Understanding Phosphorus Versus Nitrogen Manure Management

In most cases, nutrient management plans are based on balancing nitrogen. This comes from our scientific understanding of nitrogen behavior and generally greater concerns with the environmental fate of nitrogen and the potential negative human health effects of nitrates in water.

However, phosphorus has also received significant attention because of the potential for accelerated eutrophication in water bodies receiving excess P. Phosphorus is an essential nutrient for crops. A critical component of crop production is managing phosphorus for optimum economic benefit.

However, if phosphorus is allowed to move off the land and get into water, it can be a pollution problem. Unlike nitrogen, excess phosphorus is not toxic but can result in eutrophication of water bodies. Eutrophication is the increased growth of undesirable algae and other aquatic plants, which limits the use of the water for drinking, fisheries, recreation, and industrial use. Historically, a major source of phosphorus in water was wastewater treatment plants.

But as the amount of phosphorus getting into water from this source has been reduced, agricultural sources of phosphorus have gotten more attention. Manure in particular has been identified as a source of phosphorus to the environment. Agriculture has evolved toward greater and greater specialization. Consequently, animal feed is often produced in a different location from where the animals are fed. Feed containing phosphorus is transported to the animals. However, the manure containing much of the phosphorus that was in the feed is spread locally and not recycled back to where the crops were produced. This has resulted in phosphorus accumulating in excess amounts in some areas of high animal concentration.

At the same time, we have long recognized that one of the consequences of basing nutrient management plans on nitrogen is that, in most cases, excess phosphorus will be applied to the soil because the nutrient content of manure does not match the nutrient requirement of most crops. On the other hand, if the phosphorus requirement of the crops is balanced with the phosphorus in manure, two to four times as many acres are required to utilize the manure, and nitrogen fertilizer will be required to meet the needs of the crop.

This is not an ideal situation, but from our understanding of phosphorus behavior we know that there are things that we can do to minimize the environmental impact of this excess phosphorus in many cases. Consequently, we have consistently emphasized that, while the official guidelines for manure management have been based on nitrogen, we cannot ignore phosphorus. This is the reason for including practices such as soil and water conservation, balancing manure applications over crop rotations, cover crops, etc. in nutrient management plans.

Research has shown that a majority of the phosphorus from agricultural fields lost to water comes from a limited area on most farms and from a few storm events. There are two factors that must be considered in developing effective management strategies. For nutrient loss to occur, there must be a source of phosphorus and there must be a mechanism for transporting it to the water. A key concept to effectively managing nutrient pollution is to focus on where these two factors overlap; i.e., a high source coupled with high transport.

Tools to help identify where these critical source areas are, and to suggest manure management strategies to address these areas, have been developed. See the Penn State Cooperative Extension publication, Managing Phosphorus for Agriculture and the Environment, The Pennsylvania Phosphorus Index v 2.0 for more details.

Since agriculture is changing rapidly, farm classifications may change with time. Therefore, farmers periodically should evaluate their farm’s nutrient management status to adjust their strategy as appropriate. More detailed evaluation of fields and practices will be necessary to identify specific management options or best management practices (BMPs) for each individual situation.

Source: Penn State College of Agricultural Sciences, Penn State Extension

Leave a Reply

Fertilizer Stories

Potash Agrium
Crop InputsAgrium-PotashCorp to become Nutrien upon Merger Completion
June 21, 2017
Potash Corporation of Saskatchewan Inc. and Agrium Inc. have announced today that once the anticipated merger transaction closes, the new Read More
Crop InputsMidwestern BioAg Hosts TerraNu Fertilizer Plant Opening (w/Q&A)
June 20, 2017
Last Friday, Midwestern BioAg was joined by over 80 local farmers, media and staff to celebrate the grand opening of Read More
Growers looking at soybeans
Crop InputsOhio Releases New Nutrient Management Tools
June 1, 2017
The Ohio Department of Agriculture (ODA) has introduced two new nutrient management tools. The Ohio Applicator Forecast is a new Read More
Max Systems Products
Crop InputsMax Systems Products Supercharge Plant Performance
June 1, 2017
Used individually, NanoZyme 2.0 and Nano Brown Sugar from Max Systems LLC, provide plants with balanced minerals and nutrients that Read More
Trending Articles
PrecisionAg Vision Conference
Precision AgPrecisionAg® Vision Conference: Focused on the Future
June 13, 2017
PrecisionAg® is pleased to announce the return of its PrecisionAg Vision Conference, October 10-12, 2017. Based on overwhelmingly positive response Read More
Redbanded-stinkbug-on-soybean-Photo-credit-Thomas-County-Ag
Crop InputsExperts: Mild Winter, Early Planting Will Increase Soybean Insect Threat
June 12, 2017
Higher than average temperatures this past winter affected much of the nation, especially the South and Midwest. The National Centers Read More
Eric SfiligojMonsanto ‘Picks Its Battles’ by Nixing Deere Deal
May 23, 2017
Having been in the trade journalism game since the mid-1980s, I remember several watershed moments during my career. One of Read More
Migrant farm workers
LegislationTrump: Immigration Crackdown Won’t Impact U.S. Agriculture
May 16, 2017
President Donald Trump said he would seek to keep his tough immigration enforcement policies from harming the U.S. farm industry Read More
AGCO Ratliff featured
Eric SfiligojRemembering Robert Ratliff
May 15, 2017
With all the fast-paced happenings in agriculture this spring, with multiple mergers in the works and planting season in full Read More
Case sprayer nozzle closeup
EquipmentSpray Application: A Nozzle Renaissance
May 2, 2017
If you had asked four-decade ag veteran Mark Bartel, President of Wilger Inc., just a few years ago what lay Read More
Latest News
Crop InputsArkansas Plant Board Votes to Ban Dicamba — Now W…
June 23, 2017
The Arkansas State Plant Board has voted to pass a proposed emergency rule to ban the use of in-crop dicamba, Read More
Engenia soybeans
Crop InputsBASF: ‘Closely Monitoring’ Dicamba Situatio…
June 22, 2017
BASF, whose Engenia herbicide is the target of more than 200 drift complaints in Arkansas, emailed the following statement to Read More
ManagementConsolidation Update
June 22, 2017
Editors Paul Schrimpf and Eric Sfiligoj discuss progress on manufacturer consolidation, and another big move for Midwest cooperative Central Valley Read More
Palmer pigweed seedhead in cotton
Crop InputsThreat of Dicamba Ban Looms in Arkansas
June 22, 2017
The Arkansas State Plant Board has rejected a proposed ban on the use of dicamba herbicide, but a procedural error Read More
Potash Agrium
Crop InputsAgrium-PotashCorp to become Nutrien upon Merger Complet…
June 21, 2017
Potash Corporation of Saskatchewan Inc. and Agrium Inc. have announced today that once the anticipated merger transaction closes, the new Read More
Crop InputsMidwestern BioAg Hosts TerraNu Fertilizer Plant Opening…
June 20, 2017
Last Friday, Midwestern BioAg was joined by over 80 local farmers, media and staff to celebrate the grand opening of Read More
Soybean Field
Industry NewsAligned Ag Distributors Names New President
June 19, 2017
Aligned Ag Distributors LLC announced this morning the appointment of Mary Tolke to the position of President/CEO, effective July 1. Read More
ManagementPlotting Corn, AGCO/Asmark’s Applicator Training Center…
June 15, 2017
Editors Paul Schrimpf and Eric Sfiligoj talk about their recent visits to Columbus, OH, and Bloomington, IL, along with an Read More
Seed/BiotechDow AgroSciences Announces Launch of Enlist Corn for 20…
June 14, 2017
Enlist corn will be commercially available in the U.S. for the 2018 growing season. Dow AgroSciences announced the launch today Read More
ASMARK AGCO Applicator Training Center
EmployeesAsmark, AGCO Open Training Center for Beginning Applica…
June 13, 2017
AGCO Corp. and the Asmark Institute have opened a new Applicator Training Center, created in a collaboration between the two Read More
Power to Do More Contest Winners
HerbicidesDow AgroSciences Announces Three Winners in Power to Do…
June 13, 2017
Thousands of votes have been cast and three farmers have been awarded the power to do more with a $10,000 Read More
Frogeye leaf spot
FungicidesStrobilurin-resistant Frogeye Leaf Spot Threat Looms wi…
June 13, 2017
Heavy spring rainfall throughout the South and Midwest delayed planting and created the perfect environment for diseases like frogeye leaf Read More
PrecisionAg Vision Conference
Precision AgPrecisionAg® Vision Conference: Focused on the Future
June 13, 2017
PrecisionAg® is pleased to announce the return of its PrecisionAg Vision Conference, October 10-12, 2017. Based on overwhelmingly positive response Read More
CHS St. Paul, MN fertilizer terminal
LegislationICGA Praises President Trump’s Remarks on Waterwa…
June 12, 2017
Illinois Corn Growers Association President Justin Durdan, a farmer from Utica, issued the following statement regarding President Donald Trump’s comments Read More
Wheat Growers
UncategorizedWheat Growers Names Tracy Linbo as Senior Vice Presiden…
June 12, 2017
Wheat Growers has hired Tracy Linbo as Senior Vice President of Agronomy. Linbo joins Wheat Growers after having served 10 Read More
EquipmentAgTech Summit Aiming High for Modern Farming Solutions
June 12, 2017
THRIVE AgTech, in partnership with SVG Partners and Forbes, is hosting the third annual Forbes AgTech Summit June 28-29 in Read More
Central Valley Ag Randolph, NE
Precision AgLand O’Lakes Invests in EFC Systems
June 12, 2017
Land O’Lakes, Inc. has made a minority equity investment in EFC Systems, Inc., an ERP (Enterprise Resource Planning) and precision Read More
BRANDT
Crop InputsBRANDT Products Approved for Use with New Cropping Syst…
June 12, 2017
BRANDT, a leading manufacturer of specialty products for the agriculture and turf markets, has announced that 11 BRANDT formulations have Read More