What should be monitored to prevent over-fertilization in nurseries?

Monitoring soil nutrient levels and plant growth responses is crucial to prevent over-fertilization in nurseries. Over-fertilization can lead to nutrient imbalances that harm plant health, resulting in issues like root burn or increased susceptibility to diseases. By regularly testing soil nutrient levels, nursery technicians can determine if the plants are receiving the appropriate amounts of essential nutrients. Additionally, observing how plants respond to fertilization—such as their growth rate and overall health—provides critical feedback on whether the current fertilization strategy is effective or requires adjustment.

The other options, while important in their own contexts, do not directly address the specific issue of over-fertilization. Ambient temperature can affect plant metabolism and growth but does not indicate nutrient levels. Monitoring water levels is essential for irrigation management but does not directly prevent nutrient overloading. Weed growth can signal soil health and competition for resources but does not provide the specific data needed to prevent over-fertilizing. Thus, focusing on soil nutrient levels and plant responses provides a more comprehensive and targeted approach to fertilizer management in nursery settings.