Fertilizer and Sludge Comparison

In May 1997, a project was implemented at the ANC Mayerthorpe site to determine whether the sludges can economically replace a portion or all of a commercial fertilizer application to achieve a target yield.  The three-year treatment included replicated treatments of barley with:

  • A one time sludge application of 50 t/ha in 1997
  • Fertilizer application of 200 kg/ha 35-15-0 applied annually in the spring of 1997, 1998, and 1999.
  • One time sludge application resulted in plant available nitrogen levels similar to those supplied by annual fertilizer application. 
  • Fertilizer nitrogen added in the spring of each year was utilized by the barley crop by the time the harvest was completed
  • The sludge released adequate amounts of nitrogen to sustain the crop yields 3 years after application.
Barley Yields (bushel/acre)
Treatment 1997 1998 1999 Mean
Fertilizer* 38 63 34 45
Sludge** 35 67 33 45

*Fertilizer - 200 kg/ha of 35-15-0 fertilizer applied annually

**Sludge - One time application of 50 t/ha in May, 1997

Plant Available Nitrogen (kg/ha)
Date Sludge Fertilizer
     

May 12, 1997

29 30
May 20, 1997 59 140
Aug 27, 1997 56 43
     
April 30, 1998 149 50
May 8, 1998 - 165
Aug 14, 1998 53 41
     
May 25, 1999 68 35
May 26, 1999 - 177
Aug 27, 1999 22 36

 

Conclusions

  • The yield results over a three year period (1997 to 1999) demonstrated that a one time sludge application of 50 t/ha would result in the  same barley yield as the application of 200 kg/ha 35-15-0 annually, indicating cost savings associated with annual fertilizer applications.
  • The feed quality of the grain and straw was similar for both the fertilized and sludge amended treatments.
  • Barley yields were similar for the two treatments over the three year period.