It may seem quite boring to think about unless you are a farmer, but it is possible (see micronovae, etc.) that one say we will almost all be farmers again, as we were for most of human history. Luckily, we’ve learned a lot and we won’t be starting from scratch, most likely.
After several seasons of growing the same plants, for example, in the same field, farmers discovered that the plants stop growing well and become less nutritious as food. We humans have learned through long trials and errors how crop rotation works and also determined that for large scale agriculture, farmers end up needing to supplement the soil with nitrogen, which gets taken up by most plants and thus removed from the soil.
Synthetic nitrogen fertilizers are typically applied to large fields using several different methods, depending on the specific requirements and equipment available. The most common methods include:
1. Broadcasting: Broadcasting involves spreading the fertilizer granules uniformly across the field, either manually or using mechanical spreaders. This method is suitable for crops that have uniform nutrient requirements throughout the entire field.
2. Side-dressing: In this method, the fertilizer is applied directly to the side of the growing plants, usually in rows or bands. Side-dressing ensures that the nutrients are placed closer to the root zone, reducing the risk of nutrient loss through runoff or leaching. This method is commonly used for row crops like corn or vegetables.
3. Injection: Injection involves using specialized equipment to inject the fertilizer directly into the soil, either below the seed or next to the growing plants. This method helps to prevent nitrogen losses by placing the fertilizer uniformly and deeper into the soil, minimizing contact with the air and reducing the potential for volatilization.
4. Fertigation: Fertigation is a technique where the synthetic nitrogen fertilizers are dissolved in irrigation water and applied through the irrigation system. This method allows for precise control of nutrient application and is often used in situations where water is limited or for crops grown under controlled environments.
5. Aerial application: In some cases, synthetic nitrogen fertilizers can be applied using aircraft, particularly in areas with challenging terrain or for fields that are difficult to access by ground equipment. Aerial application can be done by dropping the fertilizers in granular or liquid form, typically using a calibrated spreader or sprayer attached to the aircraft.
It’s important to note that the choice of application method depends on various factors, including the crop type, soil conditions, equipment availability, and the farmer’s preferences. Additionally, farmers need to consider environmental concerns and local regulations to minimize nutrient runoff and ensure sustainable fertilizer practices.