Greening Headlands: A new method to reduce soil compaction and enhance soil health

The use of heavy machinery lead to severe soil compaction, especially in the headland. In sustainable headland management, in contrast, it is necessary to manage compacted soils and promote soil health. Therefore, a new measure of “greening headlands” was studied to analyse stabilisation effects. The aim was to detect changes in soil functionality during intensive field traffic in the headlands.

The study was carried out on two study fields in Lower Saxony, Germany, to analyse changes after a four-year period of greening. On field A, part of the headland was newly planted with clover grass over a width of 18 m. At Field B, a 6 m grass-buffer from original water protection strip was used as headland. The former headland had a width of 27 m. All turning manoeuvres during the four years occurred in the (greened) headlands. Sampling was carried out in the core field, (former) headland and greened headland at the depth of 20, 35 and 50 cm. Mainly soil physical properties (e.g. dry bulk density, air capacity) and soil nutrients (e.g. phosphorus) were analysed.

After four years, the air capacity in 50 cm depth in the greened headland of field A increased compared to the core field. Despite intensive field traffic, the dry bulk density on the greened headland did not decrease significantly compared to the headland. Furthermore, the greening had a positive effect on the yield at the former headland due to edge effects of the greening.

In field B, positive effects can be observed in the former headland, with slightly decreasing dry bulk densities and significantly increasing air capacities at all depths. The greened headland is clearly influenced by field traffic, as the bulk density increased from 1.53 g/cm³ to 1.58 g/cm³ at 20 cm depth and 1.41 to 1.58 g/cm³ at 50 cm depth after four years. The air capacity decreased from 7.78 % to 6.47 % at 20 cm depth and slightly decreased in 50 cm depth. At 35 cm, the parameters show similar tendencies compared to 50 cm depth.

Overall, a stabilising effect of a dominant root network in the vegetation cover can be identified as soil functions in field A improved in the greened headland despite the intensity of field traffic. Field B was less compacted at the beginning of the study. As a result, the negative effects of field traffic are more apparent. Nevertheless, the greening mitigates the negative effects of field traffic, as the effects are relatively small compared to field A.

The yield on compacted headlands is lower compared to the other locations. The greening of headlands can be used to reduce negative soil compaction effects in the headlands and promote soil health. However, the greening reduces the area available for arable farming. Nevertheless, the new method can additionally reduce runoff and promote sediment retention and thus prevents soil erosion.