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October 2015
ON FARM LEVEL
Soil conservation and health benefits
Stooling rye is a very valuable cover crop and can be used for ero-
sion control. When lands are going to be planted to soybean or
maize, the soil can be protected over winter by this species.
It can also be used as a winter cover crop for continuous minimum
tillage of maize when the maize crop is harvested early.
It has many positive effects on soil structure and chemical status.
Because of its quick growing fibrous root system, rye makes full
use of the various soil layers, and in doing so, it improves soil
permeability, soil moisture content and soil biodiversity (earth-
worms); stooling rye forage also prevents leaching of excess soil or
manure N (UC SAREP, 2006).
Used as green manure, rye provides large amounts of organic mat-
ter to the soil. However, when rye is sown for forage, a part of the
organic matter is not returned to the soil. This species is an excellent
cover crop to utilise unused soil nitrogen and research has shown
how it increases the concentration of exchangeable potassium (K) in
the top layer of the soil.
It is also known to suppress weeds very effectively especially
through outcompeting weeds for water and nutrients, however, it
also suppresses many weeds alleopathically (as a natural herbicide).
Management challenges
Fewer diseases attack rye than other cereals. The following dis-
eases and pests have been reported to cause notable problems in
stands of stooling rye.
Stem or stalk smut
Disease control could be achieved by seed treatment and crop ro-
tation where the spores are soil-borne. Resistant varieties are also
available.
Anthracnose
This is a common disease especially prevalent in the humid and
sub-humid areas of the country. Infected plants often ripen or die
prematurely.
Rusts (leaf rust and stem rust)
Destruction of volunteer stooling rye in stubble fields will aid in
control of this disease.
Insects
Stooling rye is attacked by many of the same insects that attack
other small grains. Serious losses are not common, however early
sown autumn rye provides a favourable environment for the deposi-
tion of insect eggs which can cause injury to other crops.
Animal production aspects
During late autumn, livestock can graze stooling rye forage once it
has reached a height of 15 cm - 20 cm and it should be removed
when the grass height is reduced to 5 cm - 7 cm.
Stooling rye allows very early spring grazing when other perennial
grasses are still dormant. It should be grazed rotationally and at high
stocking rates in order to prevent it from maturing and losing nutri-
tive value (Samples et al., 2011).
Crude protein values ranges from 11% (dough) to 23% (boot) de-
pending on the stage of maturity. Dry matter digestibility rang-
es from 64% (dough) to 81% (boot). Total digestible nutrients
(TDN) range from 67% to 75%. Approximate values of acid deter-
gent fiber (ADF) and neutral detergent fiber (NDF) are 37% and
55%, respectively.
Conclusion
Cover crops have proven to be important in improving soil health
in the winter season prior to the next summer planting of either
maize or soybean. Stooling rye offers the potential benefits of
improving soil health, but establishment and management costs
can be high.
One way for producers to recover these costs is to graze the
forage, which benefits producers by integrating crop and animal
production. Very limited information exists on the potential forage
quantity and quality for grazing livestock of cover crops and mixed
species of cover crops.
Research to date has suggested that different plant species com-
plement each other, however research is currently determining how
best to balance forage production and how competitive the various
species are when added to a mixture with stooling rye.
For more information, contact Dr Wayne Truter at wayne.truter@
up.ac.za, Prof Chris Dannhauser at
Dr Hendrik Smith at or Mr Gerrie
Trytsman at
References
Brink, M. 2006. Secale cereale L. Record from Protabase. Brink, M. & Belay, G. (edi-
tors). PROTA (Plant Resources of Tropical Africa/Ressources végétales de l’Afrique
tropicale), Wageningen, Netherlands.
Samples, D.H. & Sule, R.M. 2011. Winter rye for extending the grazing season. Ohio
State University Factsheet AGF-26-00, Ohio State University Extension Service.
UC SAREP, 2006. Cereal rye. Cover crop database. University of California, Sustain-
able Agriculture Research & Education Programme, Davis.
CONSERVATION AGRICULTURE
Conservation agriculture