Trial Results – Wheat

Evaluation of products for improving N efficiency in wheat (2011)

ADAS England

Trial type
Randomised block design with three replicates.

Late march
Hand-held sprayer with 3m boom in 200L of water / Ha

Applied between 6.30 and 7.00am in cloudy conditions at 6 degrees

Soil type
Clay loam

0, 70, 140, 210, 280 AN + urea applied at the same rates.

Yield Response to N applied as Ammonia Nitrate (AN), Urea, AN + C active or AN + Delta
Economical N rate

AN 70kg N/Ha
UREA 79kg N/Ha
AN + C active 57kg N/Ha
AN + Delta 76kg N/Ha

Filled triangles denote economically optimum N rates for each product

  • There was no significant effect of product on yield, but there was a trend for AN + C-active Microbial Technology treatments to yield more than straight AN at most N rates
  • Following a dry winter and early spring, the experiments experienced cool, dull and very wet conditions in spring and early summer, leading to low yields and high disease pressure.
  • The low yields resulted in a smaller than usual yield response to N, with average yields across all products increasing from 6.42 t/ha to an average of 7.33 t/Ha at 140kg N/Ha (P<0.001), then declining with N rates over 140kg N/ha

(Extracted from, Evaluation of products for improving N efficiency in wheat)