Nitrogen and soil moisture dynamics

[shakerator]

n is hydroscopic. It moves water quicker into roots. A disk seeder would likely run better on wet soils in a topsoil freshly fertilised with nitrate

It would force the soil water equation in favour of green plant evapotranspiration > tillage evaporation, which lets be honest many ppl only work clay soils to dry them out ....



....discuss!

 

[mikep]

n is hydroscopic. It moves water quicker into roots. A disk seeder would likely run better on wet soils in a topsoil freshly fertilised with nitrate

It would force the soil water equation in favour of green plant evapotranspiration > tillage evaporation, which lets be honest many ppl only work clay soils to dry them out ....



....discuss!

No.

 

[shakerator]

No.

No it won't effect soil moisture wicking or no you don't want to discuss it?

 

[mikep]

Sorry but the latter.

 

[Simon C]

n is hydroscopic. It moves water quicker into roots. A disk seeder would likely run better on wet soils in a topsoil freshly fertilised with nitrate

It would force the soil water equation in favour of green plant evapotranspiration > tillage evaporation, which lets be honest many ppl only work clay soils to dry them out ....



....discuss!

So what are you getting at? A dose of N on a covercrop would encourage it to suck more water out of the soil than if it was left to grow naturally? The theory being that the applied N would return to the following crop in the form of increases residue and not be wasted.

Agree that a lot of seedbed preparation on clay soils is just to get them dry enough for the drill to work. There are loads of field round here at the moment where all the moisture has been cultivated out of them and the seed is now sitting completely dry, waiting for rain.

 

[shakerator]

So what are you getting at? A dose of N on a covercrop would encourage it to suck more water out of the soil than if it was left to grow naturally? The theory being that the applied N would return to the following crop in the form of increases residue and not be wasted.

What I am getting at is this. We lament no soil movement for lack of mineralisation. And unmoved clay being too wet to drill. Does fertiliser cause the soil profile to give up its moisture in the zone where it is converted into nitrate faster than elsewhere in the profile (I.e, top inch usually) ? I..e deeper horizons stay wetter than under a "natural/ unfertilised system" where perhaps the fertility is distributed differently compared to a few prills washed in by the elements . And does this have implications on how water infiltrates to said depth, leaving us with difficulty in running disk drills unless a) covers are removed or b) light tillage or c) early autumn/late spring seeding dates or d) additional N to wick that top inch seeding zone dry

 

[KJM]

Green stubble on liquid N overlaps, clearly visible on ploughing. About 1 month and an inch or so of rain between combining and ploughing. I guess it would it be easier to DD on the overlaps than the bulk of the field. Is the effect from the N or just the crop being alive for longer?

Field 220kg N

Please excuse the implement on the DD forum.

 

[shakerator]

Green stubble on liquid N overlaps, clearly visible on ploughing. About 1 month and an inch or so of rain between combining and ploughing. I guess it would it be easier to DD on the overlaps than the bulk of the field. Is the effect from the N or just the crop being alive for longer?

Field 220kg N

Please excuse the implement on the DD forum.

View attachment 222134 View attachment 222136

Are your fert overlaps also your fungicide overlaps? I.e 200% strob dose??

 

[KJM]

Yes

No strobs used. Adexar @ 1.25L on flag. Other timings azole + CTL. Greener straw this year on SDHI treated crops. Yield difference too small to measure on split field trials.

Have seen in previous years overwinter stubble goes black except in overlaps that remain straw coloured.

 

[shakerator]

Yes

No strobs used. Adexar @ 1.25L on flag. Other timings azole + CTL. Greener straw this year on SDHI treated crops. Yield difference too small to measure on split field trials.

Have seen in previous years overwinter stubble goes black except in overlaps that remain straw coloured.

Would be interesting to see difference in slug numbers, and N lockup affects if double dosing (whether double N offsets double fung !)

 

[yellow belly]

More n produces more biomass which uses more water on deep soils
Thin soils would not have the water so would not produce the biomass in a dry time

On heavy land or wetter land not ill has to be done before it is too wet in the autumn

In the spring later drilling when it is drying is essential

The rule drill 2 weeks earlier in the autumn but 2 weeks later in the spring is a good plan