Final answer:
The correct statement is that nutrient imbalance can limit plant growth. Excessive nitrogen can lead to eutrophication, and phosphorus is essential but must be balanced. Mineral nutrients are crucial for biogeochemical cycles and ecosystems' health. Therefore, the correct option is d.
Step-by-step explanation:
An accurate statement regarding mineral nutrients in soils and their implication for primary productivity is that nutrient imbalance can limit plant growth. Excess nitrogen does not promote biodiversity; it can lead to eutrophication and harm aquatic ecosystems. Phosphorus deficiency does not enhance plant growth; it limits biological nitrogen fixation, which is crucial for plant nutrition. Mineral nutrient availability is highly relevant to primary productivity, as it influences the distribution and abundance of living things through biogeochemical cycles.
Synthetic fertilizers contain high amounts of nitrogen and phosphorus because these elements are critical for plant growth. However, too much of these nutrients can cause ecological disturbances like nutrient overload and eutrophication, leading to the depletion of oxygen in water bodies. Organic agricultural methods, which tend to increase soil quality, contribute to biodiversity and facilitate natural biogeochemical cycles, thereby supporting healthier ecosystems.