Phosphorus, a nutrient essential to crop growth, may have been the first element to be chemically discovered, but it is one of the most difficult to track. This is especially true when it comes to nutrient management on farms.
Deficiencies in plants are hard to spot, and the phosphorus cycle through soil and watersheds is a delicate balance susceptible to human influence, while losses to the environment are coming under increasing scrutiny.
Scientists have made great strides in understanding phosphorus in the lab, and in recent years, we have made significant progress in helping farmers in the field to better understand how to cost-effectively use phosphorus fertilizer to address and avoid losses.
But a wider dissemination of this knowledge is vital for ensuring the sustainable use of phosphate fertilizers to help farmers rise to the challenge of food production.
We know that phosphorus deposits are finite, making it important that we conserve and recycle phosphorus for future generations. Ensuring that the tools and technologies developed across the fertilizer sector are available to farmers to help them meet their productivity goals while minimizing environmental footprint is also paramount.
I have been very fortunate to have worked with and benefited from many scientists with different expertise during my career, which has helped broaden the impact of our research. When we can translate and share this with those who need it, such as farmers, the impact can be far-reaching.
One such example is the development of the P Index, a tool that helps farmers identify which areas on their farm are more susceptible to phosphorus nutrient loss. Using the P Index is helping to reduce the amount of phosphorus lost to the environment in the U.S., an estimated 25,000 tons.
The success of the P Index is demonstrated by the fact that in 49 states, the Natural Resources Conservation Service (NCRS) has adopted it as the cornerstone of nutrient management planning at Concentrated Animal Feeding Operations, or CAFOs. This approach is also used by the Environmental Protection Agency (EPA) to cost-effectively prioritize and target conservation measures across the US.
Another example of applied nutrient management studies is the research and demonstration Arkansas Discovery Farm Program.
Across the 12 farms, researchers are evaluating how to minimize the potential movement of nutrients from land into water to protect soil and reduce nutrient runoff. This includes evaluating the effectiveness of conservation methods, such as reduced tillage and cover crops, alongside nutrient management best practices.
Program findings so far have shown that less than five and three per cent of applied nitrogen and phosphate fertilizers are lost annually in surface run-off on average. Computerized planning tools have also helped improve irrigation water management, reducing irrigation runoff to less than 10 per cent of current common losses and saving one of the most precious commodities to many farmers.
Initial program results have already given farmers proof and confidence that they are providing safe and affordable food supplies, while protecting natural resources for future generations. Seeing the practices in action has also empowered them to further improve their nutrient management and water conservation.
Most importantly, these experiential learning programs show farmers what works, provides a powerful vehicle for them to influence future agricultural policy, and enables them to be proactively invested in both food and environmental security.
Finally, the 4R Nutrient Stewardship is a fertilizer industry–led lab-to-land initiative that promotes efficient fertilizer use. The initiative encourages farmers to apply the “Right” nutrient source, at the “Right” rate, at the “Right” time and in the “Right” place.
When used with other conservation measures, it can improve soil health in addition to improving crop yields and reducing losses to water. The 4R Plus project in Iowa, for instance, is designed to reduce nitrogen and phosphorus losses to water by at least 45 per cent.
Supporting scientific research into nutrient cycle management and its transfer to farmers is key for enabling more sustainable farming. Improvements in nutrient and soil management not only give an economic boost for farmers, by allowing them to grow more crops with fewer inputs, but also strengthen food security and environmental sustainability for all of us.