According to Teagasc, liquid fertilizers represent a highly effective way to enhance crop performance under Irish growing conditions.
As a result, their use in the tillage sector continues to grow.
When applied under the correct conditions, they represent an effective alternative to granular nitrogen sources and can provide a lower N2O emission factor compared to calcium ammonium nitrate (CAN) in certain systems.
However, poor application practices can lead to leaf scorch, especially when nitrogen settles and concentrates on the leaf. Attention to conditions and technique is essential.
Practice application
The application can be more flexible than is often assumed, teaching He said.
Liquid fertilizers can be used when the crop is wet or under light rain, or even in dry conditions, provided other risks are managed.
Avoid situations where the crop is wet, dry or frozen, as this can leave a tinge of nitrogen on the leaf, increasing the risk of absorption and burns.
Spraying in the wind is not a problem as the currents are not deflected. However, once fine droplets begin to drip or drift, the quality of application decreases and the risk of uneven coverage increases.
Meanwhile, keeping the forward speed slow and the pressure low helps maintain larger drops and even distribution.
Early morning or evening applications are safest to avoid the heat of the day.
In cases where large temperature fluctuations of up to 20°C are expected, applications should also be avoided. Weather conditions of this type are very common during the period of April/May
For cereals, growers should aim to complete applications by growth stage 32 and avoid applying to the flag leaf or second leaf, where flaring can directly impact the crop.
In terms of sequence, apply liquid nitrogen first, followed by agricultural chemicals, leaving a gap of at least two days.
Applying fungicides first can soften or dewax the leaf surface and increase nitrogen uptake, increasing the risk of burn. When using agrochemicals first, allow at least five days to allow the leaf to recover.
Phosphate fertilizers
Phosphate fertilizer can also be added to crops in liquid form.
Trials in the UK have shown that these nutrients can be applied to newly established winter cereal crops at the three to four leaf stage using a conventional spreader
It is worth noting that the product can be mixed with the insecticide used to keep the barley yellow dwarf virus away.
There will be an opportunity to apply a second liquid phosphate process in the spring, as air and ground temperatures begin to rise.
