For farmers concerned about soil health and increasing establishment costs, strip-till drilling may offer the solution.
Alex Heath takes a look into the technique...
The appeal of strip-till drilling has numerous benefits for farmers, who are now reporting positive results from years of conservation field work.
The establishment method sees less than half of the field’s soil worked, with just the immediate area the seed will be planted in worked to produce a tilth.
Because of this, reduced fuel, labour, machine hours and wearing metal all contribute to offer farm savings, but the practice is more than just about saving money.
Increasing levels of organic matter, providing crops with nutrients, binding soils together, reducing erosion and run-off, as well as providing a habitat for beneficial micro fauna are all major benefits.
The soil within strip-tilled rows is also said to warm quicker and preserve more moisture than inversion and min-till practices, promoting germination and emergence.
However, a leap from conventional inversion tillage which many farms are comfortable with poses several questions and considerations, not least crop performance in the transformative years.
To get an idea of what farmers can expect during and after the change, we spoke to a pair of leading manufacturers and practitioners of this establishment method to gain their opinions on the current state and future thinking of strip-till drilling.
Jeff Claydon, founder of Claydon Drills, says the company has been engaged with strip-till seeding and the accompanying tillage techniques for the last 17 years on the family’s 340-hectare Suffolk farm.
Similarly, Mzuri’s trial farm manager Ben Knight says its Worcestershire farm is the test pad for all the products the company sells, as well as a resource for working out best practice when it comes to strip-till.
MR Claydon says environmental and agronomic benefits of the strip-till system are converse to full inversion cultivations and min-till systems which can over-work the soil and destroy its structure, adversely impacting worm populations and activity.
He says: “This reduces the soil’s ability to drain water away in wet weather and increases moisture losses in dry conditions.
“Starving the crop’s roots of essential air and nutrients also reduces yield potential and increases the cost-per-tonne of production, while the risks from flooding and soil erosion are substantially higher.”
Mr Knight is of the same opinion, adding: “After a few years of strip-tilling, the soil structure becomes more porous. This enables the infiltration of water through the soil profile, preventing the fast run-off of rain which contributes to flash flooding, as well as the removal of soil, nitrates and residual chemistry which pollute waterways.”
From experience, by not exposing organic matter to the air and risking oxidisation, Mr Claydon says soil drains more freely in wet weather yet retains moisture in dry conditions and a healthy, well-structured soil promotes worm populations, supposedly eliminating many of the risks involved in producing crops.
Likewise, crop rooting structures are much stronger, resulting in better crops which are better able to utilise inputs more effectively and are more resistant to drought.
Mr Knight also points out a wider environmental advantage, by continuously growing a crop and seeding in between the row, it enables the return of carbon to the soil, building its organic matter and helping build a more resilient soil.
Also, by placing fertiliser in a band beneath the seed it receives nutrition as soon as its able to process it and is less prone to being wasted through volatilisation or beyond the cropped area as can happen when broadcast.
THINGS TO CONSIDER
AGRONOMIC concerns such as slug and weed pressure can be dealt with using a combination of cultural and chemical methods.
A particularly versatile tool in both manufacturers’ repertoire is the straw harrow, which can be used to produce a shallow micro tilth up to 30mm deep, destroy slugs and slug eggs and encourage volunteers and weeds to chit, before taking them out with a second pass of the harrow.
While the Claydon Straw Harrow uses tines exclusively in working widths up to 15 metres, the 7.5m-wide Mzuri Rezult has a set of leading discs which cut into the top few millimetres of soil, chopping trash and incorporating chemical residue.
With the absence of metaldehyde in future years and ongoing concerns over glyphosate license renewals, mechanical means will become important, says Mr Claydon.
A case of two birds one stone, raking out and destroying weeds at the cotyledon and one-leaf stage, removes the slugs’ food source. It also breaks up slug nests and desiccates their eggs by mixing up and exposing damp straw and chaff to sunlight.
Mr Knight says that in addition to producing a false seedbed for weeds is an economical way of reducing herbicide inputs.
Mr Claydon reckons two passes of the straw harrow is the cost equivalent of one pass with glyphosate, with up to 200 hectares being able to be covered per day with its 15m set.
Now, the advice is to only use glyphosate if needed immediately before drilling.
Mr Knight says the trial farm has been experimenting with not using glyphosate, with one field in its third season without weed killer.
He says: “This was sown on an east to west axis to maximise interrow shading to limit a weeds access to sunlight. Interrow hoeing is an option but as of yet we have not required it.”
An increasing list of companies are also starting to launch mechanical weeders of the same ilk, with narrow set tines including Horsch with its Cura ST with working widths up to 15m, and Treffler which now spans 24m.
Many are also developing interrow harrows with varying levels of complexity, including Claydon with its TerraBlade, providing low running cost, mechanical methods of controlling weeds in combinable, band-sown crops.
“It is an additional weapon in our weed control armoury at a time when the efficacy of some herbicides is decreasing and their cost increasing,” Mr Claydon adds.
Where rolling works to control slugs in conventional systems, Mr Knightsays the coulter press wheels on the Mzuri drill can be set to apply a maximum of 180kg of downforce on to each row consolidating the seed bed and ensuring sound soil to seed contact.
“Dependent on the crop we use Cambridge rolls with a leading paddle to leave a level finish to ensure maximum effectiveness of our pre-emergence herbicide,” he adds.
However, Mr Claydon says using press wheels on the drill or rolling separately immediately after drilling, particularly on heavy soils which are wet, can push the air out of the tilth created by the tine and cause soil particles to stick together, creating a cloddy finish.
“Let the soil ‘haze over’ for 24-48 hours after drilling and then rolling or harrowing to level,” he advises.
COST OF ESTABLISHMENT
THE cost of establishment is often one of the main reasons for looking at alternative systems, with farmers often quoting the mantra ‘we cannot control the grain, fuel or fertiliser price, but we can control how we put the seed in the ground’.
Of the trial farm, Mr Knight says: “We run our Pro-Til 3T drill for £55/hectare, as we are on heavy Lias clay. The conventional system that we used in the past including the plough would be more than £200/ha.”
Likewise, due to the few soil engaging components, Mr Claydon says the cost of wearing metal is also low, at just £3 to £4/ha.
“As the soil becomes healthier and in better condition the amount of power required to work it and cost of wearing metal continues to decline,” he says.
Fuel use is also lower, according to Mr Claydon.
“Instead of using 150 to 180 litres of fuel/ha to establish a crop using a plough-based system, with strip-till we use 10 to 15 litres/ha [averaging 12 litres/ha], which includes stubble management and drilling,” he says.
“The savings made at establishment allows farms to invest more in other inputs and other areas of the farm that contribute to make a difference.”
Mr Claydon says power requirement for the company’s Hybrid drills are 50hp per metre, resulting in a high output, low fuel use system.
He uses his farm as an example, where a 300hp tractor is used to pull a 6m drill, clocking up fewer than 100 hours per year to establish 340ha of crops, which gives the farm time to carry out contract drilling.
Mr Knight adds that every year the Mzuri Pro-Til drill, which initially needs about 60hp per metre, is used, power requirement decreases due to an increase in soil biology and better aerated soils.
An increase in on farm technology is also starting to merge different practices, with modern sprayers operating on GPS maintaining tramlines in the same place each year, which can be seen as a modern form of controlled traffic farming, says Mr Claydon.
Targeted cultivations ensure soil density is retained over at least 50 per cent of the field, supporting field traffic, with tramline depths kept to a minimum.
He says in compacted areas, the company’s patented leading tine has a breakout force of 600kg, which cultivates zonally, alleviating local compaction.
Mr Knight and the Mzuri trial farm have gone in a different direction.
“On the trial farm we utilise RTK and alternate our approach,” he says.
“For OSR and cover sowing in August, when temperatures are usually high and when combined with wind lead to harsh, drying conditions we interrow drill these crops between wheat stubble left between 150 and 250mm high, which helps create a microclimate that is kind to tender young plants.
“For the remainder of our rotation we sow at 30-degrees to the tramline, alternating each year. This leaves us with permanent tramlines which travel well throughout the year.”