The investigation object was to determine the dinamics of drainage discharge at the trial amelioration field "Jelensčak" - Kutina. The obtained results will be used to evaluate the efficiency of the tested drainage systems in regulating the water regime of pseudogley-gley soils.\nDynamics of drainage discharge during the 1995-1997 period was investigated in nine pipe drainage variants. The variants differ from one another in pipe spacing and in drainage trench backfilling.\nThe results obtained in all variants confirmed a strong interrelation between the dynamics of drainage discharge and soil water excess. Variants involving pipe drainage spacing of 15 m, 20 m and 25 m with gravel backfill of the trench did not give statistically significant differences in total drainage discharge in comparison with variants with identical spacing but without gravel backfill.\nStatistically significant differences in drainage discharge relative to other variants were recorded in the variant with pipe drainage spacing of 10 m without gravel backfill. This variant is also characterized by very good drainage discharge intensity: mean value = 0,377 l/s/ha and maximum value = 6,710 l/s/ha. In the variant involving shallow pipe drainage, 15 m spacing, with gravel backfill, very good intensity of drainage discharge was recorded, Medium discharge intensity amounted to ca. 0,213 i/s/ha while the maximum was 4,930 l/s/ha.\nThe lowest discharge intensity was determined in variants with pipe spacing of 20 m, and espetially 25 m, with no gravel backfill in the drainage ditch. The results point to the conclusion that priority should be given to shallow pipe- drainage, with 15 m pipe apacing and with gravel backfill of the drainage ditch, and to that with pipe spacing of 10 m without gravel backfill, to which deep vertical soil loosening must be applied.

drainage discharge; drainage intensity; pipe drainage; deep vertical soil loosening; drainage time

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia