Fertilizer Prices and Pasture/Grazing Management

Fertilizer price increases in recent years have provided a stark reality check for farmers, including those who manage pastures. Extension educators and other advisors have been regularly fielding questions about what can be done to address high fertilizer prices, especially for nitrogen products.

Pasture managers need to examine every aspect of their management program to identify areas where costs can be reduced, particularly in fertility management. Fortunately, with effective pasture and grazing management, we have the opportunity to significantly reduce, or perhaps nearly eliminate, fertilizer expenditures.

Soil testing remains crucial in guiding fertility management. Taking a proper soil test is incredibly important in pasture. For more information, please visit the Penn State Analytical Services Lab site. Pasture fields identified as having a pH level lower than optimal should be given priority in the fertility budget. Getting the pH into the optimum range can benefit the pasture program in many ways. When soil pH is below 6.0, nutrients and fertilizers can become unavailable to plants, reducing use efficiency and plant growth.

Manure from wintering barns can be applied to pastures that are deficient in phosphorus and potassium. Alternatively, winter hay feeding could be targeted to take place in pasture paddocks that are lacking in nutrients. Hay brings nutrients to the site, and if livestock are fed there for part of the winter, nutrients will be supplied to the soil through manure, urine, and feeding waste. The only way we can determine which paddocks will benefit from this type of treatment is through soil testing. If a pasture soil test report indicates moderate or medium levels of phosphorus and potassium, and effective recycling is implemented, we can typically avoid applying those nutrients at that point.

An effective rotational grazing system will foster nutrient distribution. Moving livestock to new paddocks every few days will help distribute manure and urine more effectively across the farm, compared to continuous grazing or lax rotational grazing. Furthermore, the water system should be capable of delivering water across the pasture acreage, ensuring that animals are never more than 600-800 feet from water. This will reduce the time the livestock spend traveling for water and camping at watering sites. Following these recommendations prevents nutrient excesses from accumulating in certain areas, such as alleys and near waterers. Over time, much of the fertility in a pasture should effectively recycle because only a small amount is retained in the animals.

Nitrogen prices have been especially shocking for pasture managers who regularly apply nitrogen to grass, reaching a point where the prices are high enough to be prohibitive, despite the growth boost seen in grasses receiving nitrogen fertilizers.

Legumes provide us the opportunity to reduce or eliminate supplemental nitrogen application to pastures. Red clover and white clover are the two best choices in Pennsylvania in most situations. As legumes, clovers can assimilate nitrogen through bacteria that colonize their roots. Grasses benefit from this by taking up nitrogen that sloughs off from the clover roots. We can achieve a very aggressive and productive pasture sward without incurring expenses on supplemental nitrogen. Clover seed can be frost-seeded into pastures in late winter, dormant-seeded in the late fall or early winter, and/or spread ahead of grazing to allow hoof action to push it into the soil. Getting enough clover into the pasture will take time and effort, but it will be well worth it in the quest to eliminate nitrogen expenses. For more information on frost seeding, read Frost Seeding for Cover Crop or Forage Establishment.

For pasture managers who plan to continue using grass-only pastures, nitrogen applications can be more cost-effective if applied more strategically. Most grazing farms do not need more grass growth in the spring, so avoid large amounts of nitrogen fertilizer at green-up. Applying nitrogen in the spring may not be as cost-effective as applying it in early summer, where the additional pasture growth can help create a little more cushion to get through the summer slump in cool-season grass growth. Alternatively, applying nitrogen in late summer may be more cost-effective, allowing for greater stockpiling of grass to occur throughout the fall. Nitrogen should be applied to pasture in multiple small doses, 35-50 units of N per acre, multiple times, or a polymerized slow-release product should be used. For more information and ideas for nitrogen management, review Nitrogen Source and Rate Trial in Western Pennsylvania. 

The answers to the question of what to do about high fertilizer costs will not be the same for all farms. Every situation is a little different. However, most pasture managers will benefit from incorporating some of the ideas outlined above.

Hoping that fertilizer prices will come down is not a good strategy. Most farms will benefit in the future by transitioning to a more regenerative pasture and grazing program, where we build a resilient and productive system with low levels of purchased inputs.