Iron and manganese may be in a chemical form that is unavailable to trees if the pH level is too alkaline. Is this statement true or false?

The statement is true. When soil pH levels become too alkaline (above 7.0), certain micronutrients, including iron and manganese, can precipitate in forms that are not soluble or accessible for uptake by tree roots. At higher pH levels, iron tends to form insoluble compounds, making it difficult for trees to absorb this essential nutrient. Similarly, manganese availability also diminishes with increasing pH.

Trees require a balanced supply of nutrients, and when essential elements are unavailable due to soil chemistry, it can lead to deficiencies that manifest in various growth issues, such as chlorosis or stunted growth. Thus, maintaining a suitable soil pH is crucial for optimal nutrient availability and tree health.