This article is probably not exactly what you may think but read on! Dr. Matt Akins Research Scientist and Asst. Professor at the UW-Marshfield, heard about a paper from just slightly after the turn of the century(!) which promoted some of the benefits of modern European genetic cool season grasses and in this case Italian Ryegrass. It was not forthcoming so we (at this time, Dr. Akins involved Daniel in the search) finally found part of the project in the personal files of Dr. Dan Undersander, Agronomy Professor, Emeritus and he sent it to us.
The research, done by Dr. Undersander detailed the agronomy part of a three-year trial comparing the rotational benefits of Italian Ryegrass to alfalfa for a following corn crop.
Additional work was done by Dr. David Combs, Dairy Science Professor, Emeritus with a feeding trial utilizing the resulting forages. Both parts of the study became important information which Daniel and I, plus others used to build Byron Seeds from a grazing seed supply company into a powerhouse in the supply of modern high-energy forage seeds to all parts of the dairy (and beef) industry. I dare say that this work led eventually to a lot of the digestibility work Dr. Combs did later his career.
Oh yes, why was this important research not published? I quote from his cover letter to us when he dug up this paper:
It was never published in the agronomy journal because one of the reviewers said that ryegrass was a weed and nothing should be published about it. At the time I was too busy to fight it or look for alternatives for publishing.Dr. Undersander
Well, we have used Italian Ryegrass (IRG) as at least a part of a vast majority of the winning World Dairy Expo Forage Analysis Superbowl we submitted in every hay/haylage/baleage category. IRG is one of the best forages to feed your cows I know. It is a part of virtually every cocktail mix we have designed. I would assume the objector to this submission to this agronomy journal has also long since retired whether before or after he realized his underestimation of this particular weed is unknown!
The Agronomy of a Special Weed
So, what did this weed research say? We all know of the rotational effect a legume plays on the following corn crop. It has also been shown that fertilizer cannot substitute for rotation (Smith and Lauer, 2008). Dr Undersander was trying to discover if there was a corresponding rotational effect when modern forage grasses if this case IRG was grown in the year before a corn crop.
The trial was set up to separate the nitrogen benefit from the benefit resulting from crop rotation. The study was conducted at the UW-Arlington research farm just north of Madison, WI. It consisted of planting Italian Ryegrass (which was to be harvested in either a 25- or 35-day schedule), alfalfa, and corn. In the second year, corn was planted over the whole plot. Each the process was then repeated on different ground the next year. The crop plantings each had four replications.
The IRG was seeded at 25 lbs. per acre, the alfalfa at 20 lbs. per acre and the corn was planted to produce 30,000 plants per acre. Half of the grass plots were harvested every 25 days (5 times) and half was harvested every 35 days (4 times).
The residuals were the grass and alfalfa were harvested with 3-inch residual and the corn at 6-incd residual and was harvested at 35% dry matter (DM). The alfalfa was harvested three times in the first trial and four times in the second. The crops were fertilized by the soil test with 160 lbs. N for the corn. The grass was given 50 lbs. at seeding and 50 lbs. after each cutting.
All crops were sprayed with Roundup™ at the end of the first growing season. Corn was planted across all the plots after light tillage the next year. N was applied at 100 lbs. across the whole plot with an extra 100 lbs. applied on the corn-on-corn ground.
The Weed Findings
The yields were very good (see Table 1). Corn yielded 10.4 and 10.5 t/a with the IRG right behind at an average of 8.68 t/a. with no significant difference between the 25-day and 35-day treatments.
When looking at the corn following each crop, the corn-on-corn as expected achieved the lowest yield with 7.6 and 7.8 t/a in years 1 & 2 respectively. Corn after alfalfa was next best at a 17% increase over the corn-on-corn. The corn following the IRG fared the best with 22% and 25% depending on the cutting frequency. Possible reasons for this improvement were increased soil organic matter, soil microbes and and/or soil texture. All three of the conjectures would be the result of the tremendously complex root systems resulting from the IRG.
The results of the rotational effects (see Table 2) were also very encouraging. The corn following alfalfa was as expected with a 17% improvement over the corn-on-corn. However, to many, the surprise is the corn after IRG was by far the best result of all with 25% and 27% improvement over the corn-on-corn.
All in all, we would have to conclude Italian Ryegrass is an extremely valuable and important weed! The other part to this research, i.e., the feeding trial will be detailed here in this space, when we can locate it!