When the buffalo roamed, they moved across the prairie and left behind a “pasture” that rejuvenated itself. Most cattle producers, particularly in Eastern Canada, don’t have the luxury of thousands of acres of land on which to graze their herd and are restricted to paddocks or a few hundred acres of fenced range. Sadly, some producers neglect this food resource to the detriment of their animals and the bottom line.
For producers who take pasture seriously, their management includes weighing their animals before they are put on pasture and weighing them when they come off. Most have a set formula of how much they expect the animals to gain on healthy pasture and if the weight gain drops below that expectation, it is time to consider pasture improvement.
“Pastureland is neglected cropland,” asserts Greg Patterson of A &L Canada Laboratories Inc. of London, Ont. “With the price of feed for animals and the lack of available feed, we need to pay attention to pasture. If you don’t, you are wasting a resource.”
The spring of 2010 in Ontario revealed legume winterkill, which is not uncommon. But losing most of the legume population in a pasture need not happen. Patterson believes the excessive losses this spring occurred due to neglect. He says a well-maintained pasture with attention to fertility can more easily withstand weather stress because the plants are strong with good root systems.
Producers who believe the cattle are keeping the pasture fertilized with their manure may be doing their land a disservice. If the manure is left where it drops the nutrition is only available in that spot. Some growers will harrow the pasture after the cattle are moved out and this, at least, helps to distribute the available nutrition. However, if those producers did soil tests on their pasture they may be shocked to see the actual nutrient levels in the field.
“Nutrition is lost every year from pasture when the animals are sold,” explains Dr. Ann Clark from the Department of Plant Agriculture at the University of Guelph. “If you are practising rotational grazing, you are still drawing down your nutrients, albeit slower than in a cereal crop.”
According to Ontario grazing specialist Jack Kyle, animals remove only 10 to 20 per cent of the nutrients from pasture. However, at that rate, over time, nutrition will decline. “Well-managed pastures keep most of the nutrients in the field,” he says.
Patterson says most growers have a target amount of grass they expect the cattle to remove and in that tonnage are the nutrients. He says pasture needs fertility throughout the season to maintain that level of production. The best way to know your fertility levels is to soil test. It is not the cattle producers who are ordering soil tests from his laboratory, he adds, but the horse industry, and he thinks it is time the cattle industry took a lesson from that group of dedicated pasture managers.
“Producers should be taking a soil test of their pasture every couple years so they know what is happening in the field,” Patterson explains. “If producers are practising pasture management and are rotating their pasture, when the cattle are moved out of one field that field should get some fertility.” Based on soil test recommendations, he says, pasture should get some nutrition in spring or early summer. Later in the season, an application of potassium will help with regrowth and, in late fall, an application of nutrients will help to get the field through the winter.
“Potassium can be useful if applied at the right time in the fall because it can facilitate overwintering success,” adds Dr. Clark. “Some species, particularly legumes, have diffi culty persisting in pasture without adequate fertility. You need to look at the pH of the field and phosphorus levels as well. If the soil has been depleted of phosphorus, winter kill may occur.”
“Legumes in the pasture will add nitrogen, but they tend to winterkill more easily, which was seen in January 2010 when we had some cold mornings without much snow cover,” adds Kyle. “Some growers will overseed to increase legume population, but if the pasture is run down, the legumes won’t grow because there isn’t enough nutrition. You need nutrition to stimulate growth and vigour and improve quantity and quality.”
Dr. Clark says reseeding can cost as much as $250 per acre in Ontario and she wonders how many calves would have to be raised and sold to recover that cost, when astute pasture management, including attention to fertility, could be less expensive.
A cattle producer near Cameron, Ont., says when he runs cows and calves on his rangeland, he always puts a fall application of 5-27-13 on the land. “In the spring, I would put an application of 19-19-19 on before turning the cows on to the land,” says Steve Kay. He says on large parcels of rangeland, Nature will take care of itself, but the style of grazing being used may require more management and fertility is part of that. He uses different management if he is running stocker cattle.
Understanding the relationship between nutrition and plant growth in pasture is no different than an appreciation of the relationship in cereal crops, according to Matt Pecoskie of Kawartha Lakes Agri Services in Lindsay, Ont. For example, sulphur is an important component in helping legumes to fix nitrogen, but if the pasture is low in sulphur, the legumes that producers are relying on to keep the pasture nitrogen healthy may not be capable of doing the job.
Pecoskie echoes Patterson: “Always start with a soil test.” He says, based on the results of a $25 soil test, a split application of nutrition may be a good idea with some fertilizer going on in the fall to strengthen the plants with the remaining requirements applied in the spring to encourage new growth. “Each pasture is different and a soil test will give the needed information to make nutrition decisions.”
“It’s always important to look at fertility in pasture and the value of a soil test is that it shows what amount of nutrient is available,” Kyle reiterates. “It is important to have adequate fertility to grow strong, healthy plants.”
Pasture management should be linked to the animals it supports. If the pasture does not have balanced nutrition, the animals will not gain at the expected rate. As well, a weak pasture, as seen in the winter of 2009-10, will not be in good enough health to sustain grazing. In fact, fertilizing pasture can improve pasture productivity by 50 to 100 per cent, a percentage that will directly affect the grazing animals. As another winter approaches, now is a good time to soil test the pasture and consider beginning a fall fertility program to prepare for spring grazing.