Successful cover crop (CC) establishment in the fall is important to maximize CC production, which is critical for achieving many objectives of CCs. Competition from winter weeds may reduce CC establishment and biomass production. A preplant herbicide, such as paraquat, at the time of CC planting in the fall will reduce winter weed pressure resulting in better establishment and growth. An experiment was conducted between 2019 and 2021 to test this hypothesis by evaluating a no-CC check, cereal rye, hairy vetch, crimson clover, and cereal rye + hairy vetch drilled with and without paraquat applied at planting (mid-October to mid-November) following either a corn or soybean crop. Visible weed suppression ratings were collected in mid-April, and total CC and weed biomass was collected in late April. More CC biomass was accumulated following corn than soybean, regardless of preplant herbicide application, because corn is typically harvested before soybeans. Therefore, CCs should be planted early to accumulate more biomass. Weed suppression varied by weed species from all factors, but in general weed suppression was best from a CC mixture containing cereal rye and paraquat applied at planting. If weed suppression is the main goal of the CC, then a preplant herbicide at CC planting is recommended. However, if CC weed suppression goals can be achieved through biomass accumulation, no preplant herbicide is needed. This information is useful for producers to achieve various CC objectives while managing costs.

Field studies were conducted in 2018 and 2019 in Arkansas, Indiana, Illinois, Missouri, and Tennessee to determine if cover-crop residue interfered with herbicides that provide residual control of Palmer amaranth and waterhemp in no-till soybean. The experiments were established in the fall with planting of cover crops (cereal rye + hairy vetch). Herbicide treatments consisted of a nontreated or no residual, acetochlor, dimethenamid-P, flumioxazin, pyroxasulfone + flumioxazin, pendimethalin, metribuzin, pyroxasulfone, and S-metolachlor. Palmer amaranth took 18 d and waterhemp took 24 d in the cover crop–alone (nontreated) treatment to reach a height of 10 cm. Compared with this treatment, all herbicides except metribuzin increased the number of days until 10-cm Palmer amaranth was present. Flumioxazin applied alone or in a mixture with pyroxasulfone were the best at delaying Palmer amaranth growing to a height of 10 cm (35 d and 33 d, respectively). The herbicides that resulted in the lowest Palmer amaranth density (1.5 to 4 times less) integrated with a cover crop were pyroxasulfone + flumioxazin, flumioxazin, pyroxasulfone, and acetochlor. Those four herbicide treatments also delayed Palmer amaranth emergence for the longest period (27 to 34 d). Waterhemp density was 7 to 14 times less with acetochlor than all the other herbicides present. Yield differences were observed for locations with waterhemp. This research supports previous research indicating that utilizing soil-residual herbicides along with cover crops improves control of Palmer amaranth and/or waterhemp.

Cover crops provide a number of agronomic benefits, including weed suppression, which is important as cases of herbicide resistance continue to rise. To effectively suppress weeds, high cover crop biomass is needed, which necessitates later termination timing. Cover crop termination is important to mitigate potential planting issues and prevent surviving cover crop competition with cash crops. Field studies were conducted in Virginia to determine the most effective herbicide options alone or combined with glyphosate or paraquat to terminate a range of cover crop species. Results revealed that grass cover crop species were controlled (94% to 98%) by glyphosate alone 4 wk after application (WAA). Overall, legume species varied in response to the single active-ingredient treatments, and control increased with the addition of glyphosate or paraquat. Mixes with glyphosate provided better control of crimson clover and hairy vetch by 7% to 8% compared with mixes containing paraquat 4 WAA. Mix partner did not influence control of Austrian winter pea. No treatment adequately controlled rapeseed in this study, with a maximum of 58% control observed with single active-ingredient treatments and 62% control with mixes. Height reduction for all cover crop species supports visible rating data. Rapeseed should be terminated when smaller, which could negate weed suppressive benefits from this cover crop species. Growers should consider herbicide selection and termination timing in their cover crop plan to ensure effective termination.

Residual herbicides applied to summer cash crops have the potential to injure subsequent winter annual cover crops, yet little information is available to guide growers’ choices. Field studies were conducted in 2016 and 2017 in Blacksburg and Suffolk, Virginia, to determine carryover of 30 herbicides commonly used in corn, soybean, or cotton on wheat, barley, cereal rye, oats, annual ryegrass, forage radish, Austrian winter pea, crimson clover, hairy vetch, and rapeseed cover crops. Herbicides were applied to bare ground either 14 wk before cover crop planting for a PRE timing or 10 wk for a POST timing. Visible injury was recorded 3 and 6 wk after planting (WAP), and cover crop biomass was collected 6 WAP. There were no differences observed in cover crop biomass among herbicide treatments, despite visible injury that suggested some residual herbicides have the potential to effect cover crop establishment. Visible injury on grass cover crop species did not exceed 20% from any herbicide. Fomesafen resulted in the greatest injury recorded on forage radish, with greater than 50% injury in 1 site-year. Trifloxysulfuron and atrazine resulted in greater than 20% visible injury on forage radish. Trifloxysulfuron resulted in the greatest injury (30%) observed on crimson clover in 1 site-year. Prosulfuron and isoxaflutole significantly injured rapeseed (17% to 21%). Results indicate that commonly used residual herbicides applied in the previous cash crop growing season result in little injury on grass cover crop species, and only a few residual herbicides could potentially affect the establishment of a forage radish, crimson clover, or rapeseed cover crop.

Commercial mushroom producers grow several varieties of mushrooms on compost. Upon completion of the growing cycle, the spent mushroom compost is often sold as a soil amendment for both agricultural and homeowner use. Mushroom compost ingredients often come from fields infested with weeds, and in turn compost may spread unwanted weed seed. We conducted studies to assess the viability of weed seed following specific stages of the commercial mushroom production process. Weed seed was more likely to survive if the entire production process was not completed. However, no viable hairy vetch, Italian ryegrass, ivyleaf morningglory, Palmer amaranth, or velvetleaf remained at the end of the study. Although the seeds of most species were eliminated earlier in the composting process, ivyleaf morningglory required the complete process to eliminate 100% of the seed. These results indicate that spent mushroom compost is free of many weed species upon removal from mushroom houses and is unlikely to spread weed seed.

In recent years, the use of cover crops has increased in U.S. crop production systems. An important aspect of successful cover crop establishment is the preceding crop and herbicide program, because some herbicides have the potential to persist in the soil for several months. Few studies have been conducted to evaluate the sensitivity of cover crops to common residual herbicides used in soybean production. The same field experiment was conducted in 2016 in Arkansas, Illinois, Indiana, Missouri, Tennessee, and Wisconsin, and repeated in Arkansas, Illinois, Indiana, Mississippi, and Missouri in 2017 to evaluate the potential of residual soybean herbicides to carryover and reduce cover crop establishment. Herbicides applied during the soybean growing season included acetochlor; acetochlor plus fomesafen; chlorimuron plus thifensulfuron; fomesafen; fomesafen plus S-metolachlor followed by acetochlor; imazethapyr; pyroxasulfone; S-metolachlor; S-metolachlor plus fomesafen; sulfentrazone plus S-metolachlor; sulfentrazone plus S-metolachlor followed by fomesafen plus S-metolachlor; and sulfentrazone plus S-metolachlor followed by fomesafen plus S-metolachlor followed by acetochlor. Across all herbicide treatments, the sensitivity of cover crops to herbicide residues in the fall, from greatest to least, was forage radish = turnip > annual ryegrass = winter oat = triticale > cereal rye = Austrian winter pea = hairy vetch = wheat > crimson clover. Fomesafen (applied 21 and 42 days after planting [(DAP]); chlorimuron plus thifensulfuron and pyroxasulfone applied 42 DAP; sulfentrazone plus S-metolachlor followed by fomesafen plus S-metolachlor; and sulfentrazone plus S-metolachlor followed by fomesafen plus S-metolachlor followed by acetochlor caused the highest visual ground cover reduction to cover crop species at the fall rating. Study results indicate cover crops are most at risk when following herbicide applications in soybean containing certain active ingredients such as fomesafen, but overall there is a fairly low risk of cover crop injury from residual soybean herbicides applied in the previous soybean crop.

Horseweed is a problematic weed to control, especially in no-tillage production. Increasing cases of herbicide resistance have exacerbated the problem, necessitating alternative control options and an integrated weed management approach. Field experiments were conducted to evaluate horseweed suppression from fall-planted cover crop monocultures and mixtures as well as two fall-applied residual herbicide treatments. Prior to cover crop termination, horseweed density was reduced by 88% to 96% from cover crops. At cover crop termination in late spring, cereal rye biomass was 7,671 kg ha–1, which was similar to cereal rye–containing mixtures (7,720 kg ha–1) but greater than legumes in monoculture (3,335 kg ha–1). After cover crops were terminated in late spring using a roller crimper, corn and soybeans were planted and horseweed was evaluated using density counts, visible ratings, and biomass collection until harvest. Forage radish winterkilled, offering no competition in late winter or biomass to contribute to horseweed suppression after termination. Excluding forage radish in monoculture, no difference in horseweed suppression was detected between cereal rye–containing cover crops and legumes (crimson clover and hairy vetch) in monoculture. Likewise, horseweed suppression was similar between monocultures and mixtures, with the exception of one site-year in which mixtures provided better suppression. In this experiment, the cover crop treatments performed as well as or better than the fall-applied residual herbicides, flumioxazin+paraquat and metribuzin+chlorimuron-ethyl. These results indicate that fall-planted cover crops are a viable option to suppress horseweed and can be an effective part of an integrated weed management program. Furthermore, cover crop mixtures can be used to gain the benefits of legume or brassica cover crop species without sacrificing horseweed suppression.

Weed control is a challenging aspect of pumpkin production. Winter rye mulches may offer growers a means to manage weeds in pumpkin; however, rye degradation leads to an immobilization of soil nitrogen. Combining winter rye with a nitrogen fixing legume such as hairy vetch is an interesting option that may solve this problem. Twelve combinations including three hairy vetch seeding rates, two termination dates and the use or not of glyphosate before rolling cover crops were studied during the 2013 and 2014 growing seasons at the Laval University Agronomic Station in Saint-Augustin-de-Desmaures, Quebec, Canada to evaluate weed control and effects on pumpkin production. Adding hairy vetch to winter rye provided no benefits because of severe winterkill of the legume. Using glyphosate was necessary to prevent rye regrowth. Pumpkin growth was better and yields were higher than in the plots were no glyphosate was used. Mulches established at flowering (Zadoks 69) provided about 2,000 kg ha−1 more aboveground dry biomass than at early heading (Zadoks 51). This high biomass was essential in glyphosate treated plots in order to maintain excellent weed control throughout the growing season. When compared with the no-mulch weed-free control, yield in Zadoks 69+glyphosate treatment was lower in 2013 but comparable in 2014.

Cover crop acreage has substantially increased over the last few years due to the intent of growers to capitalize on federal conservation payments and incorporate sustainable practices into agricultural systems. Despite all the known benefits, widespread adoption of cover crops still remains limited due to potential cost and management requirements. Cover crop termination is crucial, because a poorly controlled cover crop can become a weed and lessen the yield potential of the current cash crop. A field study was conducted in fall 2015 and 2016 at the Arkansas Agricultural Research and Extension Center in Fayetteville to evaluate preplant herbicide options for terminating cover crops. Glyphosate-containing treatments controlled 97% to 100% of cereal rye and wheat, but glyphosate alone controlled less than 57% of legume cover crops. The most effective way to control hairy vetch, Austrian winterpea, and crimson clover with glyphosate resulted from mixtures of glyphosate with glufosinate, 2,4-D, and dicamba. Higher rates of auxin herbicides improved control in these mixtures. Glufosinate alone or in mixture controlled legume cover crops 81% or more. Paraquat plus metribuzin was effective in terminating both cereal and legume cover crops, with control of cereal cover crops ranging from 87% to 97% and control of legumes ranging from 90% to 96%. None of these herbicides or mixtures adequately controlled rapeseed.

Cover crop–based, organic rotational no-till (CCORNT) corn and soybean systems have been developed in the mid-Atlantic region to build soil health, increase management flexibility, and reduce labor. In this system, a roller-crimped cover crop mulch provides within-season weed suppression in no-till corn and soybean. A cropping system experiment was conducted in Pennsylvania, Maryland, and Delaware to test the cumulative effects of a multitactic weed management approach in a 3-yr hairy vetch/triticale–corn–cereal rye–soybean–winter wheat CCORNT rotation. Treatments included delayed planting dates (early, intermediate, late) and supplemental weed control using high-residue (HR) cultivation in no-till corn and soybean phases. In the no-till corn phase, HR cultivation decreased weed biomass relative to the uncultivated control by 58%, 23%, and 62% in Delaware, Maryland, and Pennsylvania, respectively. In the no-till soybean phase, HR cultivation decreased weed biomass relative to the uncultivated treatment planted in narrow rows (19 to 38 cm) by 20%, 41%, and 78% in Delaware, Maryland, and Pennsylvania, respectively. Common ragweed was more dominant in soybean (39% of total biomass) compared with corn (10% of total biomass), whereas giant foxtail and smooth pigweed were more dominant in corn, comprising 46% and 22% of total biomass, respectively. Common ragweed became less abundant as corn and soybean planting dates were delayed, whereas giant foxtail and smooth pigweed increased as a percentage of total biomass as planting dates were delayed. At the Pennsylvania location, inconsistent termination of cover crops with the roller-crimper resulted in volunteer cover crops in other phases of the rotation. Our results indicate that HR cultivation is necessary to achieve adequate weed control in CCORNT systems. Integration of winter grain or perennial forages into CCORNT systems will also be an important management tactic for truncating weed seedbank population increases.

Sweet corn and pumpkin were planted no-tillage (NT) into cover crop residue treatments of vetch, rye, crimson clover, and ladino clover controlled with glyphosate, and a bare ground conventional tillage (CT) control. Objectives included evaluation of crop growth, yield, and weed suppression in NT versus CT treatments. Herbicide application was also investigated, with a plus and minus herbicide treatment (alachlor plus cyanazine for sweet corn, or ethalfluralin for pumpkin) as the main factor in the factorial experiment, and cover crops the subfactors. Weed control 4 wk after planting was dependent upon cover crop. The fewest weed numbers and least biomass were found in the ladino clover plots, but clover regrowth and subsequent competition with the cash crop were severe. Herbicides also affected weed biomass at 4 wk after vegetable planting, with least biomass in herbicide-treated plots. Neither cover crop nor herbicide treatment significantly affected weed weight by 8 wk after planting or pumpkin fruit weight at harvest. Pumpkin yield was not influenced by herbicide application. The vetch cover, although harboring greatest weed biomass, produced the greatest total yield (ear weight) in sweet corn. When averaged over cover crop, sweet corn yields were higher in herbicide-treated plots than in untreated ones. Both sweet corn and pumpkin maturity were generally delayed in the absence of herbicide treatments or in the presence of cover crop residues, especially clover and rye residues.

Hairy vetch was grown as a winter annual cover crop and evaluated for weed suppression when desiccated by paraquat or left alive until natural senescence in a 3-yr field experiment. Total weed density and biomass were variable in the desiccated hairy vetch treatment relative to a bare soil treatment but were consistently lower in the live hairy vetch treatment relative to the desiccated or bare soil treatments. An average of 87% of sites under live hairy vetch compared to 8% of sites under desiccated hairy vetch transmitted less than 1% of unobstructed sunlight. The red (660 nm) to far-red (730 nm) ratio of transmitted light was reduced by 70% under live hairy vetch compared to 17% under desiccated hairy vetch. Daily maximum soil temperature and diurnal soil temperature amplitude were reduced by live hairy vetch > desiccated hairy vetch > bare soil. Soil moisture content was greater under both live and desiccated hairy vetch compared to bare soil during droughty periods. Changes in light extinction, red to far-red ratio, and diurnal soil temperature amplitude were sufficient to explain greater weed suppression by live than desiccated hairy vetch.

Cotton and pitted morningglory emergence and dry weight decreased approximately 60 to 80% when these plants were grown under greenhouse conditions in the presence of increasing amounts (0.8 to 6.7 mg debris/g soil) of field-grown crimson clover or hairy vetch debris incorporated into the soil medium. Conversely, corn dry weight increased 20 to 75% when legume debris was placed on the soil surface; incorporated debris had very little effect on corn emergence or dry weight. Germination and seedling growth of corn, Italian ryegrass, cotton, pitted morningglory, and wild mustard decreased progressively, with species-dependent variation, when exposed to increasing concentrations (8.3 to 33.3 g debris/L) of aqueous crimson clover and hairy vetch extract. Mustard and ryegrass germination and growth were almost completely inhibited by full-strength extracts of both legumes. Bioassay species exhibited greater phytotoxic responses to hairy vetch than to crimson clover in the debris and extract studies. Emergence and growth of corn and cotton were not affected when planted into soil samples, containing root biomass and possible leaf and root exudates, collected from beneath field-grown hairy vetch and crimson clover plants. However, morningglory dry weight increased 35% in the presence of either legume root debris and accompanying soil.

Weed control by rye, crimson clover, subterranean clover, and hairy vetch cover crops was evaluated in no-tillage corn during 1992 and 1993 at two North Carolina locations. Weed biomass reduction was similar with rye, crimson clover, and subterranean clover treatments, ranging between 19 and 95% less biomass than a conventional tillage treatment without cover. Weed biomass reduction using hairy vetch or no cover in a notillage system was similar averaging between 0 and 49%, but less than other covers approximately 45 and 90 d after planting. Weed biomass was eliminated or nearly eliminated in all cover systems with PRE plus POST herbicide treatments. Weed species present varied greatly between years and locations, but were predominantly common lambsquarters, smooth pigweed, redroot pigweed, and broadleaf signalgrass. Corn grain yield was greatest using PRE herbicides or PRE plus POST herbicides, averaging between 16 to 100% greater than the nontreated control across all cover treatments depending on the year and location.

The recent interest in cover crops as component of Midwest corn and soybean production systems has led to the need for additional research, including the effects of residual corn and soybean herbicide treatments on fall cover crop establishment. Field studies were conducted in 2013, 2014, and 2015 in Columbia, Missouri to investigate the effects of common residual herbicides applied in corn and soybean on establishment of winter wheat, tillage radish, cereal rye, crimson clover, winter oat, Austrian winter pea, Italian ryegrass, and hairy vetch. Cover crops were evaluated for stand and biomass reduction 28 d after emergence (DAE). Rainfall from herbicide application to cover crop seeding date was much greater in 2014 and 2015, which resulted in less carryover in these years compared to 2013. When averaged across all herbicides evaluated in these experiments, the general order of sensitivity of cover crops to herbicide carryover, from greatest to least was Austrian winter pea=crimson clover>oilseed radish>Italian ryegrass>hairy vetch>wheat >winter oat>cereal rye. Cereal rye had the fewest instances of biomass or stand reduction with only four out of the 27 herbicides adversely effecting establishment. Pyroxasulfone consistently reduced Italian ryegrass and winter oat biomass at least 67% in both the corn and soybean experiments. In the soybean experiment, imazethapyr- and fomesafen-containing products resulted in severe stand and biomass reduction in both years while flumetsulam-containing products resulted in the greatest carryover symptoms in the corn experiment. Results from these experiments suggest that several commonly used corn and soybean herbicides have the potential to hinder cover crop establishment, but the severity of damage will depend on weather, cover crop species, and the specific herbicide combination.

Winter annual weeds can interfere directly with crops and serve as alternative hosts for important pests, particularly in reduced tillage systems. Field experiments were conducted on loamy sand soils at two sites in Holt, MI, between 2008 and 2011 to evaluate the relative effects of cereal rye, hairy vetch, and rye–vetch mixture cover crops on the biomass and density of winter annual weed communities. All cover crop treatments significantly reduced total weed biomass compared with a no-cover-crop control, with suppression ranging from 71 to 91% for vetch to 95 to 98% for rye. In all trials, the density of nonmustard family broadleaf weeds was either not suppressed or suppressed equally by all cover crop treatments. In contrast, the density of mustard family weed species was suppressed more by rye and rye–vetch mixtures than by vetch. Cover crops were more consistently suppressive of weed dry weight per plant than of weed density, with rye-containing cover crops generally more suppressive than vetch. Overall, rye was most effective at suppressing winter annual weeds; however, rye–vetch mixtures can match the level of control achieved by rye, in addition to providing a potential source of fixed nitrogen for subsequent cash crops.

A field experiment was conducted in 2009–2010 at Pennsylvania and Maryland locations, and repeated it in 2010–2011 to test the effectiveness of POST-applied herbicides at fall and spring timings on seeded hairy vetch in winter wheat. A total of 16 herbicide treatment combinations was tested that included synthetic auxins, acetolactate synthase (ALS) inhibitors, and a protoporphyrinogen oxidase inhibitor. Spring applications tended to be more effective than fall applications. Among synthetic auxins, clopyralid (105 g ae ha−1) and treatments containing dicamba (140 g ae ha−1) were effective at both timings, resulting in greater than 90% hairy vetch control at wheat harvest. Pyroxsulam and prosulfuron applied at 18 g ai ha−1 provided the most effective hairy vetch control (> 90%) at both application timings among ALS inhibitors. Spring applications of several herbicides provided moderate (> 80%) to high (> 90%) levels of hairy vetch control, including: 2,4-D amine (140 g ae ha−1), mesosulfuron-methyl (15 g ai ha−1), tribenuron-methyl (13 g ai ha−1), and thifensulfuron/tribenuron-methyl treatments (16 and 32 g ai ha−1). Winter wheat injury was evaluated, but symptoms were negligible for most treatments. Winter wheat yields declined with increasing hairy vetch biomass. Fall herbicides may be prioritized to reduce hairy vetch competition during the fall and early spring growing season. Our research has established that several synthetic auxin and ALS-inhibiting herbicides, applied POST in fall or spring, can be safely used in winter wheat to control hairy vetch in an integrated weed management program.

The integration of cover crops with selected postemergence herbicides was evaluated on the basis of weed control and grain yields in no-till soybean and corn. Soybean was planted into wheat residue, whereas corn was planted into hairy vetch residue. Full, half, and quarter rates and sequential herbicide applications were made. The wheat cover crop did not increase weed suppression but increased soybean grain yields. Half rates of thifensulfuron plus quizalofop-P as single or split applications were as effective as full rates in reducing weed weight in soybean. Soybean grain yields were similar in the half- and full-rate treatments in 1994, but yield was highest in the full-rate treatment in 1995. The hairy vetch cover crop did not increase weed suppression but lowered corn stands and grain yields in 1995 and enhanced corn grain yields in 1996. Full, half, and quarter rates (1996 only) of nicosulfuron plus primisulfuron were equally effective in reducing weed weight. Corn grain yields were similar at all herbicide rates in 1995 but were inversely related to herbicide rate in 1996. Split herbicide applications did not improve weed suppression over single applications of the same herbicide rate in either crop. Results indicate that cover crops can improve crop productivity and reduced rates of environmentally benign herbicides can minimize the herbicide requirements in no-till corn and soybean.

Cover crops and living mulches bring many benefits to crop production. Interest in winter annual cover crops such as winter rye and hairy vetch for ground cover and soil erosion control has been increasing in the last 30 yr in some areas. The integration of cover crops into a cropping system by relay cropping, overseeding, interseeding, and double cropping may serve to provide and conserve nitrogen for grain crops, reduce soil erosion, reduce weed pressure, and increase soil organic matter content (Hartwig and Hoffman 1975). Hairy vetch has increased availability of nitrogen to succeeding crops, increased soil organic matter, improved soil structure and water infiltration, decreased water runoff, reduced surface soil temperature and water evaporation, improved weed control, and increased soil productivity (Frye et al. 1988). More recent research with perennial living mulches, such as crownvetch (Hartwig 1983), flatpea, birdsfoot trefoil, and white clover (Ammon et al. 1995), has added a new dimension to the use of ground covers that eliminates the need to reseed each year. Cropping systems with the use of ground covers have been worked out for vineyards, orchards, and common agronomic crops, such as corn, small grains, and forages. Legume cover crops have the potential for fixing nitrogen, a portion of which will be available for high-nitrogen–requiring crops such as corn. In areas where excess nitrogen is already a problem, the use of ground covers may provide a sink to tie up some of this excess nitrogen and hold it until the next growing season, when a crop that can make use of it might be planted (Hooda et al. 1998). Even legumes tend to use soil nitrogen rather than fixing their own, if it is available. It is these possibilities that provide the incentive for looking at the effect of various kinds of cover crops on soil erosion, nitrogen budgets, weed control, and other pest management and environmental problems.

Cover crop systems were investigated in 2004 and 2005 for their effects on the activity-density (a function of movement and density) of a promising group of weed biocontrol organisms, the ground beetles collectively known as carabids, with particular emphasis on a beneficial carabid species Harpalus rufipes DeGeer. Marked H. rufipes released into pea/oat–rye/vetch cover crop plots were more than twice as likely to be recaptured within the same plots as beetles released in nonvegetated fallow plots (18 and 8%, respectively). Marked beetles released into fallow plots were more than twice as likely to leave their plots and be recaptured in pea/oat–rye/vetch plots as vice versa (13 vs. 5%), indicating a clear preference for habitat with vegetative cover. Overall recapture rates were not different between treatments. Unmarked H. rufipes activity-density was also higher in pea/oat–rye/vetch compared to fallow plots. Additionally, five cover crop systems, including the fallow and pea/oat–rye/vetch treatments, and two residue management methods (conventional and zone tillage) were investigated from June to August in 2005 for their effects on H. rufipes activity-density. Corn was planted in 2005 into residues of the five cover crop systems grown in 2004. H. rufipes activity-density was higher in zone and conventionally tilled corn planted in pea/oat–rye/vetch residues and conventionally tilled corn planted in red clover/oat residues than in any other cover crop and residue management combination. Pea/oat–rye/vetch cover crop systems are apparently beneficial for H. rufipes during the cover crop year as well as in subsequent crops planted into this cover crop's residues. This system was not the least disturbed system but, based on the number of tillage events, represented a medium level of disturbance among the various systems. Thus, some level of disturbance might be beneficial for H. rufipes, but how and when that soil disturbance occurs requires further research to determine the best means of conserving this species.