Boron as B2O3 has been fused with humates and is presented as a 2 to 4 mm granule for easier application. Boron is the most unstable of the trace elements and is easily leached from the soil (particularly in low humus soils). Humic acid can fuse with boron in the root zone for the full crop cycle. Benefits Biological Farmers of Australia (BFA) Registered Product 456AI. (Restricted). Boron is complexed into a humate colloid to create a slow-release response. Boron increases calcium efficiency and like calcium, is involved in cell wall strength and is important for good root development. Boron plays a critical role during the pollination stage of the reproduction process and the presence or lack of this element at this time can dramatically influence yield. A 2-4 mm granule can be combined with any granular fertiliser mixes to simplify application. Unlike traditional boron sources, this product can safely be included with seed.