Relation of soil water deficit, involved by precipitation and corn yield on Vinkovci area (Eastern Croatia)

Regime of water and moisture of loessive, semigley and hydromeliorated soil during two years in the Vinkovci area (Eastern Croatia) was investigated. Instantaneous soil moisture content was measured per decades during vegetat ion in the layer of 0-30 and 30-60 cm in a demolished sample condition and via metal cylinders after Kopecky. When we compared them (calibrating) sati sfying coincidence was achieved in a field and subfield layer expressed by high correlation coefficients (R=0.947**, R=0.862* in the first and R=0.933 **, R=0.986** in the second year) which confirms justification of soil samp ling in demolished soil sample condition by means of earth auger. Instantan eous soil moisture content was compared in relation to corn yield. The high est deficiencies were recorded in July and August when the corn is in the p retasselling/tasselling phase as well as in maize grain formation phase. Th ese water deficiencies had the highest influence on grain yield reduction w hich was in drier year at water deficiency during vegetation of 142.7 mm (J une and Jury 131.5 mm) on the average of 5.591 t ha(-1). In the second tota l water deficits during vegetation were considerably lower and amounted to 93.9 mm, which is significantly less than deficiencies monitored for many y ears' period for this region with significantly higher average corn yield o f 7.320 t ha(-1).