The effect of phosphorus and zinc applied with humic+fulvic acid on growth and mineral nutrition of wheat grown in calcareous soil

This study was conducted to evaluated humic+fulvic acid (HFA), phosphorus (P), and zinc (Zn) effects on wheat yield parameters and nutrient uptake through two-year field experiments. The experiment used randomized complete block design with split-split plot arrangement and three replications. Three factors with three doses were applied: HFA (0, 5, 10 kg/da), P (0, 4, 8 kg/da), and Zn (0, 1, 2 kg/da). Phosphorus applications increased grain, straw, and biomass yields, with highest yields of 187.2, 906.4, and 1093.5 kg/da in P8 application. 5 kg/da HFA and P8 applications positively affected yield parameters including tiller number, thousand grain weight, plant height, spike length and weight, and grain weight per spike. Plant nutrient analysis revealed P-Zn antagonism, with plant and straw Zn concentrations showing 21.8% and 6.72% decreases in Esperia variety with increasing P doses. Phosphorus-Zn antagonism reduced efficiency of both elements without HFA, while this interaction was balanced with HFA; 13.33% and 25% increases in plant P content were achieved with HFA. Phosphorus application increased total Zn uptake due to increased biomass (13.40 and 17.20 g/da for P0 and P8, respectively). Humic+fulvic acid applications had variable effects on nutrient contents and provided positive contributions, especially in micronutrient uptake. Significant differences were observed in yield parameters and plant nutrient concentrations with different HFA, P, and Zn doses. Humic+fulvic acid applications balanced P-Zn antagonism, making HFA5-P8-Zn1 combination optimal for yield, nutrient uptake, and cost efficiency. For wheat cultivation in calcareous soil, HFA5-P8-Zn1 represents a practical fertilization strategy.