Steve Barnhart, Forage Specialist, Iowa State University and DanMorrical, Livestock Specialist, Iowa State University
- Assess your resources. Be realistic. Are your grasses and legumes suited for production when you need them? Most of our pastures grow best during the “cool season” and often do not produce well during hot or dry periods. If there are anticipated shortage periods, what strate- gies exist to make up the deficit – better pasture species, other pasture, supplementation, or reducing stocking?
- Use nitrogen fertilizer to boost production. Grass-based pastures respond most quickly to nitrogen fertilizer, particularly the first 40 to 50 lbs/acre. To encourage more leg- ume presence, use modest early spring N and defer some of the seasons total N to late-spring or late-summer. With high nitro- gen costs many feel that pasture fertilization is too expensive. In reality the extra dry matter produced costs less than $50 per ton, which is very cheap feed in the bioeconomy.
- Conduct a soil test. Need Phosphorus (P) and Potassium (K)? Don’t guess – soil test! With fertilizer costs rising, don’t guess how much fertilizer to apply. Soil tests give you a better guide for applying the soil nutrients that you actually need for forage growth response. Grass and legume yield response to P and K is less noticeable compared to nitrogen (N). Adding more P and K as commercial fertilizer o4r manure to already fertile sites is not economical.
- Add lime to your pasture. Lime improves soil pH. Grasses grow optimally at pH ranges of 6.0 to 7.0. Legumes grow best at pH ranges of 6.5 to 7.0. Soil sample to a two- to three-inch depth for pH determination, and use the soil test for lime rate recommendations.
- C5onsider adding legumes. Legumes such as clovers or alfalfa improve pasture nutritive value, distribution of growth during the summer months and provide nitrogen to grasses. Legumes can be added to existing pasture sods by frostseeding or interseeding. Frostseeding is broadcast- ing seed in February or early March in Iowa. Interseeding is done with a no-till drill later in the spring (March and April) or in late summer (August to very early September), if soil moisture conditions are suitable.
- Start rotational grazing. Improved grazing management can give practical gains in forage and livestock productivity. Compared with a continuously and abusively grazed pasture, implementing grazing management along with fertility and other pasture management practices, pro- ductivity will be increased by 25 to 50% in the first year and up to 100% by year three. Plants need “rest” and time to recover from leaf removal so use of some kind of rotation grazing to maintain plant vigor and productivity is required for plant health.
- Control the weeds. Dense forage stands, with a good fertility program, proper pH and grazing management, generally do not have a weed problem. Abused, poorly managed pastures will respond with increased yields when weed pressure is reduced. Herbicide treatments used in conjunction with improved fertility and grazing management are more successful.
- Stretch limited pasture. When grass availability is limited (dry weather), stretch existing forage supplies by supplemental feeding with grain, hay or corn processing coproducts like corn gluten feed or distillers grains on pasture. If pasture is really short dry lotting the cow herd and feeding harvested feeds prevents permanent damage to the pasture stand. Early weaning or reducing stock rates are both meth- ods of reducing the forage needs of the grazing herd. One means of reducing the stocking rate is to add more acres such as hay fields during the summer slump.
- Appropriate turn out dates. Allowing the pasture plants a chance to get ahead before turn out in the spring can greatly improve carrying capacity. Tall cool season grasses should be at least four inches tall and preferably six before grazing is initiated in the spring. Blue grass should be a minimum of two inches. If one must turn out sooner make sure to use very low stocking rates so that the grass can take off. Secondly, if one allows for fall rest and root reserves to build up before winter dormancy, spring green up and early growth will be accelerated allowing earlier turn out.
- Start over with a new seeding. The most drastic and costly pasture improvement alternative is to completely renovate the pasture. While ‘starting over’ allows you to make major changes, it often requires a few years for new seedings to become fully productive, and can leave you with low pasture production for a few years while the pasture is establishing. Risks with complete renovation are soil erosion and pos- sible stand damage before seedlings become well established.
This article can be found in the June issue of Growing Beef, the Iowa Beef Center’s monthly newsletter. To read the entire newsletter go to: http://www.iowabeefcenter.org/content/IBCNewsletters/newsletter(JUNE).pdf