Integrating soil quality changes to arable agricultural systems following organic matter addition, or adoption of a ley-arable rotation

To study the sustainability of arable agricultural systems we examined a wide range of biological, physical and chemical properties associated with changes in soil quality. We integrated these using a qualitative multi-attribute model supported by the software tool DEXi to achieve a holistic estimation of soil quality. We tested the relative changes in soil quality attributes resulting from the incorporation of cattle slurry or green-waste compost, or from including a ley phase in the production of arable crops. We measured: abundances and biodiversity of the soil biota, physical properties and nutrient concentrations; twice in 2006 and thrice in 2007. These data were used to generate a model of soil quality, which showed that the addition of organic matter or a ley phase did increase soil quality. However, to fully understand the soil system results should be derived from a number of functionally related observations as there were opposing trends in individual observations. Increases in some beneficial attributes (such as decomposition, soil nutrient status and physical condition) were associated with an increased risk of nutrient losses from leaching and gaseous emissions. Assessing soil quality with only a few indicators may not identify these trade-offs. The multi-attribute modelling approach could identify the pathways responsible for changes in soil quality and identify possible environmentally detrimental effects.