Salt and Seed Germination. Specifically in the case of seeds that are germinated directly in soil, salt content is also an important consideration. When a fertilizer that causes a change in the soil's salt content comes into direct contact with a seed, a condition known as salt effect or salt burning can occur.he reason is that salt can dramatically affect a plant's growth in all its life stages, from seed to maturity to decline and death. You can avoid problems associated with salt content in soil by learning some essential information about the role of salt in soils.