Production Studies

Soybean Farm Research Production Studies

Farm research studies in this section include:  tillage system studies, cover crop studies, inoculant and product studies, planting dates/rates/row spacing studies, variety studies, and other production studies.

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Tillage System Studies

Objective:  Determine the profitability of a no-till corn and soybean rotation versus a tilled system.
Summary: Growth and seed yield of soybeans was not affected by tillage in 2001. In 2002, tillage resulted in lower grain moisture at harvest and slightly higher test weight for corn. In 2003, tillage resulted in slightly lower soybean seed test weight. Plant stands for corn were higher with tillage in 2004 and grain yield was significantly higher. In 2005, seed yield of soybeans was significantly higher with tillage. Corn yield was signifantly higher with tillage in 2006 (see weather related note in research results). Tillage had no effect on soybeans in 2007. Excellent erosion control has been observed in the no-till treatments.  (Stewart) The no-till treatment yield was higher than the conventional tillage treatment yield in 1993.

Objective:  Evaluate the effect of shredding stalks prior to planting vs. not shredding and its effect on yield and profitability.
Summary:  All four fields tested by Quad County producers in 2004 and 2005 showed no significant yield advantage to shredding vs. not shredding stalks.

Objective:  Determine the profitability of a reduced tilled system versus a conventional tilled soybean system.

Objective:  Determine the profitability of producing soybeans using a conventional versus no-till system.
Summary: There was no significant yield difference between the conventional and no-till treatments in either study.

Objective:  Determine the profitability of a ridge tillage versus conventional tillage soybean production system.
Summary:  There was no consistent yield difference to determine one tillage system over the other.

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Cover Crop Studies

Objective:  Determine the profitability of growing a cover crop in a corn and soybean rotation.
Summary:  The use of a cover crop resulted in a reduced grain yield in 2008. This could be due to nitrogen being found in the biomass of the cover crop. In 2004 grain yield was lower where a cover crop was planted the previous fall. 

Objective:  Determine the profitability of row cultivation of Roundup Ready soybeans.
Summary: Cultivation resulted in a significant seed yield reduction in 2004, but had no effect in 2005.

Objective: Determine the profitability of growing Roundup Ready versus conventional soybeans.
Summary: In 2001, soybean seed yields were significantly higher where conventional treatments were used; however in 2002, seed yields were not significantly different. In 2003, conventional treatments yielded slightly, but significantly more than Roundup Ready. In 2004, 2005 and 2006 the conventional variety yielded more than the Roundup Ready.

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Inoculant and Product Studies

Objective: Determine the profitability of using Urbana versus standard versus no inoculant on soybeans.
Summary: In 1999 seed yield of soybeans was not influenced by seed inoculation. The use of Urbana inoculant resulted in slightly drier seed at harvest and a higher plant population. The use of standard inoculant resulted in the lowest seed test weight. The field where this study was conducted has a long history of corn and soybean rotation.

Objective: Determine the profitability of Accelerator vs. LiquiPrep XT vs. no inoculant.

Objective: Determine the profitability of using CellTech vs. standard vs. no inoculant on soybean seed.
Summary: The application of Rhizobium inoculum had no effect on the growth and seed yield of soybeans in 2001 or 2003.

Objective:  Determine the profitability of using frozen inoculant (Magnify) in soybean production.
Summary: The application of Magnify had no effect on the growth or seed yield of soybeans in 2001 and 2003.

Objective:  Test new generation soybean inoculants for yield effect on fields with a history of soybean production.
Summary:   In 2006, there was no statistical yield difference between the Untreated vs. SoySuperb, Vault, or Celltech.  In 2005, SoySuperb inoculant resulted in a significant yield increase when applied to soybeans planted in fields with a history of soybean production. The average yield over 19 replications with SoySuperb was 76.1 bu./acre vs 74.2 bu./acre for untreated seed. Two other inoculants in the study, Vault and Celltech were not different from the untreated check. SoySuperb was not on the market at the time of the study so no conclusions were drawn about cost effectiveness. Overall, UNL research shows that in most cases, soybean inoculants will not provide increased yield in fields with a history of soybeans in the past 3-5 years.

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Planting Rates/Dates and Row Spacing Studies

Objective:  With rising input costs, producers are examining ways to reduce costs of production. The objectives of this study were to evaluate the effects of various planting populations on soybean yields and economics.
Summary: In 2007, there was no significant difference in soybean yield in plots planted at 90,000, 120,000, 150,000 and 180,000 seeds/acre in five ridge or no-till irrigated soybean fields in south central Nebraska (30" rows). In 2008, the average yield was 68.1 bu./acre at 90,000 compared to 69.9 bu./acre at 180,000. There was no significant yield difference between 120,000, 150,000 or 180,000 (no-till/ridge-till fields, irrigated, 30" rows).

Objective: Determine the profitability of high versus low soybean planting populations.
Summary: The high soybean population yield was significantly higher than the low population yield in one out of the three years.

Objective:  Determine the profitability of planting soybeans early versus at normal planting time.
Summary: Earlier planting increased yield in many of the studies below, but not all in situations where August rains benefited later planted soybeans in rainfed locations. 
(Quad and Saunders Co.) In all locations, the early planted soybeans (April planted) out-yielded the later planted ones (mid-May planted).  There was no stastistical yield significance with any of these individual trials between the early and later planted.
(Schlictemeier) The late planting date (5/22) resulted in higher seed yield than the early or normal planting date in 2007. This field received excellent precipitation in August. Seed moisture values are the average of all plots in each planting date, thus no statistical analysis. In 2008, the late May planting date (5/23) gave the maximum seed yield.
(Cvatal) Early planting of soybeans resulted in higher yield, dryer seed at harvest, and increased protein and oil content in 2007.
(Ohnoutka) Early planting resulted in slightly higher seed yield and slightly higher seed moisture at harvest in 2000. In 2001 seed yields were lower and seed contained more moisture when soybeans were planted early. Early planting resulted in lower plant density. In 2002 planting date did not affect seed yield; however, early planting resulted in higher seed moisture at harvest and lower test weight.
(Stewart) Statistically significant differences were found in 1992 and 1994, however, additional data is required to draw conclusions. 

Objective:  Determine the profitabilty of narrow (7") versus wide (30") soybean rows.
Summary:  Narrow row soybeans out-yielded wide row soybeans in two of the three years of study.

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Variety Studies

Objective: Determine the profitability of Dunbar versus Resnik soybean varieties.
Summary: The yield difference between Dunbar and Resnik was not significant in 1992, 1993 or 1994.

Objective:  Determine the profitability of Hobbit versus Keltgin soybean varieties using narrow (7") and wide (30") row spacing strategies.
Summary: There were yield differences between the drilled and row planting treatments in all three years. In 1992 Hobbit had a significantly higher yield than Keltgin 5327. In 1993 the yield difference between Keltgin 5327 and Hobbit was statistically significant. In 1994 the drilled soybeans yielded significantly higher than the wide row soybeans. The Hobbit variety benefited more from drilling than the Keltgin variety in 1994. Moisture content was also significantly different.

Objective:  Determine the profitability of using an indeterminant soybean variety (Pioneer 9272) versus a determinate variety (Hobbit 87) under irrigation.
Summary:  The determinate variety had a significantly higher final plant population and yield at the 99% confidence level in two of the three years.

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Other Production Studies

Objective:  Determine the profitability of a corn/soybean rotation vs. continuous corn production.
Summary: The corn following soybeans yielded significantly higher than the continuous corn.

Objective:  Determine the profitability of relay cropping wheat into seed corn residue followed by soybeans versus a conventional corn and soybean rotation.
Summary:  Relay cropping was less profitable than conventional cropping in 2004 due to reduced yields of soybeans planted in wheat and exceptional conventional soybean yield. In 2005, relay cropping was more profitable than conventional cropping.

Objective: Determine the accuracy of using a combine yield monitor vs. weigh wagon vs. certified scale to verify crop yield.
Summary: Calculated yields (bu/ac) were not significantly different between scale weights and monitor weights; however, grain moisture values averaged 0.6% lower with the yield monitor. For total yields, measurements with the monitor were slightly higher. The absolute error was 2.6% for corn and 2.2% for soybeans. The observed error was 1.4% for corn and -0.6% for soybeans.

Objective:  Determine the profitability of soybean production using a crop consultant versus using standard management practices.
Summary:  There was no significant yield difference between the two management practices.

Objective:  Determine the profitability of a corn and soybean rotation versus continuous corn production.
Summary: The corn following soybeans yielded significantly higher than the continuous corn.

Objective:  Determine the profitability of relay cropping wheat into seed corn residue followed by soybeans versus a conventional corn and soybean rotation.
Summary:  Relay cropping was less profitable than conventional cropping in 2004 due to reduced yields of soybeans planted in wheat and exceptional conventional soybean yield. In 2005, relay cropping was more profitable than conventional cropping.

Objective: To determine & document the effect of a combine platform air reel on the amount of seed harvested.
Summary: The use of platform air reel had no significant effect on the amount of soybean seed harvested in 2008 & 2010; however, yield was reduced slightly in 2009.

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