Distribution and movement of plant available forms of nitrogen in soil for maize during spring time
1997
Bizik, J. (Vysoka Skola Polnohospodarska, Nitra (Slovakia))
The relations among the content of nitrogen forms in the soil profile of orthic luvisol, nitrogen uptake by maize and yield of grain were studied in field experiments. The results of nitrogen content in soil before sowing of maize and in May and June were used to determine the limits of N(min) in 0 to 0.6 m soil layer in yield generation. Further mineralizable nitrogen and nitrate in soil solution were observed. Mineralization of nitrogen was evalued by means of three analysis of soil: 1. N(min) in wet soil immediately after sampling, 2. N(min) in dry soil, 3 N(min) in soil after incubation of soil - 1 % K2SO4 suspension for 20 h and 80 degrees C. For higher levels of grain yields, in May and June the N(min) content in 0 to 0.6 m soil layer should be 15 to 20 mg N.kg-1. The values of N(min) below 6 mg N.kg-1 evidently result in decreased yields. Nitrogen uptake is in close relation to the content of N(min) in soil during spring time and to the yield.
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