Before a fertilizer or limestone recommendation can be made for ryegrass it is important that a soil sample be taken and analyzed by a reputable soil testing laboratory. A soil analysis will determine the nutrient status and pH from which a fertilizer and limestone recommendation can then be made. To sample take six to eight soil cores per pasture from the surface six inches and mix them together as a composite soil sample. Nitrogen is by far the most important nutrient for ryegrass production, but many nutrients are essential for maximum forage production. Recent studies conducted at the Range Cattle Research and Education Center have shown that higher yields and quality of ryegrass are obtained when sulfur is included in the fertilizer mix.
Sulfur is obtained by either applying ammonium sulfate, sulfur, or potassium sulfate.
It is important that the economics of fertilizers is considered and the least expensive source of nutrients be purchased. Unlike bahiagrass, research has shown that ryegrass responds to applications of phosphorus and potassium. One reason that ryegrass responds to phosphorus and potassium fertilizer is its rooting system. Bahiagrass has extensive roots which go deep into the soil profile and get needed nutrients from a larger soil area, while ryegrass only has shallow root system. It is also important to apply approximately 50 pounds potash per acre if the soil tests low in K. Data from ryegrass fertilization studies at Ona have shown that limestone should be applied to the soil when the pH is less than 5.5.