Impact of biochar combined with nitrogen fertilization on soil structure stability of Fluvisol

Milena Mitova, Martin Nenov, Svetla Rousseva

Abstract: Field experiment with corn was carried out on sandy loam Fluvisol at the experimental field Tsalapitsa in the period 2019-2021, to study the modifications in soil structure stability under the influence of combined amendment of biochar of oak bark at 400o C (0, 10 and 20 t/ha) with nitrogen fertilization (130 and 260 kg/ha). Important and statistically significant increase in water-stable aggregates of size 3-1 mm in the soil layer 0-40 cm was found in both the second and third year of amending 5 t/ha of biochar with 130 kg/ha of nitrogen fertilizer. At his rate of nitrogen fertilization the introduction of 10 t/ha of biohar has a stronger effect in the second compared to the third year of its application. Similar relationships are observed at application of 260 kg/ha nitrogen fertilizer, but the effect of biochar was significant only in the third year of introduction 5 t/ha. The water resistance of the soil structure assessed by the water resistance index (Sd/Sw), shows similar trends as he rest of the studied structural indicators.

Keywords: biochar; Fluvisol; nitrogen fertilization; soil structure; water stability of soil aggregates

Date published: 2022-12-08