Update on Experiments from the University Park Site

Data collection is in progress for the 2013 growing season at the University Park site for Compost Amendment Study I (2 inch compost layer tilled into compacted loam soil) and Compost Amendment Study II (annual 1/4 inch compost surface application).  Ratings for spring green-up, quality, color, % ground cover, % clover cover, spring clipping yield assessments and nitrogen recovery have been collected through July, and plots are being prepared for summer clipping yield assessments and nitrogen recovery.  Microclover and tall fescue are tolerating the excessive summer heat and rains, and appear to be in excellent condition. 

Compost Study II

In Compost Amendment Study II, a ¼ layer of compost was applied to the turf surface in June.  Plots were aerated, compost was applied to the turf, and the area was sliced using a verticutting unit. A significant green-up response was noticed about 2 weeks after application.  Plots designated for the 1.0 lb nitrogen/1000 ft² application were fertilized with polymer-coated urea (Lesco Poly-Plus; 39-0-0) in June.  As with Compost Amendment Study I, a noticeable green-up from the nitrogen application occurred in late June and July.  Microclover is the dominate species in all microclover/tall fescue plots, with clover cover ratings often exceeding 90%.

The microclover herbicide tolerance experiment received early May applications of isoxaben (Gallery 75 DF), bentazon (Basagran 4.0 L), pendimethalin (Pendulum 60 WDG), prodiamine (Barricade 65 WDG), dithiopyr (Dimension 1.0 EC), and Benefin (Balan 2.5 G) to determine the tolerance of microclover to preemergence herbicides. With the exception of isoxaben, no injury to clover was detected.  All rates of isoxaben cause minor injury to clover; but injury subsided and was no longer apparent by mid-June. In June, applications of 2,4-D Amine (3.8 L), 2,4-DB Amine (1.75 L), MCPA (3.7 L) were applied to determine the tolerance of microclover to postemeergence broadleaf herbicides.  Although some minor injury was detected following 2,4-D Amine applications, the clover recovered quickly and no permanent damage occurred. No visible

injury was detected with the other herbicides.

A project website was developed and launched in July, 2013 (http://plantscience.psu.edu/reduce-runoff). The site contains information on project background, objectives, methods, and goals/outcomes.  It also provides an outreach section with information on turf fertilizer recommendations, compost selection and application methods, liming, calibration of fertilizer spreaders, and examples of how to calculate fertilizer rates.  An events calendar and other sections (pages) will be added as more information becomes available. 

Lawn Establishment: A Reality Check from the Showcase Site

In my introductory turfgrass management course I always stress the importance of establishing cool season turfgrasses in the fall of the year. Seeding turfgrasses, such as tall fescue, in September or early October offers the advantages of near optimal soil temperature for seed germination, less weed and disease problems and greater retention of soil moisture during early seeding growth due to declining temperatures and day length. Implicit in my discussion of this topic is that one has a choice of when they will establish their lawn. Nothing could be further than the  truth for a Home Builder. Lawn establishment in new residential developments usually occurs in a relatively narrow window between the time the finished grade is created on a lot and the sale of the home. Lawn establishment has to occur during this window because sediment and erosion control plans almost always stipulate that soil stabilization on the lot needs to occur before transfer of the property to the new owner can take place.

In northern climates it is usually permissible to stabilize the soil for late fall to early spring property closings by placing straw or another type of erosion control material over the seed. For the remainder of the year though vegetative stabilization of the soil needs to occur in advance of transfer of the property. This means that cool season turfgrasses are sometimes seeded at the worst possible times of the year. This was clearly the case for the two residential lots that were seeded at the project showcase site. One lot was seeded on May 29, 2012 and the other on July 3   2012. Since neither lot possessed in ground irrigation, lawn establishment was completely dependent on natural rainfall. Rainfall during this time of year typically comes in form of thunderstorms and the summer of 2012 was no exception to this type of precipitation pattern. 

 The contractor placed down what I thought was an unusually thick layer of straw ( 3 inches uncompressed)  over the 95% tall fescue 5% microclover seed mixture that was broadcast in May . I was concerned that this much straw would inhibit the growth of microclover seedlings so I had the contractor cut the amount of straw  blown over the seedbed by about a third in the July seeded lot. After a couple of severe thunderstorms had passed through the area it became apparent why the contractor had placed so much straw down in May. Three inches uncompressed straw did a good job minimizing erosive losses and seed washout. Putting down two inches of straw was much less effective at minimizing washout, especially in areas where runoff tended to be limited to sheet flow only. Neither of two depths of straw was effective stopping erosive losses in areas of two yards where flow became channelized.  

                By October, the lawn seeded in May looked great. The July seeded lawn was still struggling to achieve full soil surface coverage due to the seed wash out that occurred over the summer.  Did straw thickness affect the establishment of the microclover? There was a fair amount of microclover present in the May seeded lawn by the end of summer. However, because of the seed washout that occurred in the July seeded lot, it was difficult to determine if microclover establishment was influenced by amount of straw placed in the seedbed. To get a better handled on the effect of straw cover on microclover establishment we will be conducting a study at the University of Maryland Paint Branch Turfgrass Research Facility this fall to see how the amount of straw cover affects the establishment of a tall fescue+ microclover lawn seed mixture. This study is one of the several microclover management studies that will be discussed at the 2013 University of Maryland Landscape Contractor Field Day. For those interesting in attending this field day, it will take place on Wednesday October 23, at the University of Maryland Paint Branch Turfgrass Research Facility, in College Park, Maryland.

Lawn  composition ten weeks after a 29 May seeding of a 95% tall fescue, 5% microclover lawn seed mixture. 

Welcome to BMPs Reduce Runoff and Fertilizer Use in Lawns Blog

This blog will provide brief updates, news, and notices of events for the multistate project "Implementing Best Management Practices (BMPs) to Reduce Runoff and Lawn Fertilizer Use"; sponsored by the National Fish and Wildlife Foundation's Chesapeake Bay Stewardship Fund. The project will investigate two BMPs: use of a lawn seed mixture containing a newly-commercialized nitrogen-fixing legume called microclover; and incorporation of compost during soil preparation.  These practices can be used by builders, landscaping professionals, and homeowners to improve infiltration and reduce nitrogen fertilizer use in lawns in the Chesapeake Bay Watershed. The project includes a showcase residential development where the effectiveness of project BMPs will be demonstrated 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 shift in lawn culture from a high-nitrogen grass monoculture on runoff-prone soils to a more diverse plant community growing in a healthy soil that requires little, if any nitrogen fertilizer.