To determine the influence of nitrogen rate (10 nutrition treatments) on grain yield, grain quality, protein (%), test weight (kg/hL) and screenings (cv RGT Accroc)

• With 107kg N/ha in the soil (0 – 30cm shortly after sowing) there was no yield response to applied fertiliser N applied as prilled urea (46% N).
• As applied N was increased from 90kg N/ha to 290kg N/ha (in 2 split applications) grain yield initially slightly increased up to 130kg N/ha and then decreased, although none of the differences were statistically significant.
• The application of manure at 5 t/ha on top of 170kg N/ha applied as urea significantly increased yield relative to all other treatments except where the equivalent nutrients to what were contained in the manure were applied.
• Since additional nitrogen had a negative effect on grain yield when it was applied as prilled urea, it is concluded that the positive effect of the manure is either due to its slow release nature through the course of the season or more specifically the influence of other nutrients applied with the manure such as P, K and S.
• Unusually there was no increase in grain protein as the rate of N was increased with no differences in the level of grain protein in the trial (second highest yield).
• There was an increase in crop lodging as the rate of applied nitrogen increased above the zero N.

Rotation position: 2021 Faba Beans
Soil type: Grey clay loam
Colwell P (ppm) 0-10cm: 110.0
pH (CaCl2) 0-10cm: 5.0
Organic Carbon (%) 0-10cm: 2.4