Case study: Insecticide-free arable farming

Author: Martin Lines
Farm: Papley Grove Farm, Cambridgeshire: 160 ha farmed in-house plus 360 ha contract farmed

(c) Martin Lines

Aims:

In 2013, my agronomist recommended that I spray for black bean aphid, but conditions were too wet and windy for a period of ten days, after which aphid numbers had dropped and ladybirds were eating them, so I decided not to spray and saw no detrimental impact on my gross margin. This got me thinking about the pros and cons of insecticide use, as insecticides were becoming less beneficial due to resistance and were taking out the beneficials that were doing the natural pest control. Prior to this, I had already stopped using Dursban to control Orange Wheat Blossom Midge (OWBM) about 15 years ago because of the damage I could see this did to the insect life as a whole in the field. Also, my experience of contract farming an area of organic farmland for ten years led me to realise that insecticides were not necessary for yields in this system: the reduced yield of the organic land seemed to be more down to crop nutrition and weed pressure than pests or diseases. So I took the decision to do everything I could to control pests without insecticides and monitor the impacts on my yields and profit margins.

I took advice from my Frontier agronomist, who is very understanding of where I am coming from and where I want to get to. I also get ideas from events and social media.

Management:

Prior to 2013, insecticide spray decisions were based on a combination of thresholds and convenience. As the products cost £1.60 / ha and the operation cost £5 or £6 / ha, I would occasionally add an insecticide to a fungicide or herbicide application if its use was likely to be necessary, to save the money of running two operations. After 2013, the convenience use of insecticides stopped and I monitored against thresholds for the first few years and did not find a single justifiable case to spray. There were anxious moments in the early years when I would see signs of Barley Yellow Dwarf Virus (BYDV) on small areas, but in experience this did not result in a net economic loss. Pest numbers seem to have been suppressed from exceeding thresholds from year one. Subsequently, I keep an eye out on forecasts and look for visible signs of an issue but am more relaxed that I have built up the resilience of my soil, crops and beneficials to have confidence that I may never need an insecticide again. I am not saying that I will never use them, but as yet, I have not had a need to. I occasionally see OWBM, but timing of control for these is so critical, and the use of a summer insecticide is so damaging that I have resisted the urge I would have previously had to resort to the can. Cabbage Stem Flea Beetle (CSFB) problems seem to occur whether I use insecticides or not and the way I look at it now is that the more you use the chemical, the greater the risk of resistance build up.

I have broadened the range of crops I grow. Previously, I stuck to a rigid two wheats, oilseed rape, one or two wheats, beans, all winter-sown, and the ratio of crops in the ground would be roughly 70% wheat, 20% oilseed rape, 10% beans. Now I have added winter and spring barley and have no fixed rotation, tailoring the cropping in each field to weed pressure and soil health. So, for example, if I have a black-grass problem then I will not go with a 2nd wheat, even though this gives a better return than a break crop. In general, I grow less wheat, more barley, less oilseed rape and more beans than previously. I now average about 40% wheat, 30% barley, 20% beans and 10% oilseed rape. The reduction in area of oilseed rape is more due to the challenges of dry August / September than issues with CSFB. On paper this would seem like a less profitable rotation, but in reality, I have slashed my cost of production, which has more than made up for loss of yields and crop values and my net profits have increased. Books also say that incorporation of spring crops to reduce black-grass levels results in a net loss in profits, but in reality, incorporation of the full range of Integrated Pest Management (IPM) techniques more than makes up for this through reducing costs of production.

Ladybird on winter beans (c) Martin Lines

I use pest resistant varieties where possible, but take decisions based on the best contracts that I can get, so this is not a major consideration. I have moved back towards traditional recommended cropping intervals, but this is a balance to have full IPM and maintaining a balanced rotation, so unlike virtually all farmers, I am moving back towards five to six years between oilseed rape crops.

I drill cereals after mid-October if weather allows, rather than September to reduce black-grass and autumn aphid pressure. I avoid over-feeding crops with nitrogen fertiliser in one application to prevent rapid growth, making the crop more prone to pest and disease pressure.

Making the habitats to enable the beneficial insects and spiders to thrive is key to the success of this system. I started off with flower-rich margins around the outside of the fields, and now have been adding flower-rich strips every 4th tramline (120m) to improve natural pest control and insect pollination. I am forever increasing my habitat areas voluntarily until my agri-environment agreements expire and allow me to top up the payments based on the areas I am taking out of production. I see the benefits of the in-field strips on the yield maps of my oilseed rape and beans, with yields being 5-20% greater next to the strip and tailing off further into the field: this also reflects my observation of the number of bumblebees I see across the fields. The yield response is probably a combination of the effects of increased insect pollination and increased natural pest control. I have not looked at whether the enhanced pest control next to the flower strips shows any benefits in my cereals yields yet.

Field margin in flower at Papley Grove Farm (c) Martin Lines

What area/% of cropped land is now out of production for AES / voluntary habitats compared with pre-2013?

I have around 9% on rented land and 12% at home. I also see increasing soil organic matter and, where soil structure allows, direct drilling of crops as measures that benefit the natural pest predators in providing a more functional soil ecosystem within which they can thrive. Many of the measures I have adopted in the transition to regenerative agriculture have multiple benefits, and it is difficult to tease out individual cause and effect impacts.

As well as stopping the use of insecticides, I have also cut down on the use of herbicides, fungicides and molluscicides. I put this down to improved soil health, crop health and better rotations – a consequence of the holistic regenerative agricultural system. I am conscious that pesticides as a whole do damage to the functional ecosystem that boost my yields, and I am looking to reduce use across the board. I monitor slug levels, but if I see lots of beetles in the field, I see if they can do the job first and only treat areas that seem to be struggling. I am not looking to eliminate slugs from the field, but keep them at manageable levels, whilst maintaining a thriving food chain for the beneficials.

This year, I have tried a few new ideas to further benefit from the IPM approach. I have sown a mix of wheat varieties in my wheat field to avoid the pest and disease risks that can arise from a single variety monoculture. I have also undersown my beans with clovers and tried intercropping my oilseed rape with phacelia and clovers to see if these measures will disguise the crop from pests and boost beneficial numbers further.

Achievements:

Overall, crop yields are a little lower, but I think this is more because of the switch to direct drilling than the loss of insecticides. The yield losses are more than made up for by the reduction in costs of production and the net margins are up, despite reducing the areas of wheat, our most profitable crop. Last year, cost of production of my wheat was c.£72 per tonne, about half of the average across my peers. Prior to 2013, profit margins had stagnated, but the trend is now definitely upwards. The total farm profit is so variable from year to year, it is not possible to put an average percentage figure on it yet. I do feel my business is more resilient to the market and weather pressures.

(c) Abi Bunker, RSPB

There are visibly more beneficial insects and spiders. I don’t know what they are, but the ground is alive with them. There is noticeably more wildlife overall, especially the birds. The incidence of pest levels exceeding economic thresholds has declined to zero. This was apparent from year one, but probably accrued over the first few years. Prior to 2013, I might spray a cereal crop with insecticides in the autumn against BYDV, at ear emergence and potentially again for OWBM. In oilseed rape, I would spray between two and four times in the autumn for CSFB.

I also believe there are benefits in this approach to my personal health, with fewer potentially harmful chemicals to deal with.

There is no blueprint to IPM and I feel it has to be a whole farm and landscape approach as it is not as easy as conventional farming with pesticides. Farmers need support through Knowledge Transfer platforms to help them to reduce pesticide use – this is not readily available beyond organic farming.

Case Study: Helping hedgehogs on farmland

Author: Nida Al-Fulaij, Grants Manager, People’s Trust for Endangered Species

Species: Hedgehog

Why is farmland important for this species?

Hedgehogs are found throughout the UK in all habitats. They have historically been associated with farmland for centuries. Hedgehogs are insectivores, foraging in fields and on grassland for worms, and along field margins and at the base of hedgerows for beetles, snails and other invertebrates. They are considered a generalist species, inhabiting most areas of our countryside, our villages and many areas of our towns too. However, as the dominant habitat in the UK, farmland is particularly important for hedgehogs.

Hedgehogs, like all animals, need to feed, hide from predators and find mates. A variety of habitats that provide foraging areas and secure nesting sites is ideal. Both arable and pasture land can support healthy hedgehog populations. Wide, species-rich hedgerows with buffers of grassy margins on either side provide safe ‘highways’ for hedgehogs to move around the landscape. Hedgerows with wide bases that are managed on rotation should have healthy invertebrate populations for hedgehogs to feed on. Old hedges with dense root systems and lots of deciduous leaves are ideal for them to use as nesting sites, both during the summer and in winter as hibernation spots.

The denser the network of hedges, the more securely hedgehogs can move around, and the higher the availability of prey species for them to feed on.

Recently ploughed fields can provide a bounty of earthworms and other prey; hedgehogs can be found in-field taking the opportunity to feed on invertebrates once crops have been harvested.

Recent studies show hedgehogs are found nearer to farm buildings. These areas could be providing safety from predators on farmland with less robust and fewer hedgerows, and larger fields.

Hedgehog (c) Ben Andrew (rspb-images.com)

Habitat management

Hedgerows:

Increasing hedgerow availability provides more nesting and foraging areas for hedgehogs. Ensure that hedgerows are species-rich, contain native trees and are as wide, high and dense as possible. Maintaining hedge bases at least 2m wide with minimal or no gaps provides secure safe nesting sites. Managing hedgerows on a 3 year rotation ensures that hedges remain diverse and robust.

Field margins:

Field margins provide buffer zones to protect hedgerow bases. 2m margins in arable fields and 3-6m margins in pasture ensures the hedges are protected from trampling and grazing, whilst the grassland provides extra invertebrate prey. Beetle banks also provide buffer zones and extra foraging areas.

Fields:

Smaller field sizes with a mixed crop provides greater variety, and therefore greater food security, for hedgehogs and other wildlife. Increasing hedges and field margins on farms with fewer, larger fields, provides habitat for hedgehogs. Reducing tillage or moving to no-till or conservation agriculture reduces soil compaction, increases soil invertebrates and improves and increases the depth and quality of the soil organic layer.

Pesticide & herbicide use:

Reducing pesticide and herbicide use means that more invertebrate prey, in particular earthworms, will be available on farmland for hedgehogs to feed on.

The above management measures recommended to provide a healthy landscape for hedgehogs are typically those associated with traditional farming practices. There should be no problems, though many of the measures may be more time-consuming than those associated with farming on a larger scale.

Hedgerow with grassy margin (c) Gethin Davies

Peoples Trust for Endangered Species (PTES) and British Hedgehog Preservation Society (BHPS) have created an advice note detailing management and stewardship options that will benefit not only hedgehogs but other wildlife too (see link below).

Benefits and costs

Creating and managing hedgerows sensitively has financial costs but there are stewardship options available; individual ones for the management regimes listed above are detailed in the attached advice note.

Managing a farm for a species such as a hedgehog involves looking at the farm as a whole. Unlike species that fly, such as butterflies, hedgehogs needs the entire landscape to be suitable in order to thrive. Consequently, many of the management techniques recommended to improve habitats for hedgehogs will also provide a healthier landscape. A denser proportion of hedges and associated smaller field sizes both help to reduce soil erosion. Reducing tillage improves soil organic matter and reduces soil compaction.

PTES guide - How to help rural hedgehogs

Case Study: Cultivated margins

 

Author: Nicholas Watts
Farm: Vine House Farm, Lincolnshire

Aims:

The aim was to create an insect-rich foraging habitat for farmland birds. I farm on fertile peat soils, so effective control of pernicious weeds is essential.

Management:

I started using this option 5 years ago. For the first four years, I cultivated annually in the spring. Blackgrass is hit by spring cultivations and the seed is short-lived, so successive spring cultivations along with lack of fertiliser have virtually eliminated it.

This year, I applied a herbicide in March to control grass weeds instead of cultivating. This has the advantages of providing seed food for birds through the ‘hungry gap’ (January – April inclusive), providing pollen and nectar throughout the spring, and I think that the plant diversity has increased as a result. It has taken me 4 or 5 years to get the margins to produce food in the lean time of year, because of the need for annual spring cultivations to get on top of the blackgrass. If someone has no blackgrass then an early spring food source can be produced in year two or three. In future, I may only cultivate in alternate years and use herbicide in the 2nd year.

Creeping thistle is a major concern with potatoes and sugar beet in the rotation, so I spot spray thistles with a knapsack sprayer. This has reduced the thistle numbers over time. I had to spot-spray some areas to remove couch and field bindweed with a boom sprayer at harvest time, when the annuals were dormant.

Achievements:

The floristic diversity of these margins is unparalleled by any other habitat on the farm. Plant species richness per margin varies from 55 to 70 species, almost an order of magnitude greater than my wild flower margins, and even more impressive compared with my grass margins, ditch banks and hedgerows.

In years when the spring cultivation is not required, it delivers pollen and nectar throughout the year as well as any sown mixture. Red dead-nettle feeds bumblebees in March and a progression of a wide range of flowers take over from then onwards. When spring cultivation is undertaken, these margins provide pollen and nectar from June onwards.

The full range of farmland birds forage for insects in these margins: grey partridges, linnets, reed buntings, corn buntings and even quail. Turtle doves are scarce on the farm now: common sense suggests that they should use them as a source of seed food too, but I have not been able to witness this. I now have ten times the density of linnets feeding on this farm compared with neighbouring farms. I put this down to the availability of seeds in these margins. I think that the accessibility to the ground in combination with the abundance of insects (and seeds in the case of linnets) provides the ideal conditions for foraging birds.

The combination of spring cultivations, use of selective herbicide and spot-spraying have effectively controlled all of the noxious weed problems. Uncropped cultivated margins are more work than grass margins, but less than some of the other arable options, such as wild bird seed mixtures.

http://www.vinehousefarm.co.uk

Case Study: Wild flower margins

Author: Nicholas Watts
Farm: Vine House Farm, Lincolnshire

Aims:

The aim was to boost insect food for farmland birds through the summer. The farm is on peat soils in the Lincolnshire Fens.

Management:

The first margins were established 15 years ago. A wild flower and grass mix was purchased from Emorsgate Seeds. The seed mixture was 20% wild flowers and 80% fine grasses. Wildflowers included yarrow, common knapweed, wild carrot, lady’s bedstraw, self-heal, meadow buttercup, common sorrel and red campion. In addition, some flowering plants that were not in the original seed mix have established from the seed bank.

We cut them for hay in early August, as we have a market for it. Cutting and removing is important to reduce the fertility and maintain the floristic diversity. In addition, I have applied a herbicide in the spring whenever I have considered that coarse grasses were becoming a problem in the previous summer. One margin was sprayed this year for the first time in 7 years. I also pull ragwort and spot-spray thistles with a knapsack sprayer.

Achievements:

Although the floristic diversity of the original mix has declined, they remain as diverse flower margins absolutely humming with insect life. Knapweed has not survived in some of the mixtures on the acid soils. Our 15-year-old margin still retains mallow, sorrel, wild carrot, buttercup, lady’s bedstraw and self-heal. Yarrow has remained particularly dominant. In one margin, we incorporated cowslip and betony, but these did not appear in the sward until 5 years and 8 years after sowing, respectively.

The range of birds that use them has disappointed me. They are used by skylarks, meadow pipits and linnets (which take the sorrel seeds), but apparently not by my corn buntings and other small passerines. It may be that they are too dense for them. As a result, I have tried uncropped cultivated margins as an alternative means of providing an insect-rich foraging habitat for birds.

I feel that they are a significantly better option for wildlife than the standard grass margins.

http://www.vinehousefarm.co.uk/

Contact Information

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