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Most studies on the effects of tillage operations documented the effects of tillage on losses through surface runoff. On flat areas, the subsurface runoff is the dominating pathway for water, soil and nutrients. This study presents results from a five-year plot study on a flat area measuring surface and subsurface runoff losses. The treatments compared were (A) autumn ploughing with oats, (B) autumn ploughing with winter wheat and (C) spring ploughing with spring barley (n = 3). The results showed that subsurface runoff was the main source for soil (67%), total phosphorus (76%), dissolved reactive phosphorus (75%) and total nitrogen (89%) losses. Through the subsurface pathway, the lowest soil losses occurred from the spring ploughed plots. Losses of total phosphorus through subsurface runoff were also lower from spring ploughing compared to autumn ploughing. Total nitrogen losses were higher from autumn ploughing compared to other treatments. Losses of total nitrogen were more influenced by autumn ploughing than by a nitrogen surplus in production. Single extreme weather events, like the summer drought in 2018 and high precipitation in October 2014 were crucial to the annual soil and nutrient losses. Considering extreme weather events in agricultural management is a necessary prerequisite for successful mitigation of soil and nutrient losses in the future.

<p>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.</p>