Field assessment of soil structural quality – a development of the Peerlkamp test

TLDR

Increased awareness of soil structure’s role in fertility and sustainability has created a need for a simple, complementary assessment method. The study aims to develop a user‑friendly visual test for soil structure quality that can be employed by farmers, consultants, and researchers. The method uses a visual key with objective criteria to score soil structure quality (Sq); it was tested for operator, tillage, and crop effects, takes 5–15 minutes per site, and yields sufficient replicates for statistical comparison. The test revealed operator‑dependent variability, distinguished soil management practices linked to bulk density, penetration resistance, porosity, and crop growth, suggested indicative management thresholds, and helped identify sampling locations and useful soil measurements.

Abstract

Abstract Increased awareness of the role of soil structure in defining the physical fertility or quality of soil has led to the need for a simple assessment relevant to the environmental and economic sustainability of soil productivity. A test is required that is usable by farmer, consultant and researcher alike. Here an assessment of soil structure quality (Sq) is described which is based on a visual key linked to criteria chosen to be as objective as possible. The influences of operator, tillage and crop type on Sq value were tested. The test takes 5–15 min per location and enough replicates were obtained for statistical comparison of data sets. The assessments of individual operators were influenced to an extent by differences between fields, making the use of multiple operators desirable. Differences in soil management were revealed by the test and related to differences in soil physical properties (bulk density, penetration resistance and porosity) and crop growth. Indicative thresholds of soil management are suggested. The assessment should be viewed as complementary to conventional laboratory assessments of soil structure. Visual soil structure assessment can indicate to the soil scientist where to sample and what soil measurements are likely to be worthwhile.