Effects of Differentiated Levels of Nitrogen Fertilization and the Method of Magnesium Application on the Utilization of Nitrogen by Two Different Maize Cultivars for Grain

摘要

A field experiment was carried out at the Didactic and Experimental Farm in Swadzim near Poznan in 2004-07. Two maize cultivars were studied, six nitrogen doses and magnesium doses. The effects of the mentioned factors exerted on the utilization of nitrogen from the applied mineral fertilizer and on the nitrogen harvest index were studied. The impact of nitrogen fertilization on the mineral intake of traditional maize cultivars has been widely presented in national and foreign literature. However, there are a limited number of papers comparing the volume of mineral intake and use between the traditional and the "stay-green"-types of cultivars. Moreover, according to the "minimum" principle, the component most deficient in the soil determines harvest volume. Magnesium is obviously one of the ingredients whose deficiency has been found in most of the soils in Poland, and this justifies research focusing on improving the precision of the technology concerning "stay-green"-type maize cultivar fertilization with nitrogen and magnesium, including the environmental aspects. The hybrid LG 2244 "stay-green"-type utilized to a higher degree nitrogen from the applied mineral fertilizer and showed a higher nitrogen harvest index, as compared with a traditional hybrid cultivar: Anjou 258. Increasing levels of nitrogen fertilization decreased N utilization by the plants and the nitrogen harvest index. The application of 15 kg Mg·ha~(-1) both broadcast and in rows caused increased nitrogen utilization from the mineral fertilizer, which was distinctly shown by the smaller amount of N_(min) in the soil after the maize harvest.