Buffered Phosphorus Fertilizer
We have developed and extensively tested a new type of fertilizer for supplying phosphorus (P) to plants while reducing leaching of phosphorus from production systems. The P is bound to alumina, which is inert at pH levels used for plant growth. Loading conditions during manufacture of the product can be adjusted to provide the correct desorbing concentration of P. Since the material acts as a buffer, P is only released from the fertilizer when the concentration in the growth medium is depleted by plant uptake. This allows maintenance of lower concentrations of P in the medium than with current fertilization practices. Reduced P in the growth medium not only reduces impact on the environment but also may benefit plants. Very high P fertilization reduces root growth and can make plants less tolerant to stresses such as drought (Borch et al., 1998). In this project, we tested the impact of the buffered alumina fertilizer, Al-P, on growth and quality of a number of several floricultural crops. We developed methods for using the material in ground beds, recharging to replace P used by the plants, and worked with manufacturers on commercial development of Al-P products.
Source: • American Floral Endowment Special Research Reports #505