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Posted: Sat Oct 27, 2007 12:19 pm
Does Peter recommend using any lime minerals or does every thing return to how it should be with just mulching?
Mulch, Lime and pH.
Posted: Sun Nov 04, 2007 12:38 am
I am not sure what Peter says about lime but I have a lot of experience utilising lime and wether or not Peter agrees with the use of lime, I will share my experience with you.
As you would know, mulch is organic and organic is good
What you may not know is that this means it will be positively charged and will hold nutrients, NPK ect.ect. which are negatively charged ions
Lime can be used to alter a soils pH.
pH is some sort of acronym for percentage Hydrogen .....pH. Or in other words the percentage of other elements in the soil per Hydrogen ions.
For some reason (I'm sure it's to confuse people like me) pH is a negative logarithm. Which means the more active hydrogen in the soil the lower the pH number or the more acid
. (Totally upside down!)
Lime comes in two forms (that we as farmers are familiar with), they are lime sand (sand containing significant quantities of calcium carbonate derived from finely weathered shell material
) and crushed limestone (Calcium Carbonate).
There is some debate as to which is better but they both work rather well to raise the pH of soil. Rocklime has larger particles which is not good (finer is better) but limesand
contains large quantities of silicate which is very hard and does not react well.
It works something like this.
particles in the soil are very small compared to most other elements.
Clay particles are organic and they have a positive charge
Most nutrients (Nitrogen N, Phosphorus P, Potassium K, and others) are negative charged so they are attracted to the positive clay particle and attach to them.
A soil high in clay
particles has the ability to hold a lot more nutrients than a sandy soil for this reason.
is also negatively charged and will attach to the clay particles but in a soil with excessive active hydrogen (Low pH
or acid) the hydrogen ions
crowd out all the other nutrients by clustering around the positive clay
particle (Hydrogen is also very small, the smallest).
By adding Calcium Carbonate CaCO3
(rocklime) to the soil we create a chemical reaction where two hydrogen ions will attach to one of the oxygen ions (there are three in CaCO3) to create H2O (water).
The Carbon ion (C) will attach to the remaining two oxygen ions to create CO2 (Carbon dioxide, a gas... hense the fizzing) and the calcium will remain free for the time being.
Many other reactions are possible depending on the concentrations of other active ions.
A common reaction is very similar to the above resulting in Calcium Hydrogen Carbonate, Ca(HCO3)2 which has two hydrogens tied up.
Either way the result is the Hydrogens
that are the nasties are disolved into water or otherwise nuturalised allowing the good guy
(clay) to attract and hold the nutrients.
I hope that I have written this in a way that is able to be understood.
I think I need to take a cold shower......
Posted: Mon Nov 05, 2007 2:46 pm
Thank you for that Ian. I have had my soil tested with SWEP and they recommended a lot of lime 1.9 tons to the hectare, I was a bit surprised as the country has natural limestone outcrops and has never been supered
Posted: Mon Nov 05, 2007 11:51 pm
Hi Rose SWEP are a laboratory that we have used often and are very reliable.
1.9 tons is an interesting recommendation, why do they not just say 2?
You are right, it does seem a lot although not excessive, it depends on the results of the soil test results.
Clay soils require huge amounts of lime to adjust to pH the more acid they are.
The amount of calcium in a soil is the main factor in determining if the soil is acid or alkaline.
The action of rain, which is acid, tends to wash the calcium out of the soil, making the soil more acid over time.
This is especially true of sandy soils which lose calcium much quicker than clay soils.
Clay and heavier soils have a reserve acidity which means that far more lime is needed to result in the same increase in pH.
As general rule clay soils need three times as much lime to change the pH as sandy soils.
The fact that you have natural limestone outcrops is totally irrelevant as soil types can change from one extreme to another within a matter of feet.
The fact that your land has never been fertilised also means nothing.
Fertiliser may reduce pH depending on the soil type and conditions but pH depends very much more on just what elements are present in the soil.
A clay soil will not change at all no matter how much fertiliser is applied where as a sandy soil may be effected substantially by continued use of acid fertilisers (almost all fertilisers are acid).
What I always do when I am sailing in uncharted waters such as those you describe is undertake a trial.
Depending on the scale of the treatment area, get some lime applied, do it in strips of an increasing application, i.e. 500kg/ ha, nothing, 1000 kg/Ha nothing, 1500 kg/Ha, nothing, 2000 kg Ha nothing and so on up to about twice the amount you have been reccomended.
What you learn from a trial such as this will make you an expert on applications of lime on your particular soil.
Remember you will see not much of a result after one year, normally three years is required before the lime you apply has finished reacting in the soil.
Don't be in a hurry but get the trial started ASAP and be patient.
You will have far more knowledge than any expert you can hire.
Good luck and happy trialling
By the way, what was the pH of your soil?
I have heard of people putting as much as three tonnes on.
The thing with Lime is that it is a cheap product, but bulky to freight and is expensive to apply compared to the cost of the lime itself.
For that reason, as it does not cost any more to spread 2 tonnes as it does 200 Kg per Ha it is usual to apply as much as might be required and then some in a single dose.
There is a formula for calculating how much lime is required to affect the pH of a particular soil depending on the conditions in that soil.
Every soil is different and some soils take a lot more lime to raise the pH by one than others.
Often the cost of freight is more than the cost of the lime.
Posted: Tue Nov 06, 2007 12:00 pm
The pH 5.7. Also on this paddock I have to put on 0.2 of Gypsum as well. The Lime is cheap, the Gypsum around $72.00 a ton , but the cartage is $74.00 a ton for the lot
Posted: Tue Nov 06, 2007 7:44 pm
Rose, if you have a pH of 5.7 I would suggest that your soil has a very healthy pH and does not require treatment.
As a general rule we only consider applying lime if the pH falls below 5 and even then not always, often not until it is really going sub 4.5.
Of course it would really depend on what crop you plan to grow on the country.
Some crops are particularly sensitive to acid soils.
Most agricultural crops though will do very well at pH 5.7
Oats in particular do very well on pH around 4 to 4.5; wheat on the other hand does better around pH 5.
Can I suggest you save your money and maybe use it to tackle some other area of degradation on your land?
What is the soil type, clay, loam or sandy?
Posted: Tue Nov 06, 2007 7:48 pm
Just a added note, I would die to have some pH 5.7 dirt on my farm.
I think our average is around 4.8 to 5.3 and our country is not considered to be acid land at all.
Posted: Wed Nov 07, 2007 12:21 pm
That is very interesting The land is Clay. It was a lake thousands of years ago (maybe millions) the paddock next to this one has a pH 6.2 I have to put more Gypsum on that land it is a Lucerne paddock and always grows a lot of Barley Grass which is a real nuisance for the first cut.
The other paddock I am going to let go back to Native pasture as that is what is seems to want to grow, as every time I plough it up, Native grasses grow and I have found that native pastures are the best in these awful droughts we have been having
Posted: Wed Nov 07, 2007 1:26 pm
This is what happens about every 13 or so years, this was last summer
The rest of the time this is dry
There is a dry creek bed right through these flats and a named creek is marked on the map but there is no running water. Can anything be done with this sort of country?
Posted: Wed Nov 07, 2007 5:29 pm
I checked with Peter re your original question 'does Peter recommend the application of lime'.
His answer in brief was NO.
His explanation for not doing so was that he has not put any chemicals onto his land in the last 30 years.
firstly, it is a huge input cost.
secondly, it is chemical agriculture, against much of what Peter's nsf principles are about.
This landscape functioned for thousands of years on its own without any artificial inputs and we have upset the balance by altering the soil chemistry and consequently the microbes in the soil by artificial chemical additives. It is estimated that organic Carbon levels in our soils at the time of settlement were between 4000-20000 years old.
We all are aware that Nature does nothing unnecessarily. An understanding of how this landscape evolved to take advantage of water and fertility has never been explained or understood by australian agriculture. Our current practices are a dichotomy of modern chemical agriculture combined with practices rooted in the past.
This landscape offers hope to all of us who are prepared to listen. When properly understood we can operate our argriculture sustainably, profitably without any artifical additives, chemicals, pesticides when the land is in balance.
Posted: Wed Nov 07, 2007 9:55 pm
So there you go, I thought that Peter's response would be something like that.
Lucern, well that is one crop that does not handle acid well at all and as you have clays you would need to go top of the scale to get some sort of effect from the lime.
Try oats for hay maybe, any grasses that grow end up in the bale too and it all makes good feed.
As you are mowing to make haty the grasses will have their numbers cut right down by the mowing especially if you grow a couple of hay crops in succession.
Oats do very well on acid clays.
Posted: Fri Nov 09, 2007 4:01 pm
Duane, Thank you for your reply. I am more confused now as I thought Lime and Gypsum are Natural.
Ian those Lucerne flats have grown beautiful Lucerne over the years but they like a bit of rain. Last summer after the flood we cut a lot of hay but it got rained on and was all spoilt
Posted: Fri Nov 09, 2007 9:58 pm
Rose, there is also apart from the nsf philosphy a more rigorous scientific interpretaion of Peter's thoughts.
I will try and get time next week to write about that then.
You may want to check out Peter's property on Sunday at 9am EDST. Ray Martin has Peter as the cover story on the Sunday program....you will see, I hope, tremendous biodiversity, high productivity....all with no artificial fertilzers and no conventional irrigation.
Posted: Fri Nov 09, 2007 10:03 pm
Interestingly enough, the much maligned Pattersons Curse, has the ability to turn acid soils more alkaline.
As a biodiverse pasture mix they also have high Omega 3 levels and recent CSIRO research has shown beef fed on pasture has a 40:60 Omega 3:6 ratio whilst grain feed beef is 30:70. The research shows diets high in Omega 6 can cause obesity.
Posted: Sat Nov 10, 2007 4:41 pm
Rose, if those flats are growing beautiful lucern then the pH at 5.7 is fine and apart from whoever is advising you to lime I can't understand why you would lime the country.