Tag: phosphorus

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The Farm Manure to Energy Initiative: Using Excess Manure to Generate Farm Income in the Chesapeake’s Phosphorus Hotspots

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Abstract

Currently, all the Bay states are working to achieve nutrient reduction goals from various pollution sources.  Significant reductions in phosphorus pollution from agriculture, particularly with respect to phosphorus losses from land application of manure are needed to support a healthy aquatic ecosystem.  Producers in high-density animal agricultural production areas such as Lancaster County region of Pennsylvania, the Delmarva Peninsula, and the Shenandoah Valley region of Virginia, need viable alternatives to local land application in order to meet nutrient reduction goals.

Field demonstrations will be monitored to determine whether the technologies are environmental beneficial, and economically and technically feasible. Specific measures of performance include: reliability and heat distribution, in-house air quality, avoided propane or electricity use, costs to install and maintain, fertilizer and economic value of ash or biochar produced, air emissions, and fate of poultry litter nutrients. Technology evaluation results will be shared on a clearinghouse website developed in partnership with eXtension.

The Farm Manure to Energy Initiative is also supporting efforts to develop markets for nutrient rich ash and biochar co-products. Field trials using nutrient rich ash and biochar from poultry litter thermochemical processes for fresh market vegetable production are currently underway at Virginia Tech’s Eastern Shore Agricultural Research and Experiment Station.

Purpose

The Farm Manure to Energy Initiative is a collaborative effort to evaluate the technical, environmental, and economic feasibility of farm-scale manure to energy technologies in an effort to expand management and revenue-generating opportunities for excess manure nutrients in concentrated animal production regions of the Chesapeake Bay watershed.

What Did We Do?

The project team went through a comprehensive review process and identified three farm-scale, manure to energy technologies that we think have the potential to generate new revenue streams and provide alternatives to local land application of excess manure nutrients.  Installation and performance evaluation of two of these technologies on four host farms in the Chesapeake Bay region are underway. Partners have also completed a survey of financing options for farm-scale technology deployment and published a comprehensive financing resources guide for farmers in the Chesapeake Bay region.

What Have We Learned?

To date, we have not identified any manure to energy technologies that also provide alternatives to local land application of excess manure nutrients for liquid manures.  Thermochemical manure to energy technologies using poultry litter as a fuel source seem to show the most promise for offering opportunities to export excess nutrients from phosphorus hotspots in the Chesapeake Bay region. Producing heat for poultry houses is the most readily available energy capture option.  We did not identify any vendors with a proven approach to producing electricity via farm-scale, thermochemical manure to energy technologies. With respect to the fate of poultry litter nutrients, preliminary air emissions data indicates that most poultry litter nitrogen (greater than 98%) is converted to non-reactive nitrogen in the thermochemical process. Phosphorus and potash are preserved in the ash or biochar coproducts. Preliminary field trial results indicate that phosphorus in ash and biochar is bioavailable and can be used as a replacement for commercial phosphorus fertilizer, but bioavailability varied according to the thermochemical process.

Future Plans

We are currenty in the process of installing and measuring the performance of farm-scale demonstrations in the Chesapeake Bay region.  We are collaborating with the Livestock and Poultry Environmental Learning Center to develop a clearinghouse website for thermochemical farm-scale manure to energy technologies that will be hosted on the eXtension website.  Performance data from our projects will be shared on this website, which can also be used as a platform to share information about the performance of other farm-scale, thermochemical technology installations around the U.S. Technical training events using farm demonstrations as an educational platform will be hosted during the later half of the project. Additional field and row crop trials to demonstrate the fertilizer value of the concentrated nutrient coproducts are also planned using ash from farm demonstrations.

Authors

Jane Corson-Lassiter, USDA NRCS, Jane.Lassiter@va.usda.gov; Kristen Hughes Evans, Executive Director, Sustainable Chesapeake

Additional partners in the Farm Manure to Energy Initiative include: Farm Pilot Project Coordination, Inc., University of Maryland Center for Environmental Studies, University of Maryland Environmental Finance Center, Virginia Cooperative Extension, Lancaster County Conservation District, the Virginia Tech Eastern Shore Agricultural Research and Extension Center, National Fish and Wildlife Foundation, Chesapeake Bay Funders Network, Chesapeake Bay Commission, and International Biochar Institute.

Additional Information

www.sustainablechesapeake.org

www.fppcinc.org

Acknowledgements

Funding for this project is provided by a grant from the USDA Conservation Innovation Grant program, the National Fish and Wildlife Foundation via the U.S. EPA Innovative Nutrient and Sediment Reduction Program, the Chesapeake Bay Funders Network, as well as technology vendors and host farmers participating in the technology demonstrations.

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.

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What’s the P Index?

The P Index is the Phosphorus Index, a risk assessment tool to quantify the potential for phosphorus runoff from a field. The P Index helps to target critical source areas of potential P loss for greater management attention. It includes source and transport factors. Source factors address how much P is available (for example, soil test P level and P fertilizer and manure application amounts). Transport factors evaluate the potential for runoff to occur (for example, soil erosion, distance and connectivity to water, soil slope, and soil texture). The P Index allows for relative comparisons of P runoff risk. When the P Index is high, recommendations are made either to apply manure on a P basis or not to apply manure at all. When the P Index is low, manure can be applied on a N basis. Also, if the P Index is high, the factors that are responsible for the higher risk of P loss are identified, and this information provides guidance for management practices to reduce the risk. For example, if the P Index is high because of high soil erosion, a recommendation to implement soil conservation best management practices (BMPs) may lower the risk and allow safe manure application.

For additional information:

To find your state’s P Index, do a web search for “phosphorus index” plus your state name.

Author: Jessica Davis, Colorado State University

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Environmental Impacts and Benefits of Manure: Phosphorous and Surface Water Protection

Managing manure nutrients in an environmentally and economically responsible manner is not a mutually exclusive endeavor. This article discusses phosphorus and its potential impacts on water quality.

Phosphorus and Water Quality

Phosphorous (P) is one of the major bio-available nutrients in manure. In aquatic ecosystems, P is typically the most limiting nutrient. When P is introduced into an aquatic ecosystem there is a marked increase in aquatic plant biomass production and increased algal blooms. The increased aquatic plant production and algal blooms can have a negative effect on the aquatic ecosystem such as tying up other nutrients and decreasing the amount of light infiltration.

At the end of the aquatic plant and algae growing cycles, there is a large release of excess nutrients into the ecosystem overwhelming the natural nutrient cycle, tying up oxygen during its degradation leading to fish kills and reducing surface water aesthetic qualities with the accumulation of rotting plant material on the water surface and offensive odors.

How Does Phosphorus Travel to Water?

In cropping systems, providing a sufficient level of P for plant uptake is as important as providing the proper levels of nitrogen (N) and potassium (K). Unlike N and K, P is bound to soil particles and is at low risk of leaching through the soil profile. The greatest risk of P loss from soils is with overland flow of runoff carrying P-enriched soil sediment or manure particles. Research has shown that soils testing high in P have a greater contribution effect for P loss than soils testing low in P.

However, there is a fraction of total P in runoff that is in the dissolved form. The sediment attached P and dissolved P have slightly different impacts in aquatic ecosystems. The sediment attached P contributes to long term P additions to the system whereas the dissolved P is readily available for a high rate of assimilation by aquatic plants and algae.

There are also reported cases of soils with extremely high levels of soil test P that are at risk of P leaching. Typically, soil P is bound tightly to soil particles and has a low risk of leaching. However, in some soils with extremely high soil test P levels, the exchange sites are at maximum capacity, leading to the risk of P leaching.

Blue-green algae bloom in nutrient impaired water. Source: Ron Wiederholt, NDSU Extension

 

Management Practices to Reduce Environmental Risks from Phosphorus

Cropping system practices that lead to reduced soil erosion are the most effective means of decreasing the risk of off-site movement of P. Besides soil erosion, there are other factors that need to be identified when reducing the risk of P loss from fields.

These factors include but are not limited to:

  • distance to surface water
  • slope of the landscape
  • soil erosivity index
  • soil test P level

Many states have adopted a process of ranking the risk of P loss from agricultural fields using a P-index. The USDA Natural Resources Conservation Service (NRCS) has been the lead agency in developing most of the state-by-state P-indexes. A P-index scores the factors important for off-site movement of P and by using the combined score of these factors a land manager can decide what options are best for managing P application levels to fields when using manure or commercial fertilizer.

However, the use of a P-index is only one of the tools available to nutrient managers. When there has been a long history of P mis-management and soil test P levels are extremely high, a P-index or other tools are not as effective. In these cases, a long term approach looking at the whole cropping and livestock system needs to be adopted.

Livestock rations must be closely monitored to ensure there is no P overfeeding (see the LPELC topic, Feed Management), manure may have to be sold or bartered to other land managers, or some type of intensive manure processing system will have to be adopted that will allow for more affordable long distance hauling of the manure (see the LPE Learning Center topic Manure Treatment Technology).

Recommended Reading On Phosphorus and Surface Water

Page Managers: Ron Wiederholt, North Dakota State University and Marsha Mathews, University of California-Davis

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Separation Technologies for Capturing Nutrients from Manure

Exporting phosphorus and possibly nitrogen from larger livestock operations as well as regions of large livestock populations is often essential for protecting water quality. Solids (and nutrient) separation technologies are an option for concentrating nutrients for export. This webinar introduces three approaches to solids separation that are being applied in commercial settings. This presentation was originally broadcast on January 18, 2019. More… Continue reading “Separation Technologies for Capturing Nutrients from Manure”

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Designing Structures to Remove Phosphorus from Drainage Waters

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Abstract

Several groups have developed P removal structures, which are units filled with P sorbing materials and designed to channel runoff water through them while retaining the filter material and P.  The goal is to prevent P from entering a surface water body and allow filtered P to be removed from the watershed after the P-saturated material is removed.  The P sorbing materials utilized are typically by-products from various industries and include steel slag, FGD gypsum, drinking water treatment residuals, and acid mine drainage residuals.  A modeling tool has been developed for (1) sizing a structure based on filter media properties and watershed characteristics, (2) predicting the lifetime of a P removal structure, and (3) estimating total P removal.  In addition to the modeling tool, data from full scale filters will be presented.

Why Are We Concerned About Phosphorus in Water?

Excessive phosphorus (P) in surface waters can result in algae growth, fish kills, eutrophication, and overall poor water quality.  This problem is especially evident in the Illinois River Basin and Chesapeake Bay.  Sources of P to aquatic ecosystems include wastewater treatment plants and also non-point runoff sources (agriculture, horticulture, urban/suburban landscapes).

Soils that have continuously received excess P beyond plant needs typically become “built up” to high levels of soil P.  These soils release dissolved P during rainfall/runoff events.  Current best management practices (BMPs) mostly address particulate P (i.e. P bound to soil particles) transport, not dissolved P.  Dissolved P is more damaging than particulate P because it is immediately 100% available to aquatic life.  Even if all P applications to high P soils are ceased and BMPs are implemented to reduce erosion (i.e. particulate P transport), dissolved P transport will continue to occur for at least 15 years, assuming that plants are harvested from the site.  If plants are not harvested and removed from the site, then dissolved P concentrations may remain elevated in runoff for much longer.

Because soil P levels will remain high for many years, even if P applications cease and efforts are made to “mine” the soil P using plants, the system will continue to “leak” dissolved P during every runoff event.  This has resulted in the need to develop a new BMP that can reduce the transport of dissolved P.

What Did We Do?

Through use of various industrial by-products, we constructed landscape “filters” that remove dissolved P in runoff from “hot spots” before it reaches streams and lakes.  Many industrial by- products that are typically land-filled, including materials produced during drinking water treatment, power generation, and steel production have a beneficial re-use in improving surface water quality by adsorbing P from passing water.

Phosphorus removal structure located at Stillwater Country Club, which utilizes steel slag as the P sorbing material

Several P removal structures were constructed in residential and agricultural watersheds.  Industrial by-products such as flu gas desulfurization gypsum and steel slag were used as P sorbents in the filters.  These filters can be placed in locations known to produce high dissolved P concentrations in runoff; the materials are contained within the structure, which allows them to be removed after they are no longer effective at filtering P (i.e. “saturated” with P).  The materials can then be replaced with fresh materials.  This represents a true removal of P from the system instead of simply tying up the P temporarily.

Automatic samplers and flow meters were used to monitor flow rates and collect samples for measurement of dissolved P and other parameters.  Samples were collected throughout runoff events at both inlet (pre-treatment) and outlet (post-treatment) of structures.  Based on flow volumes and measured P concentrations at the inlet and outlet of structures, P load and P load reductions were calculated.

In addition, approximately 16 different P sorbing materials were tested under flow-through conditions in the laboratory in order to quanitify P removal under different inflow P concentrations and retention times.  With this data set, we have produced a user-friendly model to aid in construction of P removal structures, predict how much P they will remove, and how long they will last until the material is saturated with P.

Phosphorus box filters designed to treat runoff from a poultry farm located in Maryland

What Have We Learned?

Over 8 months of monitoring at the Stillwater site, dissolved P concentrations varied from 0.3 to 1.5 mg L-1 for a residential watershed.  The structure located at that site was able to remove 25% of all the dissolved P that entered the structure over a time period of 8 months.  Other materials can adsorb much more P, but the hydraulic conductivity is much lower, therefore limiting the amount of water that can be treated.  Depending on the material and conditions, P removal structures can pay for themselves if a P trading credit program is ever implemented for non-point source total maximum daily loading (TMDLs).

Future Plans

The computer program model will eventually be made available on the web for practitioners, especially the Natural Resources Conservation Service (NRCS), to aid in P removal structure design.  We are also developing a new P sorbing material that will have greater P sorption capacity and a large hydraulic conductivity, enabling it to both remove P and treat large amounts of water. A large P removal structure is under construction on an eastern Oklahoma poultry farm, where it will capture and treat runoff from areas directly around the poultry houses.

Canister filters placed in a drainage ditchlocated in Maryland

Authors

Chad Penn, Associate professor of soil and environmental chemistry, Oklahoma State University,

Josh Payne,  Area animal waste management specialist, Oklahoma State University

Josh McGrath, Associate professor of soil fertility, University of Maryland

Jeff Vitale, Associate professor of agricultural economics, Oklahoma State University

Additional Information

Stoner, D., C.J. Penn, J.M. McGrath, and J.G. Warren.  2012.  Phosphorus removal with by-products in a flow-through setting.  J. Environ. Qual.  41:654-663.

Penn, C.J., J.M. McGrath, E. Rounds, G. Fox, and D. Heeren.  2012.  Trapping phosphorus in runoff with a phosphorus removal structure.  J. Environ. Qual. 41:672-679.

Grubb, K.L., J.M. McGrath, C.J. Penn, and R.B. Bryant. 2012. Effect of land application of phosphorus saturated gypsum on soil phosphorus. Applied and Environmental Soil Science. vol. 2012, Article ID 506951, 7 pages, 2012. doi:10.1155/2012/506951

Grubb, K.L., J.M. McGrath, C.J. Penn, and R.B. Bryant. 2011. Land application of spent gypsum from ditch filters: Phosphorus source or sink? Agricultural Sciences: 2:364-374.

Penn, C.J. and J.M. McGrath.  2011. Predicting phosphorus sorption onto normal and modified slag using a flow-through approach.  J. Wat. Res. Protec. 3:235-244.

Penn, C.J., R.B. Bryant, M.A. Callahan, and J.M. McGrath.  2011. Use of industrial byproducts to sorb and retain phosphorus.  Commun. Soil. Sci. Plant Anal.  42:633-644.

Penn, C.J., R.B. Bryant, P.A. Kleinman, and A. Allen.  2007.  Removing dissolved phosphorus from drainage ditch water with phosphorus sorbing materials.  J. Soil Water Cons.  62:269-276.

Penn, C.J., J.M. McGrath, and R.B. Bryant.  2010.  Ditch drainage management for water quality improvement. In “Agricultural drainage ditches: mitigation wetlands for the 21rst century”.  Ed. M.T. Moore.  151-173.

Acknowledgements

The authors are grateful to the NRCS, the National Slag Association, The United States Golf Association, and the USDA-ARS for their support of this work.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.

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