ANC Mayerthorpe Site 

This experimental plot area was established in May, 1993 near Mayerthorpe, AB to evaluate the addition of different rates of conventional and de-ink sludge on soils and plants.  Initially the experiment included:

  • 5 x 10 m plots
  • 3 replicates
  • two sludges; conventional and de-ink (de-ink sludge is the by-product of pulp made from recycled paper and wood chips; conventional sludge is the by-product of pulp made from just wood chips)
  • six application rates (0 cm, 1 cm, 3 cm, 5 cm, 10 cm, and 5 cm/yr multiple application)
  • Nutrient levels equalized with fertilizer (N and P) once in 1992
  • Sludge incorporated by rototilling to 15 cm
  • Plots seed to Magna Brome Grass (60 kg/ha)
  • Pre and post application soil samples obtained to determine pH, carbon (TC, TOC, TIC), nitrogen, C:N, CaCO3 equiv, exchangeable cations, CEC, EC, SAR, soluble ions (HCO3, CO3, Cl, NO2, NH4, Sr, Ba, P, S, Mg, As, Si, V, Na, Mo, Se, Al, Ca, Zn, Cu, Pb, Li, Ti, Cd, Co, Ni, B, K, Mn, Fe, Cr)
  • Yield assessments and plant tissue analyses (DTPA extractable and total elements) on Brome Grass
  • Precipitation, air temperature, soil temperature, soil moisture, solar radiation, relative humidity, wind speed and wind direction continuously monitored
  • Soil moisture and density were monitored in plots to 270 cm with a moisture/density neutron probe
  • Infiltration rates were determined with double-ring infiltrometers

 

Soil carbon data for Conventional and De-ink plots were combined

Conclusions

  • Sludge had a positive effect on soil carbon concentrations 15 years after application indicating the longevity of carbon storage.
  • Soil bulk density ↓ as sludge application ↑
  • No significant change in soil pH from sludge addition
  • Small ↑ in total N and C were observed with ↑ sludge application rate
  • EC ↑ a maximum of 1.5 dS/m initially after application and subsequently decreased
  • SAR ↑ initially and decreased by 1995
  • Nitrate and Nitrite levels ↑ with depth in the years following application due to leaching and subsequently decreased
  • Slight ↑ in Cu, Ni, and Zn immediately after sludge application
  • Sludge application had little to no effect on soil suitability ratings based on pH, salinity, TOC, and CaCO3 equiv.
  • Yields were initially similar for all treatments due to fertilizer equalization
  • Subsequent yields increased with increasing sludge application
  • Beneficial sludge effect on yield diminished 3 or 4 years after application
  • In the first year after application brome plant tissue was showed elevated B, Ba, Ca, Cd, K, Na, P and Zn – by 1995 there were no discernable differences
  • Sludge addition improved physiological tissue elemental concentrations of several elements including B, Cu and Na.
Mean Grass Yield Values (kg dry weight) for the Conventional Sludge Plots in 1993 to 2002

Mean Grass Yield Values (kg dry weight) for the Conventional Sludge Plots in 1993 to 2002

Mean Grass Yield Values (kg dry weight) for the De-ink Sludge Plots in 1993 to 2002

Mean Grass Yield Values (kg dry weight) for the De-ink Sludge Plots in 1993 to 2002