August 2020 Update from Leitfie

At Leitfie Farms, Ben has had a busy season with a number of on-farm trials. He is currently waiting to see how his crops have performed and harvest is just around the corner! This is the August 2020 update from Leitfie Farms.

Varieties and Species

Maturing winter wheat at Leithfie, a mix of three varieties. The photo shows a golden crop with fully filled ears of wheat.

Within the Regen Ag group, there are numerous trials mixing plant species together, including growing beans with wheat, beans with OSR and clover with wheat. Although Ben has been experimenting with beans and winter wheat, he has also been using mixes of varieties. This year Ben established a 3-way mix of OSR and a 3-way mix of winter wheat (photo on the right). Choosing to grow Istabraq, Spotlight and Sundance together, Ben hopes to reduce disease pressure. For the coming season, Ben plans to enhance this mix adding in a fourth variety to promote the benefits he is already seeing.

The James Hutton Institute (JHI) has also been looking into varietal mixes at their trial site near Dundee. They state that mixes of many varieties can be used to partially control pathogens and JHI recommend that mixing the varieties in patches is most effective. This cultural method of disease control trialled by Ben will hopefully allow him to continue to reduce his pesticide applications in the future and increase his resilience to extreme weather events.

Fertiliser Reductions

Right at the start of this project, Ben set out to reduce his artificial fertiliser use while maintaining yields. Experimenting with foliar applications, this year Ben has reduced his nitrogen use across all of his crops with significant reductions on the winter crops. Ben has applied 100kg/ha N to the soil across all of his crops and has then opted to apply a top dressing by foliar application. Using 5kg/ha N per application, Ben has applied one application to his spring barley, two applications to his winter wheat, and three applications to his winter barley. Foliar applications can increase nitrogen use efficiency and some studies suggest that 1kg/ha N applied in a foliar fashion is equivalent to 3 or 4 kg/ha N applied as a granule. Managing nitrogen throughout the season has been more time consuming for Ben as he has regularly compared old and new plant leaves to check if the plant is deficient, only applying fertiliser when he thinks it is required. However, this additional time requirement is a small price to pay if it can save money on fertiliser and reduce his carbon footprint. Alongside reductions in nitrogen applications, Ben has reduced his phosphate and potash use in recent years, however, following soil analysis Ben has realised that he has reduced these applications a little too far and will apply an additional 500kg/ha of fibrophos once in his rotation to compensate for the offtakes.

Maximising Fallow

A field of sunflowers in bloom grown as part of the wild bird seed mix at Leitfie. There are trees in full leaf growing around the perimeter of the field and there is a field of golden wheat visible in the top right hand corner of the photo.
In Bens opinion, leaving ground bare for EFA fallow is one of the worst things you can do for soil health. Regenerative Agriculture principles suggest that a living root should be maintained in the soils at all times. However, EFA rules state that you can only establish a wild bird seed mix, or a wildflower mix within the closed period. As these two options are the only legitimate choices for EFA Fallow, Ben has sown an EFA Wild Bird Seed mix in his fallow field, to ensure the soil biology is fed all year round. This option does not have prescriptive species so

Ben chose a mix that would have the maximum benefit to his soil and the surrounding wildlife. He decided to sow sunflowers, beans, peas, linseed and fodder beet and will spray this crop off before directly establishing winter oats into the standing crop. Having watched the mix grow, Ben said: “It was slow to get going, but once it started it really took off. I think for next year I will increase the sunflower seed rate a little”.

Spring crop fungicide trial

Reducing pesticide applications is another way Ben is moving away from conventional agriculture. Ben has observed that the disease pressure in his cereals following cereals is much higher than cereals which have followed a break crop. This has led Ben to think that instead of many chemical applications he simply needs to ensure he has a long and diverse crop rotation. Basing his current cropping around a nine-year cycle, Ben hopes to reduce weed, pest and disease pressure allowing him to cut back his chemical use.

Promoting Weed Germination

Ben is also struggling to justify the cost of winter cover crops and instead has decided to focus his efforts on utilising his fallow as highlighted above and

using nature to establish a cover crop for him. Ben is planning to purchase a straw rake or set of black-grass harrows to create a small tilth after harvest, promoting a flush of weeds. This will reduce the weed build up in his cash crops and will also provide some ground cover for the winter. Ben will then spray this flush of weeds off before sowing, reducing his use of selective herbicides in the crop. Ben says, “I think the rake or harrows will be an essential management tool to control weeds as we reduce our chemical use”. Additionally, Ben is starting to notice a natural tilth underneath his crops, this is a result of several years non-inversion tillage which will also create the ideal conditions to promote seedling growth.

(Photos below left – winter barley stubble provides ideal conditions to promote weed & volunteer germination; right – the natural tilth under spring barely following OSR showing there is only a small amount of trass left on the surface – indicating active soil biology.)

Photo on left shows winter barley stubble ground at Leitfie, ideal conditions to promote weed and volunteer germination
Photo on right shows a natural tilth under spring barley at Leitfie. The crops is following OSR and there is only a small amount of trash left on the surface, a sign of active soil biology