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 r eductions 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 o f degradation on fine sandy loam soils (Orthic Podzols) in the cool, humid climate of Prince Edward Island, Atlantic Canada. Although data are prelimi nary, initial results indicate that potato yields will be substantially red uced as a result of soil physical properties being altered by excessive lon g-term soil degradation. Significant correlations were identified between p otato yield and a number of physical factors representative of soil degrada tion including the slope length and steepness factor, cation exchange capac ity, depth of topsoil and water holding capacity. If, after confirmation fr om further study, the relationship between potato yield and the level of so il degradation can be quantified, it will provide a valuable tool in terms of encouraging farmers to adopt soil conserving practices. (C) 1999 Elsevie r Science B.V. All rights reserved.