水肥耦合对荒漠区煤矸石山蜀葵和沙打旺水分利用效率的影响

Effects of water and fertilizer coupling on water use efficiency of Althaea rosea(Linn.)Cavan and Astragalus adsurgens Pall.

为改善煤矸石山土壤水分和养分状况,提高景观生态型草本植物的水分利用效率,以蜀葵和沙打旺为试验材料,采用三因素五水平二次回归通用旋转组合设计,通过盆栽模拟试验研究了土壤相对含水量、施氮量、施磷量三者耦合对两种景观生态型草本植物叶片水分利用效率的影响,并通过模型寻优得出了最优水肥方案。研究表明:三因素对蜀葵叶片水分利用效率的影响顺序为土壤相对含水量>施氮量>施磷量,三因素对沙打旺叶片水分利用效率的影响顺序为土壤相对含水量>施磷量>施氮量;二因素耦合对蜀葵水分利用效率的影响不显著(P>0.05),但对沙打旺水分利用效率有显著影响(P<0.05),其顺序为水氮>水磷>氮磷;土壤水分条件是影响蜀葵和沙打旺叶片水分利用效率的首要因素,施氮对蜀葵更重要,施磷对沙打旺叶片水分利用效率的影响更大,蜀葵的水肥耦合优化方案为土壤相对含水量37.6%~40.9%,施氮量(纯N)153.1~178.5 kg·hm^(-2),施磷量(P_(2)O_(5))89.4~120.4 kg·hm^(-2);沙打旺的水肥耦合优化方案为土壤相对含水量69.0%~70.6%,施氮量(纯N)61.8~94.6 kg·hm^(-2),施磷量(P2O5)109.9~170.1 kg·hm^(-2)。

The purpose of this study was to improve soil relative water content and nutrient condition of coal gangue dump and water use efficiency of landscape ecological herbaceous plants.Althaea rosea and Astragalus adsurgens were used as experimental materials.Quadratic regression general rotation combination design of three factors and five levels was used in the pot experiment.The coupling effects of soil relative water content,nitrogen application,and phosphorus application on water use efficiency of two landscape ecotype herbaceous plants were studied and the prioritization scheme was obtained through model optimization.The study indicated that the order of three factors on water use efficiency of Althaea rosea leaf was:soil relative water content>nitrogen application amount>phosphorus application amount.The order of three factors on water use efficiency of Astragalus adsurgens leaf was:soil relative water content>phosphorus application amount>nitrogen application amount.The coupling of two factors had no significant effect on water use efficiency of Althaea rosea(P>0.05).The coupling of two factors had a significant effect(P<0.05)on water use efficiency of Astragalus adsurgens,with the order:water nitrogen>water phosphorus>nitrogen phosphorus.Soil relative water content was the primary factor affecting water use efficiency of two plants.Nitrogen application amount was more important to water use efficiency of Althaea rosea while phosphorus application amount had a greater influence on water use efficiency of Astragalus adsurgens.The optimal water fertilizer coupling scheme of Althaea rosea was:soil relative water content 37.6%~40.9%,nitrogen application amount(pure nitrogen)153.1~178.5 kg·hm^(-2),and phosphorus application amount(P_(2)O_(5))89.4~120.4 kg·hm^(-2).The optimal water fertilizer coupling scheme of Astragalus adsurgens was:soil relative water content 69.0%~70.6%,nitrogen application amount(pure nitrogen)61.8~94.6 kg·hm^(-2),and phosphorus application amount(P2O5)109.9~170.1 kg·hm^(-2).