Effects of too much lime.

[kill]

Talking to someone the other day that had corrected his soil ph this spring on grassland ground and was on about giving it a heavy dose of slurry & limesand from the bottom of his lagon but what will be the affects of too much lime?

 

[Northeastfarmer]

A reduced bank balance?

 

[kill]

A reduced bank balance?

Is it not as bad for the grass growth as too low a ph?

 

[Northeastfarmer]

Is it not as bad for the grass growth as too low a ph?

Well no

 

[Macsky]

Possible mineral lockup.

 

[Global ovine]

Talking to someone the other day that had corrected his soil ph this spring on grassland ground and was on about giving it a heavy dose of slurry & limesand from the bottom of his lagon but what will be the affects of too much lime?

If the soil pH was corrected, ie. put into the 6.0 - 6.4 range, any additional alkalinity will alter the availability of mainly trace elements.
Over the pH of 6.5 cobalt becomes less available for the rumen flora to produce Vit B12, this will cause problems for sheep, as sheep can only use class 1 B12 (built around a Co molecule) whereas cattle can utilise class 2 B12 (built around an arsenic molecule).
A pH over 6.0 makes molybdenum available for legumes (especially clovers) for their rhizobia to fix nitrogen. If soils already have ample moly. this can cause copper deficiency as pH increases.
Once soil pH exceeds 6.5 the growth rates of ryegrasses progressively reduce.
High aluminium soils (very weathered uplands) need higher pH to allow plant root growth as Al is toxic to root growth. An increase in pH helps soil microbes to "free" phosphate from clay particles to get P cycling to be available for plants. However 6.5 is sufficient for this to happen.

Generally speaking, soil microbe activity increases with pH until it reaches over 7.0.

The sweet spot for most soils supporting mixed pastures for sheep and cattle is in the 6.0 - 6.4 range where most elements, macro and micro, should not cause problems and achieve high yields of DM/ha when P K Mg and S are near to or at optimum levels. Of course pugging and over cultivation can cause soil structure problems that can completely lead one astray if the soil lacks drainage and does not breathe.
Never put stuff on if you don't know the outcome.

There is no alternative to testing and using a spade to check the chemical and physical status.

 

[kill]

If the soil pH was corrected, ie. put into the 6.0 - 6.4 range, any additional alkalinity will alter the availability of mainly trace elements.
Over the pH of 6.5 cobalt becomes less available for the rumen flora to produce Vit B12, this will cause problems for sheep, as sheep can only use class 1 B12 (built around a Co molecule) whereas cattle can utilise class 2 B12 (built around an arsenic molecule).
A pH over 6.0 makes molybdenum available for legumes (especially clovers) for their rhizobia to fix nitrogen. If soils already have ample moly. this can cause copper deficiency as pH increases.
Once soil pH exceeds 6.5 the growth rates of ryegrasses progressively reduce.
High aluminium soils (very weathered uplands) need higher pH to allow plant root growth as Al is toxic to root growth. An increase in pH helps soil microbes to "free" phosphate from clay particles to get P cycling to be available for plants. However 6.5 is sufficient for this to happen.

Generally speaking, soil microbe activity increases with pH until it reaches over 7.0.

The sweet spot for most soils supporting mixed pastures for sheep and cattle is in the 6.0 - 6.4 range where most elements, macro and micro, should not cause problems and achieve high yields of DM/ha when P K Mg and S are near to or at optimum levels. Of course pugging and over cultivation can cause soil structure problems that can completely lead one astray if the soil lacks drainage and does not breathe.
Never put stuff on if you don't know the outcome.

There is no alternative to testing and using a spade to check the chemical and physical status.

Thank-you. Perfect response
I knew it wasn't a good idea but couldn't think why.

 

[Sharpy]

Thank you @Global ovine . Another post full of useful information!

 

[Poorbuthappy]

Is it not as bad for the grass growth as too low a ph?

My cousin has gone away from a neutralizing sand due to ph getting too high.
I think he uses quarry sand now rather than sea sand.
Must be others on here in the same situation.

 

[sidjon]

Sand has only half the NV as lime, we have used it on heavy ground without any problems.

 

[Poorbuthappy]

Sand has only half the NV as lime, we have used it on heavy ground without any problems.

Depends how much you're using I guess.
Cousin was getting ph in the high 6's, but has been on sand for several years, and would've kept lime up prior to that.

 

[sidjon]

A lot of dairy farmers seem to put it on the same field every year, rather than rotating the field which has the dregs out of the pit, but if you can get it even across the farm the over liming problem would take longer.

 

[johnspeehs]

Are we talking ordinary sand? What kinda amount would usually be applied ?

 

[scholland]

Sand has only half the NV as lime, we have used it on heavy ground without any problems.

Depends on the sand, 1 beach here has half the nv of lime, another round the coast only has quarter.

 

[newhollandcruzr]

Most of the sand used around here comes out of Padstow and has around 37nv

 

[kill]

Sand has only half the NV as lime, we have used it on heavy ground without any problems.

Nearly all of Exmoor historically is low of lime apparently except a small area near Exford where the Lime pits are at Newlands Farm

 

[sidjon]

Nearly all of Exmoor historically is low of lime apparently except a small area near Exford where the Lime pits are at Newlands Farm

There's a small deposits of limestone at Wheddon cross to Luxborough and limestone quarry at Allercott, which I guess would be the same small vein of limestone.

 

[cotswoldcs]

We're on Cotswold Limestone brash and some of our fields test at pH 8+. I think it would take an incredible amount of lime to take a field that needs liming to that level!

Stuff still grows but it does cause a lock up of other elements. It's a shame there isn't an easy solution for decreasing the alkalinity of soils.

 

[Danllan]

We're on Cotswold Limestone brash and some of our fields test at pH 8+. I think it would take an incredible amount of lime to take a field that needs liming to that level!

Stuff still grows but it does cause a lock up of other elements. It's a shame there isn't an easy solution for decreasing the alkalinity of soils.

What is the received wisdom on this? I always thought some sulphur every few years was supposed to help. I'd have thought that, if you can get enough, you could spread pine needles / mulched coniferous forestry brash at the same interval and it would have a cumulative affect on the pH. I don't think my chemistry is that bad, so is it just availability and / or cost that prevents this?

 

[MrA.G.]

Are we talking ordinary sand? What kinda amount would usually be applied ?

Think it depends on where the sand comes from, don’t think we have any suitable sand here in NI, but I could be wrong