供氮水平对一串红‘橙香公主’生长和氮磷钾吸收的影响

Nitrogen nutrient solutions for growth of Salvia splendens 'Chengxiang Gongzhu' with N, P and K absorption

氮是影响园林植物生长发育和观赏品质的关键元素。以典型园林植物一串红Salvia splendens栽培型‘橙香公主’‘Chengxiang Gongzhu’为试验材料,设置0(N_0),5(N_1),25(N_2),50(N_3),100(N_4),150(N_5),200(N_6),250 mg·L^(-1)(N_7)等8个不同氮素水平,研究了不同氮营养液施用量对植株生长指标和养分吸收的影响。结果表明:在0~250 mg·L^(-1)范围内随着施氮水平的增加,株高、冠幅、地径、干物质质量和叶绿素质量分数出现先增加后减低趋势。其中株高、植株干物质质量均在N_5达到最大值,冠幅和地径、叶绿素质量分数均在N_6达到最大值。叶面积和根长随着施氮水平的增加而增加,根冠比先下降后趋于平缓。随着供氮水平的增加,‘橙香公主’氮吸收量逐渐增加,氮的吸收率呈先下降后上升波动趋势。随着供氮水平的增加,根、茎、叶、花部位钾养分的吸收比磷的吸收影响更为明显,其中对根和花中钾的吸收,以及对叶和花中磷吸收影响最为明显。综合研究结果表明,供氮水平为150~200 mg·L^(-1)最适合‘橙香公主’的生长发育。

Nitrogen is the key element for garden plant growth and ornamental quality . The research o f the ap-plication of nutrient solution is an important way to prohibit the improper nitrogen application. To study the ef-fects on the plant growth index and nutrient （P, K） absorption, a nutrient solution was applied to a typical gar-den plant Salvia splendens % Chengxiang Gongzhu＇. Eight different N concentration levels of 0, 5, 25, 50, 100, 150, 200, and 250 mg.L-1 （named N1 , N1 , N2, N3, N4, N5, N6 , and N7）, respectively, tions were conducted for each treatment. Duncan＆ s new multiple range test was used for the statistical s ignif i-cance test, with the significance level of P 〈 0.05. Results indicated that with an increasing N level, plant height, crown diameter, ground diameter, dry weight, and chlorophyll content f irs t significantly rose and then dropped. Plant height and plant dry weight reached a maximum with N5, and crown breadth, ground diameter, and chlorophyll content al l reached a maximum with N6. As N increased, leaf area and root length significantly increasing, but the root-shoot ratio f irs t dropped then began to flatten. ‘ Chengxiang Gongzhu’ N uptake also increased gradually; whereas, the N absorption ratio decreased sharply from N1 to N2 followed by fluctuations from N3 to N7. In al l plant organs （root, stem, leaf, and flower） , the addition of N influenced the K absorptionratio more than the absorption of P. The most obvious effects of adding N were on K absorption in roots and flowers, and P absorption in flowers and leaves. Based on this study, recommended N concentration levels be-tween 150- 200 mg.L-1 would be most suitable for the growth of ‘ Chengxiang Gongzhu’ .