Do you sign up for all the proposed soil health benefits that SOP is supposed to bring to the table?
Fibrophos is just burnt chicken muck, that add SOP to it if you need potash. It is good stuff but not good to spread. Work out the cost to put on the desired level of potash.I don't know, it's a good question. There's a high K fibrophos, maybe that's how they do it.
I have a salt index of fert somewhere I'll try find itsNot really. Or put it this way I don't think K chloride is any worse than K Sulphate seems to be a . I think the salt thing is misleading. Would be interesting to see a salt index of all ferts to compare!
It's still more expensive than MOP when you take the sulphur into account, but not by as much as it looks on first inspectionSulphate of potash is an expensive product but you miss the point in the value of sulphur. SOP has 45%So3 which is worth £0.80/unit.
With no heavy industry in the UK sulphur is becoming very deficient.
Not a cheap product, but because it is potassium sulphate there is no nasty chlorine like muirate of potash. Chlorine is not too bad in light soils as it can dissipate through the soil profile. Clay and heavy soils are a different kettle of fish.
I get round the cost by doing a 50/50 blend of MOP/SOP which gives 50-55% potash 50% sulphate and 50% muirate and 22.5%So3 (sulphur worth about £0.80/unit)
Another option is using muirate of potash and polysulphate which would be the cheapest option this gives 42% potash and 18% So3 this also gives 6.2% calcium and 2.2% magnesium
Neither is chlorine used as a disinfectant, it's sodium hypochlorite. When you dissolve this in water you get the chloride ions, which are the harmful things. Is that the same net result as putting MOP into the soil? I don't know, but think it probably is. Not sure if it's enough to cause problems though.There isn't chlorine in muriate of potash for goodness sake!
Neither is chlorine used as a disinfectant, it's sodium hypochlorite. When you dissolve this in water you get the chloride ions, which are the harmful things. Is that the same net result as putting MOP into the soil? I don't know, but think it probably is. Not sure if it's enough to cause problems though.
Edit: MOP does dissociate into chloride ions in a water solution, so it should have the same sort of biocidal effect as bleaches etc.
So the fact there isn't chlorine in MOP is pretty irrelevant from what I can see.
OK, fair enough. But then consider this:MOP is just a salt, no more toxic than table salt. Infact you can buy low sodium salt for the dining table, which is a mix of salt and MOP.
Sodium Hypochlorite is a totally different beast, and I would not want to put it on my chips.
Sodium hypochlorite is the salt formed by a negatively charged hypochlorite ion (OCl-) and a positively charged sodium ion (Na+). Pure hypochlorite is highly reactive and unstable; therefore, it is usually supplied as a dilute aqueous solution. In solution, hypochlorite eventually decomposes to yield a variety of byproducts including oxygen, chlorine gas, and salt. One of these byproducts, hypochlorous acid, is a powerful oxidizing agent (meaning it can accept electrons from other materials) that lends hypochlorite excellent bleaching and disinfecting abilities. The term "available chlorine" is often used to describe the concentration of hypochlorous acid in solution (which provides a measure of the solution's oxidative ability).
It's about what happens when the compound in question gets dissolved in water.Bleach is chlorate.
OK, fair enough. But then consider this:
http://www.sciencedirect.com/science/article/pii/S0038071714000315
• Increasing the Cl concentration inhibited the soil nitrification.
• The association of AC and KCl reduced the microbial biomass.
• Chloride ions inhibit nitrification and are therefore a potential soil biocide.
Just a little hint from what a client near Samara, Russia, with Soils >7pH. they use the MOP in the late winter prior to potato planting to get rid of wire worms. Very effective he says.MOP is just a salt, no more toxic than table salt. Infact you can buy low sodium salt for the dining table, which is a mix of salt and MOP.
Sodium Hypochlorite is a totally different beast, and I would not want to put it on my chips.
Sodium hypochlorite is the salt formed by a negatively charged hypochlorite ion (OCl-) and a positively charged sodium ion (Na+). Pure hypochlorite is highly reactive and unstable; therefore, it is usually supplied as a dilute aqueous solution. In solution, hypochlorite eventually decomposes to yield a variety of byproducts including oxygen, chlorine gas, and salt. One of these byproducts, hypochlorous acid, is a powerful oxidizing agent (meaning it can accept electrons from other materials) that lends hypochlorite excellent bleaching and disinfecting abilities. The term "available chlorine" is often used to describe the concentration of hypochlorous acid in solution (which provides a measure of the solution's oxidative ability).
One small thing I consider when working out whether to use MOP or SOP is when the chloride leaches it will take with it the most available cation, which is usually calcium. So for every tonne of MOP used I add on a tonne of lime to the cost.
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Salt index of fertilisers