Healthy crop growth depends on the right balance of nutrients in soil. Soil needs macronutrients - nitrogen, phosphorus, potassium, sulfur, calcium, and magnesium - but they are only one piece of the puzzle. Just as important are micronutrients, such as iron, copper, zinc - and boron. It may be hard to imagine a nutrient found in such small quantity could be so impactful, however it is vital to many plant functions.
According to Mosaic Crop Services," boron deficiency is the second most common micronutrient deficiency problem worldwide. Without adequate amounts of boron, your overall yield and crop quality could suffer. Boron does many things for plants, it is used with calcium in forming the cell wall structure, cell division, amino acid production, flower initiation, helps manage water in the plant and also pollen development. It is required for translocation of sugars. Photosynthesis transforms sunlight energy into plant energy compounds such as sugars. For this process to continue in plants, the sugars must be moved away from the site of their development, and stored or used to make other compounds. Boron increases the rate of transport of sugars to actively growing regions and also in developing fruits. It is also required for effective nitrogen fixation and nodulation in legume crops.
While a little can be good, it does not mean more is better. Excess boron can cause toxicity and could have just as adverse effects as having too little. The key is balance. We aim to have boron show 1-2 ppm in a soil report. Given boron’s premobility in the soil and susceptibility to leaching, annual applications are required in most situations. Frequent applications at low rates also minimize the risk of toxicity.
We suggest broadcasting boron in a blended dry fertilizer in early spring or right before planting and incorporating into the soil where possible. We are now offering Super N 4-2-4, Super K 3-4-7, and Blue N 5-1-1 available with boron. Previously it had been paired with zinc. After seeing numerous soil reports where boron was inadequate and zinc was in excess, the decision was made to offer it alone. Under the National Organic Program (§205.601 J 6 i) soil deficiency must be documented by testing in order to apply boron. As always check with your organic certifier before use.