What factor does NOT impact fertilizer safety in proximity to seeds?

Soil moisture content is indeed a factor that does not impact fertilizer safety in proximity to seeds. Fertilizer safety in relation to seeds is largely influenced by factors such as the salt index, ammonia content, and nutrient mobility, all of which can directly affect seed germination and growth.

The salt index refers to the potential of a fertilizer to create osmotic pressure in the soil solution. High salt concentrations can lead to salt toxicity, which can adversely affect seed germination and plant development. In contrast, soil moisture content does not directly correlate with the safety of fertilizer in terms of causing damage to seeds.

Similarly, ammonia content can be hazardous to seeds when fertilizers release ammonia gas, particularly if the fertilizer is placed too close to the seeds. This can harm seedling development and reduce overall plant health. Nutrient mobility, which relates to how easily nutrients can move through the soil and be taken up by plants, also plays a role in fertilization safety, as certain nutrients can become overly concentrated around the seed area.

In this context, soil moisture content is primarily a consideration for the growth conditions of the seeds themselves rather than a direct factor affecting the safety of fertilizer applications near them. Thus, it is the least relevant among the options when discussing fertilizer safety in