Will's Windmill column: Enhancing effectiveness of permanent pastures
In recent summers as I have traveled throughout central Minnesota and observed pastures, it becomes readily apparent that much can be done to improve the production capabilities of what people call permanent pastures. We can greatly increase the livestock carrying capacity of these pastures.
I know there has been significant interest by a number of producers in rotational grazing, and yet many of our beef operations are not well suited to a rotational grazing system. There are many grazing acres that fall into the category of permanent pastures, and these are the acres that I would like to talk about in this article.
Most of these pastures are on marginal lands -- lands which are not suited for tillage and crop production, due to rocky soils, slope, wet soils, woods, drought conditions, or field size, but yet have the capability of producing grass for livestock. Many of these so-called permanent pastures are not even close to their potential production capabilities. With small production inputs and management, significant increases in productivity and profit can be realized.
The most significant return of investment in these pasture situations can come from the additions of relatively small amounts of fertilizer. Forty to 75 pounds per acre of available nitrogen from either a commercial or organic fertilizer source can result in yield increases of 1-3 tons per acre. For a permanent pasture, the result is that the producer now needs fewer acres or can pasture more animals on the same acreage.
Grass responds very well to nitrogen fertilization, provided there is a reasonable level of phosphorous and potassium available in the soil. Soil testing is required to determine existing levels of nutrients. If the phosphorous and potassium levels are low then there will be limited benefit to applying additional nitrogen. Nitrogen will give a response about 2 weeks after application and this increased growth will carry on for about 5-6 weeks.
To get an economic response to nitrogen, a minimum of 40 lbs. per acre of actual nitrogen should be applied. Because of the high solubility of nitrogen, a maximum application rate of 75 lbs. per acre is suggested. If you have a very productive grass pasture that you want to put more nitrogen on, you should increase the number of applications, and not the amount per application. Applications should be 4-6 weeks apart.
Timing of application will depend on a number of factors but mid-June will generally give the optimum results. By mid-June the lush spring growth will have slowed and the nitrogen will give the grass another boost. Once we are well into July, the risk of not getting enough rainfall to take the nitrogen into the root zone and the high heat of mid-summer on cool season grasses is a concern.
We seem to be always short of forage in the fall, and very little fall growth will occur without a late season nitrogen fertilizer application. Since most of these pastures are grazed through September and October, a late summer-early fall nitrogen fertilization will help sustain stands for next spring and also increase the pastures late season grass production.
I believe in many cases producers may be able to double or triple the production capability of some of these so-called permanent pastures. In 2008, I urge livestock producers to do some experimenting on their grass pasture areas by applying the above recommended rates of nitrogen, and also the soil tested recommendation rates of phosphorus and potassium. I believe you will see that this is a management tool that will make you money.
On sandy textured low organic matter soils, I also recommend that producers also apply a minimum of 20 pounds/acre of sulfur to your cool season permanent grass pastures.
For soil test information sheets and sample bags, and for more information on pasture management, please contact me: Will Yliniemi, Hubbard/Becker County Extension Educator at 1-218-732-3391, 1-218-846-7328 or by cell at 1-218-252-1042, or by e-mail at firstname.lastname@example.org.