Effects of different sources of organic matter on soil aggregate formation and stability: A laboratory study on a Lithic Rhodoxeralf from Turkey

In this study the influences of three different organic sources on aggregate formation and stability in soil were investigated.Our approach involves establishing plot experiment in the greenhouse with a Lithic Rhodoxeralf and a variety of carbon sources having specific chemical properties applied to the soil of individual plots. Treatments include K-Humate (KH, 25, 50 and 100 kg/ha), Concentrated Plant Extract (CPE, 50, 100, 200 kg/ha) and Molasses (M, 50, 100, 200 kg/ha). After a seven-month incubation period, aggregate formation and their stability were determined and their correlation to different C sources was developed.The effect of KH on aggregate formation was significant for 2–1 mm aggregates (P < 0.05) and 0.5–0.25 mm aggregates (P < 0.01). The effect of CPE on aggregate formation was significant for 0.5–0.25 aggregates (P < 0.05), while the M had no significant effect on aggregate formation in any aggregate size. The effect of KH on aggregate stability was significant for 8–4 mm and 1–0.5 mm aggregates (P < 0.01). The effect of CPE on aggregate stability was significant for 0.5–0.25 mm aggregates (P < 0.05), while the M was significant for 8–4 mm aggregates (P < 0.05).