Nitrogen application in wheat growing on the basis of nitrate determination in the soil by the N-min method
1990
Malesevic, M. | Bogdanovic, D. | Spasojevic, B. (Poljoprivredni fakultet, Novi Sad (Yugoslavia). Institut za ratarstvo i povrtarstvo)
Over a four-year period, 126 trials were conducted on the chernozem soil, in different locations. Before the beginning of the vegetation seasons, in February and March, the contents and distribution of NO3-N and NH3-N were analyzed in 30-cm soil layers to the depth of 120 cm. Correlations were calculated annually between the content of NO3 in the soil and the maximum N dose from mineral fertilizers. The results showed that the level of grain yield in wheat, as well as the amount of N fertilizer for top-dressing, depended on the sum of NO3-N in the soil layer 0-90 cm. The effect of year as a factor was manifested in different ways; through the amount and distribution of NO3-N in soil profile, the dynamics of wheat roots growth and the amount of NO3-N to be mobilized in the soil to the end of vegetation season. Deviations of the actual results from the regression line resulted from different varieties in the trials, different sowing dates, etc. The regression equation y = 146.51 - 0.721 x, where y = N from fertilizer and x = NO3-N in the soil, is applicable for the calculation of N nutrients to be used in wheat growing.
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