According to Teagasc, fertiliser costs increased in early 2021. However, in the last six months, prices have escalated to all-time highs.

Nitrogen (N) has doubled in cost due to the limited supply and rising costs of natural gas. Fertilisers are one of the largest costs in cereal crop production.

In light of these developments Teagasc has outlined a number of recommendations, the implementation of which will help farmers control their fertiliser costs in2022.

Soil analysis

The Teagasc soils database shows that approximately 31% of tillage soils are at phosphorus (P) and potassium (K) Index 4.

Farmers should, therefore, identify these fields and make savings on P and K applications in 2022. Where soil results are over four years old, growers should re-sample fields over the coming weeks.

Lime and soil pH

Farmers should apply recommended lime rates based on recent soil analysis.

This is the first step to increasing the availability of soil nutrients and increasing the utilisation of applied N, P and K as either organic or chemical fertilisers.

Organic manures instead of fertiliser

Where organic manure supplies are available they will replace expensive fertilisers and are a cost-effective source of N, P and K.

To maximise the recovery of N from high N manures (pig and poultry), it is important to apply and incorporate within three to six hours of application.

Ideally, manures should be tested in advance of application to know their nutrient values and adjust application rates to supply approximately 50% of a crop’s P and K requirements. E.g., an application of 2,200gals/ac of pig slurry can supply 52kg N, 20kg P and 50kg K/ha, which is circa 30% of the N and 50% of the P and K requirements for a crop of spring barley.

Now is a good time to look at local sources of organic fertilisers and plan for spring crop utilisation.

Straw incorporation

Straw contains approximately 10% and 50% of total crop P and K, respectively e.g., the straw from a 10t/ha grain crop of winter wheat will return approximately 4kg P and 50kg K/ha.

This offers significant savings, in the region of approximatley €80/ha in fields where straw is chopped.

Beans and peas

Where N-fixing crops are grown in a rotation, the following crop’s N requirements are reduced, as they fix atmospheric N, thus increasing soil N supply.

E.g., cereals grown after legume crops have an up to 30kg N/ha lower N requirement, which reduces N costs by around €75/ha.

Urea v CAN fertiliser

Further savings can be made by selecting urea (46% N) over CAN (27% N). At present urea is up to 20% cheaper than CAN, which represents a €20/ha saving on every 100kg N/ha applied.

Urea can be more difficult to spread, but with good particle size distribution, a good spreader and accurate setting of the spreader, good spreading can be achieved across a range of even bout widths.

Urea can also be subject to ammonia loss, which is increased by rising temperature and under drying conditions.

Combine drilling P

At sowing time, placing P fertiliser with seed will increase the efficiency of applied fertiliser.

Research, evaluating P fertiliser application methods for spring barley, clearly shows the importance of delivering P fertiliser close to the germinating seed on low-fertility soils (Index 1 and 2).

Grow crops with lower N requirements

Farmers should grow crops, where possible, with lower crop N requirements.

Depending on crop rotations and market requirements, these include: beans / peas, spring barley or spring oats.

Economic optimum N rates

With the N fertiliser price having increased threefold, adjusting N rates will be required to maximise the return on investment.

Growers should contact their local advisor to discuss economic optimum rates for the soils and crops on their specific farms.

Complete a farm fertiliser plan

Growers should also contact their local advisor now to update their respective farm fertiliser plan to put in place a strategy for lime, organic fertilisers and fertiliser requirements for 2022.