Certified Crop Advisor Practice Exam

Which nutrient is commonly associated with crop yield increase?

1. Potassium

2. Iron

3. Phosphorus

4. Calcium

The correct answer is: Phosphorus

Phosphorus is widely recognized for its critical role in promoting crop yield increases. It is an essential macronutrient that contributes significantly to various physiological processes in plants, including energy transfer, photosynthesis, and respiration. Phosphorus is a key component of adenosine triphosphate (ATP), which is essential for energy transfer within cells. It also plays a vital role in the formation of nucleic acids, which are necessary for cell growth and division. The availability of phosphorus directly affects root development and crop establishment, enhancing a plant's ability to access water and other nutrients from the soil. When crops have sufficient phosphorus levels, they typically exhibit improved flowering, seed and fruit development, and overall biomass accumulation, leading to higher yields. In contrast, while potassium, iron, and calcium are important nutrients for plant growth, their specific roles differ from that of phosphorus. Potassium, for example, is crucial for regulating plant water use and enzyme activity, but its deficiency does not always limit yield to the same extent as phosphorus deficiency. Iron is primarily important for chlorophyll synthesis and photosynthesis, while calcium contributes to cell wall structure and stability. However, these nutrients are not as directly linked to yield increase as phosphorus, especially in the context of