不同品种莴笋对氮钾的响应

RESPONSE OF DIFFERENT LETTUCE VARIETIES TO NITROGEN AND POTASSIUM FERTILIZERS

通过盆栽试验研究了不同品种莴笋对氮钾的产量和品质响应。结果表明,莴笋产量以挂丝红>尖叶>润农>双尖>大白甲。增施氮肥、钾肥显著提高莴笋产量,氮增产效率在中N水平下大白甲最高,高N下双尖最高,钾增产效率以大白甲最大,双尖次之。在N15K15处理基础上增施氮肥和N20K10处理基础下增施钾肥显著降低5个品种莴笋产量。莴笋硝酸盐含量以尖叶>润农>双尖>大白甲>挂丝红。增施氮肥提高莴笋硝酸盐含量,N15K10处理莴笋硝酸盐含量则显著降低．莴笋的Vc含量以润农、挂丝红、大白甲为高;还原糖含量以尖叶最高,润农最低;氨基酸含量以润农最高,挂丝红最低。5个品种莴笋Vc、还原糖、氨基酸含量最高的施肥处理各异。不同品种莴笋中以挂丝红产量和品质较好,双尖、挂丝红、大白甲、尖叶获得高产优质的氯钾组合处理为N15K10,润农高产优质的处理为N20K10和N15K15。

A pot experiment was carried out to study the responses of different varieties of lettuce to nitrogen and potassium fertilization in their yield and quality. The yield of the varieties was in the order of Guasihong 〉 Tip 〉 Runnong 〉 Double-tip 〉 Dabaijia, and significant differences were observed between different treatments. N and K significantly increased the yield of all the varieties. Dabaijia had the highest N efficiency of yield improvement at a medium level of N, and Double-tip had the highest at a higher N level. The highest K efficiency in yield improved was found in Dabaijia, followed by Double-tip. The yield of the five varieties dropped by adding nitrogen in N15K15 or by adding potassium in N20K10. Nitrate concentration in lettuce leaf was in the order of Tip 〉 Runnong 〉 Double-tip 〉 Dabaijia 〉 Guasihong. Application of N increased nitrate concentration, and the extent of increase was the greatest in Dabaijia and Guasihong at N20K10. Nitrate concentration in lettuce leaf in N15K10 was markedly lower than in N15K5. Runnong, Guasihong and Dabaijia had higher vitamin C content. Tip had the highest content of reductive sugar, followed closely by Guasihong. Reductive sugar content was the lowest in Runnong. Of the five varieties, Guasihong was the best if both quality and yield were taken into consideration. The recommended combination derived from this study was N15K10 for Double-tip, Guasihong, Dabaijia and Tip and N20K10 or N15K15 for Runnong.