Relating potato yield to the level of soil degradation using a bulk yield monitor and differential global positioning systems

The adoption of soil conservation practices is often dependent on linking reductions in crop productivity to declines in soil and land quality. A bulk yield monitoring system was installed on a commercial potato harvester for the purpose of showing a relationship between potato yield and the level of degradation on fine sandy loam soils (Orthic Podzols) in the cool, humid climate of Prince Edward Island, Atlantic Canada. Although data are preliminary, initial results indicate that potato yields will be substantially reduced as a result of soil physical properties being altered by excessive long-term soil degradation. Significant correlations were identified between potato yield and a number of physical factors representative of soil degradation including the slope length and steepness factor, cation exchange capacity, depth of topsoil and water holding capacity. If, after confirmation from further study, the relationship between potato yield and the level of soil degradation can be quantified, it will provide a valuable tool in terms of encouraging farmers to adopt soil conserving practices. (C) 1999 Elsevier Science B.V. All rights reserved.