Effect of Application of Biochar and Wood Vinegar on Penetration Resistance and Structure Stability of Soil under Forage Corn Cultivation

The application of organic matter and soil conditioners is essential to maintain soil efficiency and achieve sustainable agriculture. The aim of this study was to investigate the effect of application of biochar and wood vinegar on penetration resistance and stability of soil aggregates under forage corn cultivation.

For this purpose, a study was conducted in greenhouse conditions at ShahreKord University. The experiment was performed as a factorial experiment in a completely randomized design with 30 treatments in 3 replications. The studied treatments included wood vinegar in 6 amounts of zero (W0), 0.02 (W1), 0.04 (W2), 0.1 (W3), 0.2 (W4) and 0.4 (W5) g/Kg (first factor) and conditioner including raw material (pomegranate and plum wood) in 2 levels 1 (B01) and 2 (B02) weight-weight percentage and biochar in 2 levels 1 (B1) and 2 (B2) weight-weight percentage (second factor) was applied. Soil penetration resistance of the undisturbed samples at 0, 10, 50, 100, 500, 1000 and 1500 Kpa matric suctions by penetrometer and mean weight diameter of aggregates by dry sieving was measured.

The results showed that the main effect of wood vinegar and conditioner (raw material (pomegranate and plum wood) and biochar) application and the interaction effect of wood vinegar and conditioner (raw material (pomegranate and plum wood) and biochar) application on bulk density and aggregate stability and soil penetration resistance at 0,10, 50, 100 and 500 Kpa matric suctions were significant at the level of 1%. The application of wood vinegar and raw material increased bulk density and aggregate stability that the highest aggregate stability was related to W2B2 treatment, which increased the stability of aggregates by150% of the control. Also the application of wood vinegar and raw material increased the reduction of soil penetration resistance. So that at 0, 10, 50, 100 and 500 Kpa matric suctions, the greatest decrease in penetration resistance was related to W5B2 treatment, which soil penetration resistance was observed in 81.7, 82.89, 86.89, 78.65 and 78.65% of the control.

Wood vinegar and biochar has high organic carbon, which is effective in increasing the aggregates stability and creating larger aggregates and increasing mean weight diameter of aggregates and the cause can be attributed to the increase of the bonding force between the aggregates by the compounds in organic matter. Also, biochar and wood vinegar reduced soil penetration resistance by increasing soil organic carbon and reducing soil bulk density.