Impact of nutrient scenarios on the performance of cereals and oilseeds varieties (scoping review)

AHDB Recommended Lists (RL) trials for cereals and oilseeds are fertilised based on recommendations in the AHDB Nutrient Management Guide (RB209).

In 2022, AHDB launched a review of the RL project that identified a need for varietal performance information under lower-input scenarios, including crop nutrition.

Farmers are interested in reducing applied nitrogen (N) to decrease input costs and to contribute to environmental sustainability, provided productivity is maintained.

This scoping review will gather evidence from academic and ‘grey’ literature, as well as industry intelligence from breeders, to identify any varietal differences in nitrogen use efficiency (NUE) or the rank order of varieties for yield at lower nitrogen rates.

The main findings for each study will be added to a database, which will be split into two groups: those that found statistically significant differences between varieties in yield response to nitrogen (or component measures of NUE) and those that did not.

The work will also conduct a meta-analysis of data drawn from peer-reviewed literature to examine the magnitude of relative varietal effects in studies where more than one variety was grown on more than one level of applied nitrogen. The analysis will focus on winter wheat, where most data is likely to be available.

The project will also help develop consistency in the assessment of the nitrogen responses of varieties, including the nomenclature used and how statistical significance is evaluated. It will also identify knowledge gaps.

AHDB will use the findings to guide decisions on how to deliver information on varietal performance under lower nitrogen rates.