Speak to the Past and it Shall Teach Thee:
Effect of 250 Years of Agriculture on Soil Characteristics at Casey Farm

Thomas Hayes

Study of long-term ecosystem changes due to human land-use can benefit future planning. Careful research into the background of a site will control for any historical "memory" of past usage. An ideal test case for this analysis would be a farm, where the ecosystem is regularly and completely transformed by humans. Casey Farm in Rhode Island is unique in that it has been owned by a single family and has been continuously farmed since before the American Revolution. Analysis of soil physical and chemical characteristics in three different regimes - temporal, functional and spatial - was used to determine if long-term effects existed. The most significant results revealed differences between the agriculturally active and inactive parts of the farm. Physical quantities such as bulk density, rock volume and plow layer depth differed as expected between past and presently farmed fields. In addition, active sites have on average 1% less carbon by weight than inactive ones. Because the temporal comparison provided the strongest evidence for a landscape memory, it is possible that it is obscuring any other relationships between the soil and field type or distance from the barnyard.