Tillage farmers across the country have been turning on the choppers at a high rate this harvest. Low demand in many areas coupled with high fertiliser prices and shortages of phosphorus and potassium are driving this decision.
Last year, many tillage farmers were introduced to the concept of incorporating organic matter for the first time in decades through the new straw incorporation measure (SIM), or what most call the straw chopping scheme.
Over 52,000ha are to be chopped under the measure this harvest, but reports to the Irish Farmers Journal suggest that many farmers are chopping outside of the scheme.
Sheds are filled with hay in the west and midlands and there is expected to be demand for straw in the winter, but many tillage farmers appear not to be taking a chance and are putting that valuable straw back into the ground.
Why incorporate straw?
Straw incorporation brings many benefits such as increasing the friability of the soil, adding and storing carbon, removing less nutrients (especially potash) and decreasing the diesel, time and effort typically required for crop establishment. The cultivation during incorporation also helps to get volunteers and weed seeds to grow to help reduce the weed seedbank.
However, incorporation brings additional costs such as the diesel required for chopping, and the diesel and metal for incorporation. This is estimated to cost around€35/ac.
It is important to remember that extra nitrogen may required on the immediately following crop for a year or two of incorporation as the army of microorganisms needed to break down the straw must be built up in the soil initially and these organisms also consume nitrogen. However, this need will be apparent in early spring if needed, whereby the crop may benefit form an additional 10-15 units per acre.
However, after a year or two of doing this the soil system returns to an equilibrium and the nitrogen released from decomposing straw in previous years feeds the breakdown of the new crop.
Chopping the straw
Chopping and incorporating straw isn’t the most technical job, but both elements are important.
The success of a chopping operation depends to some degree on the maturity of the straw and length of the chop. Not necessarily a fixed length, but rather a length that ensures that only one node is present on each piece of stem. This means that any piece of stem can be attacked from both ends on the inside and outside of its entire length, which speeds up the breakdown of the straw to release the nutrients.
Getting straw chop length correct is largely down to the number of blades on the chopping rotor. The sharpness of these tools will affect chop quality and the fuel required. It is not necessary or advisable to chop the straw excessively.
The challenge of incorporation looks bigger when there are greater volumes of straw, but one way to lessen this task is to cut higher, leaving more stubble but less straw to be incorporated.
The even delivery of chopped straw across the working width of the combine is very important. Lack of uniform application means more straw to incorporate in some areas and less in others. By virtue of mass, small pieces of straw may not be blown uniformly across the working width of large headers so over-chopping is not advised. If the straw cannot be spread uniformly, neither can it be incorporated uniformly.
Having straw in 4in to 6in pieces has another important benefit. Earthworms gather their food by coming out of their burrow and wriggling around on the surface in a circular motion.
In doing this they pull in everything on the surface over the top of each burrow. After that they pull the straws down in the burrow over time, leaving only a little pile of small stones on the surface which were gathered with the food.
As a general rule you will grow the same tonnage of straw as grain so that’s a lot of bulky material to incorporate.
The challenge of incorporation looks bigger when there are greater volumes of straw. After a few years of incorporation, the army of biological organisms in the soil will build up and the volume of straw will quickly appear to disappear post-harvest.
Good incorporation practice
If straw is not incorporated (mixed with soil) in advance of cultivation, you will end up with a sandwich of straw between each furrow.
This can act as a highway for slugs to move from the shelter of the soil to above ground to attack a new crop. This must be avoided as there is little point in adding cost to incorporation if it results in having even more costs in the following crops.
The simple principle behind incorporation is to mix the straw in with the soil. This does not mean that all the straw will be covered or incorporated post-cultivation. However, it will all have come in contact with soil during the mixing process and will at least be peppered with little bits of soil that contain thousands of microorganisms to begin straw breakdown.
But good incorporation will leave the majority of the straw and stubble in the soil but close to the surface where there is adequate oxygen to fuel the different organisms that will begin to break it down.
Machine options
Incorporation can be carried out using a disc or tine cultivator. One of the most important things for the initial incorporation is that it is done as shallow as possible, while loosening all the ground and ensuring there is enough loose soil to get a good mixing of straw and soil.
Working shallow helps avoid a problem later in the year if loose soil gets wet. Try to produce no more loose soil than the thickness of the lugs on your tractor tyres. Cultivating deeper during this first pass will produce more soil and although appearing to incorporate more of the straw, the risks associated with having too much loose soil outweigh the benefits of achieving higher incorporation.
It is generally regarded as good practice to travel at an angle to the direction of sowing when cultivating, to provide a more uniform mixing of the stubble.
Willie Corrigan, Kilkenny – Lemken Rubin disc cultivator
“In 2019, I made the move to a new Lemken Rubin 10 5m trailed disc cultivator. I went for the Rubin as I felt it was the most versatile disc harrow out there. I do a lot of grassland reseeding on hire alongside my own work so I needed a heavy disc with a large diameter for that, while I also wanted a machine which I could incorporate straw with and sow cover crops by mounting an air seeder. The Rubin ticked all the boxes for me.
Willie Corrigan uses a 5m trailed Lemken Rubin disc cultivator to incorporate straw.
“I run the machine on a John Deere 6195R and typically work it at 12-14km/h, which means I can get through around 10 acres/hour. I would describe the Rubin as being a ‘German tank’. The hydraulic depth control is a gift and Lemken offers great backup.
“I’ve been incorporating straw since 2019 and I can see a notable difference. I’m constantly learning but I can see that the ground is much healthier looking – it’s notably looser and there are more microorganisms active. When incorporating, I aim to disturb all of the soil, while only working the top two to three inches. I typically work at a different angle to the stubble. To be honest, I have worked both ways and can’t see a major difference.”
James Mulhall, Laois – Vaderstad Cultus tine cultivator
“We bought a new 3m Vaderstad Cultus tine cultivator last year. This was our first year chopping straw and we chopped 250 acres for the scheme. We also run a disc cultivator but decided to buy the tine cultivator for its versatility. Before sowing when conditions are right, we use the Cultus to break compaction on headlands, run it on the plough joints and the tramlines.
“We had found that compaction was beginning to affect production in the ground surrounding the tramlines. Once the field is combined, we would give the tramlines a relatively deep run (6-8in), followed by incorporating the straw.
James Mulhall uses a Vaderstad Cultus 300 3m tine cultivator to incorporate straw.
“When incorporating, we look for a nice tilth, aiming to disturb and mix the soil and straw, while not working below 3in. We run the machine on a John Deere 6155R and typically run it at 8-10km/h at the shallow depth. This allows us to get through over 50 acres/day. We actually travel in the same direction as the stubble. We have tried both ways but can’t see much of a difference.
“Although this is only our second year incorporating straw, we can see the differences already, particularly on one outfarm. The soil is much looser, and there are far more earthworms. Incorporation definitely has its benefits and the price of fertiliser has changed everything – I think there will be more straw incorporated as the years go on.”
Incorporation can be carried out using a disc or tine cultivator, but the objective is to get soil on to the straw and the stubble rather than covering all the straw with soil. One of the most important things for the initial incorporation is that it’s done as shallow as possible, while loosening all the ground and ensuring there is enough loose soil to get a good mixing of straw and soil.
There are a number of benefits in keeping the straw close to the surface. Oxygen is more available here for the microorganisms that break down the straw and earthworms can respond to the feast of food they find close to the surface by multiplying in numbers.
Additional nitrogen may be needed by the crop for the first year or two following incorporation.
Tillage farmers across the country have been turning on the choppers at a high rate this harvest. Low demand in many areas coupled with high fertiliser prices and shortages of phosphorus and potassium are driving this decision.
Last year, many tillage farmers were introduced to the concept of incorporating organic matter for the first time in decades through the new straw incorporation measure (SIM), or what most call the straw chopping scheme.
Over 52,000ha are to be chopped under the measure this harvest, but reports to the Irish Farmers Journal suggest that many farmers are chopping outside of the scheme.
Sheds are filled with hay in the west and midlands and there is expected to be demand for straw in the winter, but many tillage farmers appear not to be taking a chance and are putting that valuable straw back into the ground.
Why incorporate straw?
Straw incorporation brings many benefits such as increasing the friability of the soil, adding and storing carbon, removing less nutrients (especially potash) and decreasing the diesel, time and effort typically required for crop establishment. The cultivation during incorporation also helps to get volunteers and weed seeds to grow to help reduce the weed seedbank.
However, incorporation brings additional costs such as the diesel required for chopping, and the diesel and metal for incorporation. This is estimated to cost around€35/ac.
It is important to remember that extra nitrogen may required on the immediately following crop for a year or two of incorporation as the army of microorganisms needed to break down the straw must be built up in the soil initially and these organisms also consume nitrogen. However, this need will be apparent in early spring if needed, whereby the crop may benefit form an additional 10-15 units per acre.
However, after a year or two of doing this the soil system returns to an equilibrium and the nitrogen released from decomposing straw in previous years feeds the breakdown of the new crop.
Chopping the straw
Chopping and incorporating straw isn’t the most technical job, but both elements are important.
The success of a chopping operation depends to some degree on the maturity of the straw and length of the chop. Not necessarily a fixed length, but rather a length that ensures that only one node is present on each piece of stem. This means that any piece of stem can be attacked from both ends on the inside and outside of its entire length, which speeds up the breakdown of the straw to release the nutrients.
Getting straw chop length correct is largely down to the number of blades on the chopping rotor. The sharpness of these tools will affect chop quality and the fuel required. It is not necessary or advisable to chop the straw excessively.
The challenge of incorporation looks bigger when there are greater volumes of straw, but one way to lessen this task is to cut higher, leaving more stubble but less straw to be incorporated.
The even delivery of chopped straw across the working width of the combine is very important. Lack of uniform application means more straw to incorporate in some areas and less in others. By virtue of mass, small pieces of straw may not be blown uniformly across the working width of large headers so over-chopping is not advised. If the straw cannot be spread uniformly, neither can it be incorporated uniformly.
Having straw in 4in to 6in pieces has another important benefit. Earthworms gather their food by coming out of their burrow and wriggling around on the surface in a circular motion.
In doing this they pull in everything on the surface over the top of each burrow. After that they pull the straws down in the burrow over time, leaving only a little pile of small stones on the surface which were gathered with the food.
As a general rule you will grow the same tonnage of straw as grain so that’s a lot of bulky material to incorporate.
The challenge of incorporation looks bigger when there are greater volumes of straw. After a few years of incorporation, the army of biological organisms in the soil will build up and the volume of straw will quickly appear to disappear post-harvest.
Good incorporation practice
If straw is not incorporated (mixed with soil) in advance of cultivation, you will end up with a sandwich of straw between each furrow.
This can act as a highway for slugs to move from the shelter of the soil to above ground to attack a new crop. This must be avoided as there is little point in adding cost to incorporation if it results in having even more costs in the following crops.
The simple principle behind incorporation is to mix the straw in with the soil. This does not mean that all the straw will be covered or incorporated post-cultivation. However, it will all have come in contact with soil during the mixing process and will at least be peppered with little bits of soil that contain thousands of microorganisms to begin straw breakdown.
But good incorporation will leave the majority of the straw and stubble in the soil but close to the surface where there is adequate oxygen to fuel the different organisms that will begin to break it down.
Machine options
Incorporation can be carried out using a disc or tine cultivator. One of the most important things for the initial incorporation is that it is done as shallow as possible, while loosening all the ground and ensuring there is enough loose soil to get a good mixing of straw and soil.
Working shallow helps avoid a problem later in the year if loose soil gets wet. Try to produce no more loose soil than the thickness of the lugs on your tractor tyres. Cultivating deeper during this first pass will produce more soil and although appearing to incorporate more of the straw, the risks associated with having too much loose soil outweigh the benefits of achieving higher incorporation.
It is generally regarded as good practice to travel at an angle to the direction of sowing when cultivating, to provide a more uniform mixing of the stubble.
Willie Corrigan, Kilkenny – Lemken Rubin disc cultivator
“In 2019, I made the move to a new Lemken Rubin 10 5m trailed disc cultivator. I went for the Rubin as I felt it was the most versatile disc harrow out there. I do a lot of grassland reseeding on hire alongside my own work so I needed a heavy disc with a large diameter for that, while I also wanted a machine which I could incorporate straw with and sow cover crops by mounting an air seeder. The Rubin ticked all the boxes for me.
Willie Corrigan uses a 5m trailed Lemken Rubin disc cultivator to incorporate straw.
“I run the machine on a John Deere 6195R and typically work it at 12-14km/h, which means I can get through around 10 acres/hour. I would describe the Rubin as being a ‘German tank’. The hydraulic depth control is a gift and Lemken offers great backup.
“I’ve been incorporating straw since 2019 and I can see a notable difference. I’m constantly learning but I can see that the ground is much healthier looking – it’s notably looser and there are more microorganisms active. When incorporating, I aim to disturb all of the soil, while only working the top two to three inches. I typically work at a different angle to the stubble. To be honest, I have worked both ways and can’t see a major difference.”
James Mulhall, Laois – Vaderstad Cultus tine cultivator
“We bought a new 3m Vaderstad Cultus tine cultivator last year. This was our first year chopping straw and we chopped 250 acres for the scheme. We also run a disc cultivator but decided to buy the tine cultivator for its versatility. Before sowing when conditions are right, we use the Cultus to break compaction on headlands, run it on the plough joints and the tramlines.
“We had found that compaction was beginning to affect production in the ground surrounding the tramlines. Once the field is combined, we would give the tramlines a relatively deep run (6-8in), followed by incorporating the straw.
James Mulhall uses a Vaderstad Cultus 300 3m tine cultivator to incorporate straw.
“When incorporating, we look for a nice tilth, aiming to disturb and mix the soil and straw, while not working below 3in. We run the machine on a John Deere 6155R and typically run it at 8-10km/h at the shallow depth. This allows us to get through over 50 acres/day. We actually travel in the same direction as the stubble. We have tried both ways but can’t see much of a difference.
“Although this is only our second year incorporating straw, we can see the differences already, particularly on one outfarm. The soil is much looser, and there are far more earthworms. Incorporation definitely has its benefits and the price of fertiliser has changed everything – I think there will be more straw incorporated as the years go on.”
Incorporation can be carried out using a disc or tine cultivator, but the objective is to get soil on to the straw and the stubble rather than covering all the straw with soil. One of the most important things for the initial incorporation is that it’s done as shallow as possible, while loosening all the ground and ensuring there is enough loose soil to get a good mixing of straw and soil.
There are a number of benefits in keeping the straw close to the surface. Oxygen is more available here for the microorganisms that break down the straw and earthworms can respond to the feast of food they find close to the surface by multiplying in numbers.
Additional nitrogen may be needed by the crop for the first year or two following incorporation.
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