The nitrogen utilization of two maize hybrids (Pioneer 3732 and Volga) of similar yield potential was studied under greenhouse conditions. In a three-year model experiment, plants were grown in pots filled with 40 kg dry clay soil. 150 mg N/kg soil was applied as NH4Cl or KNO3, besides PK base fertilisation. In the first two experimental years, 15N-labeled N-sources (5 atom% 15N) were also applied to study the utilization of different N-forms. Volga showed a more favorable response to nitrate-fertilization in terms of grain yield production. The N-uptake of both hybrids was considerably higher from the NO3-N source than from the NH4-N source. The 15N-fertilizer utilization was higher with the application the NO3-N source. On average, it amounted to 48-62%, while only 32-54% was measured with the application of the NH4-N source.
Debreczeni, K. 2000. Applications in sustainable production: Response of two maize hybrids to different fertilizer‐N forms (NH4‐N and NO3‐N). Communications in Soil Science & Plant Analysis, 31(11-14): 2251-2264.