Green Manures - Annual Ryegrass (Lolium multiflorum)

Sustainable Agriculture in Hawai'i info block

Annual Ryegrass

Lolium multiflorum

Click here for a downloadable, printable pdf on Annual Ryegrass.

Also known as: Italian ryegrass
Cool season annual grass

Uses

Biomass/organic matter source (Dry Matter: 2,000-9,000 lbs/ac/yr)
Very fast establishing cover
Weed suppression
Topsoil conditioner
Nutrient catch crop (high N user)

Plant Highlights

EXCELLENT for increasing organic matter and improving soil structure, for providing erosion control, for quick growth and establishment
VERY GOOD for taking up & storing excess N, for suppressing weeds, for animal grazing (production, nutritional quality & palatability), for providing lasting residue

Cultural Traits

Fair heat tolerance
Fair drought tolerance
Very good shade tolerance
Very good flood tolerance
Fair tolerance to low fertility
pH range 5.5-7.0 (NRCS), prefers 6.0-7.0 (SAN)

Planting
Planting depth: 0 - 1/2 inches
Seeding Method

Drilled: Seed at 5-10 lb./A (0.2-0.4 bu/A)
Broadcast: Seed at 15-30 lb./A (0.6-1.25 bu/A)

Seed Cost: .50 $/lb
Seed Availability: Readily available

Cultivars

Cultivars commonly recommended by the Hawai`i Natural Resources Conservation Service include: ‘Hubam’.

Mix: with legumes, grasses

Soil Improvements

Good for loosening subsoil
Good at releasing P and K
Excellent at loosening topsoil

Pest Control

Good for suppressing nematodes
Good for disease suppression
Good allelopathic properties
Excellent weed suppression
Fair for attracting beneficial insects

Management Attributes

Excellent trafficability
Rapid establishment and growth ideal for short windows

Notes

Annual ryegrass may compete with the cash crop for N and moisture when used as a living mulch. Manage it appropriately (especially during drought, prolonged high or low temps, or in low fertility soils) to prevent yield decreases.
Can become a weed if allowed to set seed.
May tie up N while residue is decomposing. Wait a few weeks after incorporation before seeding subsequent crop or grow with a legume.

Uses in the Pacific Region
No information is available in this database on this topic.

Uses in Hawai`i
The Hawai`i Natural Resources Conservation Service Technical Guide includes Annual Ryegrass (cv. ‘Tam 90’) and Lolium rigidum (cv. ‘Wimmera 62’). Their specification describes Annual Ryegrass as follows:

Minimum broadcast seeding rates of 40 lbs. pure live seed/acre;
pH range from 5.5-7.0;
Approximate growing time 90 days;
Approximate dry matter yield 1.5 tons/acre;
Approximate N content 13 lbs./T dry matter;
Add 25 lbs. of nitrogen/ton dry matter at plow down;
Optimum planting period year round at elevations over 1500 ft.
Optimum planting period fall/winter at elevations below 1500 ft.

Evensen, Osgood and El-Swaify conducted five years of research with small grains as cover crops on sugarcane plantations for erosion and weed control. Variety trials for 51 cultivars of oat, barley, wheat, ryegrass and rye grain on Hawai`i, Molokai, and Lanai were compared. Of the annual ryegrass trials, varieties ‘Alamo’ and ‘Tam 90’ were the most promising (in terms of vigorous growth, rapid soil cover, weed suppression, low plant height, and lack of flowering). This information has applications for pineapple, coffee and tropical fruit tree orchards.

FOR MORE INFORMATION:
UC Davis On-line Cover Crop Index: http://www.sarep.ucdavis.edu/cgi-win/ccrop.exe/show_crop_2

REFERENCES
Evensen, C.I., Osgood, R.V., & El-Swaify, S.A. Small grain cover crops in Hawaii for erosion and weed control. A poster paper presented at the conference on "Cover Crops, Soil Quality and Ecosystems", March 12-14,1997.

1998. Managing Cover Crops Profitably, 2nd ed. Sustainable Agriculture Network, National Agricultural Library, Beltsville, USA. pp. 212.

Online excerpts: http://www.sare.org/mccp2/

USDA Natural Resources Conservation Service, Hawai`i Field Office Technical Guide, Section IV, Code 340 "Cover and Green Manure Crop" May 1992.

If you have used this plant as a green manure in the Pacific Region, please email us with COMMENTS and FEEDBACK about this plant description so we can continue to refine this educational resource.

Last updated on 9/23/02