No one can be unaware of the current interest (dare I say obsession) in establishing multi-species and clover-rich swards across our farming systems.
I jokingly tell everyone that I’ve been managing multi-species swards for decades now, with grass and clover competing alongside thistles, nettles, docks, and buttercups. But perhaps that isn’t what they mean by a diversity of species.
I haven’t ventured down this road just yet, and any accusations that I am dragging my heels would be entirely justified because I am a bit wary of potential pitfalls, especially regarding long-term weed control, and my ability to maintain clover on a consistent level.
I don’t know if it has something to do with my management techniques, or whether certain soil types are less favourable, but over a 15-year period my success rate with clover has been mediocre at best.
I could take you to one or two fields with splendid displays of white clover. When they were reseeded, I probably added double quantities of clover seed to the mixture, and indeed this led to high establishment rates.
If I then check the soil analysis, pH levels will be over 6, with high index figures for phosphorus (P) and potassium (K).
I could then talk at length about the importance of clover in the sward, and how I was hoping to eventually rename the farm ‘Cloverhill Meadow’ or some similar load of tripe.
Devoid
But equally, I could take you to another field on the farm, reseeded successfully four years ago with an even more impressive CV for soil analysis, and this field now appears completely devoid of clover on any level.
Even worse, it has a healthy crop of nettles, thistles, and docks spread across it. This field has been variously cut for silage, and grazed with sheep, lambs, and young cattle. I’ve no idea what I did wrong, but the clover is nowhere to be found, despite holding off with the herbicide. There’s thanks for you.
Thistle
The biggest trade-off in the whole debate is between creeping thistle and clover.
With no worthwhile clover-safe herbicides currently available, our options are either to use low rates of MCPA (which will seriously set back the clover and temporarily stunt the thistles) or go with one of the triclopyr/clopyralid combinations, which will offer real control of thistles, but will decimate the clover.
Of course, we can simply run the topper over the thistles, but this offers no more than visual satisfaction for a few weeks. I do occasionally wonder what will happen to overall weed seed numbers in the soil after multi-species swards have been used for a few years, without the use of herbicide.
Advice
I wish I could find consistency in this equation because then at least I could see where I was going wrong (or right). Against best advice I have wintered ewes on heavy fields, and not found this to be detrimental to clover persistence the following season.
The same applies to silage cutting. Some opinions suggest this to be harmful to clover content of the sward, but I cannot point the finger of blame in either direction.
In some cases, I might say it had reduced clover percentages; in others it appears to have enhanced the clover canopy in the regrowth.
I suspect that lowering stocking densities (and therefore nitrogen levels) will be beneficial, but very few of the current advisory sources are emphasising this (at least, not publicly). Maybe that line would be counterproductive and wouldn’t prove popular among farmers?
On this farm, cattle are probably the reason that some level of success with clover is reached.
I can alternate most of my pasture between cattle and sheep, and I find their grazing style is much more clover-friendly than the persistent, tight nibbling of the ewes and lambs.
Having genuinely tried to establish and maintain clover through various methods and techniques, I still struggle to see how a heavily stocked, sheep-only system, can persistently achieve clover-rich swards.
But then, as my lack of grassland knowledge proves, what would I know?