Abstract
Soybean [ Glycine max (L.) Merr.] are grown under both irrigated and rainfed conditions in the western Corn Belt. We wanted to determine whether optimum row spacing and seeding rate were similar for different cultivars in different water regimes. A 3‐yr field study at Clay Center, NE, and a 2‐yr study near Oxford, NE, were conducted. We used a factorial combination of three row spacings (10, 20, and 30 in.), four seeding rates (45 000, 140 000, 230 000, and 330 000 seeds/acre) and five cultivars with four replications planted in adjoining irrigated and rainfed fields at each site. Determinate cultivar yield increased 42% (11 bu/acre) as seeding rate increased from 45 000 to 140 000 seeds/acre and then remained constant with increased seeding rate. Seeding rate generally did not affect indeterminate cultivar yield. The 20‐in. row spacing consistently had the greatest yields or yields equal to the high‐yielding row spacing. Yield of indeterminate cultivars in both water regimes and determinate cultivars with irrigation was greater with 20‐in. rows than either 10‐ or 30‐in. rows. Yield of determinate cultivars in rainfed was similar in 20‐ and 30‐in. rows and less in 10‐in. rows. The 20‐in. row spacing also consistently produced the highest yield at all four seeding rates. This report goes beyond previous research findings by concluding that, with moisture stress, determinate cultivars in 20‐ and 30‐in. rows may produce more than in 10‐in. rows. Research Question Soybean are grown in the U.S. Corn Belt over a wide range of conditions. These include areas with adequate moisture for rainfed production to western areas where irrigation is necessary for optimum soybean production. We conducted this study to determine whether optimum row spacings and seeding rates are the same for irrigated and rainfed water regimes. In addition we wanted to determine how cultivars were affected by changing cultural practices and environments. Literature Summary Most researchers have found that yields increase as row spacings decrease. Some have reported situations with no affect of narrow rows. Narrow rows have also decreased yields in environments with low yield potential. The most typical soybean response to changes in seeding rates is increased yields up to a point with increased seeding rates. Some scientists however, find occasionally that a wide range of seeding rates does not affect yields. Others have shown that increasing seeding rates may reduce yield. Study Description We conducted a 3‐yr field study in Clay County and a 2‐yr study in Harlan County, Nebraska, on silt loam soils. The two sites were chosen in part because they represent a wide range of production environments in south central Nebraska. A combination of three row spacings (10‐, 20‐, and 30‐in. rows), four seeding rates (45 000, 140 000, 235 000 and 330 000 seeds/acre), and five cultivars was planted at each site in adjoining imgated and rainfed fields. Three of the cultivars had indeterminate growth habits: ‘Hack’, Asgrow ‘A3127’, and ‘Williams 82’ the remaining two were determinate: ‘Hoyt’ and ‘Hobbit 87’. Hack and Hoyt were maturity group II and the remaining cultivars were maturity group III. These cultivars represent the normal range of maturity groups and both growth habits grown in the area. Applied Questions Was the optimum row spacing the same in all environments? Yes. Although soybean yield responses to row spacing depended on the site, water regime, and cultivar, the 20‐in. row spacing consistently had the highest yields (31 and 48 bu/acre, rainfed and irrigated, respectively) at all five sites when averaged over the other factors. The ranking of the other two row spacings varied with cultivar type and water regime. Yield of indeterminate cultivars in both water regimes and determinate cultivars with irrigation were greater with 20‐ than either 10‐ or 30‐in. rows. In contrast, determinate cultivars in rainfed regimes yielded the same in 20‐ and 30‐in. rows and less in 10‐in. rows. Canopies of both cultivar types closed sooner with narrower rows than with wider rows. Others have also found that canopy closure occurred sooner with narrow rows than with wide rows and that this resulted in greater evapotranspiration during vegetative growth and increased plant stress with narrow rows. In the extreme water stress situations in our trials, determinate cultivars in either 20‐ or 30‐in. rows produced more than in 10‐in. rows. Were optimum seeding rates the same in all environments? Yes, yields among the three highest seeding rates were greater than those of the lowest seeding rate for all row spaces and both water regimes. However, the yield difference between 45 000 and 140 000 seeds/acre was greater with irigation than with rainfed. There was no row spacing × seeding rate interaction (no change in rank). The 20‐in. row spacing consistently produced the highest yield at all four seeding rates. Were cultivars affected by changing these cultural practices in different environments? Yes, but the optimum row spacing for all cultivars in both water regimes was 20 in. Determinate cultivars in our high‐yield environments had increased yield between the 45 000 and 140 000 seeds/acre and contrary to other reports, similar yield at higher seeding rates (140 000, 235 000, and 330 000 seeds/acre. Indeterminate cultivars were normally not affected by changes in seeding rate. The 140 000 seed/acre seeding rate averaged over other factors either maximized yield or had yields equal to the highest yield for both determinate and indeterminate cultivars.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 17
Claim · model-written summary
Determinate cultivar yield increased 42% as seeding rate rose from 45 000 to 140 000 seeds/acre.
- Taxon
- Glycine max
Glycine maxe5 - Material
- Determinate cultivare0
- Treatment
- seeding ratee0
- Outcome
- Determinate cultivar yielde0
- Direction
- increasede0
- Value
- 42%e0
- Qualifier
- 11 bu/acree0
- Comparator
- 45 000e0
- Setting
- Clay Center, NEe2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Determinate cultivar yield increased 42% (11 bu/acre) as seeding rate increased from 45 000 to 140 000 seeds/acre”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
e2“field study at Clay Center, NE”
Claim · model-written summary
Determinate cultivar yield remained constant as seeding rate increased above 140 000 seeds/acre.
- Taxon
- Glycine maxGlycine maxe5
- Material
- Determinate cultivare0
- Treatment
- seeding ratee0
- Outcome
- Determinate cultivar yielde0
- Direction
- remained constante0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Determinate cultivar yield increased 42% (11 bu/acre) as seeding rate increased from 45 000 to 140 000 seeds/acre and then remained constant with increased seeding rate”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
Seeding rate did not affect indeterminate cultivar yield.
- Taxon
- Glycine maxGlycine maxe5
- Material
- indeterminate cultivare1
- Treatment
- Seeding ratee1
- Outcome
- indeterminate cultivar yielde1
- Direction
- did not affecte1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Seeding rate generally did not affect indeterminate cultivar yield”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
The 20-in. row spacing consistently gave the greatest soybean yields.
- Taxon
- Glycine maxGlycine maxe5
- Treatment
- row spacinge2
- Outcome
- yieldse2
- Direction
- greateste2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“row spacing consistently had the greatest yields”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
Yield of indeterminate cultivars was greater with 20‐in. rows than with 10‐ or 30‐in. rows in both water regimes.
- Taxon
- Glycine maxGlycine maxe5
- Material
- indeterminate cultivarse3
- Treatment
- 20‐in. rowse3
- Outcome
- Yield of indeterminate cultivars in both water regimese3
- Direction
- was greatere3
- Comparator
- either 10‐ or 30‐in. rowse3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“Yield of indeterminate cultivars in both water regimes and determinate cultivars with irrigation was greater with 20‐in. rows than either 10‐ or 30‐in. rows”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
Yield of determinate cultivars with irrigation was greater with 20‐in. rows than with 10‐ or 30‐in. rows.
- Taxon
- Glycine maxGlycine maxe5
- Material
- determinate cultivarse3
- Treatment
- 20‐in. rowse3
- Outcome
- determinate cultivars with irrigatione3
- Direction
- was greatere3
- Comparator
- either 10‐ or 30‐in. rowse3
- Setting
- with irrigatione3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“Yield of indeterminate cultivars in both water regimes and determinate cultivars with irrigation was greater with 20‐in. rows than either 10‐ or 30‐in. rows”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
Yield of determinate cultivars in rainfed fields was similar in 20- and 30-in. rows.
- Taxon
- Glycine maxGlycine maxe5
- Material
- determinate cultivarse4
- Treatment
- 20‐ and 30‐in. rowse4
- Outcome
- Yield of determinate cultivars in rainfede4
- Direction
- similare4
- Setting
- rainfede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Yield of determinate cultivars in rainfed was similar in 20‐ and 30‐in. rows and less in 10‐in. rows”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
Yield of determinate cultivars in rainfed fields was less in 10-in. rows than in 20- and 30-in. rows.
- Taxon
- Glycine maxGlycine maxe5
- Material
- determinate cultivarse4
- Treatment
- 10‐in. rowse4
- Outcome
- Yield of determinate cultivars in rainfede4
- Direction
- lesse4
- Comparator
- 20‐ and 30‐in. rowse4
- Setting
- rainfede4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Yield of determinate cultivars in rainfed was similar in 20‐ and 30‐in. rows and less in 10‐in. rows”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
With moisture stress, determinate cultivars in 20- and 30-in. rows may produce more than in 10-in. rows.
- Taxon
- Glycine maxGlycine maxe5
- Material
- determinate cultivarse6
- Treatment
- moisture stresse6
- Outcome
- producee6
- Direction
- moree6
- Comparator
- 10‐in. rowse6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“with moisture stress, determinate cultivars in 20‐ and 30‐in. rows may produce more than in 10‐in. rows”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
The optimum row spacing for all cultivars in both water regimes was 20 in.
- Taxon
- Glycine maxGlycine maxe5
- Outcome
- optimum row spacinge7
- Value
- 20 ine7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“the optimum row spacing for all cultivars in both water regimes was 20 in”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
The 140 000 seeds/acre seeding rate maximized yield or gave yields equal to the highest.
- Taxon
- Glycine maxGlycine maxe5
- Treatment
- 140 000 seed/acre seeding ratee1
- Outcome
- yielde1
- Direction
- maximizede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“The 140 000 seed/acre seeding rate averaged over other factors either maximized yield”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
Yields at the three highest seeding rates were greater than at the lowest seeding rate.
- Taxon
- Glycine maxGlycine maxe5
- Treatment
- three highest seeding ratese1
- Outcome
- yieldse1
- Direction
- greatere1
- Comparator
- lowest seeding ratee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“yields among the three highest seeding rates were greater than those of the lowest seeding rate”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
The yield difference between 45 000 and 140 000 seeds/acre was greater with irrigation than with rainfed.
- Taxon
- Glycine maxGlycine maxe5
- Outcome
- the yield difference between 45 000 and 140 000 seeds/acree2
- Direction
- greatere2
- Comparator
- rainfede2
- Setting
- irigatione2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“the yield difference between 45 000 and 140 000 seeds/acre was greater with irigation than with rainfed”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
There was no row spacing by seeding rate interaction for yield.
- Taxon
- Glycine maxGlycine maxe5
- Outcome
- interactione1
- Qualifier
- no change in ranke1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“There was no row spacing × seeding rate interaction (no change in rank)”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
Determinate cultivars in high-yield environments increased yield between 45 000 and 140 000 seeds/acre.
- Taxon
- Glycine maxGlycine maxe5
- Material
- determinate cultivarse1
- Treatment
- 45 000 and 140 000 seeds/acree1
- Outcome
- yielde1
- Direction
- increasede1
- Comparator
- 45 000e1
- Setting
- high‐yield environmentse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“determinate cultivars in our high‐yield environments had increased yield between the 45 000 and 140 000 seeds/acre”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
Yield was similar at higher seeding rates, contrary to other reports.
- Taxon
- Glycine maxGlycine maxe5
- Treatment
- higher seeding ratese1
- Outcome
- yielde1
- Direction
- similare1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“contrary to other reports, similar yield at higher seeding rates”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
Claim · model-written summary
The 20-in. row spacing consistently gave the highest yields at all five sites, 31 and 48 bu/acre for rainfed and irrigated.
- Taxon
- Glycine maxGlycine maxe5
- Treatment
- row spacinge1
- Outcome
- highest yieldse1
- Direction
- higheste1
- Value
- 31 and 48 bu/acree1
- Qualifier
- rainfed and irrigatede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“row spacing consistently had the highest yields (31 and 48 bu/acre, rainfed and irrigated, respectively)”
e5“Soybean [ Glycine max (L.) Merr.] are grown”
The same questions in other papers
density · yield · Glycine max (soybean)Positive and negative results
206 papers in the same direction as this paper · 94 in the opposite direction · 4 reporting no difference from an alternative
- no effect
- no effect
- no effect
301 papers more in this group
See all 305 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.