施加生物炭基磷肥对西北针茅光合—荧光特性的影响

Effects of biochar-based phosphate fertilizer on photosynthetic and fluorescence characteristics of Stipa krylovii

施肥是退化草原恢复的重要手段,但生物炭基磷肥在天然草地改良中少有研究。本研究以西北针茅(Stipa krylovii)为研究对象,设置6种施肥处理:对照(CK)、磷酸二铵(D)、生物炭(B)、低量生物炭基磷肥(LBD)、中量生物炭基磷肥(MBD)和高量生物炭基磷肥(HBD),测定其分蘖数、生物量、光合-荧光参数指标。结果表明:HBD处理下,西北针茅分蘖数显著多于CK和D处理(P<0.05)。HBD、MBD和LBD处理下,西北针茅生物量显著高于CK处理(P<0.05)。HBD、LBD处理的相对可变荧光、初级醌受体(QA)被还原速率值显著低于CK处理(P<0.05),而HBD、LBD处理的光化学性能指数、电子传递速率值显著高于CK处理(P<0.05)。HBD处理的净光合速率、蒸腾速率和水分利用效率呈升高趋势。主成分分析表明,光化学性能指数、QA被还原速率是反映生物炭基磷肥施用效果的重要光合生理指标。综合评价表明,HBD和MBD混合施肥处理施用效果最佳,对西北针茅光合-荧光特性具有积极的影响,促进了西北针茅的生长,对以西北针茅为建群种的退化草原的恢复有积极作用。

Fertilization is an important tool for the restoration of degraded grasslands,but biochar-based phosphate fertilizer is rarely studied in the improvement of natural grassland.In this study,we used Stipa sareptana var.krylovii as the project;six fertilization treatments were set up:Control(CK),diammonium phosphate(D),biochar(B),low application rate of biochar-based phosphate fertilizer(LBD),medium application rate of biochar-based phosphate fertilizer(MBD),and high application rate of biochar-based phosphate fertilizer(HBD),and determination of S.sareptana var.krylovii tiller number,biomass,and photosynthetic-fluorescence parameters.The results showed that the number of tillers in S.sareptana var.krylovii under HBD treatment was significantly higher than that in CK and D treatments.The biomass of HBD,MBD,and LBD treatments was significantly higher than that of the CK treatment.The relative variable fluorescence and primary quinone receptor(QA)reduced rate values of HBD and LBD treatments were significantly lower than those of CK treatment(P<0.05),and the photochemical performance index and electron transfer rate values of HBD and LBD treatments were significantly higher than those of CK treatment(P<0.05).The net photosynthetic rate,transpiration rate,and water use efficiency of HBD treatment showed an increasing trend.Principal component analysis showed that the photochemical performance index and QA reduced rate were important photosynthetic physiological indicators that demonstrate the response to the effect of biochar-based fertilizer application.The results of the comprehensive evaluation showed that the best effect on the photosynthetic-fluorescence characteristics of S.sareptana var.krylovii were attained via HBD and MBD treatments,which promoted the growth of S.sareptana var.krylovii,and had a certain positive effect on the restoration of the degraded grassland.Thus,taking S.sareptana var.krylovii as the constructive species the significance and application value of biochar-based phosphate fertilizers for improving the productivity and ecological function was demonstrated.