The effect of potassium and humic acid applications on yield and nutrient contents of wheat (Triticum aestivum L. var. Delfii) with same soil properties

This study was conducted in the farmer field between the years 2014 and 2015. In this study, 3 doses of potassium (K) (0, 10, and 20 kg da−1) of K2SO4 (50% K2O) fertilizer and 3 doses of humic acid (HA) (0, 20, and 40 kg da−1) (85% HA) were used. Increase in the HA dose reflected significant effects on pH, salt, organic matter, phosphorus, magnesium, iron, and manganese contents of the experiment area at p < .01 level. It was determined that increased potassium applications affected the salt, magnesium (Mg), iron (Fe), and copper (Cu) contents at p < .01 level. Increased HA application on plant growth criteria had a significant effect on biological yield, grain yield, and harvest index (p < .01). However, K did not reflect any effect on the growth stage of wheat. Increased number of HA applications on grain and straw nutrient content were found to have significant (p < .01) effects on P, K, Ca, Mg, Fe, and Zn. Increased potassium applications had an effect on the P, K, Mg, Fe, and Zn contents with a significant level (p < .01). It was observed that HA applications were more effective than potassium applications on both general soil properties and yield and nutrient content.