Soil health in Norway: On-farm assessments of soil health with no-till and conventional farming practices

Abstract

Soil health is defined as the capacity of a soil to function as vital living ecosystem. No-tillage is a non-inversion practice that has been highlighted as a practice for improving soil health, and thereby improving soil ecosystem delivery. However, evidence on soil health and farming practices that improve soil health is limited in Norway. We present results on effects of long-term farming practices on soil health in Southeast (SE) Norway on similar soil and topographic characteristics. Physical, chemical, and biological soil indicators were measured on two neighbouring farms, one with no-till and cover crops (NT+CC) and one with conventional harrowing and ploughing (CP), on loam soil in SE Norway. Soil samples were collected to compare soil health indicator between farming practices. We established two systematic sampling grids (~ 0.4 ha) with grid intersection points every 15 m x 15 m to produce a total of 33 sampling points and 17 and 20 cells in the CP and NT+CC field, respectively. We used a combined approach of transect-, point- and cell sampling, depending on the spatial variations of the soil indicators. Soil health indicators included bulk density, cohesion, aggregate stability, saturated hydraulic conductivity (Ksat), total organic carbon, total nitrogen, pH, permanganate-oxidizable carbon and earthworm count. Preliminary results indicate significantly different (p<0.001) earthworm count in the NT+CC (24.7±6.4) compared to CP (6.0±3.2). Moreover, higher mean Ksat was measured in NT+CC (83.5±29.5 cm/day) compared to CP (46.0±40.0 cm/day). Here we discuss further the effects of no-till and cover crops on soil health and the selection of soil indicators to evaluate soil health.