Soil-building wheat

Out of curiosity I grew some Rampton Rivet alongside the Holdfast shown in a previous post.

Rivet wheat (Triticum turgidum sbsp. turgidum) is a tetraploid wheat, related to durum (T. turgidum sbsp. durum) and was grown up until the Second World War.  Another name for it is English Wheat, although it appears that common or bread wheat (T. aestivum) was always the most important (Bell, 1948).

Rivet was recommended for "clay soils of low fertility", whilst the high yield and quality bread wheats such as Holdfast are suited to "land in good heart" (Stapledon and Davies, 1948).

Rampton Rivet was an improved selection from the Rivet landraces of Cambridgeshire, and was very much last of the line.  Rivet is no longer grown commercially in UK, except on a very small scale.  

Having seen differences in rooting between modern wheat and spelt, and reading about Rivet's suitability for clay, I expected the root system to be better than modern wheat. I was still shocked by the contrast.

On the left is Skyfall, a modern variety; on the right is Rampton Rivet.  Both were sown at the same time and grown in the same glasshouse.  Skyfall is a superb modern variety, with a yield to match barn-filling feed varieties, high quality grain and a good agronomic package.  Rivet on the other hand is a machine to pump carbon into the soil, with thick, deep scavenging roots and a mass of fine roots.  The straw is also very coarse, therefore a good source of the lignin that feeds beneficial soil fungi that are often deficient in our soils.

Have we lost something here?  Is there a place for crops that help keep the soil in "good heart"?

References
Bell G.D.H. (1948). Cultivated Plants of the Farm. Cambridge: CUP
Stapledon R.G. and Davies W. (1948). Ley Farming. London: Faber
http://www.dovesfarm.co.uk/resources/whats-new/interview-with-archaeobotanist-john-letts/