Effects of Drip Irrigation and Top Dressing Nitrogen Fertigation on Maize Grain Yield in Central Poland

Maize is a plant of a global cultivation range and great economic importance, which is mainly due to its high yield potential and versatile use as food, fodder, and energy source. To evaluate the effects of drip irrigation and nitrogen fertigation on maize growth in light soil in the climate conditions of Central Poland, a field experiment was carried out in 2015–2017, as a dependent split-plot design with four replications. Two factors were used: I. drip irrigation (W0—no irrigation, W1—optimal irrigation, ensuring 100% coverage of the water needs of maize during the period of increased water needs), II—method of top dressing application of two doses of nitrogen 2 × 40 kg·ha−1 (T—traditional application as broadcasted urea, F—fertigation with the use of a 6% aqueous solution of urea). The results presented in the paper concerning the absolute, relative and unitary average increases in corn grain yields under the influence of drip irrigation indicated the potential for increasing significantly the productivity of corn under the condition of optimizing the water factor. The average yield increase was 2.35 t·ha−1, varying depending on rainfall pattern: in the dry season it was 4.79, and in the wet season 1.03–1.22 t·ha−1. The application of top-dressing nitrogen fertigation resulted in a significant increase in the yield of maize grain in relation to the traditional method of nitrogen fertilization. Drip irrigation and fertigation are treatments that, ensuring the stability of maize yield over the years, contribute to an increase in plant yield by approximately 25% on average, and over 80% in the dry seasons.