The combination of an early harvest in many parts of the UK followed by generally warm, moist weather has provided textbook conditions for an extended stubble management programme to combat weeds, pests and diseases. But it must be done correctly to maximise its effectiveness and derive the full benefits, emphasises arable farmer and engineer Jeff Claydon.
“Effective stubble management is a cornerstone of any efficient, sustainable, profitable crop production system, regardless of which method of establishment is used. But to deliver best results it must be done correctly,” emphasises Jeff Claydon, who pioneered the development and use of direct strip seeding.
“The farming industry’s use of agrochemicals is coming under increasing public scrutiny, the number of products is reducing, while those that remain are becoming more expensive and less effective. To help preserve access to the critical chemistry which all of us need to farm efficiently we must increase our use of mechanical and cultural methods to control weeds, pests and diseases rather than relying on agrochemicals to do the job. The key is to identify the optimum combination of techniques to use, which will differ from season to season, farm to farm and field to field.
According to the Farm Business Survey, the Top 25% of arable farms spend 32% less than average on labour and 28% less on machinery per £100 of turnover, but invest almost twice as much in their businesses (£310/ha) to maximise efficiency. This includes utilising the latest products, techniques and equipment to get the job done efficiently.
On the Claydon family farm we have achieved massive cost savings, agronomic advantages and environmental benefits from 15 years’ use of the Claydon Opti-Till System, a combination of stubble management techniques and direct strip seeding. The cost of establishing combinable crops is now just £51/ha compared with £300/ha were a traditional plough-based system to still be used. During that time yields have also increased progressively, by more than 1t/ha in the case of wheat.
A key part of using the technique successfully is to achieve an optimum tilth as soon as possible after harvest so that volunteers and weeds seeds can germinate, but without moving too much soil. The conventional min-till approach is not suitable because moving 100mm-125mm of soil will significantly slow germination or even bury weed/volunteer seeds so deep that they do not germinate until after the crop emerges, which creates major cost and control issues. Deeper cultivations also present a significant weather risk, as heavy rain will reduce the soil to a sticky mess with no structure or ability to support following machinery.
When it comes to stubble management the ‘little and often’ approach is best, the key being to achieve rapid germination of weeds/volunteers so that they can be killed using mechanical or chemical methods. Where we must use a product such as glyphosate we will only do so under conditions which allow it to work most efficiently and apply it at full rate to reduce the risk of resistance developing.
The aim is to leave a maximum of 150mm of stubble, chop the straw short and spread it evenly, because slugs will proliferate where it lies thick or in piles. Immediately after combining we go in with a 15m-wide Claydon Straw Harrow, which performs three main functions: trash and residue management, slug control and encouraging weeds and volunteers to germinate.
Its 120 pairs of 16mm flexible steel tines shatter the top 10-30mm of soil, just enough to create a fine tilth. Operating at 15 – 25kmh behind a 300hp tractor, this implement will cover 20ha per hour, using just 1 litre of diesel per hectare, making it so fast and cheap to use that we repeat the operation every 7 to 14 days when conditions are favourable. So little soil is moved that if the weather does turn wet this mini-tilth will dry out quickly and allow us to carry out another pass with the Straw Harrow or drill the following crop with a 6m Claydon Hybrid.
Even if you cannot see any green shoots on the surface, weeds and volunteers will be growing under the straw. Using the Straw Harrow when they are less than 20mm tall will kill 70% of them, so repeating this several times will dramatically reduce weed and slug populations. This autumn I have seen very few slugs and it is unlikely that we will need to apply any slug pellets on the farm.
The Straw Harrow works well on most farms, but harder clay-based soils may require something a little more aggressive, which is where the Claydon TerraStar comes into its own. This simple, low cost 6m shallow cultivator is fitted with 68 cross-blade rotors which move slightly more soil than a Straw Harrow but much less than normal tine cultivators or disc-type implements.
The soil structure is left intact as the TerraStar plucks 80x80mm divots from the top layer of soil leaving the profile undisturbed. These divots are created by rotating “star” points fitted in a 200mm grid pattern to two knife bars on each side of the machine. This fine tilth contains a high level of humidity which encourages volunteers and grass weeds to germinate very quickly, the field is levelled and the soil surface is left largely intact to carry machines, while water will drain away quickly from the surface layer.
The shallow tilth can then be moved by the Claydon Straw Harrow, breaking off germinating plants at the one-leaf stage and eliminating the need to spray while ground conditions allow harrowing. Any regrowth can be taken out with the Claydon TerraBlade inter-row hoe in late autumn and spring when conditions are favourable.
Ignoring weeds, volunteers and slugs does not make them go away – you must create the right conditions to make them grow and then kill them so that they cannot return, making effective stubble management essential.
Some people will question the need to go over stubbles multiple times, but each operation is extremely fast and very cheap. The cost is certainly much less than relying entirely on glyphosate and multiple dressings of slug pellets, as well as being much more effective, more acceptable to the local community and politicians and, crucially, more sustainable for the long-term.”
Picture Caption:
“Farmers will have to further reduce production costs by using techniques such as strip seeding, in combination with a greater use of mechanical and cultural methods to control weeds, pests and diseases. Ignoring weeds, volunteers and slugs does not make them go away, so it is essential to make them grow and kill them so that they cannot return,” says Jeff Claydon, who is pictured on his Suffolk farm with a Claydon TerraStar which is used as part of a carefully-planned stubble management programme.
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