- Location
- Oxfordshire
( Not sure this thread is in the right place , I tend to see the Direct drilling section as the sustainable /conservation ag section rather than pure direct drilling )
Just wanted to share my thoughts on shallow straw incorporation to see what people think.
I think it is fair to say that common thinking is that best way to put carbon into soil is with a material that is as close as possible to the soils natural C:N ratio of around 10: 1 ( i.e. compost or similar )
Just think about it from the point of view of a soil organism. it might think " Oh, Mr farmer has just put some nicely balanced material on the field that doesn't need any breaking down to assimilate it into the soil , I can just roll over and go back to sleep! "
Another scenario might be a farmer incorporating a mass of chopped straw with a C:N ratio of around 80:1. The farmer might also have been very clever and applied a bit of Nitrogen fertiliser. The soil organism might now wake up with a start and think " Crikey Mr Farmer has just applied loads of material that needs breaking down to get it nearer to a C:N ratio of 10:1. He has also given us a nice N source so I better get S...ing and create a population explosion to deal with this stuff ! "
The resulting population explosion converts the applied mineral N into organic N in the bodies of the soil micro organisms and is therefore prevented from leaching over winter. Once the straw is assimilated the soil bugs will die off and slowly release the organic N in their bodies to the growing crop.
Point being is that we want a functioning soil with organic matter turning over rather than just sequestering carbon in highly stable forms. My scenario is obviously only sustainable if lots of carbon is going into the system to keep giving the bugs fresh material to work on..........
To summarise Hypothesis :In a high yielding ,high N input, commercial arable system incorporating high C:N ratio material + N fert better than compost ??
Just wanted to share my thoughts on shallow straw incorporation to see what people think.
I think it is fair to say that common thinking is that best way to put carbon into soil is with a material that is as close as possible to the soils natural C:N ratio of around 10: 1 ( i.e. compost or similar )
Just think about it from the point of view of a soil organism. it might think " Oh, Mr farmer has just put some nicely balanced material on the field that doesn't need any breaking down to assimilate it into the soil , I can just roll over and go back to sleep! "
Another scenario might be a farmer incorporating a mass of chopped straw with a C:N ratio of around 80:1. The farmer might also have been very clever and applied a bit of Nitrogen fertiliser. The soil organism might now wake up with a start and think " Crikey Mr Farmer has just applied loads of material that needs breaking down to get it nearer to a C:N ratio of 10:1. He has also given us a nice N source so I better get S...ing and create a population explosion to deal with this stuff ! "
The resulting population explosion converts the applied mineral N into organic N in the bodies of the soil micro organisms and is therefore prevented from leaching over winter. Once the straw is assimilated the soil bugs will die off and slowly release the organic N in their bodies to the growing crop.
Point being is that we want a functioning soil with organic matter turning over rather than just sequestering carbon in highly stable forms. My scenario is obviously only sustainable if lots of carbon is going into the system to keep giving the bugs fresh material to work on..........
To summarise Hypothesis :In a high yielding ,high N input, commercial arable system incorporating high C:N ratio material + N fert better than compost ??