Aggregate stability and carbon and nutrients distribution in an Acrisol under organic and mineral fertilization

Abstract

^{The aim of this work was to evaluate the effect of mineral and organic fertilization on the soil-water aggregate stability and on the distribution of C, N and P in different classes of aggregates in an Acrisol. The treatments were 0 and 40 m3 ha-1 per year of organic fertilizer and 0, 250 and 500 kg ha-1 of mineral fertilizer N–P–K of the formula 4–14–8. An area under Atlantic forest was used as reference. Soil samples were collected at 0–10 and 10–20 cm depths. The distribution of aggregates showed the highest values from 4 to 2 mm. In the organic fertilizer treatment, the aggregates 4–2 mm corresponded to 39.7% of the total on the soil. For the aggregates 4–2 and 0.105–0.25 mm, the total organic carbon contents were 17.5 and 36.7% higher in the organic fertilizer treatments. The organic fertilization contributed to values of N and P of 43 and 38.7% (0–10 cm) and 35.4 and 36.8% (10–20 cm), which were higher than the treatments without organic fertilizer. The carbon/nitrogen ratio did not vary among the aggregate classes in the same treatment. However, the carbon/phosphorus ratio was reduced with the use of organic and mineral fertilizer. The indexes of aggregates stability were positively correlated with the content of total organic carbon in the 4–2 mm.}