Fertility Assessment of the Piggery Wastewater Trickling Filtrate for Orchard Grass (Dactylis glomerata L.) and Soil

In search of a method to achieve sustainable agricultural practices, a trickling filter was employed for the piggery wastewater treatment, where rice straw was the support medium in place of more commonly used materials. The filtrate from the trickling filter were applied to a soil, on which orchard grass (Dactylic glomerata L.) was grown followed by amendment of the treated straw medium. Orchard grass was cut twice, and growth parameters and yields were measured. Soil chemical properties before and after harvesting orchard grass were analyzed. Development of the forage crop was greatly enhanced by the application of the filtrate in terms of fresh weight, dry weight, and the absorption of nutrients. Better growth and higher nutrient uptake were found in the second cutting of the orchard grass. Organic matter content, ionic intensity, exchangeable cations, and phosphate of the soil increased with the application of the filtrate. The relative high concentrations of salts in the piggery trickling filtrate, expressed in electrical conductivity and content of sodium, exerted no detrimental effect on the crop and soil.