18 April 2024
Tillage advice: Seeding rates, fertiliser and planting spring beans
The prospect of at least two weeks of fine, dry weather is lifting everybody’s mood. In order to make the best of the dry spell, Teagasc Head of Crops Knowledge Transfer, Michael Hennessy explains planning is needed – especially around sourcing materials which will be needed in the coming weeks.
Having both seed and fertiliser ordered and delivered to the farm can substantially increase the area which can be planted during this dry spell. Contact your merchant as soon as possible and order these inputs, and – if possible – get the goods delivered, so that you can continue to carry out field operations.
Seeding rates
As we are now a little late for planting all cereal crops, you will need to examine the seeding rate which you normally use on your farm. Crops will emerge quickly from the seedbed and we can expect these crops to race through the growth stages very quickly.
Due to the warmer temperatures and longer days, plants will not have the same amount of time to tiller. Plants which would normally expect to have three shoots, may now only have one and a half to two shoots per plant.
In order to hit the shoots/m2, it is necessary to plant more seed to counteract the lack of tillering. For spring barley, target a seed rate of between 170kg/ha to 200kg/ha (dependant on TGW) to establish between 325 and 350 plants/m2. This will give the best chance of achieving a good yield.
Fertiliser requirements
The second area to look at is what fertilisers are needed. Apply all the phosphorous (P) and potassium (K) to seedbed before the crop is sown or as the crop is being sown. For malting barley, if there is time, apply the remaining nitrogen to the seedbed; otherwise as with feed barley, apply the remaining nitrogen as soon as the crop emerges.
The general recommendation is to apply 135kg of nitrogen (N) per hectare for a 6.5t/ha crop of spring barley. Where you expect a higher yield, then increase by 20kg of N/ha per extra ton expected.
However, a word of caution, yield expectation of cereals emerging in May is modest in most years. For malting barley, it may be prudent to reduce the total nitrogen usually suited to your farm by 10-15kg/ha to improve the chances of making the malting spec. Making the spec will substantially improve the gross margin of the crop compared to feed barley.
Spring beans
Where spring beans are still to be sown, there is a fine line between overspending on inputs, eventual yield/margin and maintenance of your land. There may be a temptation to plant a lower seed rate of beans and then close gate until harvest. However, there are a number of risks with the strategy.
Ensuring eligibility for the protein payment is crucial to a positive gross margin. The Department of Agriculture, Food and the Marine outline the criteria for eligibility to claim the protein payment. The crop must be commercially viable so that there are sufficient plant numbers established and the crop is capable of being harvested.
The second consideration is if there is no herbicide applied to the beans, the field will get very weedy – allowing a substantial weed burden to develop in the field. Long-term, this will not be helpful to grow good crops in the future. Finally, don’t plant the bean seed too deep, as this will help the crop to emerge quickly.
For more advice from the Teagasc Crop Specialist team, tune in to this week’s Tillage Edge podcast where Michael Hennessy, Shay Phelan and Ciaran Collins offer advice on managing winter crops in the coming weeks.