Effect of nitrogen and potassium fertilization on micronutrient content in grain maize (Zea mays L.)

Abstract

A two-year small-plot field experiment with the grain maize hybrid KWS 2376 was conducted on heavy soil with a low supply of available nutrients incl. potassium (K) at Otrokovice, Czech Republic, during 2010–2011. The experiment included 4 treatments: unfertilized control; nitrogen (N) fertilisation with urea (120 kg N/ha) alone or combined with two forms of K fertiliser (potassium chloride (KCl) or potassium sulphate (K2SO4); 125 kg K2O/ha). Biomass samples for determination of Zn, Mn, Cu and Fe were taken as the whole aboveground biomass in the DC 32 (first node stage), the ear-leaf in the DC 61 (flowering stage) and grain during the harvest.Between the two years the content of micronutrients in the individual treatments varied irregularly. In DC 32 and DC 61 the order of the content of micronutrients was as follows: Fe > Mn > Zn > Cu. The Fe content was significantly the highest in the unfertilised control and the Mn content after the application of N + K2SO4 in both samplings. In the grain the order was as follows: Zn > Fe > Mn > Cu (mg/kg DM): at the following contents: Zn: 19.20–23.19; Fe: 15.12–19.87; Mn: 0.85–3.60; Cu: 0.19–1.34. We can recommend fertilisation of maize with urea and with both potassium mineral fertilisers without any negative effects on the content of the micronutrients in the maize biomass.

Keywords

• zinc
• manganese
• copper
• iron
• leaf
• plant