Pineapple has high requirements for the fertilizer elements nitrogen (N), potassium (K), and iron (Fe), and relatively low requirements for the fertilizer elements phosphorus (P) and calcium (Ca). Although Hawaiian pineapples grow in red soils whose iron composition may exceed 20%, they can starve for iron. Explain this based on solubility of the iron found in red soil.
Take a one gram sample of the mycelia mat of a healthy familiar pineapple grown nearby and characterize it Chemically, the best you can, using the technology you have available, including a pool kit. Then research the pineapple as an agricultural product, find the seed growing depths and other growing requirements like sunshine. Try using different water levels using several pineapples. The optimal pineapple probably has the water level you may want to use on a new batch of pineapple trees.
The high iron composition in red soils might initially seem like a beneficial factor for pineapple growth. However, the solubility of the iron in red soil can actually lead to iron starvation for pineapple plants. Let me explain why.
Iron in soils exists in various forms, including both soluble and insoluble forms. Soluble iron is readily available for plant uptake, whereas insoluble iron is not easily absorbed by plants. Pineapple plants require a specific form of iron called ferrous iron (Fe2+) for normal growth and development.
Red soils are typically rich in iron oxides, such as hematite or goethite. These iron oxides are insoluble in water and have low solubility in acidic soils, which is the case for many pineapple plantations. This means that the iron in red soils tends to remain in an insoluble form, making it less available for pineapple plants to absorb.
While the iron composition in red soils may exceed 20%, the actual amount of soluble iron that plants can take up from the soil may be much lower. This limited availability of soluble iron can lead to iron deficiency in pineapple plants, despite the apparent high iron content in the soil.
To overcome this iron deficiency and prevent iron starvation in pineapple plants, farmers often apply iron fertilizers that are specifically formulated to enhance iron uptake by the plants. These fertilizers usually contain chelated iron, which is a form of iron that remains soluble and readily available for plant uptake even in alkaline or high-pH soils.
So, in summary, the solubility of iron in red soils is low, which limits the availability of iron for pineapple plants, even though the iron composition in the soil may seem high. This is why pineapples can starve for iron and require additional iron fertilization to meet their iron requirements.