Water Holding Capacity of Soil

[shields kaiser]

In Gabe Brown's book he mentions the time he received a massive amount of rain over 24 hours, and could have driven across that field the next day - meaning his increased topsoil depth helps carry more water.

Does anyone have their own farm experience of this being the case?

We have relatively poorly draining soil on the top side of our farm (Clay loams, shallow topsoil ~6") and it is often too wet to carry cattle in April and October. We started rotationally grazing it, but I am interested in what I can do to improve this land. It has plenty of tile drains, and is in very long term Permanent pasture - although rotational grazing has improved Grass vigour.

What would you do with such a situation on your own place?
Thanks in advance!

 

[Kiwi Pete]

Yeah, it's improved out of sight on our place.

We've improved infiltration rate from just a few mm per hour to over 5 1/2 inches per hour in a very short timeframe (under 3 years), in our case the subsoil was well aggregated but the top 7 inches or so was very firm. It's a clay/silt loam.

We outwintered adult cattle on pasture for the first time this year, when we arrived here it was almost too wet underfoot to carry calves.

 

[Poorbuthappy]

Have you read the bit, and I've seen it elsewhere too, that raising organic matter content by 1% increases water retention capacity by 80000 litres per acre. I think that equates to about 20mm of rain?

Not grazing bare and having a good litter and sward cover will help carry that stock without poaching too.
Not making any claims about what I've achieved, more about what I'm aiming for.

 

[ShooTa]

wrok in progress here - we have a field that regualrly floods from a small river overflowing - so hoping that incresed capacity will reduce its effect.
deciding whether an intervention of a deep rip may help [previous flooding pan though or whether to leave nature to crack on..

 

[shields kaiser]

Yeah, it's improved out of sight on our place.

We've improved infiltration rate from just a few mm per hour to over 5 1/2 inches per hour in a very short timeframe (under 3 years), in our case the subsoil was well aggregated but the top 7 inches or so was very firm. It's a clay/silt loam.

We outwintered adult cattle on pasture for the first time this year, when we arrived here it was almost too wet underfoot to carry calves.

Thats great to know Pete, pretty much the place i want to get to in times of major rainfall. The outwintering would be a major bonus too.

Where did you start and what was the proces over the first few years? Grow and graze cover crops to speed things up?
Many thanks!

 

[shields kaiser]

Have you read the bit, and I've seen it elsewhere too, that raising organic matter content by 1% increases water retention capacity by 80000 litres per acre. I think that equates to about 20mm of rain?

Not grazing bare and having a good litter and sward cover will help carry that stock without poaching too.
Not making any claims about what I've achieved, more about what I'm aiming for.

Thats some volume of water! I think we'll have a reasonable level of organic matter, as all farm is now PPasture/grazed, but water infiltration is poor. Yes, I've been leaving residuals of 1700 -1800, which certainly helps by time we next graze as the cover is always higher than 2500.
Its our first year at rotation however, so maybe things will improve in 2 or 3 years

 

[Kiwi Pete]

Thats great to know Pete, pretty much the place i want to get to in times of major rainfall. The outwintering would be a major bonus too.

Where did you start and what was the proces over the first few years? Grow and graze cover crops to speed things up?
Many thanks!

Waste heaps and heaps of grass behind the cows!
Just keep them going forward and forward, when it gets out of control keep doing it!!

 

[Bury the Trash]

6 inches of loam over clay?

On level / lowlying ground the water will never go anywhere with clay underneath so its what ever capacity that topsoil will hold then its surplus.thats thd plain fact.

 

[Kiwi Pete]

We are on clay, too.

It doesn't matter a jot if it's clay, silt, or sand; if it's well aggregated then water will infiltrate it.
If it isn't, then it can't.

It's wet enough here to have puddles on sand, I know this because there were yesterday - another 40mm overnight yet my lawn is far "wetter" than the fields are.
Fields are good, despite being poached a little (as I intended) over winter, lawn is slush because of no grazing to drive the roots downwards - no real substitute for the golden hoof on top of diversity, and stopping the fertiliser

 

[Farmer Roy]

The vast black soil plains of northern NSW / southern Qld are all clay, with a depth ( of clay “topsoil” ) from approx 6m here, to say 14 m that I know of, west of Moree

 

[Farmer Roy]

I hear a lot in TFF about “compaction”, but it seems everyone is focussed on compaction in the top few inches & attempt to remedy that by ploughing, cultivation’s, rolling etc etc
Surface compaction obviously has an impact on initial infiltration rates, but it is
compaction at depth that really impedes deep infiltration, which ISNT addressed by any of the above, which ISNT caused by animal hooves, but which is really compounded by tyres & cultivation . . . Especially if you have a set of 5 tonne wheel tracks every 3 or 4 metres, multiple times, across the whole field . . .

 

[Farmer Roy]

We are on clay, too.

It doesn't matter a jot if it's clay, silt, or sand; if it's well aggregated then water will infiltrate it.
If it isn't, then it can't.

It's wet enough here to have puddles on sand, I know this because there were yesterday - another 40mm overnight yet my lawn is far "wetter" than the fields are.
Fields are good, despite being poached a little (as I intended) over winter, lawn is slush because of no grazing to drive the roots downwards - no real substitute for the golden hoof on top of diversity, and stopping the fertiliser

in the “wheat belt” regions of Western Australia, there are big areas of “non wetting” sands. Literally - sandy soils that repel water & don’t let it soak in. It just pools on the surface - it is due to the presence of organic waxes from the breakdown of the original vegetation, or something like that, caused largely by land clearing & cultivation in the past . . . Those farmers have developed a number of techniques to overcome this, including zero till, planting in deep furrows to collect & hold moisture, spreading clay over the surface, in-furrow injection of surfactants / wetting agents into the row at planting, re introducing livestock ( mainly sheep over there ) into arable lands. Constantly refining & adapting their methods . . .
Over here, on degraded lighter & sandy soils, I have seen the very same thing, caused by these organic waxy compounds . . .

In contrast, the best infiltration I have ever seen is out here on the ( heavy clay ) floodplain after an extended dry period. We had a flood & I was able to get around & in front of the water, as it was slowly spreading out across the plain. Upstream was completely underwater, I was standing on dry ground watching the water approach. You could literally hear it gurgling down into the soil, filling the profile, then it would move forward another few metres & just disappear into the ground again, until it filled it up & then moved forward again. It was pretty awesome to watch . . .

 

[Kiwi Pete]

in the “wheat belt” regions of Western Australia, there are big areas of “non wetting” sands. Literally - sandy soils that repel water & don’t let it soak in. It just pools on the surface - it is due to the presence of organic waxes from the breakdown of the original vegetation, or something like that, caused largely by land clearing & cultivation in the past . . . Those farmers have developed a number of techniques to overcome this, including zero till, planting in deep furrows to collect & hold moisture, spreading clay over the surface, in-furrow injection of surfactants / wetting agents into the row at planting, re introducing livestock ( mainly sheep over there ) into arable lands. Constantly refining & adapting their methods . . .
Over here, on degraded lighter & sandy soils, I have seen the very same thing, caused by these organic waxy compounds . . .

In contrast, the best infiltration I have ever seen is out here on the ( heavy clay ) floodplain after an extended dry period. We had a flood & I was able to get around & in front of the water, as it was slowly spreading out across the plain. Upstream was completely underwater, I was standing on dry ground watching the water approach. You could literally hear it gurgling down into the soil, filling the profile, then it would move forward another few metres & just disappear into the ground again, until it filled it up & then moved forward again. It was pretty awesome to watch . . .

Our land sucks, you can hear it when it stops raining as the water draws air in behind it.
I think I mentioned elsewhere that the only other property I can say I've heard that sound was our family place - "biological farming"

IMO, eucalyptus trees can compound the issue, obviously as part of a diverse ecosystem they are no problem, but when DIVERSITY has been reduced then the effects of waxy litter becomes apparent. Nothing much wants to grow under a gum.

All the Carbon/organic matter in the shire is no use without biology, especially fungi, as these basically organise the soil particles and glue them together to form stable aggregates... and basically everything farmers "do to help" is counterproductive to aggregation.
Feeding plants nutrients stops the roots and fungal networks expanding in their quest for minerals, so effectively you begin to run a hydroponic system with dirt underneath
Working the soil destroys them, moving the soil in any way is doing damage to the community
Spraying amendments on top does very little without 'already good' cycling
Nitrogen can collapse them too, certainly overusing soluble N does, 20 units per year is a guideline (no more than 3 units at a time)

Effectively the BEST way to get better aggregation is to walk off the place and stop farming it for a year.
Next best would be high-biomass, diverse covercrops laid onto the surface to feed the life within.
Third best - our approach - is to manage what grows in a much better way, where our landscape was closely grazed by mainly sheep and calves spread out, we switched to bigger cattle in a much tighter mob - this makes for a "deep tissue massage" followed by appropriate recovery for the plants, so that they are pumping liquid Carbon down 365 days a year instead of combating being overgrazed - stopping overheating makes it as effective as any other option, in a non-brittle environment

 

[Kiwi Pete]

I hear a lot in TFF about “compaction”, but it seems everyone is focussed on compaction in the top few inches & attempt to remedy that by ploughing, cultivation’s, rolling etc etc
Surface compaction obviously has an impact on initial infiltration rates, but it is
compaction at depth that really impedes deep infiltration, which ISNT addressed by any of the above, which ISNT caused by animal hooves, but which is really compounded by tyres & cultivation . . . Especially if you have a set of 5 tonne wheel tracks every 3 or 4 metres, multiple times, across the whole field . . .

Yes, ruts and wheelings and poaching - I had to learn and adapt my language to fit in....
... if you want to build a solid road, how do you begin...?
With wheels/rollers, water, and weight.

Animals do NOT cause compaction, but help relieve it if managed - if they manage themselves, they cannot.
Hence why my friend can have ponding in sandhills by the beach, management is incorrect... and we can run twice the stock on clay without any issue

Predators build better soils, I 'predate' my stock by moving them, he parks his stock.

 

[Farmer Roy]

^^^^^^^^^^^
YES
YES
YES

 

[Farmer Roy]

Wheels
Tyres
Cultivation

THESE ARE THE CAUSES OF COMPACTION

 

[Kiwi Pete]

And bare soil. Bare soil is dying/dead soil.

Hence why nature gives us pioneer plants (weeds) to fix that problem.

Once you adopt (if possible, sorry mate) a zero-bare-soil policy, with NO exceptions to the rule.... it all changes.
Move the stock before the soil is visible, no excuses.... no water problem

 

[Farmer Roy]

Oh yeah, I’ve always said ground cover is king . . .
the problem we are having now is all that ground cover has decomposed, oxidised or just blown away ( brittle environment ), with not enough moisture available to grow any more . . .

 

[Farmer Roy]

This barley won’t amount to anything, but at least it is providing some ground cover, which was the main impetus to plant it - I knew thee wasn’t enough moisture to make grain, but it was the cheapest way to get something growing
note - no “weeds” growing as not enough moisture to germinate them, barley only established as sown with minimal soil disturbance into a thin band of moisture about 70 mm deep

 

[Kiwi Pete]

In Gabe Brown's book he mentions the time he received a massive amount of rain over 24 hours, and could have driven across that field the next day - meaning his increased topsoil depth helps carry more water.

Does anyone have their own farm experience of this being the case?

We have relatively poorly draining soil on the top side of our farm (Clay loams, shallow topsoil ~6") and it is often too wet to carry cattle in April and October. We started rotationally grazing it, but I am interested in what I can do to improve this land. It has plenty of tile drains, and is in very long term Permanent pasture - although rotational grazing has improved Grass vigour.

What would you do with such a situation on your own place?
Thanks in advance!

His accent might annoy you for the first bit, but he's right on the money.