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Eddie Baggs: Apply fertilizer for pasture health

The drought of 2011 yielded less than 50 percent of an average hay crop in Denton County and depleted most of what was in reserve. This year, with good spring rains, agricultural producers are looking to replenish those hay reserves and then some. Proper fertilization is a key factor.

Growing forages by applying fertilizer is one of the easiest management practices a producer can do. Producers should be making plans for the most important fertilizer application of the year. It is recommended to utilize soil testing to outline a fertility program. However, the general recommendation for the March/April first-application fertilizer will almost always be a complete fertilizer blend. This means that a fertilizer contains all of the primary nutrients, N-P-K (nitrogen, phosphorus and potassium or potash).

Something else to keep in mind: It requires 50 pounds of nitrogen, 14 pounds of phosphorus and 42 pounds of potassium to produce 1 ton of Bermuda grass forage. However, given adequate moisture and fertility, hybrid Bermuda grass will produce twice that amount. Speaking from a research standpoint, grass is going to require N-P-K in a 3.6:1:3 ratio.

When a soil test is used, the known nutrient content of the soil is essentially factored from what we know the grass will need to produce the forage required to feed the number of livestock present or produce the amount of hay needed. As a stocking rate increases or decreases, fertility programs fluctuate accordingly.

Remember, nitrogen is usually applied several times a year, as it is very mobile in the soil and used quickly by the plant. There are many different varieties of nitrogen fertilizers for use on pastures and forage crops. Urea (46 percent nitrogen), ammonium nitrate (33 percent nitrogen) and ammonium sulfate (21 percent nitrogen) are the most common. If using urea as a nitrogen source, it should only be applied in the spring or late fall when temperatures are 80 degrees or below. If used when temperatures are above 80 degrees, moisture is needed within two to three days or a considerable amount of nitrogen will be lost through the atmosphere as nitrogen gas. After the first complete fertilizer blend application, nitrogen is top-dressed several times per year after each cutting or graze down.

The number and rate of applications will depend again on stocking rate or harvest frequency.

Also, remember that forage that is harvested for hay will remove most of the nutrients from the soil. Pastured land used for grazing will experience at least some level of “recycling” from animal defecation. If forage is going to be maintained at any level of quality, the fertility utilized through grazing or hay harvesting must be returned to the soil. The absence will result in a continuing loss of yield, an increased presence of weeds and lowered quality of grass.

Grass will be at its highest quality during early growth and not at a mature stage. Grazing and haying should be targeted to take advantage of the grass at its highest quality to get the greatest benefit from fertilizer applications.

Remember, for production of large quantities of quality forage, all nutrients (N-P-K) must remain in balance.

The Denton County Beef, Crops & Forages Committee will be have a Spring Pasture Workshop from 7 to 9 p.m. Tuesday in the lecture hall at Sanger High School, 100 Indian Lane. Registration is $10 per person.     

For more information on the workshop, call the Texas AgriLife Extension office at 940-349-2880.


EDDIE BAGGS, extension agent with the Texas AgriLife Extension Service in Denton County, can be reached at 940-349-2880.