This year we've been tracking the progress of farm advisory group Masstock's trials growing rape under three different cultivation regimes.

Our latest update includes root weights and pod counts.

The first plot received a fairly conventional but intensive cultivation regime.

It had two passes with a set of heavy Simba discs and the seed was drilled with a Kuhn power-harrow combination.

For the second technique, an Opico HE-VA Disc-Roller disc/press combination with Variocast seeder-unit was employed.

On the third plot, a Variocast seeder-unit piggy-backing on the sub-soiler was used to drop seed behind each soil-loosening leg.
The last of these methods clearly scores best on cost and, at the end of March, the crop established under this subsoiler regime was the one that had reached the highest Green Leaf Area Index (GAI).

By the end of May it was clear that seedlings able to establish themselves directly in the subsoiler legs' wake were making the most of their rooting potential.

The average root weight where seed was spread behind the subsoiler was more than 75% greater than those established using conventional cultivation techniques.

A week or so into June, most viable seed pods are set and again the subsoiler-seeded crop leads the field with the most pods per plant - 42% more than the crop established with the disc/press combination.

The main reason is that, because of its greater root mass, the subsoiler crop has been able to access more nutrients and water than the others.

Also, because the plants are growing in 50cm (20in) rows, they have more room to branch out to fill the gaps and can intercept more light and form more viable pods.

fwmachinery@rbi.co.uk