Project Objectives

Project Title: Implementing BMPs to Reduce Runoff and Lawn Fertilizer Use

I. Project Abstract

New residential developments offer the opportunity to affect community-wide changes in homeowner attitudes towards lawns. They are also sites where the treatment of soils by the builder largely dictates the potential for nutrient and sediment runoff from landscape areas, usually to the detriment of the environment. Naturally fertile topsoil is stripped, and the soil is compacted, which increases stormwater runoff potential. This project will investigate and promote two best management practices (BMPs): the use of a lawn seed mixture containing a newly-commercialized nitrogen-fixing legume called microclover; and incorporation of compost during soil preparation that can be used by builders, landscaping professionals and homeowners to reduce nitrogen fertilization and nutrient runoff from lawns. The project includes a showcase residential development where the effectiveness of the project BMPs will be demonstrated and subsequently marketed to the building and development communities. Additional satellite sites in MD, PA and VA are included to demonstrate the “watershed-wide” utility of the BMPs, and to provide targeted regional outreach opportunities to decision makers, practitioners, and educators who work directly with homeowners. It is expected that this project will initiate a watershed-wide paradigm shift in lawn culture away from a highly fertilized grass monoculture to a more diverse plant community that requires little, if any nitrogen fertilizer.

II. Proposal Narrative

A. Project Priority.

New single family home developments are frequently associated with poor soil chemical and physical conditions which drive new homeowners and their contractors to apply more lawn fertilizer than homeowners residing in older, more mature, developments. In addition, newly completed low density single family home developments often consist of high income households that are more frequent users of lawn care services, and which purchase more lawn and garden care products, than do households of lesser economic means. Improving soil conditions and establishing nutrient-efficient lawn species within new residential communities provides the opportunity to reduce new nitrogen (N) and phosphorus (P) export hotspots within watersheds.

We have identified a classic low density residential development flanking the western border of Columbia MD in which the builder/developer has agreed to cooperate on this project (The Preserve at Clarksville). The development, when completed, will consist of 34 individual single homes, each on approximately one acre lots.

The current state of development of the community will allow us to implement the project BMPs as houses are completed within the development. Symmetric configuration of the houses about a single street in the development will allow us to impose the project treatments within two portions of the development, after which stormwater flows from each area will be monitored for the duration of the project. The one acre lots within this development contain few mature trees and will have relatively large size lawns, which will improve our ability to gauge the effectiveness of the BMPs to reduce stormwater flow and N and P runoff. Moreover, the high portion of land area devoted to turf in this development will result in an appreciable reduction in annual fertilizer N and load within the lots receiving the two BMP treatments. The Preserve at Clarkville is located less than eight miles from Interstate 95 and is only four miles from the University of Maryland Cooperative Extension Home and Garden Center. Thus, it is relatively easy to reach the location where stakeholder workshops will be held to promote the use of the BMPs to the residential development community. It is also within the Middle Patuxent watershed, a watershed targeted for N reductions arising from urban sources. Finally, the homeowners within this type of community are among the most desirable to target for altering lawn care habits since they are frequent users of lawn care products and lawn care services.

B. Objectives.

The objectives of this project are: 1) to evaluate and promote the adoption of compost incorporation prior to turf establishment as a best management practice within new residential developments; 2) to reduce lawn N fertilizer use by promoting the use of lawn seed mixtures that contain microclover; and 3) to show that stormwater volume will be reduced and stormwater quality improved by implementing the first and second objectives within a residential development.

We anticipate that this project will demonstrate that the incorporation of compost prior to turf establishment is a simple, cost effective way to reduce runoff from residential lots. It will also show that compost incorporation does not involve increased maintenance requirements nor remedial homeowner actions to be an effective long term means of reducing runoff from residential developments located on flat or gently sloping terrain. The value of compost incorporation, and the use of microclover turf seed mixtures, in sustaining functionally desirable turf with little to no fertilizer use will also be demonstrated over the course of this project.

It is anticipated that this project will lead to increases in the use of compost and microclover containing seed mixtures by the building community, landscape practitioners, and homeowners. The results of this project will also provide documentation that can be used to support dramatic reductions in N fertilization recommendations for lawn turf when the two project BMPs are used at the time of turf establishment. Based on prior studies, we believe there will be a permanent reduction of at least 50% in N applications relative to current MD, VA, and PA recommendations for more commonly constructed urban landscapes.

Print and web-based educational material on the management and establishment of microclover lawns in compost-amended soil will be developed for builders, stormwater managers, landscape contractors, grounds mangers and homeowners. A likely outcome of this project will be an attitude change for what constitutes a desirable home lawn in the Chesapeake Bay watershed.

Implementation of two BMPs on 3.3 acres of turf within The Preserve at Clarksville development will result in an annual reduction of 575 pounds of applied N fertilizer (174 lb N/A), 0 pounds applied P fertilizer and 0 lbs total sediment loss for the first 3 years following turf establishment. Thereafter, the annual projected reductions would be of 287 pounds of applied N fertilizer (87 lb N/A), 0 pounds applied P fertilizer and 0 lbs total sediment. These projections are based on deviations from The University of Maryland nutrient management guidelines for commercially managed turf, and assume the BMP treated areas within The Preserve at Clarkville will received no fertilizer for the 3 years, after which homeowners in the BMP treated areas will only need to apply 44 lb N/A year-1.

C. Overall Context.

The incorporation of compost into the surface layer of soil prior to turf establishment is recognized as a low impact development practice to reduce stormwater runoff. However, little emphasis has been placed on the concurrent use of this practice to reduce lawn fertilization. The mineralization of nutrients from 2 inches of compost incorporated into the top 4 to 6 inches of soil is usually sufficient to meet the N and P needs of lawn turf for 2 to 3 years. Currently, additional N is required to sustain sufficient turf density to prevent sediment and entrained P losses from lawns. Microclover is a relatively new N-fixing species that has only recently entered the lawn market in the United States. The small leaf size of microclover allows it to blend better with turfgrasses than white clover. In addition, its small leaf size greatly diminishes the appearance of individual clover patches within lawns which most homeowners find objectionable. Researchers in Europe have found that unfertilized grass + microclover lawns have color and biomass densities comparable to that achieved when grass-only lawns are fertilized with 22 lb N/A, per month.

This project seeks to promote the adoption of BMPs that will assist builders and developers in achieving compliance with EPA’s current TMDL and stormwater directives, while concurrently dramatically reducing the use of lawn fertilizer by homeowners. The project is innovative because it packages and markets the use of the two BMPs to two disparate stakeholder groups. Moreover, one of the BMPs is a direct result of a recent success in the breeding of white clover, which makes this BMP an innovative aspect of the overall proposal.

In the near future, builders and developers will likely face the challenge of marketing single lot homes and residential developments that can retain 100% of the precipitation associated with storm events having a return frequency of 5 years or less. Similarly, homeowners and lawn care practitioners have, or will be required shortly, to restrict the amount and type of nitrogen they can apply to lawn turf. Builders and developers want to minimize the use of structural approaches and expensive microscale practices to reduce runoff. Homeowners want a dense, green lawn which the use of fertilizers promotes. The BMPs advocated in this project will meet the desired goals of both groups of stakeholders while at the same time promote a long term sustainable approach to lawn turf management. The minimal one-time cost associated with both BMPs (~ $5000 acre-1 turf) will favor rapid adoption by the builder/developers once is has been demonstrated within a residential development that use of two the BMPs reduce N and P stormwater loads. Moreover, the work outlined in this proposal will provide data that will support the addition of the two project BMPs to EPA’s list of approved BMPs for which builders can receive offset credit when the BMP are implemented within a new development. One clear advantage to targeting builders/developers for use of the BMPs is that homeowners within a new residential development where the BMPs are implemented become passive messengers and earlier adopters in promoting use of microclover to reduce lawn fertilization.

D. Methodologies and Workplan.

Our approach will be to establish several different demonstration projects within the Chesapeake Bay Watershed. The demonstration projects will be used to quantify the benefits associated with using the project BMPs, assess possible obstacles to acceptance of the BPMs, generate data that will assist in determining long term cost effectiveness of implementing the BMPs and to market the BMPs to a widest range of stakeholder groups possible.

Study locations

This project will consist of one showcase site and four satellite sites. The primary showcase site is The Preserve at Clarksville residential development. The four satellite sites will be the University of Maryland Paint Branch Turfgrass Research and Education Center (PBTREC) in College Park MD, the Pennsylvania State University Joseph Valentine Turfgrass Research Center in University Park PA, the Hampton Roads Agricultural Research and Extension Center in Virginia Beach VA, and at a Amherst VA site maintained by researchers from the central Virginia Tech campus in Blacksburg VA. The showcase site will be used to demonstrate the effectiveness of the two BMPs in a residential development while the four satellite sites will be used to demonstrate the utility of using microclover in compost-amended soils to reduce the lawn turf N fertilization in different regions within the Chesapeake Bay Watershed. The satellite sites will also be used to evaluate agronomic practices that could be used to speed public acceptance of the two BMPs; and serve as locations where stakeholder workshops can be held.

The Preserve at Clarksville has swales behind houses on both sides of the development that route runoff to a pond located at the base of the development. On the west side of the road, at the base of the development, are six recently completed homes. The homes are owner occupied with the pervious landscape in all six lots consisting almost entirely of recently established tall fescue lawns. On the eastern side of the road three new houses have been constructed with empty lots for two more houses residing immediately adjacent. Construction of the houses in the two empty lots is expected to occur sometime this year. Currently, the back yards of the three lots that have houses on them are completely undeveloped and void of any maintained landscape plantings other than a small section of lawn (ca., 2000 ft2) surrounding the one owner occupied house. We will implement the BMP's on at least two adjacent lots of the five lots on the east of the development in the fall of 2011. Existing runoff plots located at the PBTREC will be used to further document the effectiveness of the two BMPs on small size lawns. This facility has individual 2500 ft2 turfgrass runoff plots located on a 3.5 % hillside slope that has very poor infiltration properties. The runoff plots at the PBTREC site have a preexisting runoff collection system which will be connected to ISCO flow meters and sample collectors. The PBTREC site currently has projects underway examining the aesthetic appeal of various microclover containing lawn mixtures, and the ability of microclover to tolerant varying levels of tree shade. The information gained from these projects will be integrated into workshops held at PBTREC promoting the use of the two project BMPs.

Showcase site

Upon completion of each of the five houses in the showcase site, Lots to recieve the BMP treatments on the east side of the development will have 2 inches of compost incorporated to a depth of 6 inches using incorporation techniques found by project members in prior projects to be highly favorable for turfgrass establishment. The lots will be seeded with a tall fescue-microclover lawn mixture following compost incorporation. No fertilizer will be applied to the lawns for the duration of the project (i.e., 3 years) . The swales on both sides of the development will be modified slightly to isolate runoff originating from two blocks of houses from the rest of the development. At the base of the modified swales a compound sharp crested weir will be installed. An ISCO flow meter and sampler will be connected to each weir to measure flow within the swales, and to collect water samples to quantify nutrient and sediment transport from the lots. Nitrogen, P, and sediment losses from the BMP treated areas will be compared with N, P, and sediment losses from the western side of the development. The use of fertilizers and lawn care services by the homeowners on the west side of the development will be documented by asking the homeowners of these houses to complete a brief survey created by project personnel. 

Sampling will involve event-based monitoring. The flow meter will record runoff rate every 10 minutes and store it in the flow meter memory for later downloading. The samplers will collect runoff on a flow-weighted basis, with the first 0.2 inches of runoff being allowed to pass because it will contain a lot of surface detritus that is not associated with turf care. Following the first 0.2 inches of runoff, samples will be collected every 0.2 inches of runoff. Analysis of the concentration of total N, total P and total suspended solids will be performed by the University of Maryland’s Department of Environmental Science and Technology Analytical Laboratory. 

Satellite locations.

Four runoff plots at the PBTREC will be used to examine two treatments: 1) tillage with no compost incorporation followed by the establishment of a microclover-free tall fescue lawn from seed, and 2) tillage with the incorporation of 2 inches of compost followed by the establishment of a microclover containing tall fescue lawn. The fertility regimes for the two treatments will be the same as those followed at the residential development site. Similarly, the sample collection protocol and analysis of samples collected at TBTREC will be the same as that followed at the residential development site.

Activities at the University Park, Lynchburg, and Virginia Beach locations will focus on demonstrating the aesthetic and functional value of a microclover plus tall fescue mixture in these portions of the watershed. Microclover containing plots at these sites will be established with and without the incorporation of compost and will receive little (44 lbs N/A) or no yearly N fertilizer. In addition, a method to introduce microclover and incorporate compost into existing lawns will also be demonstrated at these sites. The method involves applying a thin layer (¼ to ½ inch) of compost to the lawn surface followed by core aeration, slicing, and dragging a mixture of soil and compost back into the holes. The compost and soil-filled holes create thousands of channels which provide a conduit for water to enter compacted soils. Turf color, density and overall quality will be evaluated over a three year period as will the infiltration capacity of the various compost incorporation treatments.

All four satellite locations will evaluate chemical and non-chemical cultural practices that offer the potential of controlling broadleaf herbaceous plants in microclover lawns, but will not adversely affect the persistence of microclover. Identifying such practices will lead to more rapid acceptance of microclover lawns by homeowners and land care practitioners. Stakeholders attending project workshops will participate in surveys that will be created to gauge public acceptance of microclover containing lawns. Survey results will be used to identify and characterize “resistant adopters”. Outreach efforts will focus on developing strategies to target resistant adopters.

We will evaluate and compare the costs of establishing and maintaining compost/microclover lawns with traditional turf establishment and maintenance techniques. Our analysis will consider monetary expenses as well as uncompensated labor. The analysis will be conducted from both the homeowner and builder/developer prospective.

F. Dissemination and Transferability of Results

With demonstration sites being located within the three physiographic regions (ie coastal plain, piedmont, and mountain) of the Bay watershed, and encompassing climatic zones ranging from humid subtropical to humid continental, the results of this project will be readily transferable to nearly all regions of the Chesapeake Bay Watershed. Similarly, by having demonstration sites in MD, VA and PA, and conducted by turfgrass extension specialists and researchers, the project is well positioned to promote the use of the two BMPs to local and state affiliated stakeholder groups residing within the three states. Project participants from the three states will host field day events, workshops, deliver presentations, develop a website and web-based materials, and utilize internet-based social networking outlets in targeting our audience of landscape and lawn care professionals, builders and developers, municipal planners and staff having responsibilities in the implementation and enforcement of stormwater management practices, and master gardeners. In MD, discussions are currently under way with the Maryland National Capitol Building Industry Association, and the Home Builders Association of Maryland to indentify strategic venues in which the project BMPs will be promoted. Outreach initiatives aimed at developing partnerships similar to those already existing in MD will take place in PA and VA. University-based extension specialists participating in this project have programs and distribution mechanisms already in place that regularly reach thousands of lawn and landscape professionals and home owners. These programs also have a significant multiplier effect through distributors of compost and seed mixtures, trade organizations, and master gardener volunteers, Master gardeners serve as the primary means by which university based home and garden information is conveyed to homeowners. As such, educating master gardeners in the benefits associated implementation of the project BMPs will alter homeowner perceptions of how lawns should be managed when the project BMPs have been implemented at a site. Some demonstrations to be initiated at the satellite sites are intended to promote the renovation of existing lawns to compost incorporated grass plus microclover lawns. These demonstrations will continue beyond the funding period of this project and will be used to target the largest segment of turf usage within the Chesapeake Bay Watershed for reductions in runoff and fertilizer use.

G. Partner Justification.

This is multi-state and collaborative project involving faculty from three universities and a contractor. Project members have expertise in turfgrass nutrient management, fate and transport of turf applied chemicals, and sustainable turfgrass management. Four of project members have extensive experience in the development and implementation of statewide extensions programs aimed at reducing commercial and homeowner lawn fertilizer usage, and three members have direct oversight of the turfgrass nutrient management recommendations for the states of MD, PA, and VA. Five project members currently serve as advisors to the primary turf and landscaping stakeholder organizations within their respective states and are thus well positioned to work with these organizations in promoting the use of microclover to reduce turfgrass fertilization. Five of the seven project members have prior experience in directing multi-year projects involving the use of compost. Our contractor, Environmental & Turf Services, Inc., has extensive experience designing and evaluating water quality monitoring studies, designing conceptual BMPs, and explaining environmental science concepts to regulatory and public officials and members of the public.