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					      NPK
nitrogen phosphorus potassium
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.
    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
                       DNA
 required for cell replication and plant replication.


                       DNA
controls production of all other chemicals in a plant
No cells without cell walls!!


      Phospholipids


         Cellulose
ATP, Adenosine Triphosphate

  Energy transfer molecule
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.
So where does


 potassium


  come in?
       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
What do fertilizer labels tell us?
          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 1:1:1 (N:P:K)

    Yates: Professional Blood and Bone
           (NPK analysis: 8 : 5: 1)
             ratio 8:5:1 (N:P:K)
  Chemical composition

Getting something to flower

  Thrive Granular Rose Food
(NPK analysis: 6 : 6 : 10.5 +TE)
 Approximate ratio 1:1:2 N:P:K
          Chemical composition
    Getting something to flower and fruit

Thrive Concentrate Flower & Fruit Plant Food
          (NPK analysis: 6.2 : 3 : 10)
            Approximate ratio 2:1:3

    Thrive Concentrate Tomato Food NPK
        NPK analysis: 8 : 3 : 10.2 + TE
            Approximate ratio 3:1:3
         PowerFeed NPK 12:1.4:7
          Approximate ratio 8:1:6
             Good for growth

        Seasol (NPK 0.10:0.05:2)
         Approximate ratio 2:1:4
       Good for growth, flowers, fruit

Charlie Carp Fertiliser: N: 9.0 P: 2.0 K: 6.0
          Approximate ratio 5:1:3
       Good for growth, flowers, fruit
Garden Gold Fertiliser - Australian Natives
       (NPK analysis: 18: 1.3 : 15)
        Approximate ratio 14:1:12
    Good for leaf growth, flowers, fruit
      Really a bit low on phosphorus
           for non-native plants
        Adding fertilizer isn’t 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
                       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
               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
    What is the pH of rainwater

The pH of rainwater is about 5.5 to 6.0

             It is acidic!!!
      Why is rainwater acidic!!!

 Because it dissolves gases such as
Carbon di-oxide from the atmosphere

 CO2 + H2O ---> H2CO3 (carbonic acid)

which also dissociates to form bicarbonate:
 H2CO3 ---> H+ + HCO3- (bicarbonate ion)

 the bicarbonate ion can also dissociate:

  HCO3- ---> H+ + CO3- (carbonate ion).
            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.
            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.
                  Pure Water

The only water which is “pure” and has a pH of 7
            Neither acidic nor basic
                       is

             freshly distilled water
                       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.
                                 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.

				
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