The theoretical and actual yield of winter barley as a parameter of rational fertilization
1990
Spaldon, E. | Havelkova, I. (Vysoka Skola Polnohospodarska, Nitra (CSFR))
In the evaluation of the rationalization of fertilization, an important role is played by the actual natural output (ANO) and its theoretical level (TNO) as parameters of exploitation of the supplied NPK nutrients by the stand. The authors developed a criterion for the purposes of this study by which the ANO should be at least 130 per cent of the TNO. For a three-year period (1986 to 1988), the TNO for winter barley was calculated to be 25.2 kg (Borwina 24.4 kg, Ermo 25.9). The most important factors for the development of the values of TNO and mainly ANO are the intensity of fertilization and the weather conditions in the given years. The effect of sowing rate and the properties of varieties upon both ANO and TNO is much smaller. The TNO is comparatively stable, unlike the ANO; it is less dependent on the cultural practices, varieties and the year. The correctness of fertilization and the fertilization demand were confirmed on the basis of the chemical soil analyses, with respect to the required ANO values which are high above the level of 130 per cent of TNO if the year is favourable.
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