Detailed measurement of soil properties and plant productivity over time following amelioration with one-off deep tillage.

In the first growing season, the one-off tillage treatments showed to reduced significantly the water repellency of the soil. Significantly better plant establishment and grain yield were obtained in all the tillage treatments. In terms of grain yield, better results were achieved with the tillage treatments that mixed the soil more efficiently, such as the “Deep ripping + Spading” and the “Mouldboard plough” treatments. The “Deep ripping” treatment, which effectively targeted only subsoil compaction, provided the lowest improvements in terms SWR and the lowest grain yield.

The greatest profit in the first growing year was achieved using the “Modified one-way plough” thanks to its low capital cost which reduces its operating cost. Nonetheless, further growing season will be necessary to establish its long term profitability in comparison to the “Deep ripping + Spading” and the “Mouldboard plough” treatments.

Changes in the soil pH profile were also observed after the tillage treatments, with increased acidity in the topsoil. That was particularly the case with the “Mouldboard plough” treatment and the management of soil pH with addition of lime after the tillage needs to be considered.

We expect the next four growing seasons to give us more information to better understand the long term effects of these soil modifications on soil productivity.