Malting sludges as soil amendment

Abstract

Residual sludge that results from the treatment of malt house effluents produced during the malting of barley in malt house (Argentina) was evaluated to determine its fertilising potential and capability for improving soil as a way to reuse or recycle this material. The Cabildo soil (Southwest of Buenos Aires Province), of the typic Argiustoll subgroup had a sandy clay-loam texture and was tested in this field experiments. This soil plots (4 m2 ) were amended with equivalent malting sludges doses of 5, 15, and 25 Mg/ha. When biosolids, like malting sludges, are incorporated as an amendment, many micronutrients are provided. Chemical properties of the soil, particularly the pH, EC (Electrical Conductivity) and Cation Exchange Capacity (CEC), were improved. Dactylis glomerata L. were utilised as growing crop (forage) in this field test, productivity ( Dry matter) and quality (protein %) gave results following 0,205 kg/m2 and 11.94 % at control in comparison with 0,4 kg/m2 and 15.15 % of amended soil. Calcium concentration in grasses was significantly different for control (4651 mg/kg-1) in comparison with high sludge dose (8907 mg/kg-1), the same trend was found with micronutrients like Copper and Molybdenum. This results from field test indicate that this residual sludge constitutes a suitable amendment for agricultural soils, increassing quality and productivity of Dactylis glomerata L and improving several soil properties.