APPLYING BIOSOLIDS: ISSUES FOR VIRGINIA AGRICULTURE

Farmers typically pay about $7 to 10 per soil sample analyzed and take one soil sample for every 10 to 15
acres. Thus, a farmer could save approximately $0.70 to $1.00 per acre on every field where biosolids
application is planned.

Three Case Studies

The Hanover-Caroline and Colonial Soil and Water Conservation Districts, as part of their 1997 York and
Rappahannock River Tributary Strategies Project, selected three farms for case studies of biosolids
application. Two farms are in the Piedmont Plateau (Hanover and Louisa counties), the third is in the
Coastal Plains (New Kent County). The Louisa County farm is a grazing operation, and the Hanover
and New Kent county farms are corn, small grain, and soybean operations. The results clearly indicate
positive net economic benefits in each case.

Because yields, mineralization rates, leaching, and runoff are functions of soil type, slope, temperature,
and rainfall, tables 4 and 5 are provided as references for the three case study farms.

Table 5. Average Daily Temperature and Average Annual Rainfall

J. B. Cocke Farm, Hanover County

J. B. Cocke’s farm produces cash grains—conventional till corn and full season soybeans. Approximately
7.5 tons of dry, lime-stabilized biosolids were applied to a 19.2 acre field in spring 1997, prior to planting.
This field is in a 5-year rotation: one year corn, four years soybeans. Typical yields range from 90 to 105
bushels per acre for corn and from 45 to 55 bushels per acre for soybeans. The field contains Cecil and
Appling sandy loam soils with a pH of 6.0. It last had biosolids applied in 1991.

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