McKenna\3444lec19

Soybeans

I. Topic

The most important oil seed crop in the world is soybean.

II. Learning Objectives

To understand the origin and history of the soybean plant.

To know the climatic and edaphic requirements for soybean production.

To understand the importance of light for soybean variety selection and distinguish between the two main soybean types.

To be able to describe the two distinct cropping systems for soybean production.

To be able to describe the special characteristics of soybeans and the products and by-products of soybean production.

III. Overview

The soybean is the most widely grown of all the legumes. Soybeans are an old crop, first grown in China. Their early use was for human food, but since WWII, soybeans have become the most important oil seed crop. This was especially true in North America where soybeans were grown in a crop rotation systems with maize in the Corn Belt. There are two main types of soybeans, determinate and indeterminate. Determinant beans are grown in warmer climates, where the main stem terminates in a cluster of mature pods. Indeterminate beans are more temperate in their adaptation , and they continue to develop leaves and flowers throughout the reproductive period. Soybeans are also light sensitive, giving way to ten maturity classes and varieties are limited to zones 100-150 miles across lines of latitude.

Soybeans have climatic and edaphic requirements similar to maize. They like well drained fertile soil, pH in the 6.0-6.5 range and average temperatures during the growing season in the 75 degree range. Soybeans are more broadly adapted than corn to less fertile soils because of their nitrogen fixing ability.

Here is an interesting link to the American Soybean Association. Note: This link is outside of this site.

IV. History

1. One of oldest crop plants.

Used for food in China in 2838 B.C.

2. "Soy" from Japanese word "Shoyu."

3. Brought to England in 1790, U. S. in 1804 (from China).

4. By 19th Century they were being grown as a forage and hay crop in southeast.

5. Oil demand during WWII brought about production.

4,947,000 bu. In 1924 - 193,000,000 bu. In 1945

6. Now 1,200 million bu.

7. In Virginia - increase of 14,000 A/Y from 1949-1970.

413,000 acres in Virginia

Interesting Link to Soybeans History
http://www.nsrl.uiuc.edu/historys.html

Botany (Soybean Pictures)

1. Soybeans an annual legume.

2. Bushy, leafy, erect plants, 2-4 ft. tall.

3. Two main types:

Determinate - main stem terminates in a cluster of mature pods - grown mostly in southern U. S.
Indeterminate - develops leaves and flowers throughout reproductive period - northern states

These flower early and continue to grow
Determinate varieties grow first/then flower

4. As maturity approaches, leaves yellow dropping before pods mature (seed still 20% moisture).

5. Leaves, stems, pods all pubescent.

Interesting Link about Soybean Production
http://www.soygrowers.com

Adaptation

1. Requirements parallel corn.

2. Will only tolerate short drought periods.

3. High temp/low precipitation unfavorable.

Low oil and low oil quality

4. Period of germination most critical state.

Moisture stress most critical

5. Less susceptible to frost injury than corn.

6. Minimum temperature for growth is 50⁰F.

7. Short day plants/need 10 hour of darkness to flower.

8. Mean midsummer temperature of 75-77 degrees optimum.

Lower temperatures delay flowering

9. Grown in all types of soil, better adapted to low fertility than corn as long as N-fixing bacteria present - prefers loams.

10. Will grow in soils too acid for alfalfa and red clover.

11. In Virginia, soybean production is concentrated in Coastal Plains - moving into Southern Piedmont.

Varieties

1. Because of different maturities, varieties limited to zones 100-150 mile wide.

Too far north, variety too late to mature
Too far south, mature too early for high yield

2. Listed in ten maturity classes (00-VIII).

00-0 earliest maturing varieties northern U. S. and southern Canada

3. All states grow two or more maturity classes.

Earlier varieties usually are grown in northern part of a particular state
Often are used for late planting or planted in fields to be harvested early

4. Virginia varieties:

III and IV Williams
V Essex
VI

Six varieties greater than 95% of soybeans in Virginia

Essex 49.3%
York 29.6%
Forest 7.0%
Dare 2.3%
Lee 2.3%
Ransom 1.7%

Best to grow more than one maturity.

Spreads out harvest
Escape adverse weather conditions

Variety Selection

1. Soybeans list sensitive.

Don't want to plant late variety early, excessive growth/lodging/poor pod set

2. Soybeans subject to seed diseases afer seeds mature.

Especially varieties which mature in late summer and early fall when weather favors disease
Varieties should be selected which will mature when harvest is possible

3. When varieties shed their leaves, it permits light to penetrate the rows.

Weed growth can be stimulated
Combining can be prevented
Paraquat can be used

Culture

1. Two systems in Virginia.

Full season
Double cropped

2. More are using double crop with cereals.

40% of Virginia soybeans grown this way
No-till in stubble - 75% of double crop

Reduced labor
Conservation of water
Reduction in time

3. Steps in soybean production.

Select well to moderately well drained soil (corn land)
Lime to 5.8-6.5 (6.0-6.5 optimum)
Maintain adequate fertility level

Maintain high P and K levels
Don't need direct fertilization. Can apply prior to crop in rotation

4. Use dolomitic limestone to maintain pH and Ca and Mg
5. In Coastal Plain, might need 8-10 lb/A Mn
6. Select a recommended variety
7. Plant high quality seed

If planted early/add fungicide

8. Inoculate the seed

Particularly if first time for beans in field

Plant on time

After May 5 in VA (soil tem. 65 degrees at 2" deep at 8:00 am)
Plant early varieties early
Yields decrease rapidly after June 15
If after double crop, plant medium to late maturing variety

9.Plant recommended amount of seed

May 20-June 15 - 30-36" rows (6-8 plants/ft. Of row)
After June 15, plant 8-10 plants/ft

10. Weed control best after June 15 if rows 20-24" (6-8 plants/ft. of row)

Too thick - lodging
Too thin - weed and insect problems

11. Plant at proper depth (1-1 3/4" in no-till at least 1-3/4" to avoid water problems)
12. Control weeds

No-till use contact herbicide
Residual herbicide control
Control insects

13. Follow a recommended cropping sequence

Grown in sequence with no-legumes
Don?t follow tobacco/peanuts - disease and nematode problems

14. Harvest all the beans produced

Prompt harvest (13% moisture) to prevent shattering

Insects, Diseases (Pictures Available)

1. Few insects considered economically serious.

One application of insecticide is sufficient

2. Insect problems

Grasshoppers
Leafhoppers
Stinkbug
Fall armyworms
Corn earworms

3. If history of insect problem

Soil application of soil insecticide at planting time

4. Disease problems

About 50 diseases attack soybean
Loss from 12-14% /year
Fungus diseases most prevalent

5. Disease problems

Brown stem rot
Stem canker
Pod and stem blight
Downy mildew
Brown spot
Bacterial blight

6. Plant resistance to disease best route
7. Crop rotations
8. Nematodes

Attack roots/stunt plant
Crop rotations help nematode problem

Soybean Content

1. Percent N in leaves 2x stems.

2. Plus ? of N in tops stored in the seed at maturity.

3. Seed is 14-24% plus oil, 30-50% protein.

In general low fat + protein
High fat - low protein

4. Soybean protein contains all the essential amino acids for animal and human foods.

5. Valuable source of Ca and P.

Utilization

1. Prior to 1920, used primarily as a forage crop.

2. Now practically 100% of acreage harvested for beans.

3. Processing:

Oil extracted by solvent
1 bu of beans provides 11 lb. Of oil and 47-48 lb. Protein meal

4. Oil and meal utilization.

Soybean oil is a dual purpose oil - competes with nonedible drying soils like linseed and edible, nondrying oils like cottonseed.
Plus 90% of soybean oils is used in edible production

Margarine
Shortening
Salad oils
Cooking oils
Mayonnaise

Remainder:

Paints
Varnished
Linoleum
Printing ink
Soap
Rubber substitutes

Is intermediate in polyunsaturates

Most sat. Flower, corn, soybean, cottonseed, sesame, peanut, olive, and coconut
Soybean oil production is greater than the production of all other oils combined.

5. Soybean meal.

Valued as livestock feed
Plus 90% used this way
Remainder used for industrial adhesives and wallboard and paper coating
Soybean flour and grits are used in bread and bakery products, macaroni, spaghetti, baby foods, and high protein meat extenders.

6. As world population increases, soybeans destined to play increasing role in human nutrition:

Soy flour and grits - 40-60% protein
Soy protein concentrate - 70% protein

V. Summary

Prior to the 1920's, soybeans were used as a forage crop in the southern United States. Now nearly 100% of the acreage is harvested for beans that are crushed for oil. One bushel of beans provides 11 lbs. Of oil, and 47-48 lbs. Of high protein meal. The oil is used for edible production (90%) and the meal is used for livestock feed (90%).

As world population increases, more and more soybeans will be used for human nutrition. Soy flour and grits contain 40-60% protein. A soy protein concentrate can contain 70% protein. There is an increasing world market for edible soybeans.

Other Interesting Links to Soybeans
http://www.nsrl.uiuc.edu/links.html

VI. Self Assessment

What is a brief history of soybeans? What influence did WWII have on soybean utilization?

Discuss light sensitivity and soybean type. How does this impact variety selection?

Where do soybeans grow best? Why can soybeans do better than maize in certain soils?

How are soybeans used? What are the two main products? What are some other uses of soybeans?

What is the future for edible soybeans? Why?

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Last updated January 23, 2008

	To understand the origin and history of the soybean plant.
	To know the climatic and edaphic requirements for soybean production.
	To understand the importance of light for soybean variety selection and distinguish between the two main soybean types.
	To be able to describe the two distinct cropping systems for soybean production.
	To be able to describe the special characteristics of soybeans and the products and by-products of soybean production.

	What is a brief history of soybeans? What influence did WWII have on soybean utilization?
	Discuss light sensitivity and soybean type. How does this impact variety selection?
	Where do soybeans grow best? Why can soybeans do better than maize in certain soils?
	How are soybeans used? What are the two main products? What are some other uses of soybeans?
	What is the future for edible soybeans? Why?