Forage Quality Improvement & Growth Response to Biosolids Applications

City of Edmonton

The City of Edmonton (City) desires a program of biosolids management that offers a diverse array of options to provide increased capacity to accept biosolids.  The Nutri Gold, liquid to agricultural land and the co-composting programs have been successful, yet due to logistical constraints and increasing biosolids production they do not utilize total annual production.  SYLVIS was engaged by the City to identify, develop and implement new options for biosolids management to augment the current programs.  Identified for operational-scale projects were several marginal agricultural land conversion projects, with the goal of demonstrating improved productivity and fertility as a result of biosolids applications.

SYLVIS conducted post-application monitoring for two years following biosolids applications to evaluate changes to soil fertility and productivity on five sites; four of which had an agricultural component.  The biosolids application rate was varied from an agronomic, nitrogen-based application rate and also included a control as a baseline measure.  The total biomass, seed head and protein content yields were used as measures of improved site productivity.  The numerical increases in crude protein yield on the five demonstration sites ranged from 45% to 165%.  These results suggest that biosolids applications promote site productivity and increased growth response of forage crops.  The increased yield data, coupled with environmental monitoring of soil and water, over the same two years indicated that biosolids applications at the specified rates were both environmentally beneficial and protective. 

By designing and implementing demonstrations that were operational in scale, statistically robust and evaluated over multiple years, SYLVIS was able to sufficiently demonstrate to Alberta Environment and Sustainable Resource Development (ESRD) that biosolids applications to marginal agricultural land are an environmentally sound use option.