Objectives Improving Zn utilization efficiency for crops using arbuscular mycorrhizal symbiosis is one of the effective ways for alleviating the antagonism of zinc and phosphorus. It is well established that simultaneous application of Zn and phosphorus (P) fertilizers has antagonistic effects on plant Zn uptake. Arbuscular mycorrhizas (AM) can improve plant Zn and P uptake. We conducted screenhouse experiment to test the effect of different levels of P in conjunction with mycorrhizal colonization on plant nutrition and biomass.
Methods A pot experiment was conducted with maize as the host plants in soil and three levels of phosphorus (0, 200 and 400 mg/kg), two levels of zinc (0 and 5 mg/kg) application, which included inoculation and inoculation. A total of 12 treatments were designed with 4 replicates. Plant biomass, Zn and P contents, mycorrhizal colonization after fifty days were measured.
Results Colonization by AMF and the application of phosphorus increased maize plant biomass significantly. Under the condition of no zinc application, the biomass of shoots and roots of maize were respectively increased by 6.67 times and 9.30 times when the application of phosphorus increased from 0 to 400 mg/kg, no matter inoculating AMF or not. When supplying zinc 5 mg/kg and P 200 mg/kg, the mycorrhizal inoculation increased the uptake and concentration of phosphorous in maize roots by 110% and 55% respectively, increased zinc uptake in roots and shoots by 71% and 68% respectively. Without Zn application, the zinc contents of maize plants were gradually decreased with the increasing of P application levels. When P application level was increased from 0 mg/kg to 200 mg/kg, the Zn content in maize shoot was decreased by 36%, while that was increased by 35% after the inoculation of AM fungi. When the phosphorus application level was as high as 400 mg/kg, inoculation of AM fungi was unable to influence the contents of Zn and P in maize plants significantly.
Conclusions Mycorrhizal inoculation could relief the antagonistic effect of phosphorus on zinc uptake of maize to some extent.
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