NPK

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NPK
nitrogen phosphorus potassium
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(No Transcript)
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Plants are primarily composed of chemicals made
up of carbon atoms, hydrogen atoms, nitrogen
atoms, oxygen atoms, sulphur atoms and phosphorus
atoms. The rest of the essential elements are
referred to as trace elements as there are only
tiny amounts present. But even so quite a few of
these are essential for plant growth. Atoms
themselves are built up of various parts of which
the most relevant are the electrons which can
either be donated, accepted or shared as the
elements are build up like lego blocks to form
chemicals.
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Key Chemicals in plants include DNA made up from
C N O P H, cell walls made of phospholipids C O
P H ATP energy molecule C N O P H and
proteins C N O H
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DNA required for cell replication and plant
replication. DNA controls production of all
other chemicals in a plant
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No cells without cell walls!! Phospholipids Cell
ulose
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ATP, Adenosine Triphosphate Energy transfer
molecule
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Proteins can be structural or can be functional,
making things happen. A typical protein is the
auxin binding protein. Auxin is the primary
plant growth hormone.
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So where does potassium come in?
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• Potassium is a small charged atom
• It is ionic
• It is involved in processes where the flow of
  ions is important such as the transport of water
• and
• in interacting with some key proteins such as
  those involved in photosynthesis and plant
  maturation

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• What do fertilizer labels tell us?

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• Chemical composition
• Getting something to grow
• Yates Thrive Granular All Purpose Plant Food
  (NPK Analysis 6.6 6.6 6.6 Trace Elements)
• Very approximate ratio 111 (NPK)
• Yates Professional Blood and Bone
• (NPK analysis 8 5 1)
• ratio 851 (NPK)

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• Chemical composition
• Getting something to flower
• Thrive Granular Rose Food
• (NPK analysis 6 6 10.5 TE)
• Approximate ratio 112 NPK

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• Chemical composition
• Getting something to flower and fruit
• Thrive Concentrate Flower Fruit Plant Food
• (NPK analysis 6.2 3 10)
• Approximate ratio 213
• Thrive Concentrate Tomato Food NPK
• NPK analysis 8 3 10.2 TE
• Approximate ratio 313

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• PowerFeed NPK 121.47
• Approximate ratio 816
• Good for growth
• Seasol (NPK 0.100.052)
• Approximate ratio 214
• Good for growth, flowers, fruit
• Charlie Carp Fertiliser N 9.0 P 2.0 K 6.0
• Approximate ratio 513
• Good for growth, flowers, fruit

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• Garden Gold Fertiliser - Australian Natives (NPK
  analysis 18 1.3 15)
• Approximate ratio 14112
• Good for leaf growth, flowers, fruit
• Really a bit low on phosphorus
• for non-native plants

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• Adding fertilizer isnt everything
• The absorption of fertilizer is dependent on many
  factors.
• Amount of organic matter in the soil
• Moisture content of soil
• pH
• Trace element concentrations
• Buffering capacity of the soil (how much acid or
  base can be added without the pH changing much)
• etc

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• What is pH
• pH is a scientific measure of the concentration
  of hydrogen (H) ions in solution.
• The scientific equation pH -log(10)H
  concentration
• There is a 10-fold difference in hydrogen ion
  concentration
• between a solution with a pH of 6
• and a solution with a pH of 7.
• A pH less than 7 is acidic
• A pH greater than 7 is basic

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• What is pH
• The number of hydrogen ions in solution is
  affected by what is dissolved in the water
• Vinegar (acetic acid) has a pH of about 2.4
• and it is acidic
• Sodium bicarbonate, found in many antacid powders
  has a pH of about 8 and is basic

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• What is the pH of rainwater
• The pH of rainwater is about 5.5 to 6.0
• It is acidic!!!

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• Why is rainwater acidic!!!
• Because it dissolves gases such as
• Carbon di-oxide from the atmosphere
• CO2 H2O ---gt H2CO3 (carbonic acid)
• which also dissociates to form bicarbonate
  H2CO3 ---gt H HCO3- (bicarbonate ion) the
  bicarbonate ion can also dissociate HCO3- ---gt
  H CO3- (carbonate ion).

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• Groundwater is variable
• The pH of groundwater is dependent
• on the soil composition and the fertilizers
  added.
• Nitrogen-based fertilizers such as urea tend to
  make the soil basic
• Nitrogen-based fertilizers such as ammoniun
  sulphate tend to make the soil acidic.

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• Groundwater is variable
• The pH of groundwater is dependent
• on the soil composition and the fertilizers
  added.
• Most phosphorus based fertilizers such as the
  ammonium phosphates are quite acidic and have
  some buffering capacity in the acidic range.

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• Pure Water
• The only water which is pure and has a pH of 7
• Neither acidic nor basic
• is
• freshly distilled water

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• Zeolites
• Zeolites are built up from a nice rigid and
  regular cage structure built up primarily from
  silicon and oxygen but often contain various
  other elements such as aluminium.
• The regular cage structure often encase molecules
  or ions of a particular size dependent on the
  zeolite structure. So choice of the right zeolite
  can help with both absorption and release of
  useful molecules such as water or ions such as
  ammonium ions.
• This is why zeolites are said to have buffering
  capacity.

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• Hypochlorite
• I have heard many times at the club about leaving
  tap water to stand a few days to get rid of the
  chlorine.
• How does sodium hypochlorite (NaClO) made up
  sodium, chlorine and oxygen from break down?
• At any pH you are likely to encounter in tap
  water it breaks down to form oxygen and salt
  (NaCl), not chlorine gas. The form used for
  swimming pools is lots more concentrated and
  very, very basic and can break down forming
  chlorine gas.