Storage of Fertilizer

Good storage and house-keeping practices are always important to ensure a safe workplace. Where possible, fertilizers should be stored in a closed, secure storage place to protect the product from the weather (sun, rain etc.) and reduce the risk of theft. The ideal storage conditions are:

  • 02.1 IMAGE storage first drawingEnclosed building capable of protecting the product from the weather and especially direct sunlight.
  • Clean environment, free of dust/dirt.
  • Temperature between 5 and 30˚C (some fertilizer types are sensitive to high temperatures)
  • Protect the fertilizer from moisture, which can cause lumps and dust, influencing spreading capabilities
  • Equipped with pallet racking to avoid the need for double stacking
  • Good stock management e.g. carried out on a First In, First Out basis

Indoor storage

  • The store should preferably be single store, constructed of not-readily combustible material (e. g. concrete, brick, steel)
  • All buildings should have adequate provisions for ventilation to help dissipate heat and discharge fumes in a fire or decomposition.
  • The floor should have a level, dry and even surface, free from pot-holes.
  • Limit the height of fertilizer stacks. High stacks of bagged fertilizer can be unstable and may collapse.
  • Limit the size of stacks of fertilizer bags in accordance with national regulations, if any. (300 tons for straight ammonium nitrate (> 28 % N))
IMAGE compatibility matrix trans
  • Store at least 1 meter away from building eaves and beams and, in the case of bagged fertilizer, also from walls.
  • If you stack on pallets, they have to be placed on a firm drained surface. If you place the pallets on top of each other, make sure you have a firm base.
  • Do not store in bulk materials which are incompatible near each other e.g. urea near ammonium nitrate-based fertilizers; keep them well separated. Never mix fertilizers without dividing the stock in trade. Keep lime and fertilizer well separated. (See compatibility matrix and physical properties of fertilizers)
  • In an indoor storage on a flat surface, you can increase to three sacks in height.
  • Keep the fertilizer away from any flammable material. Make sure you have a distance of at least 5 meters between the materials. Most nitrogen fertilizers contain nitrates which decomposes when heated, developing toxic nitrogen oxides already at 150˚C. Some products can even develop carbon oxides (CO, CO2) and sulphur oxides as well.
IMAGE indoor storage comb

Outdoor storage

  • Store on a raised level, well-drained, dry and smooth surface.
  • Use a pallet beneath the bags to prevent direct contact with the ground and the water (i.e. in case of heavy rain). Only use pallets with undamaged pallet caps, they must also be free from splinters and nails.
  • Stack should not lean, if they do, rebuild them immediately.
  • In order to preserve product quality, place a layer of empty pallets on top of the stack prior to sheeting to prevent product deterioration due to heat effects (as advised by the manufacturer/supplier).
  • Where pallet racking is not available certain combinations of pallets may be double stacked.
  • Stacks should be sheeted to prevent bags from getting dirty and the sheets should be secured to the bottom layer of the stacks to prevent damage, which may be caused by rubbing and friction.
  • Exercise great caution when sheeting and desheeting stacks, it should preferably be carried out in good weather conditions.
  • Verify the stability of the stack before untying the sheets. Sheets may become coated with algae. This is slippery and potentially hazardous.
  • In cold weather, sheeted stacks may be covered in ice. This is frequently heavy and sharp. Falling ice blocks are extremely hazardous. Ice is slippery and potentially hazardous.
  • All fertilizer stored outside should be protected from the elements by covering with a tarpaulin. Anchor the tarp well around the product. Splice should overlap at least 30 cm. Keep the ground and driveways free of fertilizer spills.

For outside storage, place pallets on top of the covered fertilizer to protect against damage caused by birds to tarpaulin and bags.

For stability and safety, big bags should be stored in the form of a pyramid. Pallets stack height should be no higher than 3-pallets high depending on product, stability of the pallet and handling equipment.

IMAGE outdoor storage comb

Storing Liquid Fertilizer

IMAGE Liquid fertilizerThe storage requirements for liquid fertilizers depend on the number of grades required at any one time, farm topography and logistics. 

If spilled, liquid fertilizers can be very damaging to the water environment, whether from accidental spillage, poor management or vandalism the result could be water pollution with legal and financial consequences.

Farmers share a duty of care for siting, use and maintenance, even when the supplier provides the tanks.

Using Liquid Fertilizer Tanks

  • Ensure tanks, pipework and valves are fit for purpose, ie resistant to corrosion. 
  • Ensure all tank fittings are tamperproof. Lock all valves shut when not in use. 
  • Ensure delivery companies are aware of emergency procedures. 
  • Ensure tank, pipework and valves are in good condition before deliveries are made. 
  • Check tank has sufficient capacity before delivery. 
  • Avoid overfilling. 

Maintaining Liquid Fertilizer Tanks

  • Have tanks, pipework and valves inspected internally and externally, for damage and corrosion at least annually by a suitably qualified technician. 
  • Carry out any necessary remedial work immediately. 
  • Undertake additional checks at the start of the season and when deliveries are made to and from the tank. If in doubt do not use the tank or bowser. 
  • Drain down and flush through all pipework at the end of each season. 
  • Keep a maintenance record. 

Permanent Storage Tanks 

  • All sites must be more than 10m from a watercourse.
  • Conduct an environmental risk assessment. Advice is available from the Environment Agency in England and Wales or SEPA in Scotland 
  • Construct secondary containment where environment assessment shows high risk. Use of reinforced masonry or concrete is recommended and provision should be made for at least 110% of tank capacity. Properly designed and constructed earth embankments may be an acceptable alternative. All pipes, valves and sight gauges should be within the containment area.
  • Tanks must be on a solid, stable flat concrete on a hardcore base to take the full tank weight. 
  • Consider additional stabilisation against high winds for GRP tanks. 

Bowsers and Mobile Tanks

  • Temporary storage can pose a significant hazard to watercourses. Thus suitable siting is crucial before filling or dispensing. Transport around the farm needs careful consideration. Roadways and tracks must be able to withstand fully laden bowsers passing over or being parked on them. 
  • Ensure bowsers and all fittings are fit for purpose and protected from corrosion. 
  • Ensure bowsers are set down on level, solid ground before delivery is made. 
  • Provide sufficient support beneath parking legs to carry loaded weight without it sinking into the ground or becoming unstable. 
  • Ensure all hatches and manholes form a watertight seal when closed. 
  • Do not move laden bowser unless all hatches, lids and valves are closed and locked. 
  • Open hatches slightly, when emptying bowsers, to avoid a vacuum which could cause the tank to crumple and collapse.

Further Information

Storage of YaraVita Micronutrient Fertilizers