Effect of Increasing Nitrogen and Phosphorus Fertilization Rates on the Micro-
and Macronutrient Contents in Wheat Grain Grown on Acid Soil

Veronica Tănase¹, Nicoleta Vrînceanu¹, Mihaela Preda¹,
Mihaela Costea¹, Patrick Ursan²

¹National Research and Development Institute for Soil Science,
Agrochemistry and Environment - ICPA Bucharest
²Agricultural Research and Development Station Livada

Keywords: wheat, nitrogen, phosphorus, micronutrients, macronutrients.

Abstract: Soil acidity is one of the main factors limiting wheat yield and grain quality, as it significantly impacts nutrient solubility, availability, root development, and nutrient uptake by plants. Understanding how fertilization practices interact with soil acidity is essential for sustainable crop production. This study aimed to investigate the influence of increasing nitrogen (N) and phosphorus (P) fertilization rates on the micro- and macronutrient contents of wheat grain grown on an acidic soil. The experiment was conducted under field conditions using a bifactorial design with five levels of nitrogen (0, 40, 80, 120, 160 kg/ha) and five levels of phosphorus (0, 40, 80, 120, 160 kg/ha). After harvest, the grain samples were processed and analyzed for their macronutrient (N, P, K, Ca, Mg) and micronutrient (Fe, Mn, Zn, Cu) contents. The results revealed that increasing N and P fertilization rates significantly influenced the mineral composition of wheat grain. Higher nitrogen rates (120 and 160 kg/ha) increased grain nitrogen content and enhanced zinc and manganese concentrations, indicating an overall improvement in nutritional quality. An increase in phosphorus supply commonly results in a corresponding decline in copper uptake, reflecting an antagonistic interplay between these elements. Phosphorus fertilization favored the accumulation of P and Mg in the grains, with higher phosphorus application rates leading to statistically significant increases compared to the control. These findings highlight the importance of balanced nitrogen and phosphorus fertilization in optimizing both yield and nutrient composition of wheat grain under acidic soil conditions. Proper nutrient management contributes not only to maintaining long-term soil fertility but also to enhancing the nutritional value and quality of wheat as a staple food crop.