When it comes to liquid fertiliser application, there are plenty of pros and cons associated with the method. To get a grasp of what is involved, Jane Carley visits one Shropshire farm which has fully committed to the concept.
Heal Farms has invested in a Challenger Rogator 600D self-propelled sprayer to handle all nitrogen applications as well as chemicals.
Making a significant commitment to liquid fertiliser for 2017 is Heal Farms, which has updated application equipment and invested heavily in storage and logistics.
The Shropshire family business has a large poultry unit and 1,800 hectares (4,450 acres) of crops, including 500ha (1,235 acres) of potatoes.
After starting three seasons ago with Yara’s liquid nitrogen foliar feed Nufol on all crops, Heal Farms has since converted all potato planters for liquid placement, while also committing to using liquid N to feed all other crops. The unit is also planning to use placement fertiliser on oilseed rape for September this year.
Heal Farms Director Matthew Wallace has seen significant benefits for both cereal and potato crops from the use of liquid fertiliser.
Heal Farms director Matthew Wallace says: “I joined Heal Farms last June, having come from a farming estate in Yorkshire which was all liquid fertiliser. It was on similar light, drought-prone soils to those here in Shropshire. In a dry spring I found liquid fertiliser was more available to the crop and usage was greater than when using granular ammonium nitrate or urea. Therefore, using liquids should also help improve tiller survival in dry conditions.”
There are particular advantages for potatoes. He says: “They will always benefit from having nutrients placed close to the tuber at planting, especially in resisting potato cyst nematode or free-living nematodes. We have observed the canopy stays greener for longer, and while potato yields were generally disappointing last year, due to late planting, the crop was definitely more vigorous.”
"In a dry spring I found liquiud fertiliser was more available to crops"
- MATTHEW WALLACE
Yields and proteins are priorities when growing wheat for milling, so nitrogen availability is critical, he says. “The products also have readily available sulphate, which is ideal as I like to stagger application across the season. You can visibly see the crop green up afterwards. Correct sulphur concentrations in the plant is essential for protein formation in milling wheats and vital in oilseed rape crops.”
Crop consistency across the field is another goal and Mr Wallace says the coefficient of variation (application pattern) is low due to the uniform application which is hard to replicate with granular fertiliser unless using a pneumatic spreader.
“Scorch can be an issue, but paying attention to quantities and conditions minimises risk. Although potatoes were especially vulnerable to scorch with Nufol on my previous farm, it does not seem to be such an issue in this area.”
A change in machinery policy also favoured using liquid fertiliser, with a move from two self-propelled sprayers to a single higher capacity unit.
“With the significant investment required to buy a modern, high capacity sprayer, it is essential we use the capacity fully.”
Fertiliser can be applied through the sprayer in conditions which are too wet or windy for chemical applications, Mr Wallace points out.
“Although you need to be careful in frosty conditions, we can put liquid fertiliser on when it would be too windy for a fertiliser spreader, so working windows are comparable when applying at widths greater than 30 metres.”
Heal Farms' Rogator can cover 250 hectares (620 acres) in a single day.
The land is somewhat spread out, which makes for plenty of road travel and he says two 24m, 4,000-litre sprayers did not stack up.
“We needed two operators, but this did not allow any cover for holidays or back-up with a bowser. Now we have operators who can work as a team and cover for each other.”
After studying the various options, Mr Wallace chose a Challenger Rogator RG655D sprayer with 36m boom and 6,000-litre tank, plus an 800-litre/minute pump to give the necessary output for fertiliser and allow filling in about six minutes, using a 76mm (3in) coupling.
“We had it initially on demonstration so we could evaluate the machine functions. But we still needed to see if it could cover 500ha of potatoes in two days for blight sprays, so we had the demo machine back again and filled it with water to spray the equivalent area on stubbles,” says Mr Wallace.
“Supported by a bowser, we covered 140ha in a morning at 200litres/ha, and this was with the driver having to fit the 36m bouts round our existing 24m headlands, so we knew we could do it.”
Liquid fertiliser storage tanks are easy to install.
Roadwork and filling time, he suggests, is still the biggest limiting factor. “Even with a bowser, the telematics system on the sprayer showed us it only spends about 50 per cent of its time with the nozzles on.”
Mr Wallace accepts there may be increased pressure on a single sprayer applying fertiliser and chemicals at certain times of year but says: “We still have two operators so could spray round the clock if necessary.”
Liquid fertiliser has also resolved some storage headaches. With several remote farms, tanks have been installed at four sites for easy filling.
“Some farms have no suitable buildings which would be secure enough to store bag fertiliser. The tanks take up little space and are secure, plus it eliminates the need for a telehandler and operator to load a spreader or take delivery – the sprayer driver simply fills his own machine as necessary. We can also use the tanks for potato fertiliser in spring and Nufol later in the season.”
The only requirement is for a reasonably level hard surface which can be accessed by a tanker, which needs no more turning area than required for modern tractors and sprayers, he points out.
There are plans to use the sprayer in conjunction with a Yara N Sensor this year, although there are still a few compatibility issues to overcome.
The farm is planning to use a Yara N Sensor this year, as Mr Wallace says it allows nitrogen to be used more efficiently.
“The N Sensor allows us to use N more efficiently and produces a more even crop canopy for improved yields and easier harvesting,” says Mr Wallace.
“Our February N application is usually quite small and scanning after this allows us to vary the following application according to whether crop areas are ahead or behind where they should be. I have seen some savings in overall applications in my past role, but more importantly fertiliser can be targeted to where it is needed.
“We also use it to scan the potato canopy and identify potato cyst nematode hotspots or pinpoint changes before they can be seen by eye, such as the beginning of senescence.”
The Shropshire farming business grows 500ha (1,235 acres) of potatoes and has converted all potato planters for liquid placement.
Bag product is still required to top dress potatoes with ammonium nitrate, as well as to meet P and K requirements, and may be ordered at a more favourable time when storage space is available, having previously been used for nitrogen fertiliser.
“Fertiliser ordering decisions are made in autumn for the following spring but there is still flexibility and the actual supply system is straightforward.
“We are always looking at different cropping opportunities and, if crops were introduced which are not suited by liquids, we still have a fertiliser spreader which could be used.”