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49 Cards in this Set
- Front
- Back
Liming the soil _____ the base saturation
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raises it
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Organic N ferts are the ______ quality as chemical ferts
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same
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The most important part of liming compound
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anions
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gypsum doesn't work as a liming agent because
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the sulfates are soluble
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fertilzer used as explosive
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ammonium nitrate
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first chemical manufactured in the US
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ammonium sulfate
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most popular N fert soil in CA
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anhydrous ammonia
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highest grade of solid N fert
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urea
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base forming N ferts
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calcium cynamid (CaCN2) nitrates (Ca, K, Na)
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First N fert produced in USA was a by product of the
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coking process
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most base forming N fert
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Ca Cyanamid
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serious problem with ammonium ferts
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volatilization
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gypsum effect on saline soils
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none
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Good starter ferts
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APS, MAP
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Bad starter ferts
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CaCN2, DAP
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Ammonium fertilizers are considered acid forming because
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of nitrification
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the quality of liming material depends on its
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CCE and fineness
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Common characteristic of most base forming N ferts is
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contains nitrates
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Ammonium ferts are more popular than nitrate ferts because
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cost is lower per lb of N
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Most SRNF are based on
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urea
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how fast SRNF breaks down is measured by
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activity index
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The reaction of the haber process
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N2 + 2H2 yields 2NH3 under high pressure and heat (500atm and 500C)
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how ammonia affects the soil structure
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reduces aggregate stability by dispersing clay, it is rebuilt by microbes
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how ammonia affects the pH
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first it increases when it reacts with water, then it decreases as protons are given off during nitrification
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eutectic
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when two solid ferts react and form a liquid
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2 ferts that are eutectic
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urea and ammonia nitrate
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advantage of MAP over ammonium nitrate
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good starter fert and contains P
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disadvantage of MAP over ammonium nitrate
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only has one for on N and lower solubility
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Advantage of USA over UAN 32
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herbicide, contains sulfur, used to clean lines, wont volatilize
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two N ferts with herbicidal prop
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AN 20 and USA
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SNRF methods
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organic resin coating, sulfur coating, increase size or density, inorganic with low solubilty, alter organic structure
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Organic resin coating
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resin digested by microbes, osmocote
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increased size or density
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agriform pellets the size of golf balls
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inorganic with low solubility
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MagAMP
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Coat with sulfur
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digested by certain microbes, lowers ph around pellets, sulfur coated urea
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alter organic structure
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Urea formaldehyde
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advantages of SNRF
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prevents leaching, less pollution, lower salt effect
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disadvantages of SRNF
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higher cost, higeher energy inputs, hard to control
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advantages of organic ferts
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increase humus and build structure, increase the pore size
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disadvantage of organic ferts
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do not know the grade
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N-Serve
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slows the nitrification process for SRNF, less leaching occurs
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Saline soil problems
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there is not water availabel because the salts are holding it
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Sodic soil problems
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nutrients unavailable due to high ph, poor structure
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calculation for PSI
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salt index/%grade of nutrients
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why does MAP have a lower SI than KCL
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P has lwoer solubilty rate
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CCE formula
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equivalent weight Ca(CO3)2/equivalent weight of lime material times 100
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reclaim saline soils
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leach and dispose of drainage water, 12" of water will remove 70-80% of salts in 12" of soil
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reclaim sodic soils
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add gypsum and incorporate, leach and dispose of drainage water
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reclaim saline sodic soils
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add gypsum and incorporate, do not leach due to poor structure
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