Green Manures - Rye (Secale cereale)

Sustainable Agriculture in Hawai'i info block

Rye

Secale cereale

Click here for a downloadable, printable pdf on Rye.

Also known as: cereal rye, winter rye, grain rye
Cool season annual cereal grain

Uses

Biomass/organic matter source (Dry Matter: 3,000-10,000 lbs/ac/yr)
Weed suppression
Pest suppression
Nurse crop in combination with slow-establishing legumes
Nutrient catch crop (high N user)
Windbreak

Plant Highlights

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

Cultural Traits

Good heat tolerance
Very good drought tolerance
Very good shade tolerance
Good flood tolerance
Excellent tolerance of low fertility
pH range 5.0-7.0 (SAN)

Planting
Planting depth: 3/4 - 2 inches
Seeding Method

Drilled: Seed at 60-120 lb./A (1-2 bu/A)
Broadcast: Seed at 90-160 lb./A (1.5-3.0 bu/A)

Seed Cost: .05-.20 $/lb
Seed Availability: Readily available

Cultivars

Cultivars commonly recommended by the Hawai`i Natural Resources Conservation Service include: ‘Wrens Abruzzi’.
Work by Evensen, Osgood, and El-Swaify suggests that the ‘Danko’ and ‘Elbon’ cultivars are suitable for cover crops in Hawai`i.

Mix: with legumes, grasses, or other cereal grains

Soil Improvements

Fair for loosening subsoil
Very good at releasing P and K
Excellent at loosening topsoil

Pest Control

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

Management Attributes

Very good trafficability
Rapid establishment and growth ideal for short windows

Notes

Cereal rye can tie up nitrogen as its residue decomposes. Kill rye early while it is still succulent to minimize N tie up. Alternately, increase your N application or plant a legume.
Cereal rye has allelopathic effects (which helps suppress weeds) that last about 30 days. Wait 3-4 weeks before planting small seeded crops such as carrots or onions.
Cereal rye can become a weed if tilled before it reaches 8 inches high or seedheads are allowed to mature.
Insect pests can often be reduced by using cereal rye crop rotations.

Uses in the Pacific Region
Section to be added later.

Uses in Hawai`i
The Hawai`i Natural Resources Conservation Service Technical Guide includes Rye grain (cv. ‘Wrens Abruzzi’). Their specification describes Rye grain as follows:

Minimum broadcast seeding rates of 70 lbs. pure live seed/acre;
pH range from 5.5-7.0;
Approximate growing time 90 days;
Approximate dry matter yield 1 ton/acre;
Approximate N content 18 lbs./T dry matter;
Add 20 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 Rye grain trials, varieties ‘Danko’ and ‘Elbon’ 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_12

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