cover and cropland retirement programs were funded or 
contracted for a definitive term (either 5 or 10 years). At 
the end of this term, stands were usually replaced with 
grain crops until the need for establishment of another 
cover crop was apparent. In light of an ever diminishing 
supply of fossil fuel energy, management for quality and 
longevity of vegetative cover is needed for much of the 
public land where production of grain is not one of the key 
objectives. One of the better and longest-lived replace- 
ment plant communities would likely be a mixture of 
native species from the same general area. Unfortunately, 
seed sources for such mixtures are hard to obtain and they 
are prohibitively priced for extensive cover programs for 
the glaciated prairie pothole region. Furthermore, the 
wildlife production capabilities from planted stands of 
cultivars of native plant species is virtually unknown, 
Thus until significant seed sources and proper procedures 
are obtained for stand establishment and subsequent man- 
agement of mixtures of native plant species, SNC and simi- 
lar inexpensive and easy-to-establish mixtures will con- 
tinue to be important for use in large-scale wildlife man- 
agement and agricultural grain deferment programs and 
on sites where long-term efforts needed to reestablish 
native cover would be inappropriate. 
Guidelines 
Seeded nesting cover is only one among several possible 
types of replacement plant communities adaptable to the 
Northern Plains. It is a cover crop that can be grown on 
lands within a precipitation range of 30-61 cm and for 
soils of capability class IV or better. 
Compared to other grasses or grass-legume mixtures, 
SNC is economical and easy to establish, which makes it a 
desirable mixture for use on extensive public land pro- 
grams or for wildlife management programs where the 
production:cost ratio is often narrow and the range of es- 
tablishment methods is broad. Another desirable feature 
of SNC is the low potential for species invasion into adja- 
cent habitats; however, within individual stands, if proper 
establishment procedures are not followed, unsown areas 
will produce undesirable weeds instead of SNC. 
For establishing and managing SNC, energy conserva- 
tion is dependent on stand longevity. Good stand quality 
(species composition) and stand longevity are related to 
proper establishment and management procedures and to 
environmental conditions. The goal of SNC management 
should therefore be quality-oriented. 
The main decision periods in SNC management are dur- 
ing stand establishment (first 3 years) and after stand es- 
tablishment. Decision guidelines for qualitative manage- 
ment of SNC for these periods are suggested as follows: 
e Prepare the soil and plant the SNC seed mixture ac- 
cording to the procedures described by Duebbert et al. 
(1981). 
® Inspect each stand for success of SNC establishment 
19 
and for noxious weed invasion during the first, second, 
and third growing seasons. 
e If SNC species appear to dominate stands of cover 
during the second and third growing seasons and noxious 
weeds are not an apparent problem, quality stands of SNC 
have been established. 
e If SNC species are rarely apparent in the second and 
third growing seasons and weed species are dominant, 
these stands should be eliminated and soil preparations 
and establishment procedures should be started over. This 
decision can be made in the second growing season, if 
growing conditions have been favorable and the amount 
and distribution of annual precipitation have been aver- 
age or above during the previous year or two. 
e If SNC species dominate stands of cover during the 
second and third growing seasons, yet stands also have an 
apparent heavy noxious weed infestation, managers have 
the options of controlling the weeds with herbicides, tem- 
porarily subduing the weeds with mechanical equipment 
which may enhance the dominance of SNC species in the 
future, or eliminating the stand by cultivation. The choice 
of these options should be based on the quantity and dis- 
persion of noxious weed species within stands and on the 
degree of difficulty and cost for controlling or subduing 
the target weed species. 
The SNC stands that have been successfully established 
on good sites can be expected to provide substantial struc- 
ture for at least the first 6 growing seasons and to retain 
SNC composition for at least the first 10 growing seasons 
and probably longer for most stands. 
e Except for regulated noxious weed control, there 
should be no management treatments of SNC stands dur- 
ing the first six growing seasons. 
@ Periodic checks for stand performance and invasion 
by regulated noxious weeds should be made on stands 7 or 
more years old. Beginning with the seventh growing sea- 
son, vegetation in some stands may need a rejuvenation 
treatment. An array of treatments and times for applica- 
tion are suggested for sown mixtures of cool-season grasses 
and legumes by Duebbert et al. (1981); however, decisions 
for treatments should be avoided in years of extremely ab- 
normal conditions such as drought, excessive wetness, ex- 
cessive harvest by rodents, or heavy snow or ice pack. 
Treatment decisions should also be avoided in the first 
growing season following any abnormal condition. Sub- 
stantial increases in vegetation structure, vigor, and seed 
production in SNC have been seen following abnormal 
conditions. In effect, an abnormal condition produces a 
vegetative renovation action similar to an applied treat- 
ment. 
Evaluation studies of wildlife outputs and the develop- 
ment of vegetation management guidelines for SNC stands 
which are more than 8-10 years old are lacking. Such 
studies are needed and should be conducted in the near 
future on a sample of older age-class stands. Furthermore, 
there is a definite need for more studies of methods of SNC 
renovation. 
