Even though we are still in the coldest part of the year, it is not too soon to be considering our spring and summer forage production needs. For cool season grasses, February is the time we need to consider applying our nitrogen fertilizer so mother nature has a chance to provide the rain necessary to move it into the plants root zone prior to the spring warm up. Our fescue and ryegrass will begin responding to warmer temperatures in March. A good shot of nitrogen fertilizer will go a long way toward producing the spring forage we need to get us through to when our Bermuda grass begins to produce in May. It takes about 60 lbs of N to produce one ton of winter annual forage. Both of these species have the ability to easily produce in excess of 2 tons of spring forage if the nitrogen and rainfall are available for spring growth. Livestock grazing needs for this period should be estimated (Forage Budgeting, fact sheet 2584) and a yield goal for production should be set. It is then a simple matter of determining how much nitrogen fertilization will be required to produce the amount of forage needed to provide high quality grazing for the animals we intend to support.
During this same time frame, we also need to consider the effects that winter forages have on our Bermuda grass stands. We need to determine if these winter forages may interfere with our summer Bermuda grass production through competition. We may need to decide whether or not to manage some of our acreage for maximum winter annual forage production and some of our acreage for early Bermuda grass production. Bermuda grass, like any other plant, has specific conditions under which it grows well. When another plant gets the competitive advantage over it, the Bermuda grass may suffer from one or more stresses that these other plants subject it to. Winter forages that are maturing during or just prior to the breaking of the Bermuda grass dormancy will actively out compete the Bermuda for water, fertility and light, thus making it hard for the Bermuda to respond with its customary vigor. Management strategies that give the competitive advantage to the Bermuda should be considered if early May production of Bermuda grass is desired.
If we consider a farm with two equal sized Bermuda grass pastures and both have been interseeded with annual ryegrass we might want to fertilize one in February for maximum ryegrass production and wait to fertilize the other until around the first of May for maximum Bermuda grass production. While waiting until later to fertilize this pasture, we may want to graze it closely in late April to keep the ryegrass short so that it does not use up all the water and nutrients before the Bermuda takes off. This strategy also reduces its ability to get tall enough to shade the newly emerging Bermuda grass. The pasture that was fertilized for maximum ryegrass production can be rotated with this pasture to provide high quality grazing in March and April and any excess hayed off in May for later use. It can then be fertilized in May for its Bermuda grass component and provide high quality forage for a rotation from the early producing Bermuda grass pasture.
As indicated earlier, where two or more plant species compete for the same resources one or both of their growth potential will suffer due to competition. By manipulating grazing pressure and fertility applications, we can give the competitive advantage to one or the other to suit our particular forage production needs.