Trial Site: Fairview Research Farm
Research Coordinator: Dr. Akim Omokanye
From: Peace Country Beef & Forage Association 2017 Annual Report
It is important to choose a variety of annual or Italian ryegrass that establishes quickly, a variety that is well -adapted to the area, yields plenty, is very palatable and yields consistently throughout the season after harvesting. The extension publication by Dr. Lemus of Extension Service of Mississippi State University indicates that annual ryegrass varieties fall into two types, which are called tetraploid (4n) or diploid (2n). Tetraploid varieties are usually marketed as producing more forage biomass than diploids, but this could depend on location, management, fertility, and environmental conditions. Diploids have the advantage of a greater cold tolerance and quicker recovery. Some varieties are both a tetraploid and an Italian ryegrass. This makes them very useful. First, as a tetraploid ryegrass, they have twice the chromosomes of a diploid ryegrass, higher sugar content, and bigger, more succulent leaves. They are also a true Italian ryegrass, meaning that when planted in cool-season regions they normally will not go to seedhead until following summer. Annual ryegrass as a cover crop has the following benefits: tolerance to a wide range of soils, can tolerate compacted soils, minimizes soil compaction, N scavenger, suppresses weeds in 4-6 weeks, good erosion control and improves soil aggregate.
To test annual and Italian ryegrass varieties for their forage yield, re-growth potential and suitability for fall grazing.
Project Site: Fairview Research Farm (NW5-82-3W6) on RR #35, MD of Fairview.
Previous crop: Chemical fallow in 2016; forage-type brassicas in 2015
Site soil information (0-6” depth): Soil tests done at Exova laboratory (Edmonton) prior to seeding showed pH = 5.8 and soil organic matter = 7.0 %.
The field was cultivated (disked and harrowed) before seeding.
Experimental Design: Randomized complete block design in 3 replications.
Treatments: 8 annual & Italian ryegrass varieties listed in Table 1 below were tested
Seeding Date & Rate: Seeding was done on May 30 at 12 lbs/acre
Seeding method: 6-row Fabro plot drill with 9” row spacing
Fertility (actual lbs/acre): 89 N + 50 P + 29 K + 24 S
Plot size: 11.04 m2 (118.8 ft2 )
Spraying: In-crop spraying – 2,4-D-700
Measurements: Plant height and forage yield were determined on August 12. Forage samples were analyzed for quality. Notes were taken on re-growth potential a few weeks after harvest.
Results and Interpretation
Forage Dry Matter (DM) Yield
Both Italian and Sabroso varieties produced forage DM yield of 4000 lbs DM/acre or more, while other varieties produced less than 4000 lbs DM/acre forage yield. Common (Check) had the least forage DM yield (2640 lbs/acre). Expect for Sabroso and Common (check) varieties, the re-growth potential was very good for all varieties tested, with ability to regrow for a second cut or fall grazing.
Crude Protein (CP): The forage CP values of varieties tested varied from 13.8% CP for both Sabroso and Common to 27.6% CP for Meroa. Only 3 (Meroa, Green Spirit and Danegro) of the 8 varieties tested had >20% CP. Others had <20% CP (13.8-19.0% CP). Comparing to other cool season cereals, annual ryegrasses would generally have far higher CP than barley, oats and triticale as well as soft white wheat. In the present study, all annual ryegrasses had far more than what mature beef cattle need for CP. The CP requirements of growing and finishing calves (12-14% CP) were mostly exceeded by annual ryegrass varieties tested.
Energy: The total digestible nutrients (TDN) values were generally high and mostly about 70% for annual ryegrass varieties tested. Using %TDN, the Rule of Thumb is 55-60-65. This rule says that for a mature beef cow to maintain her body condition score (BCS) through the winter, the ration must have a TDN energy reading of 55% in mid pregnancy, 60% in late pregnancy and 65% after calving. All varieties tested here exceeded the TDN requirements for pregnant beef cows. For lactating beef cows, only Sabroso and Check fell short of meeting the 65% TDN needed by lactating beef cows.
Minerals: Meroa had the highest forage Ca content. Green Spirit had the highest forage P, K, Mg, S, Zn and Mn. The forage Cu and Fe values were respectively higher for Danegro and Meroa than others. Meroa, Green Spirit and Danegro had higher forage Na than others.
All varieties tested here far exceeded the Ca requirements of growing and finishing beef cattle, as well as dry gestating beef cows in mid and late pregnancy, but only Meroa had the 0.58% Ca needed by a lactating beef cow.
Except for Sabroso, the P requirements by pregnant cows have been met by all varieties. Only Green Spirit was able to meet the P requirement of a lactating beef cow, which is 0.26% P.
The requirements of K, Mg, Na, S, Fe, Zn and Mn by mature beef cattle have been met by all varieties tested.
However, all varieties did not have sufficient forage Cu for young and mature beef cattle.
All annual ryegrasses tested in this study grew fast and seemed to be ready for grazing 6-8 weeks after seeding. In most cases, they would require a regrowth period of 2-4 weeks after cutting or grazing in this area. Sabroso variety had the least regrowth potential of the varieties tested.
Though annual ryegrasses are low in dry matter and would normally have lower forage DM yield than oats, barley and triticale, they are highly digestible and have high CP. On beef and sheep farms, producers use annual ryegrasses for grazing animals having a high nutrient requirement such as young, growing stock. When supplemented with perennial forages, annual ryegrasses extend the grazing season beyond its normal range. Having high-quality supplemental forage for a longer season increases animal returns and lowers storage costs. Farmers can also make better use of land and equipment. All annual ryegrasses tested in this study had good forage quality value, with their forage CP and TDN values far exceeding the needs of a dry gestating beef cow. For the purpose of one cut only, Sabroso would probably be a better option than most other annual ryegrasses tested here. For additional benefits, especially where more than one cut is required, where fall grazing is the objective, or where a good soil cover is needed - Italian, Dangero and Green Spirit varieties would probably be a better choice. Cover crops have become a popular option in the Peace, providing vegetative cover and building soil on land traditionally left black or in stubble after harvest. Annual plant species offer the majority of cover crop options, serving a dual function in livestock/cropping systems.