engleski

Potassium availability in hydromorphic soils of eastern Croatia

By our study 480 soil profiles were analysed which covered area of 31227 ha and they were divided in six soil types. This area was hydromeliorated in the period from 1978 to 1989. Plant availavle K was determined by Ammonium-Lactate method. One third of tested area (9989 ha or 32%) is low and moderate supplied (less than 10 mg K2O/100g). Especially a high frequency (near 50% or 4629 ha) of low K status was found on hypogley. We recommend an once application of 1000 kg K2O/ha for soils characterizing very low in K (less than 5 mg K2O/100g: about 7% of tested area) and 500 kg K2O/ha for soils low in K from 5.1 to 10.0 mg K2O/100g (about 25%). Amelorative fertilization with KCl up to 2670 kg K2O/ha for K-deficient drained gleysol were once applied. Maize yields (3-year means) were increased from 1.93 t/ha to 7.64 t/ha or four-fold. At the same time, a considerable improvement of K and Mg relationship in plants was observed.

soil test ; available potassium ; hydromorphic soils ; fertilization ; Croatia

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