With the winter barley all but complete, the winter oat and oilseed rape harvest ongoing and winter wheat just started, this is a prime time to get stubble cultivation done.
Post-harvest stubble cultivation offers the opportunity to manage surface trash and enables the light mixing of surface material before primary cultivation or inversion in the autumn.
However, shallow surface cultivation offers one of the most important and effective tools for integrated pest management of grasses and other weeds in tillage fields.
Shallow cultivation can be an effective means of stubble management.
Shallow cultivation immediately after harvest helps stimulate weed seed germination, especially bromes, wild oats, blackgrass and volunteer cereals. The moisture which has fallen over the past week of two has been ideal to help these weed seeds to germinate.
The year of the grassweeds
2019 has been a bumper year for grass weeds. After what looked like good control in autumn and early spring, a late flush of germination meant grass weed pressure is as high as it has been in a long time.
Growers from all corners of the country have reported increased infestations of brome species, canary grass or wild oats in headlands, corners, patches or even entire fields. Perhaps the most worrying of all, however, is the continued spread of blackgrass around the country. Make no mistake about it, if left to continue, this weed will find its way on to your farm.
Weed seeds are spread in very many ways including your combine, baler, sprayer, the spreading of infested organic manures, soil or even by wildlife.
Each time a weed is allowed to germinate, grow and mature, then more seeds are deposited into your soil’s weed seed bank.
Post-harvest stubble cultivation offers you the opportunity to decrease the number of seeds in your seed bank
This seed bank contains thousands of seeds per square metre which can be found right the way throughout your cultivation profile.
Post-harvest stubble cultivation offers you the opportunity to decrease the number of seeds in your seed bank and help prevent new-season seeds from being deposited.
Never has getting a good strike on weed seeds to grow out your seed bank been more important.
Apart from the time and money involved, an incomplete kill on treated weeds is the fastest route to resistance development, putting more pressure on our ever-shrinking herbicide toolbox.
Method
Weeds emerge each year, but generally only from the top 2-5cm. This is your target cultivation zone. Once fields are cleared, they should be cultivated as soon as possible.
Growers tend to use angled discs of some form but shallow cultivation can also be achieved with tine cultivators. Growers generally cultivate at an angle to the direction of sowing.
Growers run cultivators at 2-5cm.
Cultivators with a press attached are desirable as good consolidation helps to maximise moisture retention and ensures good seed-to-soil contact for weed germination. Straw rakes are used on some farms in Ireland, although if the ground is particularly dry then it can be hard to achieve the desired tilth.
Following winter crops, where you are not establishing cover/catch crops, there should be opportunities to carry out two or possibly three cultivations before drilling. The ground is generally very dry and in great shape to handle traffic this year.
Finally, germinated seeds should be burned off prior to primary cultivation and drilling, especially if there is a lot of vegetation and non-inversion establishment.
Where ploughing, growers may be able to avoid spraying in the absence of a significant volume of weed biomass.
Where cover crops are to be sown, try and leave some time between stubble cultivation and cover crop establishment to give weed seeds the best chance of germinating.
Different approaches
Stubble cultivation should be managed differently depending on the previous crop. For example, oilseed rape stubbles should be left undisturbed for a number of weeks in order to allow for the most complete germination of shed seeds.
With oilseed seed being so fine, any significant burial could increase the chances of dormancy, leading to future volunteer problems.
Read more
Choosing the best cultivation system for your farm
With the winter barley all but complete, the winter oat and oilseed rape harvest ongoing and winter wheat just started, this is a prime time to get stubble cultivation done.
Post-harvest stubble cultivation offers the opportunity to manage surface trash and enables the light mixing of surface material before primary cultivation or inversion in the autumn.
However, shallow surface cultivation offers one of the most important and effective tools for integrated pest management of grasses and other weeds in tillage fields.
Shallow cultivation can be an effective means of stubble management.
Shallow cultivation immediately after harvest helps stimulate weed seed germination, especially bromes, wild oats, blackgrass and volunteer cereals. The moisture which has fallen over the past week of two has been ideal to help these weed seeds to germinate.
The year of the grassweeds
2019 has been a bumper year for grass weeds. After what looked like good control in autumn and early spring, a late flush of germination meant grass weed pressure is as high as it has been in a long time.
Growers from all corners of the country have reported increased infestations of brome species, canary grass or wild oats in headlands, corners, patches or even entire fields. Perhaps the most worrying of all, however, is the continued spread of blackgrass around the country. Make no mistake about it, if left to continue, this weed will find its way on to your farm.
Weed seeds are spread in very many ways including your combine, baler, sprayer, the spreading of infested organic manures, soil or even by wildlife.
Each time a weed is allowed to germinate, grow and mature, then more seeds are deposited into your soil’s weed seed bank.
Post-harvest stubble cultivation offers you the opportunity to decrease the number of seeds in your seed bank
This seed bank contains thousands of seeds per square metre which can be found right the way throughout your cultivation profile.
Post-harvest stubble cultivation offers you the opportunity to decrease the number of seeds in your seed bank and help prevent new-season seeds from being deposited.
Never has getting a good strike on weed seeds to grow out your seed bank been more important.
Apart from the time and money involved, an incomplete kill on treated weeds is the fastest route to resistance development, putting more pressure on our ever-shrinking herbicide toolbox.
Method
Weeds emerge each year, but generally only from the top 2-5cm. This is your target cultivation zone. Once fields are cleared, they should be cultivated as soon as possible.
Growers tend to use angled discs of some form but shallow cultivation can also be achieved with tine cultivators. Growers generally cultivate at an angle to the direction of sowing.
Growers run cultivators at 2-5cm.
Cultivators with a press attached are desirable as good consolidation helps to maximise moisture retention and ensures good seed-to-soil contact for weed germination. Straw rakes are used on some farms in Ireland, although if the ground is particularly dry then it can be hard to achieve the desired tilth.
Following winter crops, where you are not establishing cover/catch crops, there should be opportunities to carry out two or possibly three cultivations before drilling. The ground is generally very dry and in great shape to handle traffic this year.
Finally, germinated seeds should be burned off prior to primary cultivation and drilling, especially if there is a lot of vegetation and non-inversion establishment.
Where ploughing, growers may be able to avoid spraying in the absence of a significant volume of weed biomass.
Where cover crops are to be sown, try and leave some time between stubble cultivation and cover crop establishment to give weed seeds the best chance of germinating.
Different approaches
Stubble cultivation should be managed differently depending on the previous crop. For example, oilseed rape stubbles should be left undisturbed for a number of weeks in order to allow for the most complete germination of shed seeds.
With oilseed seed being so fine, any significant burial could increase the chances of dormancy, leading to future volunteer problems.
Read more
Choosing the best cultivation system for your farm
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