In-Soil Application of NP Mineral Fertilizer as a Method of Improving Nitrogen Yielding Efficiency.

This study presents the results of a four-year field experiment assessing the effectiveness of phosphorus application in maize cultivation according to the depth of two-component fertilizer (NP) placement in the soil layer, type of nitrogen fertilizer and date of application. Nitrogen utilization from mineral fertilizer was low—on average, 37.1% during the four years of research. The nitrogen metabolism index, measuring the agricultural and physiological efficiency of nitrogen use, confirmed the significant impact of NP fertilizer placement at 10 and 5 cm as optimal in maize fertilization. The use of nitrogen in maize cultivation before sowing, compared to the application of this component at the phase of 5-6 leaves BBCH 15/16 stage (stage of leaf development with five–six leaves unfolded), significantly increased the agricultural and physiological effectiveness of nitrogen applied in mineral fertilizer. Ammonium nitrate application before sowing the maize, compared to top dressing at the BBCH 15/16 stage, significantly increased nitrogen uptake and utilization from mineral fertilizer. Date of urea fertilizer application to the soil did not have a significant impact on these indicators in maize cultivation. [ABSTRACT FROM AUTHOR]