When fertilizing crops, there are several important considerations to keep in mind to ensure optimal growth and health. Here are some key points to remember when applying fertilizer to crops, described in English:

1. Soil Testing: Conduct a soil test prior to fertilizing to determine the nutrient levels and pH of the soil. This helps in identifying any nutrient deficiencies or imbalances, allowing for targeted fertilization and avoiding unnecessary applications.

2. Understand Crop Needs: Each crop has specific nutrient requirements. Familiarize yourself with the nutrient demands of your crops to ensure you are providing the right type and amount of fertilizer.

3. Timing is Key: Apply fertilizer at the right time in the crop's growth cycle. Early spring and before planting are common times for pre-plant fertilization, while side-dressing (applying fertilizer to the side of rows during the growing season) may be necessary for certain crops.

4. Uniform Application: Ensure that fertilizer is applied uniformly across the field or garden to avoid nutrient imbalances that can lead to uneven growth and reduced yields. Use appropriate equipment such as spreaders or injectors to achieve even distribution.

5. Avoid Over-Fertilization: Applying too much fertilizer can cause nutrient burn, excessive vegetative growth, and even reduced yields. Follow recommended application rates based on soil tests and crop needs.

6. Watering After Application: Watering after fertilizer application helps dissolve the nutrients and move them into the soil for plant uptake. However, avoid applying fertilizer immediately before heavy rain, as this can lead to nutrient runoff and leaching.

7. Monitor Plant Response: Keep an eye on plant growth and health after fertilizing. Look for signs of nutrient deficiencies or excesses, and adjust future applications accordingly.

8. Safety and Environmental Concerns: Always handle fertilizer safely, wearing protective clothing and following manufacturer's instructions. Be mindful of potential environmental impacts, such as nutrient runoff into waterways, and take steps to minimize these risks.