Researchers find that soil phosphorus levels may affect plant phytate levels as much as plant breeding. Phytate is the principal storage form of phosphorus in many plant tissues, especially bran and seeds.
Phytate is generally not bioavailable to humans and non-ruminant animals. Accordingly, there has been a push to develop low-phytate crop varieties. Not only is the phosphorus in low-phytate grain crops more digestible by people, low-phytate grains free up minerals essential to human nutrition: zinc, manganese and iron. This new research shows that grain raised with higher levels of soil phosphorus can have higher levels of phytate. I have not read ($) the journal article, but my thoughts are that the discovery of this soil connection was not anticipated: normally nutritional availability does not decrease with increased soil nutrient levels. If this relationship can be validated, it is an important breakthrough that affects human nutrition, efficient use of phosphorus (a non-renewable resource), farm costs, and environmental quality.
Swine and poultry operations benefit. Low-phytate feed results in lower manure phosphorus for these non-ruminants, a welcome prospect for waste management and addressing water quality concerns. Swine rations often need phosphorus added to ensure bone and muscle development for rapid growth, driving the market development for new, low-phytate crop varieties. The alternative to low-phytate feed is to use a feed additive, phytase. Currently, neither approach is particularly cheap.
Appreciation and attribution:
Sugar Creek Farm for a great photo.
GMO Pundit aka David Tribe for posting on this.
($) According to my read of HighWire Publishers Free Online Full-text Articles list, the journal article will be made available at no cost April 2, 2008 (18 months after publication).