What is a significant risk associated with water soluble nitrogen?

Water soluble nitrogen fertilizers are designed to be readily available to plants, which can promote immediate growth. However, a significant risk associated with these fertilizers is their increased potential for leaching. This occurs because water soluble nitrogen can easily dissolve in water and, when it rains or irrigation occurs, it can wash away from the root zone of the plants before they have the chance to absorb it. This not only reduces the effectiveness of the fertilizer but can also lead to environmental concerns such as groundwater contamination, as nitrogen is a key contributor to water pollution.

In contrast, other options such as limited availability to plants or cost issues are not characteristic of water soluble nitrogen, as they are meant specifically to ensure quick uptake. Additionally, the effectiveness of these fertilizers for plant growth is generally higher compared to slower-releasing forms, hence those options do not accurately reflect the risks associated with water soluble nitrogen.