One of the challenges that we face at Mindrum is ensuring that we retain enough grazing for our stock to rest our permanent grassland during the winter. Now that we have entered organic conversion, we also have the challenge of “breaking grass” as fields come out of a forage rotation into the arable phase without either plough or herbicide.
We are experimenting with an intercropping model for a number of our fields. Developing an Idea spearheaded by Andy Cato and wild farm grains, we are growing panels of spring wheat in a field of long term grass and clover. I hope this will enable us to take a crop of spring cereal (in this case wheat) from the field, taking advantage of the fertility and disease resistance associated with the old grass.
My aim is to have a cycle whereby we take a combination of spring cereals and hay/silage from these fields during the summer months, and grazing them during the winter. My intent is to use a combination of stock, cover crops and microbiology to both support fertility, and to create conditions for drilling subsequent crops. It is hoped that a combination of perennial grass and rotational panels will support a diverse soil food web within the fields, and that with carefully controlled stocking densities through the year, and the use of a direct drill, we can minimise the adverse affects of tillage.
The results of the first year were varied. It became clear that minimum tillage was not an effective way to terminate the more vigorous ryegrass ley and the resultant wheat did suffer somewhat from grass weed competition. This having been said the overall yield from the field was nearly twice what we would have expected from a conventional cropping model on this light land. Whilst the direct cereal yield was about 2/3 of that expected, the additional yield of Silage, Wrapped straw silage mix, and grazing has effectively doubled the margin from the field, this was further increased by lower inputs. As an added bonus, a significant haul of ryegrass and clover seed came off the seed dresser. Whilst this was not available as seed, due to plant breeders licencing restrictions, it has provided excellent wild bird seed.
In addition to the commercial margin we also noted a marked increase in insect life and resultant wildlife,particularly in the species we are monitoring (Skylarks, Grey Partridges, Fungi and Dung beetles). We will need more data to determine whether this was a one off or part of a significant change.
One thing that was also of potential interest was the fertility in the soil. When we sampled the fields we found that in some cases the nutrients in tissue samples exceeded the available nutrient in the soil. Whilst this is consistent with expectations associated with our focus on soil biology, it will take a few more years to build up a body of data to draw significant conclusions. We also conducted some Whole Soil Nutrient sampling (sampling those nutrients not currently in “plant available form” as well as available nutrients to assess whether nutrient cycling was taking place. Though we await more data, initial indications would suggest that unavailable nutrients are being converted into a plant available form.
We are now in the grazing / overwintering part of the cycle and are grazing some with Sheep and others with cattle so I will update this blog as the winter progresses. Once again, we will need to collect more data before drawing any firm conclusions, but at the moment, as we come into early December, things look (and smell!) very positive!