Crop yield on hydromelioration soil in dry and humid years

Climate characteristics and soil water regime as well as their variable and complex interrelation define the efficiency of plant production, since a large part of our plant production in concentrated in regions with periodical occurrence of drought and surplus of precipitation. Therefore agricultural production is very risky on developed/undeveloped areas, especially when surplus and/or deficit of precipitation occurs before or during the growing season. Investigations were conducted during years 2011 and 2015 at the experimental field in the central part of Croatia (45o34'46" N; 23o51'30" E), on soil type defined as hydroameliorated Gleyic Podzoluvisol. The trial involved four different drainpipe spacing variants (15 m, 20 m, 25 m and 30 m), set up in four replications, which are outflowed into the open channel (combined type of drainage). Variants covered areas from 1425 m2, 1900 m2, 2375 m2 and 2850 m2. As the trial crops were grown soybean and silage maize and the same agricultural practices were applied in all variants. In the dry year 2011 there were small differences in the yield of soybean in the examined variants of drainpipe spacing, the yield ranged from 2.40 t ha1 achieved on the variant with a distance between the drainpipes from 20 m up to 2.29 t ha1, achieved on the variant with the largest distance between the drainage pipes. Determined yields were not statistically justified (p = 0.05). In wet year 2015, there were differences in the yield of silage maize on the investigated variants of drainpipe spacing. The highest yield was achieved on the parcel of distance between the pipes of 15 m (40.25 t ha1), then on the parcel of distance between drainpipes of 20 m (39.06 t ha-1). There was no statistically justified difference between these variants, that is yields (p=0.05), but between these two variants and other variants there were justified statistical differences in yieldVytauto Didžiojo universitetasŽemės ūkio akademij