11/1/2022

As temperatures cool across the United States, it is tough to mentally turn the page to the next growing season. However, just like a healthy dinner and a good night's sleep are important for a productive tomorrow, prepping your turf for fall recovery, dormancy, and spring green up are important for a healthy start to the next season.

Fall Fertility on Turfgrass Quality and Weed Control

For cool season turf, fall presents an opportunity to increase turf density (after possible thinning over the stressful growing season), correct soil nutrient deficiencies and provide prime conditions for consistent green-up. Alternatively, a lack of action can lead to sluggish turf.

To better understand the effects of fall fertility on turfgrass quality and weed control, Harrell’s initiated a year-long evaluation of a turf fertility program constructed specifically to address site-specific needs with Dr. Matt Elmore of Rutgers University. The study utilized a practical approach that can be applied to any property.

Turf Fertility Program Study

·         First: a soil sample was submitted to determine plant-available soil nutrient levels. Compared to the Sufficiency Level of Available Nutrients threshold values, it was determined that supplemental calcium, magnesium, and potassium should be added to all plots so that deficiency of these nutrients would not limit turf growth throughout the year (Table 1).

·         Second: four treatments were initiated across randomized plots in the research area. Each treatment received a unique combination of fall 2019 fertilizer, spring 2020 fertilizer, spring 2020 Dimension pre-emergent herbicide, and/or no treatment at all. Treatments are described in Table 2.

·         Third: treatments were evaluated based on turf quality and percent crabgrass control through the 2020 growing season. All treatments that included Dimension provided >90% crabgrass control as of September 7^th, 2020 (Figure 1).

Figure 1. Smooth Crabgrass Control on September 7^th, 2020. Different letters amongst treatments indicate a significant difference at an α<0.05 significance level.

Excellent crabgrass control does not tell the whole story, however. Plots that received a fall 2019 POLYON® fertilizer application had superior turf quality throughout spring 2020, compared to plots that did not. On the first spring rating date, May 24^th, plots that received a fall POLYON® fertilizer application. These plots rated a full point higher in turf quality than turf that did not (Figure 2).

A month later, on June 24^th, the differences remained evident (Figure 3). As the year wore on, turfgrass quality declined in plots that did not receive spring fertility; however, fall-only POLYON® fertilizer plots maintained higher quality than no-fertility plots through the duration of 2020.

Fall 2019 POLYON® fertilizer, followed by spring 2020 POLYON® fertilizer and Dimension at 0.5 lb ai/A provided the highest level of turf quality and crabgrass control across all treatments, through the duration of the trial (Figure 1, Figure 2, Figure 4). These results are an excellent example of the benefits a balanced, well-planned fertility program can have for turf quality, weed control, and overall playability.

Contact Your Harrell's Rep!

Undoubtedly the fall + spring POLYON® fertilizer + spring Dimension program performed as designed by providing high turf quality and crabgrass control through a full year of evaluation.

A simple approach to soil testing, followed by custom fertilizer formulation, is a fundamental way to enhance turf quality for the coming season. With Harrell’s breadth of custom blending options, there is a solution for every agronomic scenario. Your local Harrell’s rep is an experienced resource to walk alongside you in developing solutions to fit your specific agronomic needs for the coming season.