Hybrid barleys are well recognised for their high biomass potential. This is an evolving, good news story for Irish grain growers.
This has significant benefits in terms of grassweed suppression, but new data suggests that it also has a benefit regarding nitrogen use efficiency.
Syngenta trials in the UK in conjunction with the Agricultural Development and Advisory Service (ADAS) as well as trials carried out by Syngenta Germany over seven years, have shown that hybrid barley has significantly improved nitrogen use efficiency when compared to conventional varieties.
Nitrogen use efficiency
Nitrogen use efficiency is the sum of two key components – one relates to uptake efficiency, the other to actual utilisation efficiency.
Nitrogen uptake efficiency relates to the effectiveness with which nitrogen (N) is taken up by the roots as they grow and explore the soil.
Nitrogen utilisation efficiency, on the other hand, relates the efficiency with which the plant converts the N it has taken up into harvestable grain.
The aforementioned hybrid barley trials are ongoing, but initial results from the first two years of trials with ADAS suggest that hybrid barleys are doing more, with less.
Hybrid barleys
According to Syngenta’s Ben Urquhart, the larger and deeper rooting system of hybrid barley leads to it being able to scavenge for nutrients more effectively than conventional wheat and barley.
As a result, the plants take up more N despite being at a lower plant population.
“Hybrid barley is known for its hybrid vigour, and vigorous roots are associated with improved nutrient uptake,” Urquhart said
“Hybrid root systems are significantly larger than those of conventional varieties.”
Across a wide range of N rates in the trial, the hybrids also showed significantly improved nitrogen utilisation efficiency over the conventional varieties, with the biggest differences being shown in very low application level scenarios.
Weeds
Hybrid vigour is the driving force behind the higher yields recorded when comparing hybrid to conventional barley.
But hybrids also bring to bear significant advantages, where grassweed control in barley crops is concerned.
Taller plants with higher tiller numbers are more competitive with grassweeds for space and light.
Significantly larger root mass underground means that hybrid barley plants are more effectively anchored in the ground and provide a larger surface area for uptake of essential nutrients and water.
According to many agronomists, hybrid barley should be an essential element of any integrated pest management (IPM) strategy, targeting grassweeds.
It has been shown that grassweed suppression is achieved, irrespective of herbicide resistance status.
Trials have also demonstrated that the remaining grassweeds in crops of hybrid barley produce fewer tillers, smaller heads and fewer seeds. The end result is a reduced seed return for the following crop.