Antagonistic effect of copper and zinc in fertilization of spring wheat under low soil phosphorus conditions

Abstract

Sound micronutrient management requires an understanding of nutrient interactions and transformation processes in soil-plant system which can regulate bioavailability and plant uptake. A series of studies was conducted under controlled environment and field conditions to evaluate wheat response to Cu and Zn fertilization on P deficient soils from western Canada. The grain and straw yields of wheat were reduced in two (Waskada and Tisdale) of three soils used in the controlled environment study, while yield was not affected at the Echo field site in 2016 when both Cu and Zn sulfate fertilizer were applied at 5 kg ha-1 rates. Zinc concentration in soil and plant tissues were increased to apparent toxic levels with fertilizer addition in Waskada soils. An imbalance in tissue P:Zn concentration related to micronutrient fertilization was observed in Waskada and Tisdale soils. The availability Cu and Zn in post-harvest soils was increased with increasing rate of these fertilizer addition. Chemical and spectroscopic speciation using sequential extraction and XANES respectively, revealed that Cu and Zn were mostly speciated as carbonate phases, and complexation of these elements with carbonate and phyllosilicate minerals is likely the process controlling bioavailability in the soils.

Trade-Off Strategy for Usage of Phosphorus Fertilizer in Calcareous Soil-Grown Winter Wheat: Yield, Phosphorus Use Efficiency, and Zinc Nutrition Response

“…Numerous studies have shown that due to P-Zn antagonism, P fertilizer application affects Zn uptake by crop roots and Zn translocation from vegetative organs to grains, thus significantly reducing Zn accumulation in aboveground organs and affecting grain Zn concentrations [26,27,46,47]. A field experiment conducted on calcareous soil showed that long-term P fertilizer application increased grain yield by 15%, but the grain Zn concentration decreased by 6.8-9.2 mg kg −1 per 100 kg P ha −1 application, with P application significantly reducing root mycorrhizal infection rates, thus affecting root Zn uptake [13,48].…”