However, there are several factors besides nitrogen price that producers should consider when selecting the “best” type of nitrogen fertilizer for stockpiling.

Additional nutrients may be included in the nitrogen sources which will increase yields. For example, broiler litter contains phosphorus and potash and ammonium sulfate contains sulfur. Urea is most susceptible to rapid volatilization and leading to lower yields. It is recommended that producers use soil tests to determine the nitrogen source that will maximize yield.

The following example illustrates carrying capacity for one acre of stockpiled forage that received 50 units of nitrogen from ammonium sulfate:

DM yield =  base DM + added DM from N fertilization (Table 1)

DM yield = 2,500 lb. + 554 from (50 lbs of Ammonium Sulfate)

Total DM = 3054 lbs

Assume a 1,000 lb. cow consumes 2.5 lb. DM / 100 lb of body weight, then she would consume 25 lb. DM per day.

Thus, the 3,054 lb. DM from the 1 acre would provide forage for this 1,000 lb cow for 122 days.

3,054 lbs of DM/ 25 lb. DM per day = 122 days of grazing

Note: In this example grazing efficiency is not considered

 

Thus one acre of stockpiled fescue fertilized will provide ~ 120 days of winter grazing for one cow. As previously mentioned, rainfall has a major impact on the amount of forage stockpiled for winter grazing. Therefore many producers will stockpile 1.5–2.0 acres per animal in order to have sufficient forage to graze throughout all the winter months.

In contrast, producers may elect to feed hay during the winter months.

The following example shows the cost of feeding hay to a 1,000 pound cow that eats 25 lbs. DM each day for 120 days.

• A ton of tall fescue removes the following nutrients from the soil:

• 39 lbs. nitrogen, 19 lbs. phosphorous, and 53 lbs. potash.(5)

• Using June 2013 fertilizer prices, a ton of tall fescue removes ~ $65 of nutrients from the soil.

• 2,000 lbs. of hay (15% moisture) = 1,700 lbs. of DM or 0.85 ton of DM

• Dry matter requirements for one cow for 120 days is 25 lbs. DM /day X 120 days = 3,000 lbs. DM or 1.5 tons DM for the feeding period.

• 1.5 tons DM /0.85 ton DM from one ton hay = 1.76 tons of hay.

• Assuming that ~15% of the hay is wasted during feeding, each cow requires ~2 tons of hay for a 120 feeding period.

In June 2013 Virginia Cooperative Extension crop budgets showed that it costs ~$150 to produce a ton of fescue hay which includes ~$65 in fertilizer costs. Since every bale of hay that leaves a field is exporting nutrients from that field, the nutrients must be replaced to maintain fertility.  Otherwise, nutrient levels will be depleted.

For a 120 day feeding period, the cost of stockpiling two acres of fescue using ammonium sulfate or broiler litter is $93 ($38.50 fertilizer cost/acre X 2 acres + $8/acre application cost X 2 acres) compared to feeding two tons hay which has total production costs of $300. Thus there are savings in feed costs of $207/cow by feeding stockpiled forages. (The additional costs for temporary fencing for strip grazing should be considered on a farm-by-farm basis.)

Stockpiling eliminates some of the additional costs of labor, machinery, repair, manure hauling and other input costs associated with baling and feeding hay.

The bottom line, consider stockpiling fescue to reduce total feed costs.