Agricultural Land Use: The Effects on Soil Health in Northwest Florida

Abstract:

Degradation of soil health following conversion to agriculture is a global concern and will have increasingly adverse economic ramifications in the future. Soil health, or soil quality, is the capacity of a soil to maintain environmental functions and biological productivity. Agricultural conversion and use are known to degrade certain aspects of soil health when compared to a natural soil, but the rate of change of these aspects has not been described in detail. The Florida panhandle offers the opportunity to study soils that have been converted from pine forest to agriculture over varying timescales to provide insight into: 1) the rate of change of certain soil health characteristics; 2) the minimum time needed for significant impacts to a soil to develop; and 3) the magnitude of the changes that result from agriculture. Samples were collected from fields converted during various decades of the past century (1920s to 1990s). Soils were analyzed to quantify the effect of conversion to agriculture on soil pH, electrical conductivity, particle size distribution, organic carbon content, aggregate stability, soil respiration rate and bulk density. The oldest agricultural soils (developed before and during the 1940s) exhibit significant differences from natural soils under pine forest (p<0.01) in all characteristics tested. Relative differences in soil characteristics between the land uses increase as time since conversion to agriculture increases. pH and bulk density do not exhibit this increase but are significantly different from pine forest soils for all time periods studied.