The visual evaluation of soil structure under arable management

• The visual evaluation of soil structure (VESS) indicated poorer soil structure under conventional tillage compared to minimum tillage.
• The VESS result was confirmed by measured soil properties.
• VESS was not able to differentiate the effects of crop rotation on soil structural quality.
• VESS is suitable for rapid evaluation of soil surface structural quality on arable farms.

Conventional methods for assessing soil quality under different management practices require considerable time and knowledge. A visual method based on field assessment can provide a reliable, rapid evaluation of soil quality. The aim of this study was to use the visual evaluation of soil structure (VESS) method in arable soil in Ireland and to assess the ability of the method for evaluating soil structural quality under different arable management systems. The study was conducted over twenty sites used with conventional and minimum tillage, with crop rotation or mono-cropped. At each site a VESS score and soil properties associated with soil structural quality were measured in order to assess the visual soil quality score (Sq). Sq for conventional management (Sq = 2.29) was significantly greater than minimum tillage (Sq = 1.95) indicating slightly poorer structure. Measured soil parameters confirmed a negative effect of conventional tillage on soil quality and supported the VESS results. Under minimum tillage Sq indicated significantly different soil structure under mono-cropping (Sq = 1.66) compared to rotation (Sq = 2.06), but this trend was not supported by the other soil properties and the difference probably had no physical meaning as both Sq scores indicated good soil structure. The effects of crop management on soil structure could not be differentiated by VESS under conventional tillage, while the measured soil properties suggested soil structural quality was better under crop rotation. While visual Sq scores were not strongly correlated with individual soil properties indicative of soil quality, Sq scores were generally supported by the measured soil properties with regard to differentiation of tillage system. This independent evaluation of the VESS method on arable farms in Ireland indicated that it was capable of differentiating the effects of tillage management practices on soil structural quality, and is suitable for use as a reliable, rapid method for assessing soil quality on arable farms.