With Spring drilling becoming an increasingly attractive option for growers looking to control weeds, adding another string to their rotational bow, cover crops need to perform – and rightly so.
They’ve become something of a hot topic recently, and I was keen to try out my own experiments as to which varieties work best. I wanted to focus on speed of germination, resilience, over winter ground cover and their ability to die off in the spring. All too often I hear people talk about cover varieties that don’t get started soon enough, and when they do, they struggle to stop them!
On farm we chose, four different cover crop varieties comprising of Stubble Turnips & Forage Rape, Ryegrass & Vetch, Mustard and our usual Radish Mix.
As a popular choice with mixed farms, we included stubble turnips into our trial to test its suitability and viability as a cover crop. This mix is known for its speed of establishment and winter hardiness, making it popular for grazing fattening lambs after Christmas.
To make the most of the trial, we intend to graze the turnips in due course. It has also been noted that sheep grazed on turnips on top of last year’s straw stubble experience less foot rot and lameness as a result of standing on the straw rather than bare soil. This is something which we will try to observe on our own trials.
So Far… After emergence, we experienced pale edges to some of the seedling leaves. We believe this may have been caused by chemical overlap in the pikings from the previous crop’s treatments. It didn’t stop the turnips but it is something to watch out for in the future.
This is another popular cover crop mix which over winters well, suppresses weeds and fixes Nitrogen. The vetch has an extended growing period and provides a source of Nitrogen fixation, at temperatures lower than other legumes. This, along with the Rye that establishes quickly, matures later and scavenges nitrogen, whilst preventing leaching over winter.
So Far… I’m not overly impressed with this mix on first observations. It hasn’t covered the ground as well as its neighbours but time will tell if it is worth the wait.
This mix is renowned for its speedy establishment and weed suppression. Brown Mustard can have a biofumigation effect as a result of the Glucosinolate content which can reduce Wireworm incidences when chopped and incorporated into the soil at flowering. Mustard is also said to suppress grass weeds which is an attractive prospect in a strip tillage set-up.
White Mustard represents and inexpensive, vigorous and versatile cover crop that matures late. Fast establishment means good levels of ground cover although unlike Brown Mustard, White Mustard isn’t frost resistant.
So Far… This has been very quick to get going and was easy to establish which I’m impressed with. I’m interested in Mustard’s ability to suppress grass weeds which is the main weed pressure in a strip tillage system.
Tillage radish is responsible for scavenging nitrogen from the soil along with breaking any compaction, suppressing weeds and controlling nematodes. Large tubers and an aggressive tap root benefits soil structure and quick germination makes for good soil coverage.
So Far… This mix has also been quick to get going and an easy crop to establish, part of the reason we use it as our standard cover crop variety across the farm. Another benefit of Radish is we know it dies back well in January, which is possibly just as important as it starting well!
Seed for these trials were sourced from Green Farm Seeds. A special thanks to Mark and his team for sharing their knowledge of the varieties characteristics.
Keep your eyes peeled for our next instalment!