Submitted to: Modern Agriculture
Publication Type: Abstract Only
Publication Acceptance Date: 4/26/1999
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: The Rosemount biosolids watershed study was initiated by the USDA-ARS in 1973 on the University of Minnesota's Agricultural Experiment Station. The primary goal of the research was to develop efficient, practical, and environmentally safe methods for utilizing municipal biosolids on land in harmony with agricultural usage. A 16-ha watershed was terraced to give 10 treatment areas with separate tile inlets for surface runoff water. Four biosolids areas and a control area were planted to corn; four more biosolids areas and a control area were planted to reed canarygrass. Digested municipal biosolids were applied annually on corn areas at 11 Mg solids ha**-1 yr**-1 and on grass areas at 15 Mg solids ha**-1 yr**-1. Composite soil samples, runoff water, soil water and samples from 14 shallow ground water monitoring wells were collected. Twenty-year average corn fodder yields were 17.4 Mg ha**-1, and 15.9 Mg ha**-1 for the biosolids and control areas, respectively. Average annual reed canarygrass yields for 12 years were 11.0 and 9.6 Mg ha-1 for the biosolids and control areas, respectively. Stover and grain did not have increased concentrations of biosolids-borne Cd, Cr, Cu, Ni or Pb. Plant Zn did increase, reaching a mean concentration of 60 mg kg**-1 in stover tissue. Total soil C and N increased as expected on the biosolids areas. Water quality measurements showed trace element levels to be very low in runoff. Nitrate-N concentrations in soil water ranged from 97 to 160 mg L**-1 at 150-cm depth on corn control and biosolids areas, respectively. The long-term study of the Rosemount watershed is an excellent example of agronomic and environmental analysis of biosolids application to land.