Farming For a Better Climate Newsletter - Summer 2021 (No. 22)
Soil Regenerative Agriculture Group - Update
Farm work has carried on uninterrupted for our group of five volunteer farmers who are looking at a range of soil regenerative agriculture practices and techniques.
Here we take a look at some of the activities across the group since our last newsletter. You can read more about the group on our here.
The benefits of bringing livestock into the arable rotation have been widely documented. Soil Regenerative Agriculture Group member Hugh Black at Backboath brought sheep onto the farm to graze cereals for a second winter.
January 2021 saw around 300 lambs arrive at Backboath. The lambs quickly transitioned onto the cereals and didn’t appear to be grazing margins or around poles where grass is present, instead concentrating on the crops themselves.
Analysis showed that the cereals were high in protein, so provided suitable forage for the lambs for several weeks. The sheep were removed as crops began to grow to prevent crop damage.
Hugh bought temporary electric fencing two years ago and operates a system where he fences two fields. This allows one field to be grazed and the second fence to be moved to the next location. Hugh finds that putting up and taking down fences isn’t as slow as he first thought, especially if he has a helper to pass him the posts!
The lower photo shows the line where Hugh had placed an electric fence. The crop nearest has been grazed, while the crop further away has not. Although the crop biomass has been reduced by the grazing, the wheat did not appear any further behind in terms of growth stage. Hugh is also working with another project which is looking at grazing cereals, so the crop will be further monitored for tiller numbers, biomass, and disease levels.
Fellow Soil Regenerative Agriculture Group member Ben Barron at Leifie Farms is also sold on the benefits of livestock in an arable rotation. Ben is looking to have cattle grazing around the entire farm at some point in the year to put some biology back into the soil. One option is to direct drill autumn sown crops earlier than under a plough based system and then graze the more advanced crops sometime between late autumn and spring to hold the crops back, remove diseased leaf material and provide a small amount of dung. Likewise grazing of cover crops or crop residues with an understory of clover after harvest could take place. The main challenge here is to have the infrastructure of fences and water troughs in place on an arable farm to enable this to take place easily .
Hugh trialled several cover crops and they appear to have performed well. Hugh's sheep grazed the cover crops between the cereal crops. The cover crops have provided a surprising amount of fodder for the 300 sheep that Hugh has had grazing all winter. In hindsight, Hugh says he could have brought in many more sheep, potentially double the number he has had this year. S uccess was primarily due to the early establishment of cover crops which allowed better covers to be grown. The cover crops analysed between 296 and 335g/kg DM of crude protein and 9.9 to 10.7 MJ/kg DM.
A number of the Soil Regenerative Agriculture Group have added beans (winter and spring) into their rotations, providing more crop diversity but have been challenged by the cold weather over the spring.
Why beans? Beans are a great break crop as they fix nitrogen, and provide a break from common cereal diseases. They are also relatively low cost to grow, requiring no nitrogen fertiliser and in most cases only one fungicide.
What are the challenges? Beans are commonly associated with a late harvest, and the group has combined them anywhere from September to December. They can also be difficult to establish as the seeds need planted very deep (3 to 5 inches) to prevent being eaten by birds. In terms of disease, chocolate spot is commonly found and can be treated with a fungicide such as azoxystrobin.
What do they yield? Hugh first grew spring beans in 2020, and they yielded 4.6t/ha dried weight. Hugh hopes that he can beat this yield this year and is growing both winter and spring beans to see which gross margin performs best.
We made a short video in late May with Hugh in his bean crop. You can see the progress on our YouTube channel here.
Protecting farm soils
With a wet and cold start to the year, crops were slow to emerge. Strong winds dried out Douglas Ruxtons soils at Moss-side of Esslie remarkably quickly. To try and combat this, Douglas rolled his spring sown crops twice at different angles to try and increase the soil contact in the hard and dry soils. Despite such strong winds, there was little dust blowing about at Moss-side of Esslie, showing that the lack of ultra-fine seedbeds can have a positive effect on soil loss through erosion.
The group have been carrying out some small scale on-farm trials looking at the foliar application of fertiliser, writes SAC Senior Consultant and Farm Facilitator for the group Zach Reilly
Foliar feeds aim to supply small amounts of nutrients in a targeted manner to potentially increase fertiliser use efficiency and tailor crop nutrition to growth within a season. It may also have the added benefit of reducing a farms carbon footprint by using less fertiliser, but does it really work? If so, just how much can we reduce fertiliser use by?
Building on 2020’s positive trial results carried out by the group which saw 100kg/ha nitrogen (N) applied to a range of arable crops, followed by a number of 5kg/ha applications of foliar N, the trial has been scaled up and expanded. With funding from the Loirston Charitable Trust, formal replicated trials featuring one spring barley and two winter wheat varieties have been set up at three sites. Six base rates of fertiliser have been applied to the crops to produce a full fertiliser N response curve. Two rates (100kg/ha and 150kg/ha for winter wheat, but lower for barley) will receive up to three applications of foliar N at 5kg/ha. Fertiliser uptake will be calculated by measuring the crops nitrogen content at harvest. This will allow the efficiency of fertiliser use to be compared between treatments. Trial Manager SRUCs Ian Bingham said “the design of the trials will allow us to quantify how much of the N supplied through the soil and leaf is captured by the crop and contributes to yield”. We will aim to update you on progress in the next newsletter, or keep up to date via our Facebook and Twitter page @SACFarm4Climate.
Reducing compaction risk
Managing compaction can be a large issue on arable farms. One of the ways that soil structure can be protected is by using flexion tyres. The carcase of these tyres flex, causing the machinery to have a larger contact area with the soil, reducing ground pressure. Very High Flexion tyres or VF tyres, can reduce ground pressure by up to 40%, meaning that a larger weight can be carried or that a lower ground pressure can be achieved compared to standard tyres.
As a rule of thumb, a high weight with a low pressure can create a small problem deep down, whereas a low weight with a high pressure creates a large problem near the surface. A target ground pressure of less than 10 psi should be aimed for, to ensure minimal crop loss. This is due to the fact that many roots can survive when exposed to a pressure between 7 and 9 psi. Soil Regenerative Agriculture group member James Hopkinson at Cloud Farming has been using VF tyres for a number of years. James says "Using flexible tyres allows us to look after our soils, we have found that alongside our reduced tillage regime, these tyres have improved water and root movement within the soil and the pore space is much better within the soil profile".
This article is abridged from Farming Scotland Magazine. You can read the original article here.
Also in this edition...
- Reducing on-farm emissions - if there was just one thing...
- New Farming for a Better Climate YouTube Channel
- Farming for a Better Climate library
- Sell or ‘sequester’ carbon on your farm?
- New Podcasts from Farming for a Better Climate
- Paddock or mob grazing?
- Integrating trees on your land
- Climate extremes - making your farm more resilient
- COP26 - coming to a city near you
- COP26 at a glance
- Working towards net-zero - where to begin?
- Further information and contact details