CCA Ontario Crop Management Practice Exam

Assessing soil pH is important for crop production primarily because it directly influences nutrient availability and microbial activity within the soil. Each plant species has a preferred pH range within which it thrives best. If the soil pH is too low (acidic) or too high (alkaline), certain nutrients may become less available to plants, which can lead to nutrient deficiencies and negatively impact crop yield and overall health.

For example, micronutrients like iron and manganese become more available in acidic conditions, while phosphorus and calcium availability can be inhibited in very low or very high pH levels. Furthermore, soil pH also affects the activity and diversity of soil microorganisms, which play essential roles in nutrient cycling and organic matter decomposition. Thus, maintaining an optimal soil pH is crucial for ensuring that crops have access to the nutrients they need for healthy growth and for supporting a vibrant soil ecosystem.

The other options do not directly pertain to the critical role pH plays in crop production. While factors like planting time, water retention, and pest presence are important, they are not primarily influenced by soil pH.