Soybean meal fertilizer is an organic fertilizer primarily made from soybean cake (residue) through fermentation, drying, and other processes. It is rich in essential nutrients for plant growth, such as nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur, playing a critical role in improving soil structure, enhancing crop yield, and boosting quality. soybean meal fertilizer is not a high-phosphorus fertilizer but rather a low-phosphorus one. The reasons are explained below:

1. Relatively Low Phosphorus Content in Soybean Meal Fertilizer: The phosphorus in soybean meal fertilizer mainly originates from the phosphorus in soybean cake. During fermentation, part of the phosphorus is released, resulting in a relatively low phosphorus content. Depending on sources and production processes, the phosphorus content in soybean meal fertilizer typically ranges between 0.5% and 3%. In contrast, conventional chemical fertilizers contain 20% to 30% phosphorus, significantly higher than soybean meal fertilizer.

2. Higher Phosphorus Absorption and Utilization Efficiency: Although the phosphorus content in soybean meal fertilizer is low, its phosphorus absorption and utilization efficiency is relatively high. This is because the phosphorus in soybean meal fertilizer exists primarily in organic forms, which are easily absorbed by crop roots. In comparison, phosphorus in chemical fertilizers is mostly in inorganic forms, requiring conversion by acid phosphatases secreted by crop roots before absorption. Thus, soybean meal fertilizer reduces the need for chemical fertilizers, lowering agricultural costs.

3. Phosphorus Forms Suitable for Crop Absorption: The phosphorus in soybean meal fertilizer mainly exists as organic phosphorus, which is more accessible to crops. Conversely, chemical fertilizers provide inorganic phosphorus, which is less directly absorbable by roots. This makes soybean meal fertilizer ideal for use as base fertilizer or topdressing, effectively improving phosphorus uptake by crops.

4. Flexible Application Methods: Due to its low phosphorus content and high absorption efficiency, soybean meal fertilizer can meet crop phosphorus demands without increasing chemical fertilizer usage. It can also be mixed with other organic fertilizers (e.g., chicken manure, cow dung) to further enhance phosphorus utilization. In contrast, chemical fertilizers require strict adherence to recommended dosages to avoid issues like soil acidification and compaction from overapplication.

Soybean meal fertilizer is classified as a low-phosphorus fertilizer due to its low phosphorus content and high absorption efficiency. Its organic phosphorus form aligns better with crop needs, and its flexible application reduces reliance on chemical fertilizers. These advantages position soybean meal fertilizer as a promising tool in sustainable agriculture.