Cereal Fertiliser Requirements and Compound Choice

The traditional approach of three 50Kg bags per acre of 18-6-12 as the intial fertiliser application for cereal crops is a poor choice in the majority of situations for today’s cereal growers.  The Potassium (K) level supplied by three bags of 18-6-12, is only 50% or less of requirements of most cereal crops.  Potassium is vital for yield, grain quality and straw strength.  The need for high yields coupled with high fertiliser prices and tight margins, dictate that care is required in choosing the best fertiliser compound to match the nutritional needs of your cereal crops. 

Insufficient Potassium (K) applications can contribute to lodging

Before selecting your cereal fertiliser compound, first ensure the basics are right:
• Have an up to date soil test for each area under cereals
• Apply lime as required
• Identify the crop nutrient requirements (see below)
• Make use of organic fertiliser where available-take care that any organic fertiliser being applied is reasonably consistent and that it is applied evenly.

Cereal Crop Nutrient Requirements and Recommendations

An extra 20Kg/ha (16 units/ac) of N is allowed for every ton yield above 9 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture)
**An extra 3.8Kg/ha (3 units/ac) of P is allowed for every ton yield above 6.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture)
***Add/subtract 10Kg/ha (8 units/ac) of K for every ton target yield above/below 11 tons/ha

*An extra 20Kg/ha (16 units/ac) of N is allowed for every ton yield above 7.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture).  An extra 30Kg/ha (24 units/ac) may be applied for milling wheat under contract
**An extra 3.8Kg/ha (3 units/ac) of P is allowed for every ton yield above 6.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture)
***Add/subtract 10Kg/ha (8 units/ac) of K for every ton target yield above/below 8.5 tons/ha

P and K status and time of sowing influence recommendations on the quality and timing of compound applications for spring cereals.  As there is greater risk of N loss from February sowings, no more than 40 Kg/ha (32 units/ac) N should be applied at sowing.

*An extra 20Kg/ha (16 units/ac) of N is allowed for every ton yield above 8.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture)
**An extra 3.8Kg/ha (3 units/ac) of P is allowed for every ton yield above 6.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture)
***Add/subtract 10Kg/ha (8 units/ac) of K for every ton target yield above/below 8.5 tons/ha

Given the importance of tiller numbers per m2 in determining barley yield, it is more important to apply early N (and therefore early compound application) in winter barley than winter wheat particularly if crops are thin or backward.

It is important to maximise tiller numbers in barley to achieve high yields

*An extra 20Kg/ha (16 units/ac) of N is allowed for every ton yield above 6.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture).  An extra 20Kg/ha (16 units/ac) may be applied for malting barley under contract with agronomic advice.
**An extra 3.8Kg/ha (3 units/ac) of P is allowed for every ton yield above 6.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture)
***Add/subtract 10Kg/ha (8 units/ac) of K for every ton target yield above/below 7.5 tons/ha

One of the recommendations to help meet malting barley protein requirements is not to apply more than one third of the total N allowance in the first split (at sowing/tramlines just visible) for early sown crops (sown prior to mid-March).  Incorporating 30Kg/ha (24 units/acre) at sowing may also be useful in this regard depending on weather conditions.

*An extra 20Kg/ha (16 units/ac) of N is allowed for every ton yield above 7.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture)
**An extra 3.8Kg/ha (3 units/ac) of P is allowed for every ton yield above 6.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture)
***Add/subtract 15Kg/ha (12 units/ac) of K for every ton target yield above/below 9 tons/ha

*An extra 20Kg/ha (16 units/ac) of N is allowed for every ton yield above 6.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture)
**An extra 3.8Kg/ha (3 units/ac) of P is allowed for every ton yield above 6.5 tons/ha (proof required-best yield in any of 3 previous harvests at 20% moisture)
***Add/subtract 15Kg/ha (12 units/ac) of K for every ton target yield above/below 7.5 tons/ha

Phosphorus
• At soil P index 1 and 2 it is recommended that P is incorporated at or before sowing (unlikely to be possible under the nitrates directive for winter cereals). 
• Avail, is a new P fertiliser enhancer that increases the availability of P in soils (75-95% of P is normally locked-up in soils and unavailable to the crop).  While it has benefits in many situations it is particularly useful at soil P indices 1 and 2.

Sulphur
Cereals normally benefit from the application of 15Kg/ha (12 units/ac) Sulphur (S).  Responses are more likely on sandy, free-draining soils and land in continuous tillage.

Magnesium (Mg) and trace elements should be applied based on soil test results, herbage test results, historic deficiencies or where symptoms appear in the field.

Trace Elements
Soil tests can establish the status of Zinc (Zn) and Copper (Cu) in your fields.  However, soil test results for Manganese (Mn), the most common trace element deficiency, are unreliable and it is better to rely on field history or plant tissue test samples.

Trace element deficiencies are usually corrected by way of foliar spray applications when symptoms are seen in the field.  However, by the time symptoms are seen in the field, yield may already have been lost. 

Wolf Trax DPP (dry dispersable powder) micronutrients are a very effective way to achieve even application of micronutrients across a field.  Individual fertiliser granules are coated with Wolf Trax DPP and are carried into the soil with the dissolving fertiliser granule.

Dairygold Cereal Fertiliser Range 2013
Dairygold are able to offer a wide range of fertiliser compounds as made available by our wholesale fertiliser suppliers.  However, in addition to this, we have specifically formulated a number of compounds to match cereal crop needs in our catchment area:
• Greengrow Grain 12-6-20+4%S
• 12-6-18+3%S plus AVAIL plus Wolf Trax Mn plus Wolf Trax Zn
• 12-6-18+3%S plus Wolf Trax Mn plus
• 12-5-18+3%S plus AVAIL

These compounds applied at 370-500Kg/ha (3-4 cwt per acre) more closely match the requirements of cereal crops than traditional compounds like 18-6-12. 

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