施磷水平对菊芋块茎产量、品质、植株生理特性与磷利用率的影响

探究不同磷肥施用量对菊芋块茎产量、品质、植株理化特性及磷肥利用率的影响，为实现菊芋高产优质栽培和农田磷素高效利用与科学施磷提供参考依据。于2019-2020连续两年分别于河南省原阳县和方城县布置磷肥用量田间试验，2019年设0、60、120、180和240 kg P₂O₅·hm^-2 5个磷肥用量水平，2020年则分别设0、45、90、135、180和225 kg P₂O₅·hm^-2 6个施磷水平。研究磷肥施用对成熟期菊芋块茎产量、品质（菊糖、还原糖含量）以及营养生长和生殖生长期地上部植株磷素积累量、叶片绿原酸、SPAD值、可溶性糖、可溶性蛋白含量等理化指标的影响，计算分析菊芋收获指数、磷肥利用率和农学效率等肥料吸收利用状况。结果表明：磷肥供应均显著提高2019和2020年菊芋块茎产量，肥料效应呈“线性+平台”趋势变化，适宜施磷量分别为155和107 kg·hm^-2。此外，磷肥供应显著提高菊芋块茎菊糖和还原糖含量。与不施磷相比，2019-2020年度块茎总糖含量增幅分别平均为11.6%和18.3%。各生育期菊芋地上部植株磷素积累量、叶片绿原酸含量、SPAD值、可溶性糖和可溶性蛋白含量均随施磷量增加而明显提高。菊芋磷素收获指数（PHI）、磷肥利用率（AUP）和农学效率（AEP）均随着磷肥用量增加而明显下降，施磷处理两年平均PHI、AUP和AEP分别为0.813、15.1%和23.9 kg·kg^-1。因此，合理施磷可显著提高菊芋成熟期块茎产量、改善品质，增强各生育期生理活性。在本试验条件下菊芋适宜施磷量为105~150 kg·hm^-2。

Effects of P fertilization rate on tuber yield,quality,plant physiological attributes and P use efficiency of Helianthus tuberosus

This research aimed to provide reference data to promote efficient utilization and scientific management of phosphate （P） in farmland， and investigated the effect of P fertilization rate on Helianthus tuberosus tuber yield， tuber quality， plant physiological attributes and P use efficiency. Two field experiments were conducted over two consecutive growing seasons （2019-2020） at two sites （Yuanyang and Fangcheng County） in Henan Province， China. The details of the P fertilization treatments in the two growing seasons were as follows： 0， 60， 120， 180 and 240 kg P₂O₅·ha^-1 in 2019 and 0， 45， 90， 135， 180 and 225 kg P₂O₅·ha^-1 in 2020. The tuber yield， quality （inulin and reducing sugar content） at maturity and plant P accumulation， leaf chlorogenic acid content， leaf SPAD value， soluble sugar and soluble protein were determined. In addition， phosphorus harvest index （PHI）， apparent use efficiency of phosphorus （AUP， %） and agronomic efficiency of phosphorus use （AEP， kg·kg^-1） for H. tuberosus were also analyzed. The results indicated： 1） the application of P fertilizer significantly increased the fresh yield of H. tuberosus in both 2019 and 2020 growing seasons. An overall linear effect of P rate on tuber yield was observed with a yield step ［here say if it is a yield increase or yield decrease and at what rate of P fertilization it is seen］. The optimal P fertilization rates for the two growing seasons were 155 and 107 kg·ha^-1 for 2019 and 2020， respectively. Additionally， P application significantly increased the inulin and reducing sugar content of H. tuberosus tubers. Compared with the control treatments （0 kg·ha^-1） in the study， the average increase in the total sugar content was 11.6% in 2019 and 18.3% in 2020. 2） The plant physiological indicators， such as plant P accumulation， leaf chlorogenic acid content， leaf SPAD value， soluble sugar and soluble protein were increased with increasing P rate. 3） The PHI， AUP （%） and AEP （kg·kg^-1） were decreased with increasing the P rates. The values of PHI， AUP and AEP， averaged across P rates and for the two growing season were 0.813， 15.1% and 23.9 kg·kg^-1， respectively. Therefore， high rates of P fertilization in H. tuberosus significantly improved tuber yield and quality and enhanced the physiological and biochemical traits measured. Considering the yield and utilization efficiency of P fertilizer， the recommended P application rates for H. tuberosus， based on this experiment， are between 105-150 kg P₂O₅·ha^-1.