Until recently, nitrogen waste reduction has been the focus of conservation efforts. According to soil scientists, however, application of manure based on desired nitrogen levels results in an overabundance of phosphorus. In the Chesapeake Bay area, poultry manure is a major source of phosphorus waste. Dietary intake determines the phosphorus content of manure. Poultry feed is composed largely of corn and soybean seeds, which are an excellent source of protein, vitamins, and minerals.
Soybeans are also naturally rich in phosphorus, an important dietary mineral.
Unfortunately, the majority of this phosphorus is present in a form that is nutritionally unavailable to the animal. Monogastric animals such as humans, fish, chickens and pigs lack digestive enzymes necessary to break down phytate. Phytate is also considered an anti-nutrient because it chelates important dietary minerals such as calcium, iron, and zinc. In addition, phytate complexes with proteins, lowering amino acid availability. To meet dietary requirements, inorganic phosphorus and other minerals are routinely added to poultry diets.