To determine the canola yield response to N, P, K & S in HYC environments, and to determine the factors driving the positive yield response observed from applying chicken manure to canola in HYC trials in previous seasons.

• Canola yield response to N application plateaued at 3.7 t/ha with 150 kg N/ha applied, 0.6 t/ha higher than where nil N was applied.
• The addition of 3 t/ha (dry basis) Chicken Manure (see analysis Table 3) with nil N had no impact on grain yield but did increase yield when applied with the 225 kg N/ha rate, yielding 0.4 t/ha more than 225 kg N/ha alone.
• Although the manure supplied ~105 kg N/ha, the lack of response where no N as urea was applied suggests that this N may not be readily available to the crop.
• The Inorganic Nutrient treatment (NPKS in inorganic fertiliser equivalent to 3 t/ha chicken manure) applied with 225 kg N/ha yielded similarly to where Chicken Manure was applied with 225 kg N/ha.
• Where the macro-nutrients N, P, K & S were sequentially dropped out of the Inorganic Nutrition treatment, the only one that affected yield was the subtraction of P. Dropping P out reduced yield by 0.4 t/ha compared with where both 3 t/ha Chicken Manure and the Inorganic Nutrient equivalent were applied with 225 kg N/ha.
• This response to P comes even where there was 15 kg P/ha applied pre-sowing (as single super) and 28 kg /ha P applied at sowing (as MAP).
• Further work determining optimum P levels is required for canola yields > 4 t/ha. Potentially growers should aim to increase their soil P reserves gradually over time (similar to N bank approach) to increase yield potential in high yielding situations.

Variety 45Y95 CL

Rotation position: Wheat 2022, Canola 2021, Pasture 2020
Soil type: Silty loam
Available Nitrogen (kg/ha) 0-100 cm: 119
Colwell P 0-10 cm: 34 mg/kg
pH (CaCl2) 0-10 cm: 5.3
Organic Carbon 0-10 cm: 2.1