It is of paramount importance that young horses get a lot of exercise and a balanced diet. They get that in the field, their natural habitat. But what does the ideal meadow look like? We put this question to Marcel Vossen (74) from Het Pajottenland, a bio engineer who dedicated his life to meadows. Vossen is a former director of Het Agentschap Natuur & Bos (Nature & Forest Agency , ed.) and as an engineer has conducted countless tests with grass species along public roads, in large grass areas, parcs and borders. He also used that knowledge for his own fields. You see, Marcel also happens to be a breeder of the Brabant draught horse and Warmbloods.
Marcel Vossen wastes no time in making clear what the difference is between meadows for cows and for horses: ‘Cow meadows are an ingredient of intensive cattle farming. Those fields are treated with slurry (liquid manure) and hence contain lots of nitrogen and phosphorus, which is disastrous for young horses. I even go as far as calling it poisonous. That soil then contains too many proteins and sugars. If you allow young horses to graze on such fields they will become too heavy in proportion to their young skeleton and we are all familiar with the kind of problems that causes for their growing process. For cattle that is a different story because they immediately convert the ingested energy into the production of milk. For that reason cattle fields are heavily fertilised, but that is not something you should do when horses are turned out in the field. I am opposed to using slurry. That is absolutely bad for horse meadows. It’s okay to do it once every three years or so, but then you have to make hay first before the horses can graze it. With the hay harvest most substances from the liquid manure disappear so it is less of a problem when the field is grazed by horses afterwards. I am greatly in favour of a balanced fertilisation regime. In concrete terms you have to work towards a good balance between the elements N-P-K: nitrogen, phosphate and potassium. That is the basis. Also interesting would be to fertilise with calcium cyanamide every two to three years because that targets a number of herbs as well as the worms that emerge from the droppings. The worms are killed by the calcium cyanamide. Make sure not to fertilise too heavily, the maximum is 400 to 500 kg/hectare. Calcium cyanamide also contains nitrogen, but in a proportion that is beneficial for grass growth.’
If you want a good field for horses it all starts with soil analysis. Numbers tell the tale, the engineer tells us: ‘Soil analysis doesn’t cost money and is the basis for everything. Existing elements such as phosphate, potassium, magnesium, iron and so on have to blend together and that requires correct proportions. I won’t bother you with technical details and correct values. The soil analysis will do that for you. These data will help with field management. The pH value or acidity is the basis. And calcium for instance can reduce acidity of the soil. Soil analysis can help to make adjustments and if necessary add elements. That produces the perfect proportion between nitrogen, phosphate and potassium. The soil must also contain trace elements such as magnesium and iron. Horses ingest those nutrients via the grass and the grass gains the nutrients from the soil.
For the ideal meadow little nitrogen should be used and if you do use it then use it for haymaking. Grazing after haymaking is fine because by then the nitrogen has largely disappeared. And it’s okay to leave a few herbs to grow in the field so that these trace elements are also included in the diet. Take care acidity levels do not rise too high in the field. A pH value somewhere between 6.5 and 7 is ideal. Fertilisation is done in the spring, depending on temperatures which should be at least 6°. Grass won’t grow when temperatures are too low and then don’t absorb the fertiliser.’
For loamy soils it suffices to carry out soil analysis every ten years, according to Vossen. Fields situated on sandy soils should be checked about every five years.
Vossen keeps reiterating: numbers tell the tale, After all, you cannot see it, he argues. Although, we understand that his expert eye is well capable of assessing a field. Vossen smiles: ‘Of course experience teaches you to look at fields and the presence of specific plant species is an indication of the soil composition. Driving past fields I can see at a glance which products have been used for spraying. Over-fertilisation and some shortages can also be spotted just by looking. Dandelions for example are welcome in horse meadows, but too many dandelions imply overgrazing. The grass disappears and its place is taken over by dandelions. These are called pioneer species. When buttercups are overly present you can be sure soil acidity is too high. Then it’s time for a soil analysis. White clover develops on poor soils. Dandelion, buttercups, white clover, daisies, they are all welcome in horse fields, they provide an excellent herb mix. However, none of these herbs should be allowed to dominate. It’s the same as with people, you have to aim for a varied balance in feeding patterns. Sometimes it is said that no weeds should be allowed in the field. The opposite is true. There are so many herb mixes that contain trace elements that are beneficial.’
‘A few thistles pose no problem but best practice is to remove them. Never allow them to come into flower because they will soon start to dominate and ruin your field. All that white fluff you can see everywhere at this time is thistle seed and that travels with the wind for miles. If you have a lot of thistles and nettles in your field the grass doesn’t get a chance to grow.
The ingredients for a balanced buffet are in the soil, which varies between regions. Some regions have sandy soils, others have loamy soils, each with their specific characteristics and composition. ‘You have to try and create the perfect soil, but over-abundant elements in the soil cannot be removed. Phosphates for instance remain in the soil for years. In fields that have been exposed to years of intensive farming with slurry it’s guaranteed that phosphate levels in the soil are too high and you have a serious problem. That stays in the soil for decades, disrupting the balance. Compare this to a person who eats chips everyday, over time that will invariably result in shortages. Usually young horses spend their first years in the field and for their development and skeleton a varied diet is key. That means those fields should contain clover, dandelions, in short, a great biodiversity with dozens of different herbs. Every plant has its own characteristics and nutrients. Horse meadows are herb-rich meadows, a mix of grass species. But always with the right proportions.’
Are there specific grass species you can recommend? ‘Yes, there are specific grass species on the market for seeding in horse meadows. When seeding never use a cattle grass mix. Take for instance grasses like English ryegrass, bluegrass, creeping fescue. These are grasses that spread close to the ground because horses close-crop the grass. Cattle mow the grass with their tongues. Horses bite the grass with their teeth, up to a millimetre short. In case of trailing grass species the growth points, or meristems become less vulnerable.
The grass that establishes well is always dependent on the type of soil and field management. Seeding is one thing, fertilising and the intensity of grazing is another. That is why correct fertilisation is so important. Overgrazing is also very detrimental. ‘Look at the fields now! There’s hardly any grass left, but still lots of horses are turned out in those fields. That’s when weeds can get the upper hand. Overgrazing gets too little attention and that causes a lot of damage. For when horses eat the growth points of the grass the grass will die and other plants appear: trample-resistant species like the common plantain. People make the same mistakes with the lawn in their gardens. Just take a look around, during the summer many lawns are mown much too short, including the growth points. The grass gets damaged and is replaced by mosses, which people then start spraying. Grass should be left to grow, especially in summer grass must be allowed to grow to a certain length. Close-cropping of lawns is a common mistake, many people prefer lawns like that. In the spring this is not so much of an issue, but from the start of June and particularly in dry spells I advise against mowing the lawn too short. Give it a chance to grow to about 8 to 10 cm high. Mow down to 4 cm and allow a few daisies and dandelions to grow in your lawn. Now let’s get back to our horse meadows. So when the horses have stripped all the grass from the field it’s end of story and the horses must be moved off the field.’
How much can a meadow cope with? What is its capacity? Under normal circumstances Marcel Vossen advises three to four horses per hectare on loamy soils. That is if they are turned out there from April to November. ‘If you’re talking a full year’s grazing then you’re looking at one, at maximum two horses per hectare.’
Is it an idea to divide the field into several plots? Vossen is not overly enthusiastic: ‘It is an option but there's no added value to it. Obviously, it all depends on the size of the field. Starting point is that the more exercise the young stock can get the better, they must be able to frolic to their hearts’ content from time to time! I prefer one large field over two or three smaller plots.’
‘If horses are kept in small plots over winter they will trample the grass sods, leaving only muddy areas and afterwards the only plants that can grow are those that can deal with being trampled all the time. Then you have effectively destroyed the meadow. When, say in November, it starts getting wet you have to take the horses out of the field. Unless you’re prepared to sacrifice one small area. Small, wet fields are disastrous.’
Fields are not just for grazing but also for haymaking. ‘Fields that are used for haymaking require a lot of patience before they can be used for grazing again. Anyone who has made hay in the past months will not be able to put horses out to graze on the same fields after the dry conditions we’ve had. And it’s the same story all over again, if you do decide to put horses out to graze on those fields anyway, that’s the end of your meadow.’
‘Also essential when purchasing hay is knowing where it was harvested. Never buy hay from roadside grass. That is not even permitted, but you know what people are like. Roadside grass contains too much lead from exhaust fumes. At any rate, I’m pretty critical regarding the Government roadside directives. Nature lovers embrace it like Gospel, in my view it is bad nature management. Precisely because the directives are so one-sided from the sea right through to Maastricht, whereas we come across so many different vegetations in that whole area. The directive for instance dictates mowing at exactly the same time, where it would be better to take the variation in vegetation as leading. No one knows what to do with Japanese knotweed that spreads rapidly everywhere. All kinds of dumb guidelines are issued to get rid of it, but without success. Stop using Phyto agents is the motto, but that influences the spread of invasive species. There is no monitoring of roadside management. Plain logic however would be to conduct roadside management with the vegetation in mind. In sandy regions we find a completely different vegetation than in for example loamy regions. Roadside directives are a general policy and for instance dictate that mowing is prohibited before June the 15th. Which boils down to allowing invasive species to produce seeds so we’re effectively helping it to continue to spread. That’s exactly how ragwort succeeded in spreading so profusely, a species which is extremely toxic and stays active in the hay. You also find it in hay that was won from nature areas which are also mown just once. Always refuse that hay! Those areas contain many toxic plants. I remember a time when the Netherlands suffered shortages in the supply of hay. They then resorted to using roadside hay and it didn’t end well.
Before haymaking always meticulously check the field for the presence of harmful plants. They usually flower towards the end of May. The grass in horse meadows should be left to ripen well, but that means harmful plants also get the time to produce flowers. The yellow flowers can be spotted from a distance and then you have to be extra alert! In principle, there are certain products that could be used to control ragwort, but these also kill the good weeds. As soon as ragwort is spotted in the field you have to remove it immediately. And that means root and all, not just the flowers.’
‘We also have to start factoring in the climate, meaning that everything is earlier these days. That is a plain fact. Other than that it’s pointless to speculate about climate, for the simple reason that climate change manifests itself over decades. And what are thirty years in the grand scheme of the earth and the universe? Nothing! No reasonable conclusions can be drawn on the basis of a few dry summers. I have been actively involved with this subject matter and don’t see any notable changes. Anyway, people are droning on too much about climate. As a scientist I principally like exact figures and data. In the 70s we also had many dry years. There are good vintages and bad vintages. Right now we cannot draw any conclusions from this dry period. All I did this year was use my common sense and started making hay early because the opportunity presented itself.
Is sprinkling an option in times of drought? ‘First, in times of drought sprinkling is forbidden anyway, secondly, it’s useless because if you start sprinkling you would have to do it more or less constantly. Every square metre needs a minimum of ten litres and that is simply not doable. That would add up to one hundred thousand litres per hectare, three times per week at that. And when conditions are so hot the best part of the water would evaporate anyway. And grass needs water to grow. There are no grass species that can grow without water.
Good field management requires thorough monitoring of the existing plants. Marcel Vossen warns that some dangerous and toxic plants should be avoided at all costs.
‘Owners of more soggy meadows can be troubled by the presence of Equisetum arvense, the common horsetail aka field horsetail. This plant is fairly poisonous. Horses will naturally avoid such plants, except in times when there is a shortage of grass. When you spot field horsetail in your meadow you have to remove it. Neither are horses inclined to eat buttercups. As a rule they ignore those but it’s the same story all over again: sometimes you see horses in fields with hardly any grass left, except some remnants of buttercups. Especially the flower of the buttercup is very toxic. Eating one flower won’t affect the horse, but if fields are covered in buttercups there is a fair chance they start eating too much from it, resulting in an increased risk of poisoning.’
Marcel mentions a few other toxic plants: ‘St John’s wort, the yew tree (Taxus baccata)’. Also keep an eye out for wild privet, whose flower is particularly toxic. Sometimes wild privet is planted out in nature reserves, or even in land consolidations. White acacia should be avoided because of its bark. Acacia trees serve very well for fencing off meadows but they first have to be debarked, since horses have a penchant for chewing the very toxic bark. Such poles are very durable. Acacia poles have a much longer life span than oak poles. Laburnum too is terribly toxic, also for people and especially children.’
‘And then there's the maple tree we have to be very cautious with. That’s nothing new, although it took a long time before we learned that maple is a killer. The maple tree is most dangerous during two periods of the year: in the autumn when storms can set many seeds adrift. The seeds are particularly toxic, so that’s a risky time. In spring the maple is also very dangerous. The seeds lose much of their toxicity in frosty conditions and also when more than two seed leaves have developed after germination. The problem also occurs in the autumn on close-cropped fields because that gives the maple seed a chance to germinate. Every year hundreds of horses die in Europe as a result of maple-leaf poisoning. I cannot stress it enough: be very vigilant about it. Make sure your horses are no longer turned out in fields which have maple trees in the vicinity when storms rage in the autumn. The horses will ingest the seeds together with the grass they are eating. Again be vigilant in spring time! Ingestion of maple seeds is usually fatal. When your horse’s urine turns brownish it's too late, the disease progresses very fast. Death follows after three or four days. Fifteen years ago I lost a few horses to this condition too. And don’t think the maple tree only causes damage when it grows close to your fields. Maple trees at a hundred metres from your meadow can also pose a threat. You have to check the meadow because the seeds are like little helicopters that can drift great distances on the wind, especially when they come from tall trees. In stormy conditions these can easily travel a hundred metres.’
Marcel Vossen is all for harrowing meadows. ‘Horse droppings are always found in the same spots. In order to distribute the manure evenly across the field harrowing is a useful practice. But it should not be overdone, I have it done once every year, sometimes even every two years. The best time for harrowing is the spring.’
Should fields be reseeded on a regular basis? ‘Constant overgrazing ruins the turf and after a while all that’s left are trample-resistant plants. That’s the moment when intervention is necessary. When the field is not overcrowded and has a normal turf I don’t see why the grass should be sprayed dead for reseeding. I don’t see the point, on the contrary. I’m quite opposed to that practice. If all the grass has disappeared from the field reseeding is essential, but this also implies previous mismanagement of the field. The cause is often overgrazing of fields: too many horses in proportion to the available acreage. Reseeding is possible, but the turf will be very vulnerable in its first year and horses cannot be turned out in these fields yet. It is advisable to reconsider the number of horses that are turned out in the field.‘
Marcel Vossen is greatly in favour of alternating grazing and mowing. ‘Occasionally the grass needs a chance to grow high, that is better for deep rooting of the grass and for regular haymaking too. By mowing everything the turf gets a reset. If you choose not to do this, the latrines with the horses’ droppings have to be mown in June or July because otherwise these areas will expand. Horses refuse to graze these areas. Occasional harrowing of the field is an alternative for mowing. In times of drought though, one has to be careful not to ruin the meadow by mowing.’