Download Nursery Production 3

Nursery Production 3
Commercial Plant Production
Green Manures vs. Cover Crops
Green Manures
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Various plant species grown for a growing
season on land not being used for
production.
Mowed down and incorporated into the
soil while they are still “green”.
Fast growing green manure crops may be
mowed several times prior to
incorporation.
The following species have been
used as green manures…
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Annual rye grass
Alfalfa
Field corn
Soybeans
Sudan grass
Sudan x sorghum hybrids
Sudan Grass
Sorghum: Important cereal grass native to Africa
that ranks 4th after rice, corn and wheat in terms of
importance for human nutrition. There are 4 main
types: 1) grain sorghums, 2) sweet sorghum (animal
feed), 3) Sudan grass, and 4) Broom corn.
Benefits of Green Manure Crops
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Add organic matter to the soil.
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Improves soil structure and aeration.
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Improves water holding capacity.
Improves nutrient holding capacity (CEC).
Organic matter binds small soil particles
together into larger aggregates.
Acts as a cover crop to help prevent soil
erosion.
Why Use Green Manures
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In a B&B nursery operation every time a
plant is harvested from the field some soil
leaves the field as well.
After many years of harvesting the soil
becomes depleted.
Green manures can help “build” soil and
replace some of what is being lost.
Soil Loss Data from a B&B Nursery
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The amount of soil lost will depend upon the
spacing and ball size.
The table (next slide) assumes a spacing of 42
inches between rows and 36 inches between
plants in a row. Also, assume all balls are 15
inches deep.
Ball diameter in
inches
15
Percent of soil
removed during
harvest (15 inch
depth)
10 %
18
15 %
24
25 %
30
40 %
15 inches
Soil Loss from a Nursery Field
Cover Crops
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Similar to green manures.
Protect the soil against erosion.
Cover Crops
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Typically late summer/fall sown.
Typically sown between the rows of
nursery stock.
Some research has shown that they help
“harden-off” nursery stock by removing
excess nitrogen from the field.
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Oats: die off when the ground
freezes.
Buckwheat: dies off when the
ground freezes.
Winter rye: survives the winter
and is incorporated in the
spring.
Rye grass: survives the winter
and is incorporated in the
spring.
The End