Joe Lawrence, Allison Kerwin – Cornell PRO-DAIRY
The growing season across much of the Northeast started out with below average temperatures. Despite the cool start, relatively dry conditions coupled with warmer temperatures as the month of May progressed provided generally good conditions for corn planting with all trial locations planted between May 5th and May 21st (Table 1). As the season progressed, all locations experienced below average precipitation and above average heat accumulation. Several locations were designated as abnormally dry to moderate drought throughout June and July; however, in most cases, the crop proved quite resilient and rainfall in mid-July was critical to generally successful pollination. It is worth noting that at several locations, seasonal rainfall totals were inflated by extreme rain events that generally pose greater risk (in terms of the potential for strong winds, runoff and other potential crop damage) than benefit to the crop.
It should also be recognized that some areas of the state experienced more severe drought conditions than these locations leading to more significant negative impacts on yield and forage quality. In these areas greater shifts in management strategies will be needed to make adjustments in feeding programs.
Table 1
| Maturity Group | Location | Planting Date | Harvest Date | Seasonal GDD (86/50) | Seasonal Rainfall (inches) |
|
80 – 95 day RM 38 entries |
Willsboro, NY
Albion, NY Alburgh, VT |
May 21
May 20 May 13 |
September 1
September 4 September 9 |
2073
2163 2099 |
10.54
12.63 15.47 |
|
96 – 110 day RM 52 entries |
Madrid, NY
Aurora, NY Alburgh, VT |
May 5
May 13 May 14 |
September 15
August 31 September 21 |
2231
2144 2198 |
10.44
11.43 15.68 |
As 2020 corn silage sits in storage, hopefully fermenting for the next few months before being fed out, it is helpful to understand how this crop might feed compared to previous years. Using the trial results as an indicator of corn silage performance gives us an idea of average performance. Data for the detailed hybrid specific report of the trials is still being processed, but we do have enough information to look at overall performance trends.
Keep in mind this is an average of certain locations and your conditions may vary. On your own farm, it is helpful to take samples of your forage at harvest and again prior to feed out to understand the opportunities and challenges as you begin to feed this year’s crop. We also need to remember that while fresh samples can be a helpful indicator, some characteristics of the forage will change during fermentation, particularly starch digestibility.
As additional years of data are collected, patterns begin to form. As the 2020 season progressed, there were many similarities to the 2018 growing season (Figure 1a &1b). While total rainfall varied from 2018 at several locations, the rainfall totals are a bit misleading as the pattern and timing of this rainfall led to abnormally dry to drought conditions at all locations at different points in the season.
The influence of weather on key forage quality parameters, such as fiber digestibility, has been an area of focus in this work. As the season progressed, the similarities to 2018 suggested the potential for a highly digestible crop. This projection was validated as the 2020 trial data shows a crop with high fiber digestibility as well as high starch levels (Figure 2a & Figure 2b).
Another way to look at these key parameters and to compare with previous years is to look at the sample spread across a range of values for these parameters. Table 2 and Figures 2a and 2b show the differences in undigested neutral detergent fiber after 240 hours of digestion (uNDF240) and starch content, respectively. The data in Figure 2 represents the last four growing seasons (2017 – 2020) with results combined from all locations (Albion, Willsboro, Aurora, Madrid and Alburgh) by year.
Each year brings its own challenges and opportunities. Given the variation in growing conditions across the region, it is critical to test your own forages to understand the site-specific impacts of the growing season.
It is important to evaluate this data in the context of your farm when selecting hybrids. The top performing hybrid at any one location or in any one category may not be a good fit for your feeding program. Factors that influence this vary by farm but include land base, soil resources, forage inventory, quality of available hay crops, access and cost of supplemental ingredients, and expectations of cow performance.
The trial results and location averages serve as a means to calibrate hybrid performance to a particular growing season. These averages can be used in conjunction with a company’s data on hybrids in their lineup, including hybrids not entered into these trials, to understand how a hybrid performed relative to what is realistic for a given growing season. For example, in Figure 2, we see that the highest percentage of samples have an uNDF240, %DM value in the 9-10% category and over 50% of samples having a starch content of 50% or greater. This can be used to evaluate how close or far away from these values other hybrids performed in 2020.
It is important to recognize the companies that make these trials possible through their entry of hybrids. The following companies participated in the 2020 trials.
Albert Lea – Viking, Blue River Organic, Brevant, Channel, Dekalb, Growmark FS, Hubner, King Fisher (King’s Agri-seed), Local Seed Company, Masters Choice, Nutrien Ag Solutions – Dyna-Gro, Pioneer, Redtail (King’s Agri-seed), Schlessman (Gold Star Feed & Grain), Seed Consultants, Seedway, Syngenta – NK
