Vesicular arbuscular mycorrhizae-mediated uptake and translocation of P and Zn by wheat in a calcareous soil

Abstract

Vesicular-arbuscular mycorrhizae (VAM) have been credited with improving the growth and mineral nutrition of many host plants but these effects are moderated by soil factors and nutrient balance. We investigated the combined effects of VAM, zinc and phosphorus application on the growth, uptake and translocation of nutrients in wheat using a calcareous soil marginal in P and Zn. Wheat was grown in a growth chamber under various combinations of VAM, P and Zn with measurements done at heading stage and maturity. Vegetative dry matter accumulation was increased by P additions and reduced by VAM infection. Both P addition and VAM infection increased grain yield. Zinc concentration and uptake were generally reduced by P additions and VAM infection. There was an absence of antagonistic effects of Zn additions on P concentration and uptake. In contrast, VAM infection had both positive and negative effects on P uptake depending on the growth stage and translocation of nutrients. We observed that in calcareous soils where the Zn and P fertilizer combinations were adequate for growth, the role of VAM in enhancing the translocation of Zn and P from root and straw to grain is beneficial towards seed set and yield. Key words: VA mycorrhizae, P and Zn fertilization, calcareous soil, wheat, yield, nutrient acquisition, translocation