Anaerobic Digestate Administration: Effect on Soil Physical and Mechanical Behavior

Abstract

A field experiment was conducted on an alluvial soil with winter lettuce [Lactuca sativa (L.) cv. Bacio] plants to study, in the second year of testing and in both field and laboratory conditions, the effects of fertilizers—compost by farm residues [(FC, 2.0% nitrogen (N)], mineral (MIN, 21% N), organomineral (OM, 10% N), mycorrhizas inoculum (MYC), wine-production residue [distiller's residue (DR, 3.6% N), anaerobic digestate (AD), and mycorrhizas (ADM)—on soil physical and mechanical parameters. Application of DR plus mycorrhizas improved the available phosphorus (P) and copper (Cu) contents of the surface (0–0.20 m) soil. The soil surface macroporosity increased significantly (>20%) in treatments FC, MYC, and OM, compared to the control. Results of the oedemeter test showed that with a load of 10 daN the compression susceptibility was greater in the compost treatment compared to other fertilizers, whereas with a load of 200 daN this parameter was lower in FC, AD, MYC, and ADM treatments. The least penetration resistance in the 0- to 20-cm layer of AD and MYC treatments showed lesser values and only in treatment AD in the 20- to 40-cm layer. Hydraulic conductivity values were enhanced in AD, MYC, and ADM plots.

Keywords:

• Colloids index
• distiller's residue
• fertilization
• lettuce
• macroporosity
• mycorrhizas
• shear strength

Acknowledgment

The authors acknowledge the assistance of Bonollo distiller company (Anagni, Frosinone Province, Italy) in furnishing the distiller's residue used in the field research.