Effect of Nitrogen Supply on Nutritional Status of Maize.

Up-to-date fertilizer recommendation systems are based not only on soil analysis but also on diagnostic plant analysis. Plant analysis provides information on many aspects of plant nutrition. This work aimed at providing data about the effect of nitrogen (N) supplies on the grain yield and nutrient concentrations in maize leaves at the beginning of tasselling as well as on interactions between nutrients, based on the result of long-term fertilization experiments carried out on Chernozem meadow soil. The experiments were set up with a total combination of 64 fertilizer treatments [4 N × 4 phosphorus (P) × 4 potassium (K)]. An increase in the nitrate (NO3) N reserves in the soil prior to sowing, according to the N application rate (0, 80, 160, 240 kg ha-1), resulted in higher grain yield and caused a rise in the leaf N and manganese (Mn) contents, and occasionally in the P and zinc (Zn) concentrations. The calcium (Ca), magnesium (Mg), and copper (Cu) concentrations of the leaf were influenced by the N supply in only 1 year, when the water supply was the best and the grain yield was the highest. At the beginning of tasselling, the satisfactory N concentration limit value at 95% of maximum of maize grain yield was 2.2-4.0%. Satisfactory N concentration was observed if the NO3-N content of the 0- to 60-cm soil layer prior to sowing reached 80-100 kg ha-1. Interactions were observed between the N concentration and the Mn, P, Zn, Ca, Mg, and Cu contents of the leaf. The changes caused by N supply in these element concentrations remained within the limits of satisfactory supplies. [ABSTRACT FROM AUTHOR]