The Effect of sugarcane filter cake on selected soil quality indicators in Haft Tape region (Khuzestan)

The application of organic amendments is vital for poor soils of sugarcane fields in south Khuzestan. Recently, filter cake which is a byproduct of sugarcane factories rich in nutrients has received attention as a potential organic amendment. Therefore, an experiment was conducted to study the effects of sugarcane filter cake on selected soil quality indices at Haft Tape agro-industrial complex in 2014. The experiment was carried out in a randomized complete block design with three treatments including: 1- uncultivated, 2- sugarcane field with 100 kg ha-1 filter cake application for two continuous years, and 3- sugarcane field without filter cake (control), and three replications. Soil bulk density (BD), porosity (Pt), mean weight diameter (MWD) and geometric mean diameter (GMD) of water stable aggregates were determined in surface layer (0-30 cm). Moreover, the same properties as well as total organic carbon (TOC), active carbon (AC), total nitrogen (TN), available phosphorus (P) and available potassium (K), basal (BR) and induced (IR) microbial respiration, and alkaline phosphatase enzyme activity (PE) were compared in surface (0-30 cm) and subsurface (30-60 cm) of different treatments. Filter cake application resulted in significant increase in TOC (4.1 folds), P (7.4 folds), BR (1.5 folds), IR (1.9 folds), PA (1.6 folds), MWD (2.8 folds) and GMD (1.2 folds), as well as a significant decrease in BD (0.84 folds) compared to the control. The interactions of treatments and soil depth were exclusively significant for AC and TN. Available K was highest in uncultivated field (157 mg kg-1) with no significant disparity compared to filter cake treatment (135 mg kg-1). Furthermore, no significant improvement was detected in soil total porosity with filter cake application. The results suggest that short-term application of sugarcane filter is beneficial for soil quality improvement.