Rules for storage, transportation and preparation of mineral fertilizers for application

Storage and transportation: how to protect fertilizer from moisture and losses

Mineral fertilizers are produced all year round, but they are required in the field within strictly defined agrotechnical timeframes. The main task of an agronomist during storage is to prevent the deterioration of granules and powders by protecting them from their main enemy: moisture. Any warehouses or temporarily adapted facilities must have an absolutely dry, leak-proof roof and drainage ditches around the perimeter of the building. When transporting unpacked fertilizer, vehicles should be covered with a tarpaulin or metal-roofed trucks should be used, while pulverized forms are transported in cement tanker trucks.

In the warehouse, each batch is weighed and distributed into separate sections divided by partitions or panels. Each compartment must be labeled with the type, form of fertilizer, and exact content of the active ingredient. When storing in bulk, it is important to strictly observe the maximum pile height to avoid caking and structural damage.

Fertilizers bagged in paper or plastic sacks are manually stacked in a crisscross pattern. For ammonium nitrate and urea, the limit is 15 layers. Complex fertilizers and granular superphosphate can be stacked higher—up to 20 layers.

Preparation of fertilizer mixtures and field application technologies

For balanced plant nutrition, it is often necessary to prepare fertilizer mixtures. This should be done immediately before heading to the field, as ready-made mixtures cake quickly during storage. The entire preparation process is automated using specialized fertilizer-mixing units, where raw components are loaded by front-end loaders and the finished mixture is discharged by belt conveyors into trucks or spreaders.

1. Unpacking of bagged mineral fertilizers using specialized machines.
2. Crushing of the caked mass and its screening.
3. Mixing of the components in a mixer.

Depending on the growing season of the plants and the objectives, the optimal method of fertilizer application is chosen:

• Broadcast surface application — using fertilizer drills and centrifugal spreaders with a 5% overlap of the unit’s working width.
• Localized application — using attachments for row-crop cultivators.
• Localized subsurface application — simultaneously with sowing using combination drills.
• Root top dressing — during inter-row soil cultivation with row-crop cultivators.
• Foliar top dressing — using ground-based sprayers or aviation (airplanes and helicopters).

During subsurface application with combination drills, fertilizer is placed at a depth of 5 to 15 cm from the soil surface, maintaining a distance of 2–7 cm from the Depth of placement seed placement depth. For cereals and grain legumes, the interval between fertilizer bands should be 12–17 cm, and 20–30 cm for row crops. In this case, for row crops, the bands are offset from the seed row by 2–10 cm. The precision of field equipment directly determines the efficiency of plant nutrition, so the quality of equipment adjustment is monitored according to strict technological tolerances.

• Non-uniformity for granulated — no more than 20%
• Non-uniformity for powdered — no more than 25%
• Non-uniformity during top dressing — no more than 15%
• Dose deviation from the target — no more than ±10%
• Non-uniformity between coulters — no more than 10%
• Placement depth deviation — no more than 1.5 cm

Logistics of aerial application, liming, and working with liquid fertilizers

Fertilizers are applied from the air using a shuttle or plot-based method with partial overlapping of adjacent strips. The optimal flight radius from a single site is 8–10 km. Fertilizers are delivered to the airstrip by road transport and loaded into hoppers by specialized loaders. If there is a warehouse at the airfield, the batch of fertilizer is brought in advance.

• Aviation operating radius — 8–10 km
• Lime and ammonia dose deviation — up to 10%
• Limit losses of anhydrous ammonia — 0.8%
• Direct transport of liquid organic fertilizer — up to 5 km

When performing liming, the choice of technology depends on the transport distance. For powdery materials, a direct-flow scheme is used at a distance of up to 13 km for tractor units and up to 90–100 km for bulk cement tankers. In other cases, transshipment technology is used.

Low-dusting lime and gypsum-containing materials are applied by tractor or truck spreaders. For short distances, they are transported directly; for long distances, a transfer method is used. Transshipment technology for such materials is used rarely, within a range of 5–10 km. In this case, the unevenness of lime distribution should not exceed 25% of the application rate, and the deviation of the actual dose from the target one — 10%.

It is cost-effective to transport ammonia water directly from the plant within a radius of 20–30 km. If the fields are further away, rail-side and deep-storage warehouses are built. Transportation is carried out in railway and road tankers, and application to the soil is performed using top dressing sprayers.

Liquid complex fertilizers (LCF) are stored in rail-side (with a capacity of 1000–4000 t) and deep-storage (100–800 t) warehouses. On farms, steel reservoirs are used for this purpose, and directly for field work — mobile or stationary tankers with an internal coating. LCF are applied by standard machines before tillage, during sowing, or as top dressing. Aviation can be used for surface distribution.

Rules for the application of anhydrous ammonia and organic fertilizers

Liquid (anhydrous) ammonia is delivered from the plant to rail-side warehouses in railway tankers. It is transported to the fields by truck or tractor tankers and applied to the soil by special units. Operations are carried out using direct-flow, transshipment, or transfer technology.

When setting the working tools of an applicator for anhydrous ammonia, the following intervals are observed:

• For broadcast-sown crops: 30–45 cm;
• When cultivating row crops: pre-sowing local application along the seed placement line (during top dressing, the distance must correspond to the row spacing);
• On hayfields and pastures for two-cut use: up to 60 cm;
• On hayfields and pastures for multi-cut use: 30–34 cm.

For solid fertilizers, a direct-flow scheme is used for small volumes and when fields are located close to livestock buildings. If the manure output is large, transfer technology is used: organic matter is transported to field piles all year round and then distributed by manure spreaders at optimal agrotechnical times.

Liquid organic fertilizers (LOF) are applied using one of three schemes:

• Direct-flow technology: liquid manure is transported by machines or pumped through a pipeline directly from farm storage facilities to a distance of up to 5 km.
• Transshipment technology: if fields are more than 5 km away, fertilizers are delivered by large-capacity transport and transshipped into machines for surface or soil-injection application.
• Transfer technology: used at a distance of more than 5–7 km. Manure is pumped or transported in tankers to field storages, from where it is distributed by spreader tankers, by gravity flow, or by sprinkler irrigation at optimal times.