Pasture Reminders for April 2006
Jim Green
Crop Science Department
North Carolina State University
April is a busy month on most farms and the following reminders may be helpful as you set priorities on what can be done.
If cool season grasses have not received fertilizer it is getting late and you may want to hold the amount of N to 50 lbs/acre; additional N could/should be applied in late August to spread out the distribution of growth for the year.
Limestone, phosphate (P2O5) and potash (K2O) may be applied on most soils any time during the year, however, on sandy textured soils consider splitting the Potash with some put out in spring and some in mid summer. K is subject to leaching much like N and S on such soils.
Fertilize warm season grasses (bermuda, bahia, dallis, switchgrass, bluestems) as soon as the green leaves emerge.
Growth of pasture plants will be rapid during this period and one may be able to rotate back onto previously grazed pastures in 10-18 days. Strive to graze pastures between 6-10 inches back to 2-4 and when it appears that some pastures have too much growth for efficient grazing consider skipping them until they can be harvested as hay/silage.
Fall planted fescue, orchardgrass, and clovers should be established well enough to graze from 6-8 inches down to 2-4 inches. If clover is in the new plantings, do not let the grass shade it out. Lack of light reaching the growing points of clover is one of the main things that discourage clover success. Keep the grass grazed below 4-inches during the first month following overseeding, and do not let it reach more than 6-8 inches during the April-May period.
Harvest or graze winter crops (cereals, ryegrass, and prairiegrass) which were overseeded onto bermuda or other summer crops to minimize shading during the spring “green up” in April. Bermuda can be significantly thinned or almost completely killed by allowing winter crops to go to full head stage during April-May.
Native warm season grasses like Switchgrass may be grazed when they reach 16 inches height, but do not graze below 6-8 inches.
Winter annual pastures should be completely used before grazing begins on other pastures, which may be harvested as hay.
For best compromise between yield and quality of hay harvest fescue, orchardgrass and other cool season pastures or hay fields as soon as the seed heads begin to emerge from the flag leaf but certainly before flowering ends. This often occurs in mid to late April.
Endophyte fescue fields which are targeted to be replanted to endophyte-free or “friendly endophyte” fescue, orchardgrass or other species should not be allowed to produce seeds during April-June. Such seeds will result in volunteer seedlings of endophyte infected fescue the subsequent fall.
Switchgrass in the news after the State of the Union address by President Bush. As most of you know the President mentioned that Switchgrass could be useful in addressing some of the energy demands by converting it into biofuel. Over the past 15 years there has been significant work done to evaluate Switchgrass for yield, performance of grazing animals, wildlife habitat, stabilization of soil on stream banks and field borders. It is a widely adapted plant that is found growing in most of the 50 states. It is a native grass that has a deep root system and tolerates drought well and produces its maximum yield with relatively low N input.
There has been research ongoing in NC for more than 30 years and some stands have been around for more than 20 years. The stand in figure 1 is on Wagram loamy sand at the Upper Coastal Plain Research Station. It has been growing there since 1992 without ever receiving any fertilizer after the first year. The stand is clipped or burned once per year. The photo illustrates that long term stands can be maintained for wildlife and field borders. Switchgrass is high quality and growing animals will perform well when grazing it, but the amount of gain per acre will not rival that from bermuda with heavy N fertilization. It is not suitable for overseeding with winter annuals because when they need to be grazed in March-May the Switchgrass is trying to emerge and the close grazing that is needed for the winter annuals would not be good for the persistence of the Switchgrass.
If the biofuel potential materializes in the next few years it is possible that Switchgrass could be used flexibility on many livestock and crop farms.
Switchgrass is excellent for stabilizing pond banks and it makes good field borders and wildlife corridors. Switchgrass provides excellent wildlife habitat during winter.
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