Effect of organic amendments on some physical, chemical and biological properties in a horticultural soil.

The aim of the present work was to assess the response of selected soil physical, chemical and biological properties, after two applications of different organic amendments to a soil with an extended horticultural use. Vermicompost from household solid waste (HSW) and from horse and rabbit manure (HRM), and chicken manure (CM) were applied at rates of 10 and 20 Mg ha(-1). The proportion of water stable soil aggregates (Ws) was significantly higher (p < 0.05) in HSW, HRM and CM at 20 Mg ha(-1). The proportion of ethanol stable soil aggregates (Es) was significantly higher in HSW, HRM and CM at 20 Mg ha(-1), and CM at 10 Mg ha(-1). After the first amendment application, HSW and HRM at 20 Mg ha(-1) resulted in higher soil organic carbon (SOC), while all the treatments showed a significant increase after the second amendment application. Linear relationships were found between Ws and Es with SOC. An increment in microbial respiration in all the amended plots was observed with the exception of HRM at the rate of 10 Mg ha(-1).