EFFECT OF LAND USE CHANGE ON THE STRUCTUREOF GLEYIC FLUVISOLS IN WESTERN SERBIA

Changes in land use can significantly affect aggregate distributionand water stability of structural aggregates. this study was conducted in thekolubara river valley, western serbia, to determine the effects of land usechanges on composition and water stability of aggregates in humus horizons(0–30 cm) of noncarbonated gleyic fluvisols. this study was conducted at ninesites, where each site contained two adjacent land uses of natural grassland andarable land which underwent crop rotation for >100 years. soil samples were takenfrom depths of 0–10, 10–20 and 20–30 cm for each land use. when the grasslandwas converted into arable land, the content of the agronomically most valuableaggregates (0.25–10 mm) of cultivated soils for a depth of 0–30 cm wassignificantly reduced by 22–40%, while the percentage of cloddy aggregates(>10 mm) increased by 41–68%, compared to grassland. in addition, the long-termarable soil had significantly (p<0.05) lower aggregate stability, determined by wetsieving, than grassland. the lowest aggregate stability was found in aggregates> 3 mm. their content is ≈ 2.3 times lower in arable soil (12.6%) than in grassland(28.6%) at a depth of 0–10 cm. in addition, meanweight diameters of dry and wetstableaggregates and structure coefficient showed significant differences betweenland use at a depth of 0–30 cm. the results showed that the conversion of naturalgrassland to arable land in the lowland ecosystems of western serbia degradedaggregate distribution and stability.