Fertilizer application

Question 1

What are the main macronutrients?

Answer 1

Three main macronutrients:

• Nitrogen (N): Leaf growth.
• Phosphorus (P): Development of roots, flowers, seeds, fruit.
• Potassium (K): Strong stem growth, movement of water in plants, promotion of flowering and fruiting.

Three secondary macronutrients:
■ calcium (Ca),
■ magnesium (Mg), and
■ sulphur (S)

Question 2

Describe the main Qualifications of a disk spreader?

Answer 2

• Equal distribution of the fertilizer in both transversal and longitudinal direction, with full and partly empty hoppers, with different travel speeds and different application rates
• Sufficient capacity of the hopper
• Possibilities for adaptation to relative high crops
• Easy and accurate adjustment of mass flow
• Possibilities for border spreading
• High resistance against corrosion
• Easy cleaning
• High capacity

Question 3

What is the difference between a pneumatic spreader and a sprayer?

Answer 3

Spreader:
- Broadcasting of fertilizer
- Site-specific fertilisation considering field heterogeneity

Sprayer:
- Foliar application of diluted nutrient solutions or suspensions by spraying the leaves
-Site-specific fertilisation considering field heterogeneity

Question 4

Why is the fertilizer placed next to the seeds when they are sown at the same time?

Answer 4

Enhanced Nutrient Availability: Placing fertilizer in close proximity to seeds ensures that nutrients are readily available to the young seedlings as they begin to germinate and establish root systems. This proximity allows roots to access nutrients more efficiently, promoting early growth and development.

Reduced Nutrient Loss: By banding fertilizer near the seeds, there is less risk of nutrient loss through leaching or runoff compared to broadcasting fertilizer across the entire field. This targeted application reduces the amount of fertilizer that may be lost to the surrounding environment, minimizing environmental impacts and improving fertilizer use efficiency.

Conservation of Fertilizer: Banding fertilizer reduces the overall amount of fertilizer needed to achieve desired crop yields. By concentrating nutrients in the root zone where they are most needed, farmers can optimize fertilizer usage and reduce input costs.

Prevention of Seed Burn: Placing fertilizer directly in contact with seeds can help prevent seed burn, which occurs when high concentrations of fertilizer salts come into direct contact with germinating seeds, potentially damaging or inhibiting seedling growth.

Ease of Application: Banding fertilizer alongside seeds can be easily accomplished using various seeding equipment and techniques. This makes it a practical and efficient method for delivering nutrients to crops during planting.

Question 5

Describe the different parts of a disc spreader

Answer 5

Voir slide 17

Question 6

What is boundary spreading?

Answer 6

If the field is adjacent to a road or cycle path, no fertiliser must be thrown beyond the border of the field.

Question 7

What is the difference between working width and spreading width?

Answer 7

Working width=> area you want to cover, vs spreading width, the actual widht you are spraying.
As the fertilizer quantity decreases towards the outside, the individual spread patterns must overlap when driving back and forth across the field. This is the only way to ensure even distribution over the entire area. This creates a triangular shape.

Question 8

Why do you need overlapping when applying fertilizer?

Answer 8

overlapping when applying fertilizer is essential for achieving uniform nutrient distribution, minimizing variability in nutrient availability, preventing striping or streaking, optimizing fertilizer use efficiency, and reducing environmental impacts.

Question 9

Spreader Qualifications

Answer 9

■ A fertilizer spreader has to meet the following qualifications:
□ Equal distribution of the fertilizer in both transversal and longitudinal direction,
with full and partly empty hoppers, with different travel speeds and different
application rates.
□ Sufficient capacity of the hopper.
□ Possibilities for adaptation to relative high crops.
□ Easy and accurate adjustment of mass flow.
□ Possibilities for border spreading.
□ High resistance against corrosion.
□ Easy cleaning.
□ High capacity.

Question 10

Calibration of the dose rate

Answer 10

■ Desired flow rate [kg/min] = (speed [km/h] x working width [m] x Nutrient rate
[kg/ha]) / Nutrient content [%] x 60
■ Example: At a driving speed of 10 km/h and a working width of 24 m, 50 kg N/ha
in the form of calcium ammonium sulphate with 26% N should be applied
■ (10 [km/h] x 24[m] x 50 [kg/ha]) / 26 [%] x 60 = 7,69 [kg/min]