As many of you know, the nesting season that restricts management activities in fields enrolled in the Conservation Reserve Program (CRP) is fast approaching. Most contracts restrict large-scale management beginning on May 15^th through August 1^st without prior approval from the Farm Service Agency (FSA). The majority of management in enrolled fields revolves around the new requirements for mid-contract management of these fields. In brief, new regulations require periodic management (every 5-6 years) of cool season grass fields to suppress the grasses and increase plant diversity. Management options recommended by the Natural Resource Conservation Service (NRCS) include burning, disking, and herbicide applications. The optimal timing for burning has passed in most areas in Wisconsin as many of these grasses are already green and several inches tall, but herbicide applications and disking could still be applied before the restriction timing.  Research conducted in 2008 evaluated the effectiveness of various herbicide treatments and compared them to disked and untreated areas. First year results were presented at Wisconsin’s Crop Production Conference. A copy of the proceedings paper can be found at: http://www.soils.wisc.edu/extension/wfapmc/2009/pap/Renz_1.pdf . A brief description of the experiments and initial results are summarized below.

 

Experiments were conducted in Greene and Dodge county, Wisconsin to evaluate the effectiveness of glyphosate (Roundup), sethoxydim (Poast) and fluazifop (Fusilade) in suppressing smooth brome dominated stands compared to tillage and untreated plots (see Table 1 for rates). Herbicides and tillage were applied in the spring on 4/29/08 and 5/12/08 at each site respectively. While all methods were effective in establishing a more diverse plant community, the use of glyphosate was more effective at suppressing populations than other treatments. While disking suppressed smooth brome, results did not persist throughout the year as cover was only significantly reduced at the Dodge county site (38% 106 DAT). No rate response was seen with glyphosate applications at each site in 2008, future observations will determine if this trend continues in future years.

 

 

 

² included 1% crop oil concentrate and 2.5 lbs/A of ammonium sulfate

³ included 10 lbs/A of ammonium sulfate

* indicates value is significantly different than untreated controls (p<0.05) within the column

^{^} DAT=Days After Treatment