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Mar 01

Forage Plant Establishment, Growth, and Management Practices Throughout the Year

Posted on March 1, 2017 at 2:27 PM by Allan Warren

Sidebar pg 8 (web)From Steve Fransen, Forage Agronomist, WSU Cooperative Extension

Part 1: Spring

Let’s say you have a sick animal on your farm and the vet is called.  The vet makes a diagnosis, prescribes the appropriate medication and even administers the first dose with detailed instructions for you to follow for a complete recovery.  You are left to do the rest and bring the animal back to proper health. Are you willing to do the same thing for your pastures?

The most common questions I’ve been asked over the years is “What should I plant in my pastures?” followed by “What should I spray to control the weeds in my pastures?”  Many pasture owners can identify some of the important forage species in our region and certainly some of the most common weeds.  Some folks take soil tests, are willing to apply lime and fertilizers (both organic and inorganic), some make hay when excess forage is available, and some even attend grazing conferences to learn more about what to and not to do!

The adapted perennial cool-season grasses (such as perennial ryegrass, Italian ryegrass, orchardgrass and tall fescue) in the PNW region advance through various stages of its growth cycle, just like livestock.  It’s just that until recently we really didn’t recognize all the independent components of the cycle and put them into an understood order.  This process continues to evolve as we learn more from research, so this article should be considered a progress report of PNW pasture ecology, management and utilization.  As we gain new information about the cycle and its parts the story will change to reflect this new knowledge.

Spring comes in slowly as winter rains begin to retard.  Grass roots start growth first, and are then followed by top growth.  As temperatures increase, so does the growth of our perennial cool-season grasses. Let’s use 42 degrees Fahrenheit as our average baseline temperature for grass growth while legume baseline temperature is closer to 50 degrees Fahrenheit.  Grass root growth continues through the spring period but slows down just after peak forage yield.  Spring is an excellent time to apply nitrogen and other important plant nutrients (see OSU publication FG-63 revised).  Avoid the temptations of turning livestock in too early as hoof action will still compact the soils; destroy plant crowns, etc.  More importantly, grasses are trying to recover from the winter and build strength to support the largest amount of forage to be produced during the entire growing season.  Spring overgrazing (allowing livestock to graze the plants shorter than 3”), can establish areas of different palatability within the pasture.   Here selective grazing will be more magnified in the summer, and summer regrowth likely will be less and plants will be under greater stress because higher temperature and drought.  As we change in latitude from south to north in the PNW region, spring occurs faster in the south and can be delayed three weeks or more in the north.  Selection of the proper maturity group within the grass variety by latitude and soil conditions will enhance spring and total forage production.  Grass roots expand and remain white during the spring growth and this root system is establishing the plants and ability to survive the upcoming summer stress period.