Effects of wheel damage on peat grasslands at low bearing capacity at high ditch levels

From the 1960s onwards in the Netherlands, many relatively wet peat lands were deep(er) dewatered to a ditch water level of 50 to 60 cm below the surface to improve dairy agriculture. As a consequence of this deeper drainage, peat degradation took place due to mineralisation, resulting in a relatively rapid land subsidence. An increase of the low ditch level may inhibit subsidence. Although much research has been done on the effects of deep drainage, hardly any research has been done at the effects of increasing ditch water levels. In a six-year trial, the agricultural effects of increasing ditch level were examined. This article discusses the effects of soil damage caused by rutting when slurry is injected under poor bearing conditions in spring. The damage caused by shallow injecting of slurry at a bearing capacity under 4 kg cm-2 was equal at both ditch levels (deep and shallow drainage), although there were differences in bearing capacity at both levels. When damage occurs it takes place in the wheel tracks. On average, shallow injection of slurry with a manure tank with a capacity of 7 m3 led to 4.5% yield loss per hectare.