Land, machinery and nitrogen fertiliser, and whether to consider urea, are the big ticket items that farmers have to address as they work through their annual commitments.
Where bagged fertiliser is concerned, both phosphate (P) and potash (K) are substantially more expensive than was the case in 2022, with nitrogen (N) close to being as expensive as it has ever been.
There are hints that N prices will ease over the coming weeks. But this may not happen in time for the 2023 growing season.
However, there is a large differential in the price of different nitrogen sources. And this may well guide farmers’ purchasing decisions.
Urea
The latest Tillage Edge podcast focuses on the potential for urea as a fertiliser nitrogen option in 2023.
Teagasc’s Dr. Richie Hackett joined the podcast to discuss the relative merits of urea and calcium ammonium nitrate (CAN) as nitrogen sources on farms this year.
According to the Oak Park-based research scientist, urea has traditionally been cheaper than CAN.
“But this difference seems to be much bigger now than would have been the case in previous years,” he explained.
“My understanding is that CAN is a European product, where prices were very high last year. On the other hand, urea is a truly international product.
“It may well have been made in places where the gas price wasn’t so high and this is accounting for the enhanced price differential with CAN at the present time.”
Pricing
Hackett has worked out the difference in price, per kg/N sourced as either urea or CAN, at the present time.
“There’s roughly €1/kg of difference in favour of urea,” he said.
“CAN at €810/t works out at €3/kg for every kg of nitrogen available. Urea, on the other hand works out at €920/t. This brings the unit nitrogen price down to €2/kg. This is a very substantial difference.”
On a block of land extending to 40ha, a crop of winter wheat will require 230kg of N/ha. In a normal year, a grower may apply 50kg of N as part of a compound. However, the remaining 180kg will be applied as either CAN or urea.
“At current prices we are looking at a total saving of over €7,000, if urea is selected as opposed to CAN,” Dr. Hackett continued,
“This is a substantial difference in favour of urea. It also means that growers really should consider using urea as a straight N source on their crops this season.”
Protected urea
There are two types of urea on the market at the moment. There is the normal product. And then there is the protected urea. This is a product that has been treated with a protectant, to make it more effective.
“Comparing the CAN with protected urea, it’s safe to say that there is no difference regarding the crop impact of both products,” said Hackett.
“One of the issues with normal urea is the fact that the nitrogen is not immediately available to the plant. The product has to be broken down to ammonia and then nitrate before it becomes crop active.
“During this process, some of the ammonia can be lost to the atmosphere.”
According to Hackett, N losses of 20-30% from urea are not uncommon, depending on weather conditions.
“Protected urea is every bit as effective as CAN,” Hackett stressed. “But with the unprotected product, there is the risk of N losses.”
The inhibitor, on the other hand, works to slow down the breakdown process that takes place within the urea granule, once it reaches the soil.
“This is not an issue from a plant growth point of view. The reality is that crops will not be able to instantly utilise all the fertiliser that might be sown out today,” Hackett continued.
“The reality is that plants will want to take up applied fertiliser of a four-week period.
“Urea N becomes available quite quickly once it dissolves. The inhibitor simply slows down the N release process.”
Nitrogen losses
Losses of N from urea are maximised when the fertiliser is spread on to a wet soil, which subsequently dries out. However, if it is put onto a dry soil and ground conditions remain unchanged, N losses from urea will be quite small.
“When the urea dissolves and then breaks, this is when losses will occur,” Richie Hackett said.
“Other risk factors would be high pH soils, which would tend to increase the volatilisation of ammonia. The soil pH in the direct vicinity is increased as the urea granules break down.
“Higher temperatures will also increase N losses from urea fertilisers. Lighter soils will tend to be more at risk, where N losses are concerned.”
If unprotected urea is washed into the soil by rain shortly after its application, this will tend to reduce the risk of N losses.
During spells of very wet weather, there is very little difference between the rate of nitrate leaching from the soil that will take place post the application of urea or CAN.
In most years, there is very little leaching of N from soils while crops are actively growing. The exception to this might be in the wake of heavy rain during the month of March.
Urea for malting barley
Hackett was asked if urea will meet the fertiliser needs of specialist growers e.g., those producing the likes of malting barley.
“A number of trials have been carried out at both Oak Park and Johnstown Castle, comparing the impact of CAN and urea on spring barley,” he replied.
“We have found there to be no difference, in terms of yield, between protected urea and CAN. On average, there was also no difference in the protein levels of the final crops produced.
“The plant sees protected urea and CAN as the same thing.”
Spreading urea
Farmers may have used urea in the past and found that it did not spread as well as CAN.
Hackett addressed this point specifically. He explained that farmers must have machinery that will apply the product evenly across a field.
“The first issue to be addressed is to establish the tram line widths that have been established for a crop, 24m for example,” he said.
“Then it’s a case of looking at the settings on the fertiliser spreader and adjusting them accordingly.
“Some spreaders may need different veins to handle urea. There may also be a requirement to set the veins at different angles or different speeds.
“Basically, if growers use the same fertiliser setting for CAN while using urea, poor spreadability may well be the end result,” he added.
Dr. Hackett said that the end result could be the creation of stripes within a crop.
“I would urge all growers using urea for the first time to check that their spreader is set up properly,” he urged.
Fundamentally, urea is much lighter than CAN. For growers still on 12m or 15m tram lines, the issue of poor spreadability is not that critical.
But for those farmers working off much wider tram line widths, the need to recalibrate the spreader will be significant.
Urea in blends
Urea can be mixed with a combined sulphur (S) and K source to produce a blended fertiliser. In this instance a mix of two different densities will be going into the spreader.
According to Richie Hackett, this mixing effect can create additional challenges for growers when it comes to calibrating the spreader properly.
“The analogy that can be made here is that of throwing a golf ball and a ping-pong ball with the same force.
“Under these circumstances, the expectation is that the golf ball would travel further. So, in other words, the heavier product will be pushed out further from the tractor with the lighter product staying closer to it.
“This results in an uneven spreading of the nutrients. So where blends are concerned, farmers need to be very careful when it comes to spreading them,” he said.
S is now recognised as an important nutrient for all crops. But for those growers not wishing to use a urea blend, what is the method of getting additional nutrients out into a crop?
According to Richie Hackett, the option here is to use a compound with S in it. There is also the option of using sulphate of ammonia or ammonium sulphate nitrate (ASN).