rate(31.5%-61.2%)of applied K2O below 300 kg/ha and agronomic efficiency(42.8-105.5 kg/kg)of applied K2O below 225 kg/ha was observed.The proper rate of K2O of Chinese cabbage based on yield,biomass accumulation and distribution,potassium uptake and distribution,and potassium use efficiency ranged from 225 to 300 kg/ha under this experimental condition.

Key words: Chinese cabbage, Potassium levels, Yield, Potassium utilization

中图分类号: 

• S143.3