APPLYING BIOSOLIDS: ISSUES FOR VIRGINIA AGRICULTURE

Table 8. J. R. Smith farm, Louisa County: Partial Budgeting Results

Even though the drought in 1997 affected wide areas of the state, Smith’s farm received three rains
during the summer that were sufficient for good forage growth. Smith reported that the biosolids-treated
pasture stayed green all summer while pastures treated with commercial fertilizer did not do as well.
Smith estimated that the biosolids-treated pasture received 50 percent more grazing pressure than the
untreated pastures. He observed that the treated pasture not only stayed greener during the summer, but
also grew back more quickly after grazing, grew well until the fall frosts, and looked better than untreated
pastures in December.

Evanylo and Ross conducted a rainfall simulation project during summer 1997 on Smith’s pasture where
biosolids had been applied. Control areas without biosolids were compared to areas receiving biosolids.
The plots with biosolids produced 2,280 pounds of dry matter clipped six weeks after application compared
to only 1,380 pounds of forage produced on the control plots during the same time. Greater water
infiltration also occurred on the plots receiving biosolids compared to the pasture control area. Simulated
rainfall of 3.86 inches was absorbed by the area with biosolids compared to 3.64 inches on the control
area: an increase of 0.22 inches water stored.

ENVIRONMENTAL IMPACTS

Water quality problems generally result when the non-point source pollution contributions from multiple
land users combine to reach a critical mass, producing observable negative effects. The damages from
an individual environmental contamination event on a single site are probably limited in extent and
significance. Thus, overall land use and water quality usually must be monitored and understood at the
watershed level to define non-point source pollution problems, to identify causes, to effect linkages
between land use and environmental pollution, and to implement strategies to solve such problems.

Incorrect application of nutrients coupled with wet weather and steep slopes can result in non-point
source pollution to surface and ground waters. As is generally the case with non-point source pollutants
(soil delivered to waterways, agricultural chemicals, commercial fertilizers, and livestock manures), the
greatest potential for environmental degradation from biosolids applications would result from severe rain

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