Sustainability Indicators Used to Compare Properties of Organic and Conventionally Managed Topsoils

ABSTRACT

Differences between organic and conventional management were investigated for 14 paired topsoil sites (28 fields) from around the south and east of England, the majority being in arable management. Parameters used were soil organic matter content, total nitrogen content and available phosphorus, potassium and magnesium, pH, topsoil depth and shear strength. The aim was to assess differences in management and to draw inferences for sustainable soil management practices. Organically managed topsoils were found to be characterized by deeper plough horizons and higher percentage organic matter, total nitrogen and available P. They had lower shear strengths and were substantially lower in available K than their conventional counterparts. No significant differences in available Mg or pH were found between management classes. It is concluded that soil organic matter content, total N, available P and K, topsoil depth and shear strength were effective ‘sustainability indicators’.