Soybean Planting Date Research Articles

Influence of Soybean Planting Date and Maturity Group on Stink Bug (Heteroptera: Pentatomidae) Populations

Field experiments were conducted in Stoneville, MS, to determine the impact of soybean planting date and maturity group on stink bug (Heteroptera: Pentatomidae) populations. Maturity group IV and V soybeans were planted on three planting dates in 2003 and 2004. Planting dates were late March-early April, late April-early May, and late May-early June. Plots were sampled weekly with a standard 38.1-cm-diameter sweep net. Planting date and maturity group each had a significant effect on stink bug populations. In general, the earliest planting date had the lowest densities of stink bugs, whereas the latest planting date had the highest densities of stink bugs. Over the 2-yr period, cumulative numbers of stink bugs (SE) ranged from 17.9 (6.25) per 25 sweeps for the first planting to 190.9 (20.03) per 25 sweeps for the third planting date when averaged across maturity groups. Additionally, stink bug populations were generally lower on maturity group IV soybeans than on maturity group V soybeans. Cumulative numbers of stink bugs on maturity group IV soybeans averaged 52.4 (26.23) and 25.2 (6.93) in 2003 and 2004, respectively. On maturity group V soybeans, cumulative numbers of stink bugs averaged 96.9 (28.05) and 85.7 (40.84) in 2003 and 2004, respectively. These data provide valuable information about the population dynamics of stink bugs and indicate that early plantings of maturity group IV soybeans in the mid-South will escape heavy stink bug densities.

Rice–soybean rotations: opportunities for enhancing whole farm profits or water savings

The objective of this paper is to examine the impacts of terminating rice [ Oryza sativa] irrigation earlier than usual. One straightforward result of this would be the associated cost savings (≈$10 ha −1 per irrigation or more with deep wells) without placing a value on the water itself. However, another option exists for some farms. An assumption is that the typical farm will be constrained from irrigating all of the soybean [ Glycine max (L.) Merr] crop due to constraints in any or all of water supply, pumping capacity, and labor availability. In these cases, a portion of the land in soybean production would be non-irrigated for the first part of the growing season. This study explores the possibility of transferring irrigation water to the soybean crop after the needs of the rice crop are met. If rice and soybean planting dates are planned optimally, this partial irrigation can lead to substantial soybean yield improvements and therefore a more profitable rice/soybean production system. On average, across a 41 year period, net revenue gains from partially irrigating the soybean crop were consistently positive, ranging from $41 to $458 ha −1. While these numbers are interesting, the reader is cautioned that the results are based on simulation models and therefore the marginal analysis results are more realistic. On clayey and silt loam soils at Keiser and Stuttgart, respectively, the change in returns for moving from the least to the most water saving rice irrigation strategy was $190 and $99 ha −1, respectively. In addition, for any given year, financial losses are typically restricted to the irrigation setup costs of $17 ha −1. The irrigation termination strategies therefore show high economic potential with little risk of loss.

Cultural Practices and Glyphosate Applications for Sicklepod (Senna obtusifolia) Control in Soybean (Glycine max)1

A study was conducted in 1995 and 1996 to determine the effect of soybean planting date, tillage level, and glyphosate application on sicklepod control and seed production. Soybean was planted in April, May, June, and July into conventional and no-till seedbeds. Herbicide programs evaluated were metribuzin plus chlorimuron preemergence (PRE) followed by (fb) chlorimuron postemergence (POST) (standard program [STD]), metribuzin plus chlorimuron PRE fb glyphosate POST as-needed, and glyphosate POST as-needed. Control was similar across planting dates in both years with slight variations due to weather. The July planting date had the lowest total sicklepod seed production over the 2-yr study. Sicklepod control was better in conventional tillage, but soybean yields were greater in no-till. Herbicide programs that included glyphosate provided greater sicklepod control, lower sicklepod seed production, and higher soybean yields than the STD. Use of glyphosate in combination with later planting dates, especially...

Herbicide Effects on Visible Injury, Leaf Area, and Yield of Glyphosate-Resistant Soybean (Glycine max)1

The failure of glyphosate to control all weeds throughout the entire growing season has sometimes prompted growers to use herbicides other than glyphosate on glyphosate-resistant soybean. Field studies were conducted in 1999 and 2000 to investigate potential crop injury by several herbicides in glyphosate-resistant soybean and to determine the relationships between soybean maturity group, planting date, and herbicide treatment on soybean injury, leaf area index (LAI), and yield. Glyphosate-resistant soybean generally recovered from early-season herbicide injury and LAI reductions; however, some treatments reduced yield. Yield reductions were more common in double-crop soybean than in full-season soybean. In full-season soybean, most yield reductions occurred in the early-maturing ‘RT-386’ cultivar. These yield reductions may be attributed to reduced developmental periods associated with early-maturing cultivars and double-crop soybean that often lead to reduced vegetative growth and limited LAI. Reductions in LAI by some herbicide treatments were not necessarily indicative of yield loss. Further yield reductions associated with herbicide applications occurred, although soybean sometimes produced leaf area exceeding the critical LAI level of 3.5 to 4.0, which is the minimum LAI needed for soybean to achieve maximum yield. Therefore, LAI response to herbicide treatments does not always accurately indicate the response of glyphosate-resistant soybean yield to herbicides.Nomenclature: Glyphosate; soybean, Glycine max (L.) Merr.Additional index words: Double-crop soybean, full-season soybean, soybean maturity group.Abbreviations: EPSPS, 5-enolpyruvylshikimate-3-phosphate synthase (EC 2.5.1.19); fb, followed by; LAI, leaf area index; PRE, preemergence; POST, postemergence; WAP, weeks after planting.

Starter Nitrogen and Growth Habit Effects on Late‐Planted Soybean

AbstractIn the Gulf Coast region of the southeastern USA, soybean [Glycine max (L.) Merr.] is often planted in a double‐cropped system following corn (Zea mays L.). In this system, soybean planting date is delayed from the optimal range (mid‐May to mid‐June) to late July, causing a substantial yield reduction. Potential grain yield response has led to increased interest in indeterminate growth habit and N application for late‐planted, double‐cropped soybean systems. Our objective was to determine the interactiv effects of growth habit (determinate and indeterminate stem termination types) and starter N (0 and 50 kg ha−1) on soybean growth and yield when planted following corn in a double‐crop system. Three Maturity Group VIII soybean genotypes [the near‐isolines Au86‐2397I (Dt1Dt1, indeterminate) and Au86‐2397D (dt1dt1, determinate) and a determinate check cultivar, Cook] were planted in late July in seven Alabama environments during 1995 and 1996. Starter N increased R1 dry matter for both Au86‐2397D and Au86‐2397I by 0.50 Mg ha−1. Au86‐2397I had 1 cm greater average plant height at the R1 developmental stage and 14 cm greater height at R8 than Au86‐2397D. Au86‐2397I yielded 0.16 Mg ha−1 more than its determinate near‐isoline. Application of starter N decreased the number of nodules per root, but increased plant N concentration and dry matter yield. Grain yield was increased on average by 0.15 Mg ha−1 with addition of starter N. In this study, an indeterminate genotype soybean coupled with application of starter N promoted greater soybean growth and yield in a late‐planted, double‐cropped system.

Effect of Date of Preplant Tillage and Planting on Weed Populations and Mechanical Weed Control in Soybean (Glycine max)

Additional information on mechanical weed management systems is needed so producers can develop systems that meet their production and weed control goals without sacrificing profitability. Field research was conducted at Rosemount, MN, in 1989, 1990, and 1991 to determine the effect of preplant tillage and soybean planting date on weed populations and effectiveness of mechanical weed control operations. Delaying soybean planting from mid-May to early-June reduced weed densities and yield losses from weeds. Weed control with a herbicide treatment was not affected by planting date, but control with rotary hoeing and cultivation was often increased by delaying soybean planting. Early-planted soybean usually yielded better following herbicide treatment than mechanical weed control. However, when preplant tillage and planting were delayed, weed densities were reduced and mechanical weed control operations usually resulted in soybean yield similar to the herbicide treatment. While delaying soybean planting reduced weed densities and improved mechanical weed control, there is potential for reduced soybean yields with delayed planting.

Effect of Soybean Planting Date on Bean Leaf Beetle (Coleoptera: Chrysomelidae) Abundance and Pod Injury

Studies were conducted near Ames, LA, from 1989 through 1992 to quantify the effects of soybean planting date on bean leaf beetle, Cerotoma trifurcata (Forster), abundance and soybean pod injury and seed yield. Experimental treatments were seeding the 1st wk of May and the last wk of May, which spanned the recommended planting time in central Iowa. Plots were located adjacent to alfalfa, separated by a com buffer, and arranged according to 3 (1989 and 1990) or 4 (1991 and 1992) randomized blocks. Bean leaf beetle and soybean developmental stage were determined twice weekly. Pod injury and seed yield were measured from harvest samples. Results indicated that soybean planted toward the end of May had reduced bean leaf beetle colonization and lower seasonal densities than those planted the 1st wk of May. Lower densities resulted in significantly fewer beetle feeding days during pod development and reduced pod injury in 3 of the 4 yr of study. Additionally, seed yield potential was not significantly reduced by late planting. However, bean leaf beetle migration from early into late plantings during 1 yr of the study caused greater pod injury there, pointing to the need to determine the effectiveness of late planting when it is used as a pest management tactic.

Effect of planting date on severity of frogeye leaf spot and grain yield of soybeans

The influence of soybean ( Glycine max) planting date on seasonal epidemics of frogeye leaf spot caused by Cercospora sojina and on grain yield, was evaluated during the 1991 and 1992 cropping seasons. Two susceptible (Samsoy 1 and TGx 849-313D) and one resistant (TGx 996-26E) soybean cultivars were used in field trials at Zonkwa, in the southern Kaduna state of Nigeria. Four field plantings were made at 14-day intervals from late May to mid0July. For each planting date, half the plots received foliar applications of benomyl at R 1 and R 3 growth stages, and the other half was untreated. Frogeye disease severity ratings were taken for all plots at R 4 to R 5 growth stages, and grain yield for each plot was measured at harvest. There was a significant ( p < 0.05) increase in disease severity between the first and third plantings on the two susceptible cultivars in 1991, and on TGx 849-313D only in 1992. Corresponding yield reductions for the two susceptible cultivars averaged 13 and 31% for the treated and untreated plots, respectively, with each 2-week delay beyond the first planting date in 1991, and 5 and 6%, respectively, in 1992. There was no significant difference in disease among all treatments on the resistant cultivar, TGx 996-26E. Under Nigerian conditions, an increase in frogeye leaf spot severity can be expected with delayed planting of soybean after 1 June, and this can result in a corresponding loss of crop yield.

Cropping system influences on extractable water for mono- and double-cropped soybean

For rain-fed agriculture in the southeastern United States, efficient soil water use when double-cropping is essential. Water use by soybean [ Glycine max (L.) Merr.] following winter wheat ( Triticum aestivum L.) is, however, poorly documented. Winter wheat may deplete soil water, thus limiting subsequent soybean yield. Cropping system variables, such as soybean planting date and row spacing, may also affect water use. Therefore, a 4-year field experiment in northeastern Mississippi was conducted on Leeper ( Vertic Haplaquept) and Catalpa ( Fluvaquentic Hapludoll) silty clays. The objectives were to (1) determine the influence of soybean planting date, cropping system (monocropped versus double-cropped), and row spacing on extractable water (similar to available water) for soybean, and (2) identify a production system to improve the use of extractable water over a growing season. In mid- to late-May (the first soybean planting date), “Centennial” soybean in 38- or 76-cm rows was planted either between rows of standing wheat or in bare (monocropped) plots. After the wheat was harvested and the straw chopped, soybean was planted into bare soil or planted no-till into wheat stubble in mid-June for the second planting and in early July for the third. Soil water content was measured with a neutron probe from soybean emergence to maturity. Differences between each water content profile and a dry profile (constructed using the lowest recorded water content at each depth) were regarded as extractable water. Neither soybean planting date nor cropping system, as a main effect, exerted much influence on extractable water for soybean. As interacting factors later in the season, however, they were important. Plots with soybean in 38- rather than 76-cm rows contained more extractable water throughout the 1982 and 1983 seasons, and yielded over 9% more seed. Canopies closed about 20 days sooner with narrow rows than with wide rows. These full canopies protected and shaded the soil surface, probably reducing crusting and decreasing water losses by evaporation. We concluded that double-cropped soybean in 38-cm rows planted either into standing wheat in late May or into wheat stubble not later than mid-June utilized extractable water efficiently in silty clay soils in northeastern Mississippi.

Influence of Cotton (Gossypium hirsutum) and Soybean (Glycine max) Planting Date on Weed Interference

Separate field experiments were conducted for cotton and soybean in 1990 and 1991 to determine the influence of planting date on yield loss due to interspecific interference from entireleaf morningglory and sicklepod and to determine the relative competitiveness of each weed species. Percent soybean yield loss due to weed interference increased as planting date was delayed from early May to early June. Averaged over weed species, yield losses from 1.7 weeds m−1row were 10, 18, and 20% for soybeans planted in early May, mid-May, and early June, respectively. Yield loss from 6.7 weeds m−1row were 17, 31, and 35% at the early May, mid-May, and early June planting dates, respectively. Percent seed cotton yield losses averaged over weed species in 1990 were 33 and 28% for the early May and early June planting dates, respectively, at 1.7 weeds m−1and 50% for both planting dates at weed densities of 6.7 plants m−1. The only experimental factor that significantly affected seed cotton yield in 1991 was weed density. Unlike soybeans, planting date had little effect on weed interference in cotton. Entireleaf morningglory was more competitive than sicklepod in both crops. Results suggest that selection of optimum soy bean planting dates may be a viable means of reducing losses due to weed interference.

Effects of Cropping Systems on Population Density ofHeterodera glycinesand Soybean Yield

We evaluated the effects of soybean planting date and maturity group (MG) on final population density of Heterodera glycines and yield in cultivars susceptible to H, glycines grown in monoculture and in rotations with 1 or 2 yr of nonhosts. Population density of eggs and eggs plus second-stage juveniles of H. glycines declined to barely detectable levels after 2 yr of nonhost culture. Population densities of this nematode were consistently greater (P=0.05) for an MG VII cultivar than an MG V cultivar. Planting date had variable effects on final population density of H. glycines: early planting resulted in the highest nematode numbers in some years, whereas late planting was associated with significantly greater (P=0.05) population densities in other years

Influence of Soybean Planting Date and Leaf Age on Resistance to Corn Earworm (Lepidoptera: Noctuidae)

Soybean, Glycine max (L.) Merr., resistance to insects has been shown to vary with planting date and leaf age. This study determined effects soybean genotype, planting date, and leaf age had on feeding behavior of corn earworm, Helicoverpa zea (Boddie). Soybean genotypes ‘Cobb’ (susceptible) and ‘GatIR81-296’ (resistant) were planted early (29 May) and late (28 June) in 1989 in the field. Trifoliolate leaf samples from the top, middle, and bottom one-third of the plant were sampled four times throughout the season. Leaves were arranged in a free-choice fashion and presented to third-instar H. zea in the laboratory. Leaf area removed was calculated with a computer-based leaf area analysis system. Larvae preferred ‘Cobb’ over ‘GatIR81-296’ in each sampling date. Leaves from the late planting had greater leaf area removed on the first two sampling dates compared with leaves from the early planting (15.8 versus 11.7 and 34.5 versus 22.9 cm2), but leaves from the early planting had more leaf area removed compared with leaves from the late planting on the last two sampling dates (30.9 versus 22.7 and 21.3 versus 16.2cm2). Thus, H. zea exhibited a bimodal feeding preference for early- and late-planted soybean. Older leaves (middle or bottom one-third) of all plants were typically preferred over younger ones (top one-third) throughout the season. Because resistance may vary during plant development, an accurate identification of soybean resistance should be done only with genotypes at a similar stage of development.

Soybean Planting Date, Row Width, and Seeding Rate Response in Three Tillage Systems

Soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) are commonly grown in rotation, but information regarding soybean production in conservation-tillage systems has lagged behind corn. This study was conducted to determine the influence of planting date, row width, and seeding rate on soybean grain yields, plant stands, and other agronomic characteristics, as affected by tillage intensity. Two field studies were conducted at Arlington, WI, with no-tillage (NT), reduced tillage (RT), and complete tillage (CT) systems, using ‘Hodgson 78’ (Group I) and ‘Corsoy 79’ (Group II) varieties. In one 4-yr study, soybeans were seeded in 8- and 30-in. rows in mid-May, late May, and mid-June. Yields in NT were 5.3 and in RT 2.8 bu/acre lower than in CT. Solid-seeded soybeans (8 in.) yielded 3.1 bu/acre more than wide rows (30 in.). This yield advantage for solid-seeding, however, reversed at the latest planting dates in CT and RT. Early and late plant populations, plant height, and lodging were also lower in NT and RT than in CT. In a second study, soybeans were seeded in 8-in. rows at 50 000 to 300 000 viable seeds/acre in three tillage systems for 3 yr. Plant emergence was 13 and 15% greater in CT than either RT or NT, respectively, when averaged across seeding rates. Late-season stands did not differ among tillages at the lower seeding rates (50 000 and 100 000 viable seeds/acre). At the higher seeding rates (150 000 to 300 000), however, the NT and RT systems required an additional 50 000 seeds/acre to achieve harvestable plant stands equivalent to CT culture. When averaged across all seeding rates, CT outyielded NT and RT by an average of 4.5 bu/acre. When yields at equivalent final stands were compared, however, yields in CT were less than 3 bu/acre higher than RT or NT. Soybean seeding rates in NT and RT systems must be approximately 15% to 32% higher than those normally used in CT if equivalent yields are to be expected.

Influence of Planting Date and Row Width on Abundance of Velvetbean Caterpillars (Lepidoptera: Noctuidae) and Southern Green Stink Bugs (Heteroptera: Pentatomidae) in Soybean

The influence of soybean planting date and row width on seasonal abundance of velvetbean caterpillars, Anticarsia gemmatalts Hubner, and southern green stink bugs, Nezara viridula (L.), was examined in large field plots during 1987-1988. Late-season populations of velvet bean caterpillars were more abundant in ‘Braxton’ soybeans planted in early June than in early May. They also were more numerous in narrow rows (45 cm) than in wide rows (90 cm), regardless of velvet bean caterpillar population density or sampling date. Southern green stink bugs were more numerous from July to mid-August in soybeans planted in early May than in soybeans planted in mid-Mayor early June. In late September to mid-October, when peak numbers were observed, there were more stink bugs in the narrow-row plantings than in the wide-row plantings. Several planting date, row spacing, and sampling date interactions were noted and are discussed. The canopy closure index (space left open between rows) was higher in the later plantings and wide rows, whereas plant height was higher in the earlier plantings and about the same for both row widths. Plot yields varied among planting dates between years but were higher in narrow rows both years.

Effects of Wheat and Soybean Planting Date onHeterodera glycinesPopulation Dynamics and Soybean Yield with Conventional Tillage

The influence of winter wheat (Triticum aestivum) cover crop vs. winter fallow and of soybean (Glycine max) planting date on the populations dynamics of soybean cyst nematode (Heterodera glycines) (SCN) was determined during a 2-yr period. Numbers of SCN cysts, eggs, and second-stage juveniles were unaffected by wheat as opposed to winter fallow. Delay in soybean planting associated with double-cropping wheat, however, allowed for a significant decline in the numbers of SCN between early May and late June. Midseason densities of early May soybean plantings were greater than those of mid-June to late June plantings (.)

INFLUENCE OF CULTIVAR, PLANTING DATE, AND ROW WIDTH ON ABUNDANCE OF GREEN CLOVERWORMS (LEPIDOPTERA: NOCTUIDAE) AND GREEN STINK BUGS (HETEROPTERA: PENTATOMIDAE) IN SOYBEAN

The influence of soybean planting date, row width and cultivar selection on abundance of green cloverworms, Plathypena scabra (F.), and green stink bugs, Acrosternum hilare (Say), was examined during 1984 – 85 at the Virginia Agricultural Experiment Stations located at Painter, Suffolk, and Warsaw. Green cloverworms were more abundant in soybeans planted in narrow - row widths (25 cm) than in soybeans planted in wide - row widths (100 cm). Early planting (early June) vs. late planting (early July) did not influence population densities. Green stink bugs were more abundant in the early maturing varieties planted early. Row width did not influence stink bug population levels.

Intercropping Soybean into Standing Green Wheat1

AbstractScientists and farmers have been evaluating the intercropping of soybean [Glycine max (L.) Merr.] into wheat (Triticum aestivum L.) before harvest as an alternative to doublecropping in the lower Midwest. It was our objective to examine the interrelationships of soybean row spacing, planting date, and N applied to wheat in a wheatsoybean intercropping system. The experiment was conducted near Columbia, MO, in 1983, 1984, and 1985, on a Mexico silt loam (Udollic and Mollic Ochraqualf). Whole‐plot treatments consisted of two cropping systems (conventional and intercropped), drilled and skiprow planting patterns (0.2‐ and 0.8‐m row spacings of soybean), and three soybean planting dates coinciding with wheat growth stages. Subplots consisted of spring applied N treatments (0, 56, and 112 kg ha−1). A wheat‐soybean double crop was also included. Wheat yields were reduced 23 and 16% when soybean was intercropped in the drilled and skiprow patterns, respectively. The date of planting did not significantly (P &lt; 0.05) influence wheat yield in the skiprow patterns. However, wheat yield was significantly (P &lt; 0.05) decreased as planting date was delayed in the drilled pattern because of mechanical damage. Intercropped soybean yielded 27% less than conventional soybean but 28% more than doublecropped soybean over all years and treatments. Drilling soybean at the heading stage of wheat resulted in greatest yields. In 1985, N applied in excess of 56 kg ha−1 produced excessive wheat vegetative growth resulting in competition for light which caused a reduction in drilled, intercropped soybean yield. Where mechanical damage to wheat can be minimized, drilling soybean in wheat at heading can result in optimum intercrop performance.

Population Dynamics of Heliothis zea (Lepidoptera: Noctuidae) as Influenced by Selected Soybean Cultural Practices

Corn earworm (CEW), Heliothis zea (Boddie), third filial egg and larval populations were monitored in field trials during 1980–82 in eastern North Carolina to investigate the effects of soybean planting date, cultivar, phenological stage, and degree of canopy development on CEW oviposition and survival. In 1982, soybeans were sampled every 3–4 d during the entire CEW F3 generation. This allowed for calculation of total within-generation production of eggs, egg parasitism, and stage-specific mortality. Planting date and phenological stage were the most important factors affecting CEW oviposition and survival. Late-planted soybeans had more eggs and higher insect survival than did early-planted soybeans, and treatments beyond the pod-set stage received few eggs. The highest correlations were found between the number of eggs and the number of plant terminals ( r = 0.7) and flowers ( r = 0.79). Greatest CEW mortality occurred between the egg stage and the third instar. Total incidence of natural enemies was higher in early-planted soybeans.

Overwintering Behavior and Spring Colonization of Soybean by the Bean Leaf Beetle (Coleoptera: Chrysomelidae) in Illinois 1

Adult bean leaf beetles, Cerotoma trifurcata (Forster), were trapped as they entered Illinois woodlots during October 1979 and 1980. Soil litter samples and emergence traps detected the presence and distribution of overwintering beetles within woodlands. Spring beetle emergence from overwintering sites began in April and extended through May. In 1980 the majority of beetles emerged in May, but in 1981 the majority emerged during April. Beetle emergence and soybean planting dates were well synchronized in 1980, and poorly synchronized in 1981, resulting in a population crash. A simple predictive model for beetle emergence based on degree-day accumulation was developed. This proved superior to simple calendar date predictions of peak colonization flights.

Relay Intercropping Soybeans into Winter Wheat and Spring Oats1

AbstractRelay intercropping of soybeans [Glycine max (L.) Merr.] into small grains might allow the two‐crops‐in‐1 year concept to be moved further northward in the U.S. Corn Belt. The small grain crops in such a system might also provide protection against soil erosion on sloping soils currently in conventional soybean production. The objective of this study was to compare monoculture oat (Avena saliva L.), wheat (Triticum aestivum L.), and soybean yields with soybeans relay intercropped into spring oats or winter wheat. Variables considered included small grain and soybean row widths, soybean planting date, and soybean cultivar. Field experiments were conducted on Typic Haploquoll and Typic Argiudoll soils in central Illinois.Interseeding soybeans into small grains did not affect small grain yields. In three of four environments tested, small grain yields in rows 41, 61, and 81‐cm wide averaged yields of 91, 72, and 58%, respectively, of small grains in 21‐cm row widths. In a fourth experiment, where winter wheat rows wider than 21‐cm were created by spring removal of intervening rows, yield reductions were greater than for those planted in wider rows. Monoculture soybeans produced significantly higher yields and taller plants than intercropped soybeans. Reduced growth of intercropped soybeans, especially in narrow rows, was associated with below normal precipitation during both years of experimentation. Soybeans intercropped between 41 and 61‐cm small grain rows yielded between 7 and 93% of monoculture soybeans grown in similar row widths. Soybeans aerially seeded into small grain stands failed to establish a stand, but soybeans conventionally placed in the soil produced acceptable stands. A short determinate soybean cultivar did not appear to withstand early season stress associated with intercropping as well as a tall indeterminate cultivar. In years with normal early season precipitation, successful relay intercropping of soybeans into small grains should be possible.