Improvement of soil ph in DD crops.

[Sprayer 1]

Has anyone found any improvement of their soil ph from DD into FYM stubbles? We are into our 4th year of DD and most fields have a covering of muck, but although the soil looks and smells a lot more healthy, the ph stays at 6. I have been using some granular lime on the crop but it doesn't seem to do a lot although wheat always does fine but im thinking about growing some spring osr so is the only answer a good 2ton dollop of lime to the acre or should trust in my soil?

 

[Brisel]

You might want some lime to help with breaking down a big straw crop but otherwise without cultivation you’re keeping your buffering capacity up by not leaching smaller particles.

 

[Philip Hedeng]

You might want some lime to help with breaking down a big straw crop but otherwise without cultivation you’re keeping your buffering capacity up by not leaching smaller particles.

Lime to accelerate residue break down? I thought N would be the biggest factor.

 

[Brisel]

Lime to accelerate residue break down? I thought N would be the biggest factor.

Residue breakdown creates temporarily acid conditions. Read the "Two Simons Theory." If your soils are low in calcium you have a double benefit.

You could also use molasses as bacterial food to speed breakdown instead. Yes, raising the carbon levels with residues does lock up N so you're right, though this is going away from the OP's question.

 

[SilliamWhale]

Has anyone found any improvement of their soil ph from DD into FYM stubbles? We are into our 4th year of DD and most fields have a covering of muck, but although the soil looks and smells a lot more healthy, the ph stays at 6. I have been using some granular lime on the crop but it doesn't seem to do a lot although wheat always does fine but im thinking about growing some spring osr so is the only answer a good 2ton dollop of lime to the acre or should trust in my soil?

Yes for sure. I find over the years the pH stays a lot more stable. There are various obvious reasons for this eg your not tilling your soil particles and therefore your fertility away either via oxidisation or erosion, earthworm casts are ph6.5 etc and also you are cycling the lime much for efficiently via natural process. I find the same with Phosphorous - much more efficiently held onto if you leave the soil alone.

Obviously fert and rain does acidify things but its not to say its a one way street - I reckon throughout the year the soil would have a pH flux depending on soil biology activity same as above ground

If you think about it the old 2t/acre every 5 years may have made sense under a very wasteful tillage regime but perhaps not so much under no till. What would be the pH of the top 2cm after 2t lime? Probably ph 10!!!

Wheat is happy at ph 6 though.

 

[Brisel]

pH 6 is a bit low for many crops, especially brassicas and barley.

Does anyone find stratification of soil pH at different depths?

 

[Sprayer 1]

I am pleased when you say that worm casts are ph6.5 as the one thing we are doing is breading worm., I would presume that if the casts are 6.5 then the soil around the tunnels will be as well. I was tempted to run a subsoiler through some fields post harvest as I feel some ground is a little tight but reading Clives posts on letting the worms work for you, with the amount that are developing I will give them a feed and have another look next year.

 

[SilliamWhale]

I am pleased when you say that worm casts are ph6.5 as the one thing we are doing is breading worm., I would presume that if the casts are 6.5 then the soil around the tunnels will be as well. I was tempted to run a subsoiler through some fields post harvest as I feel some ground is a little tight but reading Clives posts on letting the worms work for you, with the amount that are developing I will give them a feed and have another look next year.

Worms move more than ploughs over the year - what is more they do it all year for you. Plough is just a one hit thing.
Tight ground doesn't mean much without spade - even then the only thing that can make ground looser is Glomalin, fungal hypahe, worms, biology etc as it creates aggregates and pores

 

[SilliamWhale]

pH 6 is a bit low for many crops, especially brassicas and barley.

Does anyone find stratification of soil pH at different depths?

In our climate I don't really look for it. Surface applied lime can only go one way - either via rain or biology. We're too wet for significant stratification in my opinion