Pasture Productivity Values
I am looking to track down some published information about average values of pasture nutrition for various areas of Colorado. I am most specifically interested in energy and protein values for irrigated pasture species with and without clover interplanting. I know pastures vary widely, but are there some general guidelines that can be followed without having to send off forage samples for every pasture that I come across? I am mostly concerned with irrigated pastures on the western slope and northern front range. Also, are there some productivity values for lbs or kgs of dry matter production for the average irrigated pasture? Data for dryland pasture would be nice by comparison. NRC values are typically more for hay and supplemental feeds.
Unfortunately, there is no good data to compare forage values across Colorado. However, there is data for select locations for some species of forage under irrigation. In general, you could assume the clover mix would be higher in protein (N), but it would not be easy to estimate what that value might be. The energy will depend on when the forage is harvested or what time of the growing season it is being grazed in pasture. Testing a forage sample is the only real way of determining the protein and energy. Forage value changes continually through the growing season and depends on many factors including soil fertility, irrigation, species, and so on. If you give me your email address, I can get you some values for over a dozen irrigated grass pasture grasses in Colorado under different irrigation treatments. I can also send you some information on how forage quality changes depending on season and when it is harvested. Feel free to email me directly.