Drainage pays dividends during difficult season

Variable wheat yields this harvest are due to a number of factors – with drainage playing a key role in crop performance.

Some wheat crops have performed extremely well given the extremely challenging season, while others have barely reached half their potential – sometimes even within the same field.

The trend seems to be better or free-draining soils have maintained their yield capabilities, albeit with no record yields. Conversely, heavier and more poorly structured soils have seen their potential plummet.

More significantly, it has all been about soil drainage and root development. The ratio of 20:1 – the final above ground biomass production to below ground root production – tells you everything.

If root development is hindered, the knock-on effect on biomass will be all too evident.

The effects of temporary root drowning were not only limited to the winter. In some areas, heavy rain late in the season caused premature senescence just as the crop approached ripening.

Lack of biomass was all too evident from early spring onwards. Wet soils hindered uptake of nitrogen at a vital stage. Lack of sunshine has significantly hindered biomass production.

Cool weather

This lack of sunshine was particularly early in the season at the construction phase – and many crops never caught up during the critical growth stages of the growing season that followed.

“In the latter stages it has not helped with grain fill either, subsequently bushel weights have suffered. Elevated temperatures towards the end of the growing season also led to accelerated leaf aging leading to negative effects in the grain filling phase.”

That said, lower temperatures throughout most of the critical spring and summer growth period helped to reduce the stress on crops.

Blackgrass control, or lack of it will have impacted yield, not because of poor residual control in the autumn, quite the contrary, because of the wet spring surviving plants were able to negate the effects of the autumn residuals.

Disease pressure played a key part in most areas.

Septoria pressure was high in the early part of the season, continuing through the critical months of April and May. The early drilled crops as expected were at the greatest risk with many growers struggling to keep leaf two clean.

Rust was a major risk this season, both yellow and brown in susceptible varieties, once in the crop in the base of the crop fungicide programmes struggled to hold the disease beyond three weeks.

Fusarium and ergot are more prevalent this year than most, primarily because of a wet flowering period. Other issues also mean it is no wonder we have seen a range of yields across farms and even fields.

Partly because the wet soils delayed applications, BYDV was more common among winter than spring crops this season. The wet winter did not help with take-all in cereals this year either, it has even shown through in first cereals.

Neil Watson is technical support manager for agronomy specialists Hutchinsons.