Arable Monitor Farms in the North: yields, soils, worms, cover crops and moths
The summer meetings started with the launch of the new Warrington Monitor Farm at the beginning of June. Attendees were able to hear a very open account from monitor farmer Robert Cross describing current rotations and practices on the farm near Grappenhall where Robert farms in partnership with his father. The farm tour included the opportunity to view all but one of the crops in the rotation: oats, barley, wheat and spring beans. This year the oilseed rape is on an outlying block of land several miles away – you can see it from the M6 near Knutsford. Robert is keen to look further into how to overcome the yield barriers in the break crops he grows, particularly oats and oilseed rape, and this will be an important feature in further meetings in the Monitor Farm programme. Other plans for further meetings include what variety ratings actually mean, eg. in terms of fungicide use and also precision farming.
Two of the established monitor farms focused on different aspects of soils this summer. At Driffield we looked at soil biology, what lives in the soil and how we can keep it healthy. Monitor Farmer Phil Meadley has been trying to improve soil health by increasing organic matter levels, and this year has started to apply digestate supplied by a nearby anaerobic digestion plant.
Professor Karl Ritz from the University of Nottingham supplied us with some fascinating statistics on soil life. Below ground there are 5t/ha of living things and a handful of soil contains 100 trillion bacteria made up of 10,000 different types. We might think of them as insignificant because we can’t see them but they play an important role in the soil food web and so to crop production.
Add in the earthworms and it becomes even more interesting. Did you know there are three different types, each with a different role? Some live on the surface, some burrow down and produce casts, and some live in the soil. Large quantities of soil pass through worms – in the case of the burrowing ones, this can be up to 30 times their body weight in a day. I think this explains why a healthy worm population can incorporate organic matter into the soil so quickly.
According to Karl, research has shown that the presence of worms leads to a 25% increase in crop yield. This suggests it pays to look after your worms.
Both Karl Ritz at Driffield, and Philip Wright at the Berwick Monitor Farm meeting, emphasised the importance of soil porosity. Soils need a mixture of pore sizes because this allows soil to hold more water. Karl showed X-ray photographs that indicated an interesting difference between ploughed and zero-till soils: in ploughed soil the water was held in large pores whereas in no-till soil it was held in tiny micropores. Philip stressed the importance of good porosity in relation to rainfall.
In a good soil you need 4 inches of soil depth to hold an inch of rain whereas a compacted soil would need 10 inches. In the Berwick meeting we looked further at how to reduce the risk of compaction by reducing axle loads and tyre pressures. Reducing tyre pressures not only reduces compaction but can also lower costs through substantial savings in fuel use. We will be coming back to this hugely important area in the first meeting of the winter programme at Berwick, on 10 November, when Philip will be making a return visit.
Richard Reed, the monitor farmer at Berwick, is adopting partial controlled traffic farming in order to reduce soil compaction, and it will be very interesting to hear how the first harvest on CTF has gone.
During the Berwick meeting there was the opportunity to assess the soil under a crop of spring barley that followed black oats grown as a cover crop. There were plenty of residues in the soil, rooting was good, and the soil was not resistant to a knife pushed through it. Richard is planning to grow some again.
The subject of cover crops is always an interesting subject for discussion. Are they worth growing and do any benefits outweigh the costs? As well as at Berwick, the Monitor Farms at Driffield and York are also growing cover crops. At Berwick and Driffield we will be looking at these in more detail in the winter meetings (Driffield, November and Berwick in December).
During the summer meeting at York the group had the opportunity to view a cover crop mix of black oat, phacelia, berseem clover, buckwheat and a brassica. This had been sown in early May following the loss of the wheat crop to flooding. This farm seems to have more than its fair share of slugs, which have proved difficult to control, and the cover crop had suffered significant damage.
But monitor farmer David Blacker was even more concerned about the large numbers of diamond-back moths infesting the brassica. The plan had been to follow the cover crop with oilseed rape but this was now in doubt. When I got home, a quick look in the AHDB Encyclopaedia of pests and natural enemies in field crops confirmed that a change of plan was a good idea. It is the larvae that do the damage – they can eat most of the leaf area, destroy whole leaves, and a serious infestation can affect every single plant.
Another focus of the York meeting was disease control in wheat. Jonathan Blake of ADAS discussed the opportunities available to cut costs without compromising yields. To spray or not to spray? Low disease situations offered scope for reducing the number of sprays. Jonathan posed the question – is T0 effective and could it be missed out? Evidence from some trials indicates it doesn’t achieve anything. But it depends what you are dealing with. In years when there is little yellow rust you could get away with it.
This indicates the importance of assessing the crop for disease and considering why you are applying the T0 spray. The group were shown a crop of Grafton which had received a full fungicide programme and looked very clean. The effectiveness of the spraying was indicated by a small strip of yellow rust at one side of the crop where the sprayer had missed.
Another clear message was the importance of choosing resistant varieties and taking into consideration the different performance of varieties in different regions.
Monitor farm meetings are open to everyone. If you are interested in finding out more about the monitor farm(s) in your area, visit the website, where you will also find details of upcoming meetings. Alternatively you can contact me at firstname.lastname@example.org.