soil amendment

biochar application

biochar addition

biochar soil

biochar amendment

aggregate stability

effects biochar

Soil & Tillage Research

• Biochar generally improved soil aggregation by 16.4 %, regardless of biochar/experimental/soil conditions. • Soil aggregation increased gradually with the rate of biochar increased. • Wood biochar and higher pyrolysis temperatures had the highest effect on aggregation. • Wet sieving method is more prominent than dry sieving for assessing soil aggregation. • Biochar additions increased soil aggregation in neutral and acidic soil but did not in alkaline soil. Biochar as a potential soil amendment has been widely used in agricultural soils for improving soil physical properties. However, the effects of biochar addition on soil aggregation are inconsistent in many individual studies. Therefore, we conducted a meta-analysis of 641 comparisons from 119 published studies to assess the combined effects of biochar application on soil aggregation through biochar attributes, initial soil properties, and experimental conditions. Overall, our results indicate that biochar application significantly improved soil aggregation by 16.4 ± 2.5 %, regardless of biochar/experimental/soil conditions. The response ratio (ln R ) of biochar-induced soil aggregation had significant variability across different studies. In the context of biochar attributes, there was a higher favorable influence of wood biochar with higher pyrolysis temperature (> 600 °C). With the amount of biochar increased, the effects of biochar on soil aggregation significantly improved ( P < 0.001). Considering experimental conditions, the advancement of soil aggregation was more significant over a longer period of time (> 3 years). In particular, the wet sieving method (18.2 %) is better than the dry sieving method (4.05 %) for assessing soil aggregation. Moreover, soil aggregation intensified in neutral and acidic soil, while alkaline soil was not significantly changed. Also, biochar amendment strengthened soil aggregation in the loam-textured (19.9 %) soils relative to sandy soils (13.4 %). Our meta-analysis demonstrates that biochar as a soil amendment can impro...

Does biochar application improve soil aggregation? A meta-analysis