Nitrogen Leaching in Different Pipe Drainage Distances
Ž. KLAČIĆ, D. PETOŠIĆ, L. ČOGA
Pages: 331-338
Summary
The investigation object was to determine the effect of different pipe drainage distances upon the concentration and quantity of nitrogen leached in crop production on hydromorphic soils of the central Sava River Valley. The obtained results indicate that abundant precipitation in the studied period had a decisive effect on the dynamics of nitrogen leaching in all trials variants. The overall drainage discharge in the investigated drainage variants ranged from 197 mm to 351 mm.
Average NO 3 -N concentrations in drainage water of all variants were below 10 mg/l, whereas maximum concentrations went up to 30 mg/l. NO 3 -N concentrations higher than 10 mg/l were recorded during rainy periods, after fertilizers was applied. Average NH 4 -N concentrations in drainage water of all variants were higher than 1,00 mg/l, while maximum concentrations went up to 8,65 mg/l. From the hygienic point of view, drainage water from all variants may be regarded as polluted and hence a potential factor of surface water pollution.
Significantly highest quantities of leached nitrogen were recorded in variants involving pipe-drainage distance of 10 m and 15 m. In these variants, leached nitrogen ranged from 20.553 kg N/ha to 21,688 kg N/ha. Between 11,031 kg N/ ha and 14,688 kg N/ha was leached in the variants with medium drain spacing (20 m and 30 m). About 56 % of total leached nitrogen originated from fertilizers added in basic and pre-seeding soil preparation.
Wheat yields obtained in variants were between 26,11 dt/ha and 40,85 dt/ha. The significantly highest yield was achieved in the variant involving pipe drainage spacing of 20 m with gravel backfill (40,85 dt/ha), which was also the variant with the lowest quantity of leached nitrogen.
Average NO 3 -N concentrations in drainage water of all variants were below 10 mg/l, whereas maximum concentrations went up to 30 mg/l. NO 3 -N concentrations higher than 10 mg/l were recorded during rainy periods, after fertilizers was applied. Average NH 4 -N concentrations in drainage water of all variants were higher than 1,00 mg/l, while maximum concentrations went up to 8,65 mg/l. From the hygienic point of view, drainage water from all variants may be regarded as polluted and hence a potential factor of surface water pollution.
Significantly highest quantities of leached nitrogen were recorded in variants involving pipe-drainage distance of 10 m and 15 m. In these variants, leached nitrogen ranged from 20.553 kg N/ha to 21,688 kg N/ha. Between 11,031 kg N/ ha and 14,688 kg N/ha was leached in the variants with medium drain spacing (20 m and 30 m). About 56 % of total leached nitrogen originated from fertilizers added in basic and pre-seeding soil preparation.
Wheat yields obtained in variants were between 26,11 dt/ha and 40,85 dt/ha. The significantly highest yield was achieved in the variant involving pipe drainage spacing of 20 m with gravel backfill (40,85 dt/ha), which was also the variant with the lowest quantity of leached nitrogen.
Keywords
Soil; nitrogen leaching; pipe drainage; distance; water pollution; drainage discharge
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