Transcript of SOIL RESOURCE ASSESSMENT TO GUIDE PRODUCTION PRACTICES Newell Kitchen USDA-ARS Cropping Systems and...
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SOIL RESOURCE ASSESSMENT TO GUIDE PRODUCTION PRACTICES Newell
Kitchen USDA-ARS Cropping Systems and Water Quality Research Unit
Columbia, MO Translating Missouri USDA-ARS Research and Technology
into Practice A training session provided by USDA-ARS-CSWQRU, 10-11
October 2012, Columbia, MO
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1803 Louisiana Purchase and in 1804 a treaty between U.S.
Government and Indian tribes (ignored by many Indians for several
decades) 1850-1880 Railroads accelerated growth and
commercialization 1820-30s Land purchase and settlement exploded
with most of the public land purchased within these decades.
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With early homesteading, timber was an essential resource used
for homes and sheds, tools, cooking, and heating. Thus, most homes
were near streams. The broad flat grassland was viewed less
valuable and was mainly used for free-roam grazing for many
decades. Early in the 1900s the face of the Midwest rural landscape
1.Farms increased in size 2.People migrated to cities
3.Agricultural mechanization improved
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This major shift in land use and intensity in the early 1900s
had an immediate impact on the rivers and streams During World War
I, corn grain prices soared, and so did corn acreage. Extensive
flat grasslands were plowed and put into grain production for the
first time, typically corn, oats, wheat and a new crop,
soybean.
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With the exception of two years, multiple and damaging large
flood events caused severe soil erosion and property damage between
1926- 1936. Grain crop yields for many fields actually declined
when compared to the previous century (Bennett, 1939). Since,
billions of dollars have been spent on soil and water conservation
projects. But with some soils, the damage has been catastrophic and
irreparable.
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The first erosion plot research in the U.S. was established on
the campus of University of Missouri-Columbia, on May 1, 1917.
Where in the Midwest was the negative impact of modern agriculture
the greatest?
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Cascading Soil Degradation Poor Land Management Decisions on
Sensitive Soil Landscapes Degraded structure & aggregation
Compaction & crusting Water erosion Reduced plant growth Poor
soil biology Decreased yield Reduced Sustainability
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1.Lost Topsoil. In less than 150 years, claypan soils have
greatly lost topsoil, and consequently other important qualities
(e.g.,microbial diversity, structure). Average 13 cm (5 in) of soil
loss over the whole field. That averages ~7.5 tons/A/yr. Areas of
extreme have lost 40 cm (16 in).
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2.Historical topsoil loss from erosion has greatly impaired
claypan soil field productivity, creating marginal areas under some
cropping.
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3.Soil quality and ecosystem function for claypan soils will
not likely improve much under grain cropping practices.
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4.Claypan soils are especially good candidate fields for
in-season variable-rate N management, because of the high
propensity for denitrification losses.
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5.No-till corn-soybean on claypan soils often ends in failure
and a return to tillage, because erosion persists. Adding cover
crops with no-till is more successful.
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6.Depth to the claypan and slope are key soil properties for
identifying marginal vulnerable areas within claypan soil
fields.
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7.No-till cropping increases losses of runoff and soil active
herbicides on claypan soils.
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8.Claypan soil fields exhibit strong spatial patterns of
variability for soil properties and crop growth. Important fdepth
and past practices. 8.Claypan soil fields exhibit strong spatial
patterns of variability for soil properties and crop growth.
Important factors include topsoil depth and past practices.
Potassium Phosphorus pH Topsoil Depth
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9.The claypan drives surface hydrology and the environmental
problems found on these fields. They behave as if they have much
greater slope.
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10.Depth of topsoil over the claypan is a strong measure of
soil erosion and serves as a useful basis for future crop
management planning.