Enhancing the Agronomic Performance of Potassium Fertilizer and Potassium-Bearing Minerals in Sandy Loam Soil by Adding Humic Acids and Mycorrhiza

Abstract

Potassium (K) is a vital macro-nutrient needed for proper growth and development of plants. Therefore, the objective of this study is to evaluate the agronomic performance of potassium fertilizer and potassium-bearing minerals added with humic acids and mycorrhiza on wheat plant growth and nutrient uptake in sandy loam soil. The field experiment was conducted on low-potassium-content sandy soil. The sandy soil was treated with potassium sulfate (KS) or feldspar (FS) either alone or in combination with humic acid and/or mycorrhiza fungi. Applying KS and FS either alone or in combination with humic and/or inoculation with mycorrhiza significantly enhanced plant growth parameters (plant height, spike length, and weight of 100 seeds) and yield than those of control soil. Applying treatments significantly increased straw yield by 126-401%, grain yield by 155-806%, and total yield by 138-559% than those of control soil. From the obtained results, the treatments of mycorrhizal inoculation and humic acid significantly increased plant growth parameters, yield, and harvest index, but the mycorrhizal inoculation combined with humic acid had better effects in growth parameters, yield, biochemical properties (protein, carbohydrates, and total sugar content) and nutrients (NPK) uptake. It could be concluded that both humic acid and/or mycorrhiza increased the plant uptake of macronutrients in the experimental soil and improved soil productivity. Therefore, our findings suggest that the application of feldspar mineral combined with mycorrhiza and humic acid could be considered as an alternative and a replacement for K-mineral fertilizers in sandy soils.